Beneficial microorganisms, such as microalgae and bacteria, have a strong ability to restore health and fertility in degraded soils. However, the use of these microorganisms interacting in a mixed consortium has yet to be well explored. Furthermore, most of the current knowledge on the effects of these microorganisms on soil fertility derives from studies focused on the potential of either of these groups as biofertilizers; thus, more information on their real impact on degraded soils is required. This mini-review addresses the current knowledge on using a consortium of microalgae and bacteria for this purpose.Soil restoration is one of the biggest challenges of this century. Besides the negative impacts of climate change, the current increase in food demands has put severe pressure on soil resources, resulting in a significant area of degraded land worldwide. However, beneficial microorganisms, such as microalgae and plant growth-promoting bacteria, have an outstanding ability to restore soil health and fertility. In this mini-review, we summarize state-of-the-art knowledge on these microorganisms as amendments that are used to restore degraded and contaminated soils. Furthermore, the potential of microbial consortia to maximize beneficial effects on soil health and boost the production of plant-growth-promoting compounds within a mutualistic interaction is discussed. The ability to meet the continuous increase in food demands as a consequence of population growth is one of the biggest challenges of this century. Climate change and freshwater limitations are realities that we must consider when developing sustainable agricultural systems . The cur2 to the subsurface, solubilizing and mobilizing macro- and micronutrients, mineralizing simpler organics, and serving as a source of organic matter and nutrients pyrene (BaP) to below detection levels in soil slurry within 30 days [Selenastrum capricornutum and Mycobacterium spp.) to degrade recalcitrant PAHs. In addition to a complete degradation of pyrene in 10 days, the authors reported that the bacterial degradation of pyrene mitigated its toxicity for microalgae, whose growth was substantially inhibited when growing alone. Additionally, microalgae and bacterial growth were mutually enhanced with the co-culture.Despite the proven potential of microalgae and bacteria for the bioremediation of contaminated soils, few studies have explored their use as combined consortia. One of these studies reported that the biological degradation of high-molecular-weight PAHs was successfully achieved on long-term contaminated soil with the inoculation of the microbial consortium co-formed by the microalga  30 days . The syn 30 days  demonstrAnabaena spp.) and unicellular green microalgae (mostly Chlorella spp.). Furthermore, a better understanding of the synergistic interaction between cyanobacteria and bacteria is imperative for the success of restoration programs using these consortia.The enormous area of degraded land worldwide demands sustainable solutions to climate change and food scarcity. However, despite the several advantages of using microbial consortia for soil restoration, there are few studies on microbial microalgae–bacteria consortia inoculants. Additionally, although the biodiversity of microalgae is huge, most studies include only filamentous cyanobacteria (mostly Finally, most of the published information regarding the effect of microbial inoculants on soil fertility derives from studies focused on the fertilizer potential of the inoculants and their growth-promoting effect on plants; therefore, more information regarding the actual impact on degraded soils is required.


The detrimental effects of climate change on global health and wellbeing have become increasingly apparent and concerning. According to the World Health Organization (WHO),To address these environmental issues, the concept of “green surgery” has emerged as a promising solution. Green surgery involves incorporating environmentally friendly materials and practices that conserve energy, reduce waste, and minimize greenhouse gas emissions, while still ensuring high-quality patient care.Sustainability in health systems, as defined by the WHO, is a comprehensive approach that balances health outcomes with minimizing environmental harm. This approach recognizes the interconnectedness of health and the environment and stresses the importance of considering both when delivering healthcare services.The incorporation of green surgery presents a significant challenge due to the high costs associated with the use of green energy. Hospitals need to alter their processes and structures to achieve sustainability goals, which involves the entire chain of patient care. For instance, hospitals need to adopt new sterilization devices that emit fewer pollutants, consume less water, and deliver the same level of quality as disposable devices. The entire surgical team needs to be sensitized to the need to change the way it behaves in the use of resources, from proper handling of contaminated materials to energy savings. Additionally, surgical blocks should be equipped with modern LED devices to reduce energy consumption and automatic faucets to control water usage.The Royal College of Surgeons of England has devised a comprehensive list of recommendations aimed at reducing the environmental impact of operating theaters. This list has been compiled based on an exhaustive review of all relevant guidance and published evidence and is available in the Compendium.In the healthcare setting, sustainability efforts must go beyond the facility walls and begin from the preadmission stage. This involves the development of health promotion strategies and encouraging the use of eco-friendly transportation modes for patients, healthcare professionals, and medical supplies. Within the hospital, the implementation of renewable energy sources, optimization of energy systems, and reduction of disposable materials can significantly lower the carbon footprint and contribute to sustainability efforts. The use of intravenous and local anesthesia instead of anesthetic gases during surgical procedures is another environmentally friendly option. Implementing recycling programs and utilizing telemedicine can also play a crucial role in reducing waste production and supporting sustainability goals.Hospitals in developed countries play a significant role in the generation of solid waste and greenhouse gas (GHG) emissions, accounting for 1% of the former and 2.1% of the latter on an annual basis. A considerable portion of these emissions is attributed to the operating room (OR) due to the usage of energy-intensive equipment and the emission of anesthetic gases. Additionally, the transportation and incineration of waste also contribute substantially to GHG emissions. It is estimated that the incineration of 1 kg of clinical waste generates 3 kg of carbon dioxide. Despite these facts, the WHO reports that a substantial amount of hospital and OR waste, ∼ 85% and 90%, respectively, is non-hazardous and similar to domestic waste, providing opportunities for recycling and reducing emissions.To mitigate this impact, green surgery focuses on reducing waste through the use of reusable surgical instruments and reducing single-use plastics. Reusable surgical linens and instruments are an eco-friendlier alternative as they result in lower waste generation and decreased expenses for landfill and incineration. A comprehensive evaluation of the production-to-sterilization process showed that the carbon footprint of reusables is more favorable compared with that of disposable options. For instance, the use of reusable surgical devices in laparoscopic procedures can save an estimated 122 kg of waste per case.Minimally invasive surgery (MIS) is known for its benefits, but it also generates a significant amount of waste due to the reliance on disposable surgical instruments. To address this issue, healthcare providers need to adopt a comprehensive approach that includes minimizing material usage, transitioning to eco-friendly anesthetic gases, maximizing instrument reuse, and reducing energy consumption during off-hours in the operating room. The combined efforts of these measures can reduce the carbon footprint of an average laparoscopic hysterectomy by up to 80%.In addition to considering changes in general medical procedures, it is crucial to incorporate sustainable practices in obstetric care as well. Maternity services should focus on developing and disseminating green and sustainable practices, which can be implemented quickly.Green surgery aims to minimize energy consumption through the implementation of energy-efficient technologies and practices, such as LED lighting and low-flow anesthesia machines, thereby reducing OR costs and enhancing the overall sustainability of healthcare facilities.Sustainable supply chain management is a crucial aspect of green surgery, with the aim of minimizing the environmental impact of the production, transportation, and disposal of surgical supplies and equipment. A significant portion of carbon emissions produced by healthcare facilities arises from the procurement of drugs and medical devices, including the production methods, packaging, transportation to the hospital, and the energy and materials required for drug delivery.Optimizing efficiency, reducing waste generation, and conserving energy not only positively impacts the environment but also results in cost savings. A systematic review conducted by Sullivan et al. (2023)Hospitals are significant consumers of energy, using more than 10% of the energy consumed for commercial purposes.While there are numerous benefits to implementing green surgery, significant challenges must be addressed to effectively adopt this approach. These challenges include the lack of standardized guidelines and protocols, high costs associated with green technologies, and limited resources for their acquisition. Furthermore, insufficient knowledge among healthcare providers and inadequate training on how to utilize related technologies hinder the adoption of sustainable approaches in healthcare. Economic and financial challenges, including limited access to funding for implementing climate action, also pose significant barriers. Additionally, challenges related to policy, leadership, conflicting interests, and the lack of global awareness and advice on green surgery further impede progress. Finally, social and cultural challenges, such as the influence of adaptation and decision-making, as well as technological and infrastructure challenges and limited adaptive capacity due to a lack of human resources must also be addressed.In conclusion, green surgery is an important concept in gynecology and obstetrics, with potential benefits in reducing the carbon footprint of surgical procedures, improving patient outcomes, and reducing healthcare costs. The implementation of green surgical practices, such as the use of reusable instruments, biodegradable materials, and energy-efficient electrosurgical generators, can have a significant impact in reducing the environmental impact of surgical procedures, as well as improving patient outcomes and reducing healthcare costs. However, there are still several barriers to the widespread implementation of green surgery, including the high cost of green technologies and the limited resources available for their purchase, as well as a lack of awareness and training among healthcare providers.


