The SARS-CoV-2 viral pandemic has had an immeasurable global impact, resulting in over 5 million deaths worldwide. Numerous vaccines were developed in an attempt to quell viral dissemination and reduce symptom severity among those infected. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antinuclear autoantibodies (ANAs) with heterogenic clinical manifestations, secondary to immune complex deposition in a multitude of organ systems. There are scarcely reported cases of SLE development following COVID-19 mRNA vaccination. We present a case of a 24-year-old male without preexisting conditions or family history of autoimmune disorders, presenting with SLE following the first dose of the SARS-CoV-2 Pfizer-BioNTech mRNA vaccine. T and CD4 T lymphocyte levels, both integral modulators of the humeral immune response [Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of antinuclear antibodies (ANA) and formation of immune complexes, which can directly and indirectly cause inflammatory damage to multiple organs . While tresponse , 4.The SARS-CoV-2 viral pandemic has had an immeasurable global impact, responsible for over 5 million deaths worldwide , and IsrA 24-year-old Israeli male of Ashkenazi descent, with no premorbidities or family history of autoimmune conditions, visited his family physician two days following administration of the first dose of the SARS-CoV-2 Pfizer-BioNTech mRNA vaccination complaining of a facial rash. He was prescribed calamine lotion for a suspected allergic reaction. The patient's environmental exposures included outdoor agricultural work and daily smoking. He did not drink alcohol or use illicit drugs. The patient subsequently returned to his physician ten days later due to progression and worsening of the rash, and fexofenadine trima tablet 180 mg was added.The patient presented to the Soroka University Medical Center (SUMC) 8 weeks later due to continued symptoms. At that time, the patient described multiple joint pains with morning stiffness lasting up to two hours. Dermatologist evaluation was significant for psoriasiform-papulosquamous plaques over the face, neck, and arms, nonscarring hair loss over the head , and bilA diagnosis of SLE was established based on the 2019 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria . HydroxyThe patient was recommended not to receive the second dose of the SARS-CoV-2 Pfizer-BioNTech mRNA vaccine. He was found to have COVID-19-neutralizing antibodies in the follow-up serology testing.The patient responded well to treatment and demonstrated improvement in subsequent visits, including the disappearance of rash.In the case study described above, a patient exhibited an initial presentation of SLE following the mRNA COVID-19 vaccine. The exact etiology of SLE is likely multifactorial but still only incompletely elucidated. No correlation between mRNA COVID-19 vaccine administration and the imminent development of SLE has been reported. The clinical manifestations of SLE, such as nephritis, pleuritis, cardiomyopathy, and dermatitis, are mediated by antibody formation and the creation of immune complexes, ultimately causing small-vessel vasculitis. Studies have demonstrated the critical role of B-cell hyperactivity and excessive autoantibody production in SLE pathophysiology . AdditioThe notion of vaccine-induced autoimmune response has been suggested in the context of immune thrombocytopenia, autoimmune myocarditis, and autoimmune hepatitis –21. WhilWhile the SARS-CoV-2 Pfizer-BioNTech mRNA vaccination has thus far demonstrated outstanding efficacy and safety, rare and long-term side effects are still not known. Further research is needed to determine if the Pfizer-BioNTech mRNA vaccine can cause untoward immune modulatory effects, including the development of autoimmune disorders such as SLE.