This is a narrative review about the mechanisms involved in bacterial sepsis in preterm infants, which is an illness with a high incidence, morbidity, and mortality. The role of the innate immune response and its relationship with oxidative stress in the pathogenesis are described as well as their potential implementation as early biomarkers. Moreover, we address the impact that all the mechanisms triggered by sepsis have on the dysbiosis and the changes on neonatal microbiota. Neonatal sepsis is a major cause of morbidity and mortality in preterm infants. A recent meta-analysis estimates the worldwide incidence of neonatal sepsis in 28.24 cases per 1000 live births .These rates increase in case of late-onset sepsis (LOS), where are estimated to be around 12–28% among 22 to 26 weeks’ preterm infants, with a mortality close to 35% in the most vulnerable, lowest-gestation infants ,5.Remarkably, signs and symptoms of neonatal sepsis are subtle and nonspecific and frequently undistinguishable from clinical characteristics of preterm infants during postnatal adaptation, rendering clinical diagnosis extremely difficult. Moreover, consensus definition is still lacking ,7.The gold standard for the diagnosis of sepsis is a positive blood culture with an identified microorganism. However, despite the use of innovative laboratory methods, results are often delayed more than 24 h or do not yield conclusive results for the clinician. Various circumstances such as low bacteriemia, small blood volume inoculation or antibiotics administered to the mother often hamper achieving prompt and reliable results .Recently, the use of multiplex polymerase chain reaction and molecular assays based on microbial genome hybridization or amplification have been tested in an attempt to detect the presence of bacteria early in the course of disease .However, these techniques need a period of incubation that ranges from 4 to 6 h and a high blood volume to improve sensitivity. Moreover, bacterial PCR assays do not discriminate between viable and nonviable organisms or free and cell-associated DNA, and they do not provide enough information about antibiotic resistance . For theThe availability of a rapid and reliable diagnostic tool for neonatal sepsis still represents a major challenge for clinicians. It would allow not only early identification of infected infants and improve outcomes but also reduced exposure to unnecessary antimicrobials, subsequently avoiding the risk of inducing antibiotic resistance . FurtherSince sepsis is a widespread process that is not confined to any specific organ, most studies have investigated the role of several mediators of the inflammatory cascade in the early diagnosis of sepsis. Some diagnostic biomarkers based on the immune response such as acute phase reactant proteins, procalcitonin, cytokines or cell surface antigens have been proposed to early detect bacterial sepsis ,16 and/oConsidering the findings in the latest publications, the diagnosis of neonatal sepsis should focus on the host’s response and not so much on the search for the causative germ. The differences identified in the immune response, depending on the type of infectious agent, will guide the treatment, not only earlier, but also with a shorter duration. On the other hand, metabolomics will allow us to go a step further toward the investigation of profiles suggestive of sepsis in non-invasively accessible biological fluids, such as urine or saliva .Sepsis activates the immune and inflammatory responses that generate oxidative stress, and both generate a pro-oxidant environment in the intestine that alters the microbiota. Not only sepsis, but also the use of antibiotic therapy as a treatment, plays a relevant role in this complex mechanism. Therefore, the main purpose of this review is to delve into the pathophysiological mechanisms of the immune response of the premature newborn against sepsis, its influence on the oxidative balance and how both factors influence the host microbiota. The relationship between these components will allow us to improve the understanding of this pathology in order to design future diagnostic, prognostic and therapeutic strategies.The immune system in early life goes through rapid and radical changes. Given the malleability of the immune system in the newborn period, interventions aimed at modulating its trajectory thus have the potential to translate into considerable reductions in the infectious disease burden with short and long-lasting benefits. However, an improved understanding of the underlying molecular drivers of early life immunity is a prerequisite to optimize interventions and transform the window of early life vulnerability into one of opportunity .The immune response in neonates is triggered by the innate immunity reacting to the exposure to an infectious agent. Local immune sentinel cells such as monocytes and macrophages are involved in pathogen-associated molecular patterns (PAMPs) recognition through the activation of pattern recognition receptors (PRRs), essentially Toll-like (TLRs) receptors but also other intracellular receptors that include nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and retinoic acid-inducible protein (RIG)-like receptors (RLRs) . The paradigms of PAMPS are lipopolysaccharide endotoxins (LPS) of the Gram-negative bacteria surface and lipoteichoic acid (LTA) and peptidoglycan of the Gram-positive bacteria wall. The immune response initiated by PRRs yields to the production of pro-inflammatory cytokines via mitogen-activated protein kinases (MAPK) and the transcription factor nuclear factor κB (NF-κB) . In an aThe production of pro-inflammatory cytokines leads to the activation of endothelial cells and overexpression of cellular adhesion molecules that promote leukocytes recruitment and diapedesis. Although cytokine concentration levels seem to be adequate, leukocyte chemotaxis is limited in neonates and probably related to an insufficient up-regulation of complement receptor and inhibition caused by bacterial products . ComplemIn an attempt to control the inflammatory response, anti-inflammatory cytokines such as IL-4, IL-10, IL-11, IL-13 and transforming growth factor beta (TGF-ß) are released to suppress the activation of macrophages and production of pro-inflammatory cytokines. 2, lymphocytes B and macrophages in response to TNFα, block the activation of phagocytic cells and fever, modify the expression of coagulation factors, and decrease intermediate reactive species of oxygen and nitrogen and other vasoactive markers. However, an overproduction of all these biomarkers can lead to the suppression of the immune function .,65.2O2 wSeveral key differences in the redox signaling and redox-mediated damage clearly delineate neonatal sepsis as a separate entity from adult sepsis. In fact, the mechanisms, the inflammatory response, response to treatment, and outcome of neonatal sepsis vary not only from that of adults but vary also among neonates as a function of gestational age. Underlying differences can be attributed both to the immature innate immunity and antioxidant defense system. Extremely premature infants suffer from a relative immune deficiency, as the transplacental transfer of immunoglobulins does not occur until 32 weeks of gestation. In fact, the NOX system is thought to be a first-line mechanism of innate immunity, as there is a direct negative correlation between oxidative burst product generation and gestational age. In neonates, the immature innate immunity results in alterations in the cytokine response  and show2 concentrations at the same time, providing high levels of free iron, which enhance the Fenton reaction leading to the production of highly toxic radicals [Enterobacteria and a reduction in Bacteroides and Bifidobacterium spp. in fecal samples, leading to a global reduction in beneficial anaerobic bacteria [Due to the poorly developed antioxidant defenses of preterm infants, they are prone to oxidative stress . In addiradicals . Proliferadicals . In a reradicals . Hence, bacteria .Reports are consistent on the importance of the involvement of ROS/RNS in neonatal sepsis and its complications. In clinical studies, determinations of antioxidants and oxidative stress and inflammation biomarkers have been employed. In newborns with sepsis, plasma levels of lipid peroxidation and protein damage were higher in infants with proven and clinical sepsis versus healthy controls . In anotTo date, literature reports on the determination of oxidative stress biomarkers in preterm infants are scarce, and none of these biomarkers have entered routine use for clinical diagnosis. Intriguingly, it could be shown that the determination of oxidative stress biomarkers of damage to proteins, DNA and lipids can be conveniently determined in non-invasive urine samples of preterm infants ,72,73,74Human milk is considered the gold standard for infant nutrition and is of paramount importance in preventing infections and other morbidities in neonates and especially in preterm and low-birth-weight infants and providing long term health benefits ,76,77,78Human milk constitutes an alive complex source of multifunctional components including nutrients, cells , microbiota, bioactive proteins, glycans, cytokines, and antioxidant and anti-inflammatory factors) . Human mcoliforms, enterococci, and Bacteroides spp. predominate in formula-fed infants [Many of the beneficial effects of human milk are linked to lactoferrin, which is a glycoprotein found in human colostrum and milk. Lactoferrin is thought to stimulate the fast proliferation of the enterocytes in the nascent intestine, thereby creating a less permeable environment as gut wall leaks and gap junctions become tighter. This potentially results in fewer colonizing pathogens disseminating to the bloodstream through translocation via a leaky gut wall . Lactofe infants . The int infants  and crea infants .The early host–microbe interaction is a crucial component of healthy immune and metabolic programming of term and preterm infants, which is jeopardized by sepsis and resulting oxidative stress . The intDuring gestation and after birth, the gut is exposed to a broad spectrum of organisms, mainly bacteria but also viruses, fungi and parasites that will shape the development of the immune system. During infancy, the gut is progressively colonized by a rapidly diversifying microbiota until it reaches the adult-like pattern at around 3–5 years of life .Postnatal gut microbial colonization is driven by a variety of factors such as mode of delivery, environment, gestational age (prematurity), hygienic measures, and type of diet ,85,86. SGut microbiota provides the necessary stimuli required for an adequate developmental programming of the epithelial barrier function, gut homeostasis, angiogenesis, and innate and adaptive immune functions . It is wOf note, microbial dysbiosis and/or microbial infections have been associated with preterm delivery ,93. It hA body of evidence suggests that microbial evolution begins prior to birth . In pretEnterobacter, Enterococcus, Lactobacillus, Photorhabdus, and Tannerella was associated to lower gestational age and then linked to preterm birth [Enterobacteriaceae, Enterococcaceae and Staphylococcaceae and a lower presence of Bifidobacterium and Bactericides [A higher presence of specific bacteria such as rm birth . After bericides ,100,101.Staphylococcus and Enterococcus spp. [Enterobacteriaceae family may trigger a pro-inflammatory response and favor an increased predisposition to inflammation status [It has been also reported that the gut microbiome of extremely low birth weight (ELBW) preterm neonates harbors a lower bacterial diversity and higher presence of the Enterobacteriaceae family and the genus belonging to cus spp. . Furthern status . It has n status . In preterm infants, increased intestinal permeability favors bacterial translocation and has an effect on systemic inflammatory host response, subsequently increasing the risk of sepsis or NEC followed by the multiple organ dysfunction syndrome (MODS) ,105. In Mounting evidence suggests that communication between indigenous microbes, leukocytes and neurons begins during early life. Pronovost and Hsiao review evidence suggesting that interactions between the early life microbiome and the immune system are important for neurodevelopment and that alterations in microbiome–neuroimmune communication may predispose individuals to neurological and neurodevelopmental diseases .Microbiota perturbations, including the elimination, reduction, or alteration of endogenous microbes, lead to altered immune development in multiple tissue sites. In the brain, the absence of the microbiome in germ-free mice alters morphological and transcriptional features of brain-resident microglia. Several recent studies reveal that manipulating the gut microbiota alters the development of brain-resident microglia of the neuroimmune system. To determine whether the microbiome impacts microglial development, transcriptomes were profiled in newborn and adult microglia from germ-free (GF) mice compared to conventionally colonized controls. Across two independent studies, adult microglia from GF mice exhibited decreased expression of genes relevant to inflammation and immune defense, such as CST7, P2RY13, MCM5 and TPI1 .Neurodevelopmental disorders, such as autism spectrum disorder and schizophrenia, are co-morbid with immune dysregulation across the gut, periphery and brain, and they are associated with many immune-related genetic and environmental risk factors .Both early life immune activation and microbial dysbiosis are regarded as susceptibility factors for the etiopathogenesis of neurobehavioral issues that underlie the diagnostic features of the disorders .Consistent with the ability of the gut microbiota to regulate immune homeostasis, differences in the composition of the gut microbiome were important for determining the severity of inflammatory responses to immune activation and the downstream consequences on fetal brain development and adult behavior. Notably, manipulation of the offspring microbiome at weaning was sufficient to correct only a subset of behavioral abnormalities in the model .Lachnospiraceae and decreased S24–7 later in life and decreases in IL-2, IL-3, and stem cell factor (SCF) in the cerebrospinal fluid. Interestingly, early life antibiotic exposure and alterations in the gut microbiome reduced adult amyloid-β plaque burden in the cortex and hippocampus, which coincided with fewer plaque-associated, ramified microglia and astroglia, and a greater abundance of Tregs [Lactobacillus spp. in particular, that correlate with stress-induced immunological and behavioral abnormalities relevant to anxiety and depression [Lactobacillus reuteri improved behavioral impairments in the forced swim task, which was used to measure features of depression-related “despair” [In a mouse model for Alzheimer’s disease , early lof Tregs . In addipression . The trapression . In anotdespair” .These studies suggest that the microbiome can tune neuroimmune interactions and neurodevelopment to alter predisposition to later-life symptoms of neurological disease.The intestinal microbiome integrates environmental inputs with genetic and immune signals that affect the host’s metabolism, immunity and response to infection. The innate immune system, located in the gut, has the ability to sense microorganisms and translate the signals into host physiological responses and the regulation of microbial ecology .Enterobacteriaceae, and a reduction in Bacteroides and Bifidobacterium spp., in the gut of septic preterm infants when compared to their control twin. Sepsis induces a change in the intestinal microbiome not only due to the action of the pathogen bacteria, oxidative stress and inflammatory response but also due to the effect of the antibiotherapy. Moreover, Cernada et al.  reportedEnterobacter (belonging to Proteobacteria phylum) and Staphylococcus spp. (belonging to Firmicutes phylum) in preterm gut has been associated with NEC and LOS [On the other hand, this dysbiosis is considered not only as a consequence but also as a possible risk factor for the appearance of sepsis and other pathologies such as necrotizing enterocolitis. Dysbiosis, understood as a change in the qualitative or quantitative microbiota composition, in preterm infants has been associated with sepsis without an increased prevalence of potential intestinal pathogens . Neverth and LOS . Proteobacteria and decreased relative abundances of Firmicutes and Bacteroidetes [Moreover, lower bacterial diversity in preterm meconium is related to a higher risk of sepsis . Microbiroidetes . Overallroidetes . This stSince the use of antibiotherapy for the treatment of sepsis can affect the gut microbiome and modulate microbial communities, impacting on the abundance and diversity  with theNowadays, there is still not evidence that the use of probiotics in the NICUS decreases the incidence of sepsis or NEC, despite have been realized trials with different probiotic strains and different quantities of probiotics ,122. On Metabolomics globally evaluates the totality of the endogenous metabolites in patient’s body, at the same time reflecting the gene function, enzyme activity and degree of organ dysfunction in sepsis. Staphylococcus had the most positive correlations, including several classes of sugar metabolites, organic acids, and central metabolites. Fatty acids, lipid metabolism, and amino acids positively correlated with the commonly abundant gut colonizers Enterobacteriaceae and Bacteroides and negatively with the common low-abundance colonizers Sthaphylococcus and Enterococcus. Bacteroidetes were found to positively correlate with succinate (r = 0.85) [It is known that bacterial metabolism in the gut is expected to contribute to the abundances of metabolites detected in fecal samples. Wandro et al. found that  = 0.85) .Nevertheless, metabolic dysbiosis is not mandatorily accompanied by appreciable quantitative and/or qualitative changes in microbiota composition called taxonomic dysbiosis, indicating the need for further research in this area to find different approaches to its assessment using metabolomics . This line of research is currently in full swing, seeing that metabolites concentrations in colon, blood, urine or exhaled air, as well as the metabolic profiles of examined substrates, can serve as biomarkers .The sepsis in preterm infants triggers the innate immune and inflammatory responses, leading to oxidative stress and tissular damage. The pro-oxidant environment linked to the mediators of inflammation is capable of producing dysbiosis and changing the gut microbiome. The knowledge of all these mechanisms and the study of transcriptomic, metabolomic and microbiome profiles could help us reach an earlier and more accurate diagnosis. We conclude that this is a field still to be explored, where more research should be carried out to be able to transfer it to the clinical practice in order to achieve a reduction in the morbidity and mortality of this population.


The period from 2019 to 2022 has been defined by the COVID-19 pandemic, resulting in an unprecedented demand for and use of Personal Protective Equipment (PPE). However, the disposal of PPE without considering its environmental impact and proper waste management practices has become a growing concern. The increased demand for PPE during the pandemic and associated waste management practices have been analyzed. Additionally, the discussion around treating these residues and exploring more environmentally friendly alternatives, such as biodegradable or reusable PPE, is crucial. The extensive use of predominantly non-degradable plastics in PPE has led to their accumulation in landfills, with potential consequences for marine environments through the formation of microplastics. Therefore, this article seeks to establish a connection between these issues and the Sustainable Development Goals, emphasizing the importance of efficient management aligned with sustainable development objectives to address these emerging challenges and ensure a more sustainable future. The years 2019 to 2022 will be recorded in history due to the significant loss of human life that occurred during the COVID-19 pandemic, which was caused by the SARS-CoV-2 virus. The tumultuous circumstances brought about by COVID-19 have not only impacted the healthcare system but have also exerted influences on economic, political, and environmental systems, prompting nations to adopt suppression and mitigation strategies in order to curb transmission within their populations. These measures encompass compulsory social distancing, limitations on non-essential medical services, the closure of non-essential establishments, and the utilization of Personal Protective Equipment (PPE) [Nations with resilient healthcare systems and robust economies experienced swift overburdening during the pandemic, prompting attention to shift toward more vulnerable regions of the world, specifically low- and middle-income countries (LMICs) . In thesDespite the intense efforts of the scientific community in the production of vaccines like Coronavac, which is of Chinese origin, AstraZeneca, which is produced by the University of Oxford, and BioNTech, which is produced by Pfizer, precautionary measures in relation to human contact must remain to reduce the risk of transmitting the SARS-CoV virus-2 , includiGovernments have advised their populations to use fabric masks made at home, which can be washed after each use. This is consistent with the objective of reducing the spread of the COVID-19 since the use of a mask hinders the dispersion of droplets and aerosols of the mucous membranes, especially during speaking, coughing, or sneezing. Furthermore, disposable masks are used exclusively by front-line workers to avoid contact with the virus. However, a problem that has arisen is the scarcity of Personal Protective Equipment since it is being constantly replaced to prevent the proliferation of the virus within hospitals and to mitigate the risk of contaminating patients and, importantly, the health professionals themselves ,6,7.Consequently, the PPE used by all health professionals and by other citizens has been overloading landfills and the environment, given the amount of waste generated, and the inappropriate disposal of masks and gloves is creating environmental problems ,9. The dIn addition to the environmental problems related to the increase in the generation of solid waste, inadequate waste management practices increase the potential for the spread of COVID-19 in developing countries . TherefoThe issue of the escalating generation of waste is among the preoccupations outlined by global leaders and was anticipated within the objectives of the Sustainable Development Goals (SDGs) put forth by the United Nations (UN). These goals are founded upon a collection of widely accepted values, aiming to enhance human living standards, safeguard the planet, and foster prosperity. One of the primary objectives of SDG 12  is to significantly diminish waste generation by 2030 through preventive measures, reducing, recycling, and reusing.Concerning the problem of waste generation in response to COVID-19, the aim of this study was to compile research related to the production of Personal Protective Equipment (PPE) waste during the COVID-19 pandemic. Further, it sought to delve into the feasibility of making PPE either biodegradable or reusable, scrutinizing appropriate strategies for managing such waste and evaluating its prospective impact on attaining the Sustainable Development Goals (SDGs) outlined in the United Nations’ 2030 Agenda.Personal Protective Equipment (PPE), as the name suggests, consists of vital items designed to safeguard lives in the workplace. Within the healthcare field, gloves, masks, white (lab) coats, and glasses play a fundamental role in combating the transmission of diseases, whether through saliva, mucous droplets, aerosols, or other bodily fluids like blood ,14,15.N95 masks are recommended as single-use items and are primarily utilized by healthcare professionals treating patients with COVID-19. This is due to their efficient filtration capabilities, as they are able to remove up to 95% of particles with a diameter of 3–5 μm. The mask’s filtration system is composed