Nafion®, a representative perfluorinated sulfonic acid (PFSA) ionomer-based membrane, is generally incorporated in fuel cell systems as a polymer electrolyte membrane (PEM). Since the PFSA ionomers are composed of flexible hydrophobic main backbones and hydrophilic side chains with proton-conducting groups, the resulting membranes are found to have high proton conductivity due to the distinct phase-separated structure between hydrophilic and hydrophobic domains. However, PFSA ionomer-based membranes have some drawbacks, including high cost, low glass transition temperatures and emission of environmental pollutants  during degradation. Hydrocarbon-based PEMs composed of aromatic backbones with proton-conducting hydrophilic groups have been actively studied as substitutes. However, the main problem with the hydrocarbon-based PEMs is the relatively low proton-conducting behavior compared to the PFSA ionomer-based membranes due to the difficulties associated with the formation of well-defined phase-separated structures between the hydrophilic and hydrophobic domains. This study focused on the structural engineering of sulfonated hydrocarbon polymers to develop hydrocarbon-based PEMs that exhibit outstanding proton conductivity for practical fuel cell applications.Polymer electrolyte membrane fuel cell (PEMFC) is an eco-friendly energy conversion device that can convert chemical energy into electrical energy without emission of harmful oxidants such as nitrogen oxides (NO A. A68]. Aoperties . Due to The graft or comb-shaped copolymers used in PEMFCs are usually composed of physically and chemically stable hydrophobic main chains and proton-conducting hydrophilic side chains. By geometric separation of the structural units of the copolymers that are responsible for stability and ion conductivity, the PEMs with graft copolymers were found to have a distinct phase-separated structure between hydrophilic/hydrophobic domains and reveal better proton conductivity, oxidative and dimensional stabilities compared to their linear counterparts of similar compositions ,70,71. N® 117 measured in water under the entire range of temperatures from 20 to 80 °C. It was also demonstrated that the 2a membrane showed a smaller dimensional change value than Nafion® 117, although it had a larger IEC (1.40 meq g−1) than Nafion® 117 (0.96 meq g−1). Moreover, the 1a membrane having a similar IEC of Nafion® 117 showed half the dimensional change in the longitudinal direction compared to Nafion® 117, which is significantly lower than previously reported hydrocarbon-based PEMs . S. S92]. S® 117 at 80 °C. The ionic cluster size of the 20:80 SPES-based PEM was around 5 nm, which is also similar to that of the Nafion® 117. To reduce the RH dependency of the SPES-based PEMs, a follow-up study was performed by the same group . T. Tp-phenThe development of sulfonated hydrocarbon polymer (SHP)-based PEMs has been actively pursued in order to overcome the inherent drawbacks of the PFSA ionomer-based PEMs. SHP-based PEMs composed of well-known aromatic random copolymers have shown relatively low proton-conducting behavior and physicochemical stability compared to PFSA ionomer-based PEMs due to the difficulty in forming the well-defined hydrophilic/hydrophobic phase-separated structures. To improve the proton conductivity of SHP-based PEMs without deterioration in physicochemical stability, control of the polymeric architecture is necessary to form distinct phase-separated structures between the hydrophilic and hydrophobic domains. Therefore, this review has focused on the synthetic procedures which underlie structure-engineered copolymers, such as block, graft/comb-shaped and densely sulfonated copolymers, and their PEM properties. Studies on SHP-based PEMs using block copolymers indicated that the length and structure of each hydrophilic and hydrophobic block can affect the size of ionic clusters as well as the phase-separation architecture, thereby affecting the PEM properties of the corresponding membranes. For graft/comb-shaped copolymers, degree, length and structure of side chains control the PEM properties such as proton conductivity and physical stability of the corresponding membranes. Finally, studies on densely sulfonated copolymers indicate that the degree of sulfonation of the hydrophilic reagents and location of the densely sulfonated moieties significantly affect nano-phase structures as well as the proton-conducting behavior of the resulting PEMs. Based on this review of existing literature, we strongly believe that, with rational designs of polymeric architecture beginning with the synthetic process, it will be possible to develop high-performance SHP-based PEMs surpassing the PFSA ionomer-based PEMs operating at harsh conditions of low RH. In addition, the exclusion of chemically vulnerable heteroatom linkages via the novel synthetic processes should be further considered to develop next-generation SHP-based PEMs for practical PEMFC applications.


In this communication, we report on the genomic surveillance of SARS-CoV-2 using wastewater samples in Jefferson County, KY. In February 2021, we analyzed seven wastewater samples for SARS-CoV-2 genomic surveillance. Variants observed in smaller catchment areas, such as neighborhood manhole locations, were not necessarily consistent when compared to associated variant results in downstream treatment plants, suggesting catchment size or population could impact the ability to detect diversity. The successful viral detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater at various pooled scales –4 and diThe diversity of SARS-CoV-2 sequences reported to be circulating in the USA, have been determined by sequencing clinical samples; however, these variants can also be surveilled by sequencing wastewater samples –9. As ofIn this communication, we report on the genomic surveillance of SARS-CoV-2 using wastewater samples in Jefferson County, KY. Samples were collected from manholes and treatment facilities, covering populations of 8,000 to 350,000 people . RNA isoIn February 2021, we analyzed seven wastewater samples for SARS-CoV-2 genomic surveillance . We did Given the highly variable viral genome sequence coverage recovered from wastewater samples, there is an urgent need to develop a set of consistent thresholds constituting positive/negative presence of a variant. Monitoring SARS-CoV-2 variants in wastewater may warn of an emerging variant of concern and identify variant dominance occurring when a new variant is introduced in a community. Wastewater genetic monitoring may be particularly useful in the context of limited clinical sample sequencing capacity because a broad perspective on the genetic diversity can be obtained from a few samples. To develop comprehensive epidemiological frameworks required to guide policy, population-level wastewater surveillance of viral genetic diversity should be complemented by clinical sample testing.1