of electrostatically charged polypropylene layers arranged with microfibers, enabling the effective removal of microorganisms .The medical utilization of N95 masks is relatively recent, having begun in the 1990s as a means to safeguard healthcare workers from drug-resistant microorganisms carried by patients infected with the human immunodeficiency virus (HIV). Subsequently, these masks were employed during the SARS outbreak in 2003. During the current COVID-19 pandemic, these masks are extensively employed by healthcare professionals. Although they are not intended for reuse, the scarcity of such materials during a pandemic is a known challenge. Reusing N95 masks poses the risk of compromising filtration efficiency and a less secure fit on the face, leading to reduced protection ,16.Sterilization methods for masks have been studied; the main methods that have been investigated are dry and steam sterilization (autoclaving), the use of vaporized hydrogen peroxide, and ultraviolet germicidal irradiation ,18. SomeAnother type of mask used is the surgical mask, which has three layers. The innermost layer is in direct contact with the face and absorbs moisture from the user’s breath, and the intermediate layer acts as a filter, while the outer layer repels liquid fluids. Although the outer layer is hydrophobic, dangerous viruses can remain on it, so it is recommended that a surgical mask is used for a few hours and then immediately discarded .Surgical masks are primarily composed of non-woven fabric (NWF) and polypropylene, providing resistance for a maximum duration of 4 h, after which their filtration effectiveness diminishes. Due to the inability to wash or sterilize them, reusing surgical masks is not practical . AlthougRegarding the use of disposable gloves, there are no recommendations for the general population to utilize them in routine household tasks. The priority is to allocate their usage to healthcare professionals. Latex, nitrile, and vinyl gloves offer benefits to both the patient and the healthcare professional by preventing direct contact with microorganisms, mucous membranes, blood, and other fluids, regardless of whether they are contaminated or not . The reuAs in the case of masks, it is also important to consider the materials used to produce gloves, since their performance is mainly dependent on the nature of the material used. Gloves with a higher percentage of elongation, for example, are more likely to stretch than tear when pulled, while those with higher tensile strength are more rigid and are more suitable for delicate procedures . In the The white coats commonly used by health professionals help in avoiding contamination through clothes, serving as shields between the professionals and the patients. This prevents fluids from accidentally reaching the clothes of the health worker, and microorganisms cannot be transferred along the home–work translocation route of contamination. Consequently, it is important to keep these white coats properly cleaned. Industrial washing is an excellent option since this process eliminates any microorganisms . When thIn one study, white coats washed at home showed an increase in contamination of 54% at the end of the day, mainly in the regions of the wrists and pockets. Therefore, there is a need to change white coats within short time intervals. In the face of this pandemic, disposable white coats are replaced for each patient, avoiding cross-contamination. In this context, research studies are seeking efficient textile technologies, mainly looking for materials that repel fluids and have antimicrobial agents incorporated into the fabric; however, further discussion and studies regarding the price of these uniforms and their overall health efficacy are needed .Another critical type of PPE utilized in hospital settings, though they are less frequently discussed, are goggles. It is of the utmost importance to emphasize the use of this type of protective equipment as goggles prevent liquids from splashing directly into the eyes and minimize the risk of contamination through touch. It is crucial for the design of goggles to provide excellent peripheral vision while ensuring a secure and comfortable fit . AdditioThe majority of goggles and face protectors are manufactured using petroleum-based materials like polyethylene. When disposed of, these items generate residues that are challenging to decompose. While the replacement frequency for this type of PPE may not be as high compared to others, there has undeniably been a surge in their utilization due to the ongoing pandemic . As withLastly, it is crucial to emphasize the significance of the proper removal of Personal Protective Equipment (PPE) as healthcare professionals can potentially be exposed to pathogens present on the outer surfaces of equipment. Therefore, comprehensive training should be provided to all healthcare professionals to ensure effective and safe removal of equipment . AdditioCurrently, during the COVID-19 pandemic, following government recommendations, a considerable number of individuals have become skilled at producing homemade masks. Consequently, this form of Personal Protective Equipment is now widely utilized on a daily basis across the globe. The effectiveness of this type of mask has been analyzed, and in terms of protection against nanoparticles, it has been demonstrated that masks made with traditional fabrics protect against particles of significantly different sizes. The level of protection varied from 30% to nearly 90%, with some cloth masks offering particle barrier properties similar to commercial surgical masks .Although they guarantee protection against the virus, most masks consist of non-renewable polymers derived from petrochemicals, such as polypropylene, polystyrene, polycarbonate, polyethylene, and polyester, contributing to environmental pollution and subsequent secondary health challenges. In light of the aforementioned discussion, there is an urgent need to quickly develop fully biodegradable facial masks that fulfill the objectives and are low-cost, light, and comfortable .Finally, the importance of conducting studies that contribute to mitigating the adverse effects of the current pandemic, such as the present and future environmental impacts, is highlighted. Additionally, there is a need for research to develop biodegradable face masks derived from natural materials in order to ensure an improved quality of life and the protection of marine and terrestrial ecosystems during this global health crisis .The COVID-19 pandemic has triggered global emergencies in relation to social and economic aspects which extend to environmental issues, such as solid urban waste management (MSW), the management of hazardous biomedical waste, and the treatment and disposal of MSW ,26. AlthThe pandemic has altered the dynamics of waste generation, creating problems for policy makers and workers involved in sanitation ,27,28. AChallenges to municipal waste management practices and procedures have arisen, including updating health and safety measures for employees, waste treatment requirements, and general procedures for the waste sector ,12. The Thailand, China, Singapore, and the USA have experienced significant increases in plastic waste generation, encompassing a range of items including face masks, Personal Protective Equipment (PPE), and packaging materials. Notably, Thailand has witnessed a threefold increase in plastic waste production. Additionally, Hubei, China, has observed a concerning surge of 370% in medical waste that is predominantly composed of plastic materials. These statistics emphasize the mounting concern over the increased generation of plastic waste in various regions, underscoring the pressing need for effective waste management strategies and sustainable practices to mitigate the environmental impact caused by such waste .In India, an increase in the generation of yellow biomedical waste (Y-BMW) has been observed during the COVID-19 pandemic. The sudden influx of COVID-infected patients seeking healthcare services has placed a substantial burden on existing incineration units dedicated to the disposal of biomedical waste. On average, each COVID-infected patient in India generated approximately 3.41 kg of biomedical waste per day, with Y-BMW accounting for approximately 50.44% of the total waste generated .Notably, on 13 July 2020, the combined Y-BMW generated by both regular patients and COVID-infected individuals exceeded the incineration capacity of India’s biomedical waste management system. These findings emphasize the urgent need for effective strategies to address the escalating volume of Y-BMW as it poses significant environmental and public health concerns in the country .Singh and Mishra (2021) underscore the significant impact of COVID-19 on India, positioning it as the second-most affected country following the United States. A comprehensive report published on 18 September 2020, shed light on the staggering daily production of biomedical waste in India, which surpassed 180 tons. Notably, the state of Maharashtra emerged as a major contributor, accounting for approximately 17% of the total biomedical waste generated nationwide .The period from June to September 2020 witnessed a substantial surge in the volume of biomedical waste generated in India solely due to the COVID-19 pandemic. In June, the country generated an estimated 3025 tonnes of biomedical waste, followed by approximately 4253 tonnes in July. August recorded an even higher volume, with an approximate generation of 5238 tonnes, while September marked a further increase, reaching around 5490 tonnes. These statistics highlight the unprecedented scale of biomedical waste generation during the specified timeframe, emphasizing the pressing need for robust waste management strategies and infrastructure to mitigate potential environmental and public health hazards .During the COVID-19 outbreak in China, there was a significant 30% reduction in municipal solid waste (MSW) in large- and medium-sized cities due to lockdown measures. However, in Hubei Province, the epicenter of the outbreak, there was a concerning 370% increase in medical waste generation, including infectious and non-infectious waste. This highlights the challenges faced by healthcare facilities and the importance of adapting waste management strategies to handle the surge in medical waste effectively .China experienced a significant surge in the demand for Personal Protective Equipment (PPE), particularly masks, during a specific period. Mask production increased by 450% within one month to meet the heightened demand due to the COVID-19 pandemic. Additionally, the demand for N95 respirators rose from 200,000 to 1.6 million units, underscoring the crucial need for effective respiratory protection among healthcare workers and the general population .These statistics highlight the rapid adaptation of PPE manufacturing and distribution systems in China to address the growing demand during the pandemic. The significant increase in mask production and the surge in demand for N95 respirators illustrate the urgent need for adequate PPE supplies to ensure the safety and protection of frontline workers and the general public .The WHO has estimated a need for 89 million medical masks each month, 76 million exam gloves, and an international demand for 1.6 million goggles per month ,33. ImprIt should be noted that infectious waste is not limited to hospitals and health centers, as people with minor symptoms or who are asymptomatic also generate contaminated waste, such as disposable masks and gloves ,33,34. TEven prior to the pandemic, projections had already indicated a worrisome estimate of approximately 12 billion metric tons of plastic waste accumulating in landfills and the natural environment by the year 2050. Due to this context, the authors point out that efforts must be made to promote recycling, reduce single-use plastics and implement comprehensive waste management systems to address this growing concern . Bown  reported that plastic-based Personal Protective Equipment (PPE) has been extensively employed as a means of mitigating the risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This