Homecare has increased its value as an alternative to nursing homes and adapted to evolving COVID-19 challenges. However, little is known about how COVID-19 has impacted community-dwelling older adults who need assistance with daily activities, including dressing, cooking, and shopping. Guided by the stress process framework, this mixed-method study examined how older homecare recipients experienced the acute and chronic stress during the first eight months of the pandemic, focusing on the role of home care aides (HCAs) in the context of Medicaid-funded in-home services. Thirty-five dyads of care recipients and HCAs participated in a COVID telephone survey as part of a larger study. Care recipients were typically older minority  women (77%). Their COVID-related anxiety level, assessed by a 6-item Spielberger State Anxiety Inventory , was 2.2 (SD=0.9). While COVID-19 drastically reduced contacts with family members and healthcare providers, HCAs continued to provide care in person. One care recipient said, “Fortunately, I still have my HCA come and that keeps me sane.” HCAs showed resilience while facing their own family- and work-related stress: “I have followed the rules and just adapted. (COVID) did not affect the activities for my client.” Some dyads, however, experienced care disruptions because of COVID infection or fear in one or both parties. COVID-19 has demonstrated homecare resilience at the person-, dyad-, and organization-levels, calling for equitable, sustainable home-based care for a growing number of older adults who desire to stay in the home.


Proteases play a central role in various biochemical pathways catalyzing and regulating key biological events. Proteases catalyze an irreversible post-translational modification called proteolysis by hydrolyzing peptide bonds in proteins. Given the destructive potential of proteolysis, protease activity is tightly regulated. Dysregulation of protease activity has been reported in numerous disease conditions, including cancers, neurodegenerative diseases, inflammatory conditions, cardiovascular diseases, and viral infections. The proteolytic profile of a cell, tissue, or organ is governed by protease activation, activity, and substrate specificity. Thus, identifying protease substrates and proteolytic events under physiological conditions can provide crucial information about how the change in protease regulation can alter the cellular proteolytic landscape. In recent years, mass spectrometry-based techniques called N-terminomics have become instrumental in identifying protease substrates from complex biological mixtures. N-terminomics employs the labeling and enrichment of native and neo-N-termini peptides, generated upon proteolysis followed by mass spectrometry analysis allowing protease substrate profiling directly from biological samples. In this review, we provide a brief overview of N-terminomics techniques, focusing on their strengths, weaknesses, limitations, and providing specific examples where they were successfully employed to identify protease substrates in vivo and under physiological conditions. In addition, we explore the current trends in the protease field and the potential for future developments. Proteases catalyze an irreversible post-translational modification called proteolysis in proteins by hydrolyzing peptide bonds . More thProteolytic cleavage results in the formation of two novel proteins/peptides, creating a new N- or C-terminus . As a reIdentifying protease substrates and proteolytic events under physiological conditions can provide crucial information about how the change in protease regulation alters the entire cellular proteolytic network. However, the identification of physiological protease substrates remained challenging for a long time due to their low abundance and the unstable nature of the newly generated peptide fragments, which can be further targeted for the subsequent proteolytic degradation . AdditioIn recent years, mass spectrometry-based techniques have become instrumental in identifying protease substrates under physiological conditions ,33. ThesN-terminomics methods detect the protease substrates from the complex mixture by identifying the native or neo-N-terminal generated upon proteolysis using LC-MS/MS analysis. In this review, we discuss the four major N-terminomics methods: Combinatorial Fractional Diagonal Chromatography (COFRADIC), Terminal Amine Isotopic Labeling of Substrates (TAILS), Subtiligase and Chemical enrichment of Protein Substrates (CHOPS). The most challenging step in the N-terminomics method is separating and isolating native or neo-N-terminal peptides from the internal tryptic peptides generated during the sample preparation . The tryforward N-terminomics and reverse N-terminomics [forward N-teminomics is used to identify the global proteolytic events, while the reverse N-terminomics is used to identify the proteolytic events occurring from a protease of interest  is one of the earlier N-terminomics methods [ methods . This ne methods . LC-MS/M methods .Zahedi and co-workers recently modified COFRADIC to charge-based fractional diagonal chromatography (ChaFRADIC) ,81. InstThe COFRADIC method is widely used to study the backbone N-terminal acetylation in eukaryotes . COFRADITAILS Terminal Amine Isotopic Labeling of Substrates (TAILS) an alternative negative enrichment method developed by Christopher Overall and co-workers to overcome the limitations of COFRADIC [COFRADIC . In contCOFRADIC . AlternaCOFRADIC .TAILS possesses several advantages over the COFRADIC approach, such as N-terminal specificity biases are minimal with this approach, a smaller quantity of starting material is required, and kits and reagents are available commercially . HoweverSince its development, the TAILS method has been successfully applied to identify protease substrates from many different systems. Using TAILS, Klein et al. identified HOIL1 as a substrate of the paracaspase, mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1). In the presence of antigens, HOLT1 amplifies the immune response during the NF-kB mediated signaling . Using Tpro) of coxsackievirus B3 and poliovirus. These studies showed that the heterogeneous nuclear ribonucleoprotein M (hnRNP M), an RNA-binding protein that plays a role in pre-mRNA splicing, is a substrate of 3Cpro [TAILS has been widely used to identify the novel physiological substrates of metallo and other proteases. Using iTRAQ-TAILS, Padova et al. identified the substrate profile of substrates of MMP-2 and MMP-9. These studies confirmed that insulin-like growth factor-binding protein-4, thrombospondin-2, and galectin-1 are substrates of MMP-2, and MMP-9, establishing the role of their proteases in angiogenesis . Moreoveof 3Cpro .Subtiligase: In contrast to COFRADIC and TAILS, Subtiligase is a positive N-terminomics method that directly enriches and isolates native or neo-N-terminal peptides. The Subtiligase method is developed by Jim Wells and co-workers, which uses the enzymatic biotinylation of the native or neo-N-terminal peptides using a modified Subtiligase enzyme [reverse Subtiligase approach, Scaman et al. showed that apart from aspartic acid, caspases 3 and 7 can cleave after glutamic acid residues, while caspase 3 can also cleave specifically after phosphorylated serine residues [reverse Subtilgase approach, Hill et al. identified the substrate profile of Zika virus protease NS2B-NS3 from HEK293 cells. The authors showed that the Zika virus protease cleaves host eukaryotic translation initiation factor 4 gamma 1 (eIF4G1) and autophagy-related protein 16-1 (ATG16L1) [The aspases) ,54,89, aaspases) ,49,90. Caspases) ,51. Usinresidues . In addiATG16L1) .CHOPS: Chemical enrichment of Protease Substrates (CHOPS) is a positive enrichment method recently developed by Daniel Bachovchin and co-workers as an alternative approach to Subtiligase [tiligase . In contSince CHOPS uses chemical biotinylation instead of enzymatic biotinylation, it removed the major flaw of the Subtiligase method, i.e., biases in labeling towards N-terminal sequences, while still retaining all advantages of the Subtiligase method, including direct enrichment and explicit identification of neo-N-termini without ambiguity. However, this method still needs to be optimized for live-cell labeling. Nonetheless, CHOPS remains the most versatile and promising N-terminomics method for future use.CHOPS was used to identify substrate specificity of dipeptidyl peptidases (DPP). The dipeptidyl peptidases (DPPs) cleave after proline residues present on the second position in polypeptide chains, releasing dipeptides from the N-termini. The DPPs regulate the activities of many biologically important molecules such as neuropeptides, cytokines, and hormones . HoweverIdentifying protease substrates and proteolytic events under physiological conditions is a fundamental step towards understanding the proteolytic landscape of biological samples. The N-terminomics methods discussed in this review are emerging as indispensable tools to identify and understand the global proteolytic events and protease substrate specificity under physiological conditions. The main steps in N-terminomics methods are the labeling and enrichment of the native N-termini or neo-N termini peptides generated from the proteolytic cleavage, reducing the complexity of the samples, and enabling the unambiguous identification of the protease substrates and protease cleavage sites.In recent years, multiple positive and negative enrichment N-terminomics strategies have been developed. Although the N-terminomics field is rapidly expanding, few challenges are associated with these techniques, requiring further technological and computational progression. For example, the precise annotation of the protease cleavage sites still remains challenging as they are annotated based on protein backtracking from the single peptide hit. In addition, some unfavorably cleaved neo-N-terminal peptides cannot be detected during LC-MS/MS analysis. Furthermore, the regulation of proteases by post-translational modifications remains another challenging avenue to study by N-terminomics as these post-translational modifications can lead to a generation of non-tryptic or semi-tryptic peptides and can be difficult to detect. Such challenges can be overcome by an integrated approach, including both neo-N-terminal and neo-C-terminal peptides analysis. The simultaneous analysis of N- and C-terminomics could improve the annotation of cleavage sites and provide much more information about the global proteolytic events in complex biological mixtures.reverse N-terminomics can be increasingly used to map the protein–protease interactome of the target proteases under physiological conditions. Such data can then be used to dissect the protease regulation in a proteolytic cascade and generate a proteolytic network in health and diseases. In addition, such data can help to develop a library of proteolytic biomarkers that could be used to diagnose multiple pathological conditions.The current N-terminomics strategies can be further used in several different directions to increase our knowledge of the complex interactions between proteases, their substrates, and inhibitors. For example, N-terminomics can be used to identify and annotate the unpredicted and undefined proteins and proteoforms to improve the existing genomic databases. Moreover, the In conclusion, N-terminomics methods have opened a new horizon to study protease regulation from the complex biological mixtures, far from our reach a decade ago. More studies are underway using these techniques to decode the biological protease pathways and understand the crosstalk between proteolysis and post-translational modifications. Such studies will generate a future roadmap for identifying novel disease mechanisms, drug targets, and biomarkers for multiple pathologies.