includes the widespread utilization of millions of surgical masks, medical gowns, face shields, safety glasses, protective gowns, disinfectant containers, plastic shoes, and gloves, all aimed at minimizing the potential of encountering the virus ,37.Plastic items made of non-woven materials (such as certain masks) typically contain polypropylene and polyethylene, which degrade into smaller microplastic particles. Consequently, the utilization of these face masks by non-professionals contributes to a significant environmental issue, amplifying microplastic pollution in marine and freshwater ecosystems ,34.Dozens of disposable masks were found on a beach in the Soko Islands in Hong Kong, according to the NGO Oceans Asia. Also, in the Magdalena River, in Columbia, the degradation of non-woven synthetic fabrics was the predominant origin of microplastic microfibers found in samples of water and sediments ,36. The Modifications were implemented in municipal solid waste (MSW) management services during the COVID-19 pandemic in both developed countries like the United Kingdom, USA, Singapore, and Japan, and in developing countries, including India, Malaysia, Brazil, Indonesia, and Vietnam ,39,40,41Furthermore, the COVID-19 pandemic can give rise to significant environmental pollution issues due to the production and generation of microplastics (MPs), as highlighted by Fadare and Okoffo (2020) . MPs areThe most prevalent types of MPs found in the environment include polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), nylon-polyamide (PA), and acrylonitrile butadiene styrene (ABS), as well as various copolymers and plastic mixtures ,44. WhenTherefore, the practices that are currently saving lives may inadvertently contribute to environmental harm in the future, underscoring the significance of proper disposal methods for the aforementioned materials and the implementation of effective waste management and treatment systems to prevent the emergence of new problems stemming from the ongoing pandemic. The extensive production of millions of PPE items made from synthetic materials like PE, ABS, PVC, and others to meet the demands of the COVID-19 pandemic has raised concerns among environmental agencies.According to a survey conducted by PlasticsEurope (2018) , the gloThe materials used in PPE, such as NWF, polyethylene, and plastics, are primarily derived from petroleum and are not easily biodegradable. These items are typically used for short durations, and depending on their disposal methods, their accumulation can lead to significant environmental impacts, particularly with respect to the buildup of waste in landfills and the bioaccumulation of microplastics. It is important to address the proper disposal and management of these materials to minimize their negative environmental effects.Plastic reduction policies and plastic waste management strategies have recently experienced setbacks or temporary delays due to COVID-19 as the prioritization of human health has taken precedence over environmental protection . The monIt can be stated that the potential environmental risks associated with microplastics (MPs) include physical abrasion and the obstruction of ingestion pathways in marine organisms . Other hHuman beings are exposed to plastic debris through the consumption of seafood and drinking water and via contact with food and beverage packaging and other materials, such as PPE. The accumulation of MPs in humans presents potential health risks, including cytotoxicity, hypersensitivity, unwanted immune responses, and acute responses, such as hemolysis. In the scientific literature, it is possible to observe experiments conducted to investigate cellular responses upon contact with primary and secondary polypropylene microplastics (PP) of approximately ~20 μm and 25–200 μm, respectively .The results showed that the presence of PP particles in the medium, especially those below 20 μm, were cytotoxic, and that this toxicity was caused by an increase in ROS (reactive oxygen species) and occurred as a function of size and concentration. However, larger PP particles and PP powder particles showed less cytotoxicity. The authors concluded that cells that come into direct contact with PP particles pose a potential health risk via the induction of cytokine production from immune cells rather than direct toxicity to cells. They noted that there are thousands of other types of plastic in various concentrations and size configurations that should be studied .Experiences and successes in Wuhan suggest that improving the emergency management system for medical waste is crucial to mitigating risks to human health. Therefore, the following four steps can be followed: (1) implementing a sophisticated medical data system, (2) improving hospitals’ medical waste storage capacities to handle significant increases during emergencies; (3) developing emergency plans to coordinate disposal resources across the region; and (4) strengthening Wuhan’s emergency response capacity through collaboration and support from other areas in the country .Life cycle assessments (LCAs) study environmental aspects and possible impacts on the environment through the life cycle of a product, that is, from the cradle to the grave, from the acquisition of the raw material and through the production system to its use and final disposal. Through the analysis of environmental impacts, such as climate change, the depletion of fossil fuels, the depletion of water, marine and freshwater ecotoxicity, and marine and freshwater eutrophication, it is possible to measure how much something will harm the environment from the extraction of raw materials until its conception and final disposition .Personal Protective Equipment is important to discuss since its use in the face of the COVID-19 pandemic has become essential. Research regarding the use of life cycle assessments, measured emissions, and the waste generated from locally produced reusable face masks and disposable surgical face masks has also been conducted. The results of the LCAs of both show that the use of a reusable embedded filtration layer (EFL) face mask will generate less waste and will have an impact of at least 30% less among the impact categories considered when compared to the use of single-use surgical mask, indicating it as a popular alternative to the use of reusable masks to mitigate environmental impacts .Biopolymers are polymers produced from raw materials from renewable sources, such as corn, cassava, cellulose and others, and have shorter life cycles when compared to those of fossil origins, such as polyurethane. Biopolymers are factors of environmental and socioeconomic interest due to the mitigation of the environmental impacts of oil extraction and refining. Studies have identified some technical limitations of biopolymers due to their properties, such as their thermal resistance, mechanical and rheological properties, and the applicability of their properties on an industrial scale .Regarding the development of Personal Protective Equipment with biodegradable materials, the market for biopolymers stands out, including materials derived from plants, biomasses, celluloses, and even microorganisms, many of which stand out for their excellent properties, such as poly (lactic acid) (PLA), which is a kind of aliphatic polyester produced via the fermentation. of sugar, which demonstrates biodegradability, biocompatibility, non-toxicity, a high level of mechanical resistance, and a good cost/benefit ratio. PLA has been widely studied and used for food packaging and tissue engineering applications and can be an attractive field of study for the construction of biodegradable PPE . In partAnother very widespread polymer like PLA is polybutylene succinate (PBS), which is obtained from the condensation polymerization of succinic acid (AS) and butanediol. It draws attention for its thermal and mechanical properties . BacteriResearch on the production of 3D printed safety protective devices, with a focus on the production of respiratory masks in response to the COVID-19 pandemic, has been observed. Topics such as material selection and assessments of mechanical strength and biological safety, as well as analyses of the mechanical and safety characteristics of masks, have been covered. The study concluded that masks 3D printed using home-grade printing equipment have similar levels of performance to industrial-grade masks, and it develops new approaches for the post-processing phases of additive manufacturing, aiming to ensure human safety in the production of personalized medical devices that have been 3D printed .The use of 3D printers can be observed in various studies, such as the case of a project involving a fibrous mask filter made with polybutylene succinate and microfiber and nanofiber mats and coated with chitosan nanowhiskers. It is worth noting that a wheat gluten biopolymer was used as a filtering medium in face masks, and an air-permeable mask was developed using electroshocked licorice roots. A biodegradable mask filter was made via electrospinning and 3D printing polylactic acid which filtered 79% of the air at a particle size of 500–600 nm, which is superior to standard face masks. Polylactic acid was suggested as a suitable material for reusable respirators, and its microstructure was not affected after the efficient disinfection of bacteria, fungi and viruses .Some of the largest environmental problems caused by the pandemic are municipal solid waste (MSW) and hazardous biomedical waste. The proportion of non-infectious waste, which is more than 80% of the total amount of health waste generated, needs to be collected and disposed of as municipal waste .The widespread use of protective equipment worldwide in conjunction with the pandemic has led to massive waste management difficulties and improper disposal practices worldwide. The plastic products used are correspondingly pathogenic and should be regarded as hazardous wastes as landfills manage them by promoting the biodegradation of plastics. Plastic waste management was considered a primary environmental concern before the beginning of the COVID-19 pandemic due to increasing concerns about pollution in marine and terrestrial ecosystems .According to the World Health Organization (2020), the use of masks by ordinary citizens quickly became controversial due to the lack of correct handling and disposal and the shortage of this material in healthcare facilities . GuideliHowever, the major factors associated with managing MSW outside of health facilities also need to be addressed, such as virus resistance, differences in waste management systems, and the climatic conditions in each affected region . Also, tA lack of proper waste management strategies and the uncontrolled combustion of medical plastic waste has accelerated the release of greenhouse gases (GHGs) and other potentially dangerous compounds, such as dioxins, PCBs, furans, and heavy metals, creating significant environmental concerns. The COVID-19 pandemic has placed this issue on the front line of environmental research through the increase in single-use plastics. In addition to increasing the use of Personal Protective Equipment (PPEs), there was in an increase in the plastic packaging of foods and groceries intended for home delivery during the lockdown and home quarantine periods .The integration of waste management in disaster management planning will result in inclusive response measures and guidelines for operating better in the dynamics of a future pandemic, prioritizing the formulation and implementation of homogenous plastics, eco-friendly bio-plastics, and circular technologies while phasing out single-use plastic through taxation. To safely manage biomedical wastes, an automated system of waste storage, collection, treatment, and disposal should be developed using advanced technologies and the Internet of Things .The US Occupational Safety and Health Administration (OSHA) has established predefined safety guidelines for personnel involved in health waste management, recognizing it as an essential service and requiring employees to take appropriate precautions . The EurIn Spain, the regulations currently allow infectious waste to be co-incinerated with other waste for use in cement factories. Norway has temporarily authorized landfills for the final disposal of infectious waste, as well as the transport of waste to other disposal sites, due to the increase in the generation of this type of waste .In Brazil, the Brazilian Association of Sanitary Engineering  has prepared a document advising contaminated patients who are in home isolation to pack their generated waste in double bags up to 2/3 full, tightly close them, and leave them out for conventional collection. Regarding recyclable waste, this is to be stored at home during quarantine for an undefined period, paralyzing the activities of many recycling associations .The Brazilian Association of Public Cleaning and Special Waste Companies  has a different position and recommends the continued separation of recyclable waste for those individuals who are not infected by the virus . The two▪Sheet 1—Introduction to COVID-19 waste management;▪Sheet 2—National medical waste capacity assessment;▪Sheet 3—How to choose your waste management technology to treat COVID-19 waste;▪Sheet 4—Policy and legislation linked to COVID-19 pandemic;▪Sheet 5—Links with the circularity of non-hospital waste;▪Sheet 6—Linkages of air quality and COVID-19;▪Sheet 7—Household medical waste management strategies;▪Sheet 8—Disaster and conflict; and Sheet 9—COVID-19, wastewater, and sanitation .The United Nations Environment Program (UNEP) has prepared nine technical sheets with information that can help individuals, companies, and government authorities manage the waste generated during the pandemic, namely:The great challenge pointed out by UNEP is the objective of avoiding possible long-term impacts on the environment via the available waste management solutions. To this end, within its short-term recommendations are (i) to manage the increase in waste production, maximizing the use of existing facilities; (ii) ensure that operations respect emission limits and thus avoid secondary health impacts; (iii) in the absence of appropriate technology, consider adopting the 3S methodology  and install temporary/palliative solutions .Incorrectly managing and disposing of waste during the pandemic can further spread the virus, especially in developing countries, due to poor waste-handling conditions associated with the inappropriate use of Personal Protective Equipment and poor sanitation conditions . StudiesHospital waste is usually incinerated, turned into energy, or disposed of in landfills . In moreWhile some countries or municipalities are able to properly manage this waste, others are being forced to apply inadequate management strategies, such as direct landfilling or burning . The sigOn the other hand, countries with larger economies managed to overcome the adversities of COVID-19 in the management of plastic waste. Wuhan was a city that demonstrated efficiency in the disposal of medical waste during this pandemic, even with an increase of almost six times more than normal, reaching almost 247 tons/day. The technology designed by the waste management authority of this city of 11 million people was the distribution of mobile incinerators to safely dispose of the extremely high amount of potentially contaminated PPE waste generated .Wuhan’s medical waste management experience, in the context of the COVID-19 pandemic, can be presented as a valuable example of an emergency response that can inform cities around the world about the formulation of environmental policies that occur simultaneously with pandemic control and other urgent environmental stressors. Despite the lack of capacity to dispose of medical waste in the early stage of the COVID-19 pandemic, Wuhan employed three emergency measures in response to the rapid spread of COVID-19: the use of facilities’ disposal furniture, the expropriation of municipal waste incinerators, and the implementation of external disposal .It can be stated that some lessons have been learned from the pandemic in certain municipalities regarding the management of healthcare waste. The importance of adopting automated systems in which there is no need for human contact in handling this highly contaminating waste, based on Internet of Things technology, which enables the tracking of waste information, has been observed. Additionally, there is a need to maintain larger facilities for medical waste in emergencies like the COVID-19 pandemic .Due to the COVID-19 pandemic, health and safety recommendations have been expanded, prioritizing the treatment of solid waste, especially plastics, through incinerator systems and final disposal in landfills. This has resulted in waste management strategies that lead to an increased use of natural resources for the production of plastics and higher emissions of greenhouse gases and other compounds that pose a risk to the environment .▪Ensure the regular maintenance of vehicles;▪Implement well-organized public transport systems;▪Improve traffic management systems;▪Reduce emissions of chlorofluorocarbons (CFCs);▪Use eco-friendly products;▪Implement a well-organized and effective waste management system;▪Promote reused and recycled waste materials; and▪Ensure the proper treatment of wastewater before discharging it into the environment .To effect positive changes in the environment, individuals and governments can adopt the following strategies:The huge amount of PPE can cause harmful impacts to several ecosystems, especially marine wildlife, as PPE debris in marine environments is considered an emerging form of plastic debris and an addition to the existing microplastics crisis. It should be noted here that numerous studies have already documented the impacts of COVID-19 litter on wildlife through entanglement, entrapment, and in-management .A survey carried out on the Indian coast on waste monitoring assessments, conducted at various points along the coast, pointed to ineffective waste management, citing the behavior of the population  as one of the fundamental causes of pollution from marine litter. Approximately 60 to 85% of plastic waste in India has been mismanaged, with a tendency for it to enter the environmental matrix, including surface water systems [In recent years, several studies have been published on the ingestion of micro-plastics by marine animals in India. The bioaccumulation of microplastics in mesopelagic and epipelagic fish, the Indian edible oyster, Indian white shrimp, bivalves, and in some commercially important fish and other marine wildlife has been documented very recently . The preIt should be noted that this problem is not found only in marine environments but on land as well. Abandoned protective masks in the terrestrial system can obstruct urban sewage systems and impact the aeration and percolation of water in agricultural soils. Incorrect disposal of masks can also threaten fauna through entanglement or by being mistaken for food, as in the reported case of a bird entangled in masks and killed in Colombia. The accumulation and translocation of small plastic particles in plant tissues, which can influence plant growth and agricultural productivity, have also been reported .As emerging pollutants, MPs have received global attention due to their wide distribution, high abundance, toxic substance enrichment, and potential threats. Researchers indicate protective masks as new sources of microplastic pollution and proposed the need to take measures to prevent the problem of microplastics derived from PPE .More coordinated engagement is necessary for circular economic approaches, particularly in policies and practices related to the recycling of Personal Protective Equipment (PPE). Various methods such as glycolysis, aminolysis, hydrogenation, hydrolysis, gasification, and pyrolysis are now focused on exploring advanced technologies to convert PPE waste into value-added products. Recent studies demonstrate that the pyrolysis of COVID-19-related PPE waste is the most effective method and an ecologically sound solution with significant potential for application ,86.PPE recycling can generate value-added products and mitigate disposal issues while providing energy sources . For exaThe reuse of face masks after decontamination is also a strategy to reduce their use and disposal. Efforts were made to decontaminate and reuse FMs to address product shortages and the environmental burden produced. Various methods, such as ultraviolet germicidal irradiation, dry and wet heat treatment, vaporized hydrogen peroxide, and ethanol treatment, have been developed for mask decontamination. Most decontamination methods are tested and proposed for reuse of N95 masks ,87.The proper management of used FMs is imperative to decrease the release of MPs into the environment. In addition, the plastics in protective masks can be recycled via mechanical recycling. The direct recycling of masks can be achieved through injection molding or by improving mechanical performance with additives from industrial waste . The dir▪Improvements in design, such as reducing the amount of plastic used or replacing it with more eco-friendly alternatives wherever possible;▪In the case of Personal Protective Equipment (PPE), opting for reusable alternatives like cotton masks or treating disposable PPE to enable the reuse of N95 masks that can be decontaminated by steam; and▪Substituting disposable plastics with bio-based solutions  framework, has suffered an existential blow due to these new circumstances, exemplifying how the environment truly encompasses every aspect of existence to synergistically benefit humans and nature and cannot be compromised, especially from a policy perspective ,89,90,91In this section, the relationship between COVID-19 and the SDGs is discussed; more specifically, the waste generated from the PPE used in hospital environments is addressed. In the article “COVID-19 and the UN Sustainable Development Goals: Threat or Opportunity for Solidarity?”, the importance of the impacts of the pandemic caused by COVID-19 with respect to the SDGs 1, 2, 3, 4, 5, 8, 10, and 16 was discussed. However, in this study, the focus was on SDGs 8 and 12 as objectives directly achieved due to the protection of health professionals and the generation of solid waste, respectively. Subsequently, SDGs 6, 11, 14, and 15 will be addressed and considered in this study as indirectly achieved objectives .In the case of SDG 8, in the context of the study, the effect of COVID-19 in promoting safer work environments for all workers, including health professionals, is added here. Goal 8.8, for example, is aimed at safe and protected work environments for all workers, including healthcare workers, through the use of Personal Protective Equipment .The solutions must be directed toward both the protection of the health professionals involved in the pandemic and to the proper management of hospital solid waste. Surgical masks should not be used for more than a few hours and should be properly discarded to avoid cross-contamination since with the incorrect disposal of PPE, the virus can spread quickly in various public places and in the environment. Therefore, it is observed that at the same time that health professionals need protection, accumulations of solid hospital waste are multiplying ,27.In this way, COVID-19 also impacted the SDGs by increasing the generation of waste, mainly from hospitals, such as masks, glasses, white coats, and other types of PPE. However, due to the rapid progression of the COVID-19 pandemic, the preventive measures implemented to control and mitigate its high transmission rate demanded a sudden increase in the demand and consumption of plastic products by the general public, health professionals, and service providers .In this sense, SDG 12 aims to ensure sustainable standards of production and consumption, and goal 12.5 aims to substantially reduce the generation of waste through prevention, reduction, recycling, and reuse by 2030 . The consequences of COVID-19 have seriously disrupted waste management policies, especially on plastic reduction at the regional and national levels .It is also of great importance to highlight SDGs 6, 11, 14, and 15, which are indirectly related to the current pandemic context. The objective of SDG 6, goal 6.2, is to achieve access to adequate and equitable sanitation and hygiene for all. During this global health crisis, many people in developing countries, like Brazil, do not have access to clean water and basic sanitation. Furthermore, it is necessary to contemplate SDG 11, which deals with sustainable cities and communities.Goal 1.1 of SDG 11 stands out, aiming to guarantee access for all to safe, adequate and affordable housing and to basic services and to urbanize the favelas by 2030; by 2030, goal 11.5 aims to significantly reduce the number of deaths and the number of people affected by disasters and to substantially decrease the direct economic losses caused by them in relation to the global gross domestic product, including water-related disasters, with a focus on protecting the poor and vulnerable people; and goal 11.6 aims to reduce the negative environmental impact per capita of cities, including paying special attention to air quality, municipal waste management, and others, by 2030.The targets mentioned above cite issues that were very evident in this pandemic, especially in developing countries; after all, many locations do not have basic services such as sanitation and running water, and millions of people are unprotected because they do not have adequate housing, among other facts that impair the effectiveness of the 2030 Agenda goals. It can be asserted that these impacts are already negative for wealthy countries and will likely be felt even more strongly in developing nations, which lack the capacity or resources to address the numerous economic and social challenges imposed by the disease. Ultimately, the COVID-19 pandemic reveals the urgent need for action in areas such as security, employment, social and public health, environment, among others .Consequently, the indirect negative impacts in relation to compliance with SDGs 14 and 15, resulting from the inadequate disposal of solid waste during the pandemic, are also highlighted. As mentioned in The importance of prioritizing environmental goals still applies in a post-pandemic scenario. Few of the goal targets proved to be especially significant from a pandemic context; lockdowns helped achieve and/or prevent future environmental disasters .Apparently, the COVID-19 outbreak has brought several positive and negative effects on the environment globally. During this outbreak, the GHG emissions, pollutants in the water, noise pollution, et cetera, suddenly decreased due to travel restrictions and the closure of industries and companies. On the other hand, the use of plastic increased in the food and grocery home delivery service to maintain social distancing, hygiene, and cleanliness to reduce the spread of the COVID-19 virus .This COVID-19 pandemic seems to be preserving the UN sustainable development goals (SDGs) 2030  by reducing pollutants in the air and water ,68. HoweFinally, after analyzing and studying the literature, The COVID-19 pandemic has brought to light the dependence on plastic disposables and the fragility of solid waste management systems. Among these disposables, notable items include those used as Personal Protective Equipment (PPE), the main line of defense of health professionals which prevents them from becoming contaminated and spreading the virus among patients. PPE must be changed several times a day as it can carry the COVID-19 virus. Therefore, hospital waste multiplied in the face of the pandemic, raising questions about the management of this hazardous material.Studying the impact of this waste on the world is now an issue of extreme importance, with tons of PPE being produced and discarded daily. In addition to research on better ways to manage hospital waste, investments aimed at producing PPE with biodegradable materials have never been more important in order to achieve a more sustainable life cycle compared to the use of petrochemical components.In addition to the attention provided to the safety of workers in the handling of PPE waste, especially at the present time, the devices adopted through the application of policies such as the shared responsibility for the life cycle of these products, reverse logistics, sectoral agreements, economic instruments, goals for reuse, recycling and the final disposal of these residues, contributes to minimizing the environmental impacts of PPE waste on the environment, as well as to reducing the use of natural resources.Furthermore, it should be emphasized that in view of the COVID-19 pandemic, it is essential to reinforce the search for concrete actions and strategies at the federal to the institutional levels, in an articulate manner and among all sectors, for the implementation of guidelines aimed at the improvement of solid waste management practices. In particular, this should address the huge increase in PPE waste, which can contribute to the generation of micro- and nanoplastics in the environment, with adverse impacts on ecosystems.It was noted that the Wuhan medical waste management experience, in the context of the COVID-19 pandemic, can be presented as a valuable example of an emergency response that can inform cities around the world about the formulation of environmental policies that occur simultaneously with pandemic control and other urgent environmental stressors.It is of great concern that the pandemic presents a concrete threat to the commitment made by nations regarding the achievement of the UN sustainable development goals (SDGs), especially with respect to the environment, health, and well-being, notably the much-needed reduction in the generation of waste. This study provides an in-depth theoretical insight into the impacts of the use, in large volumes, of PPE in hospital environments, which is necessary for the direct protection of workers and the indirect protection of patients but is generating a serious problem in the form of waste. It also demonstrates the possibility of using biodegradable Personal Protective Equipment to mitigate environmental impacts.The discussions presented in this article, based on the extensive literature, highlight the adverse effects of PPE due to the materials from which it is produced and its intensive use, with serious consequences in relation to the reach of the UN SDGs 6, 8, 11, 12, 14, and 15. The importance of sanitation and access to water for the hygiene of people, the conditions of protection and safety for health professionals, the influence of management in sustainable cities, responsible production and consumption, waste management, and even impacts on soils and water resources were addressed in this article.Therefore, it is suggested to encourage new research relating to the management of solid waste and treatments during the pandemic, whether hospital or domestic waste, as well as the importance and need to address topics such as new textiles and smart textiles for the manufacturing of PPE.


Bone regeneration and repair present significant challenges in the field of regenerative medicine. Whether caused by fractures, bone diseases, or trauma, the restoration of damaged bone tissue requires innovative strategies . Tissue Tissue engineering strategies for bone regeneration often rely on biological approaches that aim to mimic the natural regenerative processes within the body. This includes the use of bioactive scaffolds, growth factors, and stem cells . BioactiIn addition to biological approaches, mechanical strategies play a crucial role in bone regeneration and repair. Mechanical stimulation, such as through the application of biophysical forces, has been shown to enhance the healing process . This caThe ultimate goal of tissue engineering strategies applied in bone regeneration and repair is their successful translation into clinical practice . SeveralBioengineering aims to explore the very latest advances in tissue engineering strategies applied to bone regeneration and repair, highlighting the potential of this field to revolutionize the treatment of bone-related conditions. This current Special Issue includes three original articles.As part of advanced approaches in this field, this current Special Issue of The first article, entitled “Mechanical Characteristics and Bioactivity of Nanocomposite Hydroxyapatite/Collagen Coated Titanium for Bone Tissue Engineering” and authored by D.J. Patty et al., explores the application of a nanocomposite coating consisting of hydroxyapatite and collagen on titanium substrates for bone tissue engineering . The com® KF 3.2  and Rheotest RN 4.1 (rotary), to measure dynamic viscosity. Additionally, the thermophysical studies are conducted using the Hot Disk TPS 2500S analyzer, which allows for accurate measurements of thermal conductivity and thermal diffusivity. The measurements are performed over a wide range of temperatures and concentrations, providing valuable data for engineering calculations of hydrodynamic and heat-exchange processes in biotechnological equipment. The authors also present empirical equations for calculating the density of aqueous solutions of beet molasses. These equations contribute to a better understanding of the relationship between the concentration of dry substances and the density of the solutions at different temperatures. The diagrams illustrating the dependence of dynamic viscosity, thermal conductivity, and thermal diffusivity on shear rate, temperature, and concentration provide clear visual representations of the experimental results. Furthermore, the article highlights the significance of research for biotechnological industries, particularly in the cultivation of microorganisms for food production. The authors emphasize the importance of maintaining optimal conditions, such as temperature and nutrient supply, for the growth and reproduction of microorganisms. The findings of this study offer valuable insights into the hydrodynamic and heat-transfer processes involved in aerobic submerged cultivation. Overall, this article makes a significant contribution to the understanding of molecular transport processes in biotechnological industries. The comprehensive experimental approach, along with the empirical equations and diagrams presented, enhances our knowledge of the factors influencing momentum transfer, thermal energy transfer, and mass transfer in nutrient media [In the second article, entitled “Comprehensive Studies of the Processes of the Molecular Transfer of the Momentum, Thermal Energy and Mass in the Nutrient Media of Biotechnological Industries”, the authors A.G. Novoselov et al. present a detailed examination of the molecular transport coefficients that play a crucial role in biotechnological processes . They emnt media . The finThe third study, entitled “Retrospective Evaluation and Framework Development of Bone Anisotropic Material Behavior Compared with Elastic, Elastic-Plastic, and Hyper-Elastic Properties” and authored by F. Hamandi et al., aimed to retrospectively evaluate bone tissue damage and develop a realistic bone model with anisotropic material properties based on CT imaging data . The stuTissue engineering strategies applied to bone regeneration and repair show great promise in addressing the challenges associated with bone conditions. The integration of biological and mechanical approaches, along with advances in biomaterials, scaffold design, and stem cell technologies, offer exciting opportunities to develop innovative therapies that promote bone healing and regeneration. Although there are still hurdles to overcome before widespread clinical adoption, continued research and collaboration will pave the way for the successful translation of tissue engineering strategies into effective treatments for bone regeneration and repair, improving thus the lives of countless patients.The contributions to this Special Issue take readers on a journey to topical research activities in the specific area of tissue engineering applied to bone regeneration and repair. As the guest editor for this Special Issue, I am optimistic that this specific area of research will again spark inspiration and ideas for further research and development in the field.


Paternal programming is the concept that the environmental signals from the sire’s experiences leading up to mating can alter semen and ultimately affect the phenotype of resulting offspring. Potential mechanisms carrying the paternal effects to offspring can be associated with epigenetic signatures , oxidative stress, cytokines, and the seminal microbiome. Several opportunities exist for sperm/semen to be influenced during development; these opportunities are within the testicle, the epididymis, or accessory sex glands. Epigenetic signatures of sperm can be impacted during the pre-natal and pre-pubertal periods, during sexual maturity and with advancing sire age. Sperm are susceptible to alterations as dictated by their developmental stage at the time of the perturbation, and sperm and seminal plasma likely have both dependent and independent effects on offspring. Research using rodent models has revealed that many factors including over/under nutrition, dietary fat, protein, and ingredient composition , stress, exercise, and exposure to drugs, alcohol, and endocrine disruptors all elicit paternal programming responses that are evident in offspring phenotype. Research using livestock species has also revealed that sire age, fertility level, plane of nutrition, and heat stress can induce alterations in the epigenetic, oxidative stress, cytokine, and microbiome profiles of sperm and/or seminal plasma. In addition, recent findings in pigs, sheep, and cattle have indicated programming effects in blastocysts post-fertilization with some continuing into post-natal life of the offspring. Our research group is focused on understanding the effects of common management scenarios of plane of nutrition and growth rates in bulls and rams on mechanisms resulting in paternal programming and subsequent offspring outcomes. Understanding the implication of paternal programming is imperative as short-term feeding and management decisions have the potential to impact productivity and profitability of our herds for generations to come. Developmental programming is the concept whereby environmental factors inflicted on gametes during their development and concepti during their gestation can have subsequent and long-term impacts on post-natal offspring development. Early evidence of developmental programming came from human epidemiological studies  of pregnThough extensive research has been conducted regarding the impacts of maternal environment during pregnancy on subsequent offspring outcomes, a growing body of work indicates that the experiences of a sire during spermatogenesis, sperm residence in the epididymis, and development of seminal fluids in the accessory sex glands may be implicated in offspring outcomes . This coEpigenetic alterations, oxidative stress, immune responses, and the seminal microbiome are potential contributors to sire-borne effects on developmental programming. Sire environment can influence epigenetic marks of sperm including DNA methylation, histone modifications, and alterations of several types of coding (mRNA) and non-coding RNAs –miRNA, tRFs, piRNA, lncRNA, circRNA .Though eOxidative stress in sperm can occur under conditions of heat stress, obesity, hypertension, insulin resistance, altered dietary ingredients or planes of nutrition, and psychological disorders , which lInsemination is followed by an immune response in the female reproductive tract . The uteSemen also carries with it a rich and diverse microbiota . BacteriIt’s important to point out that some of the potential programming may originate in the testicle, in the epididymis, in the accessory sex glands during development of seminal plasma that is only added to sperm near the time of ejaculation. Sperm DNA methylation and histone modifications mainly take place within the testicle during early stages of sperm development, with sperm miRNA loading thought to occur in later portions of the tract. However, a portion of the miRNAs present in testicular parenchyma of rams and bulls are also present in segments of the epididymis , indicatExtracellular vesicles are released in the epididymis (i.e. epididymosomes) and contain miRNAs which are subsequently loaded into sperm. Once the sncRNA are transferred from the epididymosomes to sperm, they can be delivered to the oocyte at the time of fertilization to regulate maternal RNAs in the cytoplasm of the oocyte, or into the nucleus of the cell to affect the transcriptome of the early embryo . As prooInterestingly, there is a body of work in rodents comparing vasectomized and intact males that demonstrates specific and independent effects of sperm and of seminal plasma . In thesThe timing of sperm or seminal plasma alterations can also be broken into several categories; time in terms of sire age, relative age of developing sperm, lag time from insult to observable effect, and persistence of effects in the epididymis or other regions of the male reproductive tract . The effMethylation patterns can be changed with advancing peri-pubertal age. Bulls increasing in age from 10 to 16 months had alterations in their sperm miRNA profiles and DNA methylation patterns . Once alThe time required for spermatogenesis varies among species, with bulls completing the process in roughly 61 days  and ramsAdditionally, the nutrient-sensing mTOR pathway can contribute to the regulation of blood-testis barrier and affect sperm at several stages of development , providiThe lag time from a perturbation until an effect manifestation likely depends on the site of the effect . When male mice were given a single dose of dexamethasone to induce acute stress, relatively few changes were observed in metabolism of offspring sired by sperm collected at 3 hours after dexamethasone administration. However, modest alterations were observed in the offspring sired by sperm collected at 7 days after administration, and many alterations in RNA payload and offspring metabolism were observed from matings with semen collected 14 days after dexamethasone administration . In a moThe concept of the lag from injury/stressor to effect is also related to the concept of length of time post-insult that the respective effects persist. In a model of a 4-week chronic stress in mice , untreated sperm were incubated with extracellular vesicles from stressed males at different time points after the stress, and then used to produce in vitro fertilization (IVF) embryos . InteresAn exhaustive review of rodent models of paternal programming is beyond the scope of this paper. However, it is important to note that many studies have clearly demonstrated that the environment experienced by sires during spermatogenesis impacts offspring phenotype. Paternal programming effects have been observed in offspring of sires managed in over/under nutrition models , on highThe array of effects on offspring outcomes is model-dependent. Altered phenotype variables that have been reported include changes in appetite regulation; glucose and insulin metabolism; energy metabolism; growth and development of muscle, fat, and bone; reproductive efficiency; cardiovascular health; temperament; social and cognitive abilities; predator avoidance; drug and alcohol preference and dependency; and propensity for depression-associated behaviors [recently reviewed by The body of literature in livestock species is not nearly as extensive as in rodent models. Several models exists where management-related strategies have shown mechanisms of paternal programming in livestock similar to those reported in rodent models and will be reviewed below.Several authors have focused on discovering biomarkers for fertility-related epigenetic changes in bulls used for artificial insemination (AI), and have reported that sperm methylation , miRNA aPlane of nutrition was reported to influence mechanisms of paternal programming, with underfed rams having differentially expressed miRNAs in testicular tissue , increasSpecific examples do exist in swine, sheep, and bovine models in which paternal programming was evident . A recenFollowing up on their observations of altered miRNA and DNA methylation in bulls of different ages, Sirard’s research group reported alterations in methylation patterns and gene expression in oocytes derived from IVF using semen collected from the same bulls at 10, 12, and 16 months of age . InteresSeminal plasma has been targeted as having the potential to enhance fertility in cattle breeding systems . Though Though human epidemiology and rodent models have established solid proof of paternal programming effects, the body of evidence in livestock species is limited. Potential mechanisms, magnitude, timing, and persistence of effects, and whether and to what extent specific paternal programming effects are present in livestock species all warrant further exploration. Our group is focused on common management scenarios of plane of nutrition and growth rates in bulls and rams and their effects on mechanisms responsible for paternal programming with the goal of understanding offspring outcomes. Once we demonstrate the impacts of common scenarios under direct control of our herd and flock managers, however, the work is likely just beginning as longer-term and interactive situations must be explored.Though previously reported in rodent models , a recen