Bone is one of the most common metastatic sites among breast cancer (BC) patients. Once bone metastasis is developed, patients’ survival and quality of life will be significantly declined. At present, there are limited therapeutic options for BC patients with bone metastasis. Different nanotechnology-based delivery systems have been developed aiming to specifically deliver the therapeutic agents to the bone. The conjugation of targeting agents to nanoparticles can enhance the selective delivery of various payloads to the metastatic bone lesion. The current review highlights promising and emerging advanced nanotechnologies designed for targeted delivery of anticancer therapeutics, contrast agents, photodynamic and photothermal materials to the bone to achieve the goal of treatment, diagnosis, and prevention of BC bone metastasis. A better understanding of various properties of these new therapeutic approaches may open up new landscapes in medicine towards improving the quality of life and overall survival of BC patients who experience bone metastasis. Breast cancer (BC) is the most common malignant tumour among women . AccordiAccording to the molecular profiles, BC could be classified as luminal subtype, HER2 enriched+ subtype, and basal-like subtype with a high expression of basal markers . The lumMetastasis is one of the main reasons for the high mortality rate among BC patients. About 20–30% of recurrences among early BC patients are accompanied by metastatic diseases . Common The BC metastasis process includes several complex steps: invasion, migration, adhesion, and survival of the tumour cells at the metastatic sites. The ‘‘seed and soil’’ theory was first reported in 1889. This means the development of cancer metastasis depends on the interactions between the ‘‘seeds’’, which indicate the tumour cells, and the ‘‘soil’’, which suggests the microenvironment of the potential metastatic site . In. In42]. TGF-β is a pleiotropically expressed multifunctional cytokine that controls tissue homeostasis by regulating cellular apoptosis, proliferation, and differentiation . In metaThe main therapeutic aims of metastatic BC treatment are to prolong life and relieve symptoms . In the In targeted DDSs, the targeting agents play vital roles. The drug can be accurately delivered to the metastatic tumour sites with targeting agents, increasing the treatment efficacy and decreasing side effects generated by some cytotoxic compounds. Various bone targeting agents include tetracycline, bisphosphonate, γ-carboxylated glutamic acids (Gla) and some amino acids , and glutamic acid (Glu)), and aptamers are investigated in different cancers . HoweverIntegrins are a group of divalent cation-dependent heterodimeric membrane glycoproteins composed of α and β subunits, playing vital roles in cell-cell and cell-extracellular matrix (ECM) adhesion . Among aRGD is an arginine-glycine-aspartic acid (Arg-Gly-Asp) tripeptide, which can bind specifically to ανβ3 integrin. Several preclinical studies showed that RGD peptide successfully blocked osteoclast-mediated osteolysis in bone metastatic animal models by acting as ανβ3 integrin antagonist . As a peBisphosphonates (BPs) are a group of chemical compounds showing high affinity to hydroxyapatite (HA) crystals commonly seen in bones and teeth. The reason for this high affinity is that BPs can generate bidentate or tridentate chelation with the calcium ion on the HA . The BPsVarious functional groups at R1 and R2 can affect the ability of BP to bind to HA and their antiresorptive efficacy, respectively. For example, with a hydroxyl group at the R1 side chain, the binding capacity of BPs increases significantly compared to those having a hydrogen (tiludronate) or chlorine (clodronate) on this carbon. The reason is that they can form a tridentate instead of bidentate chelation between BPs and calcium ions . The antBesides, it has been reported that BPs could have an antitumour effect directly and indirectly among several tumours, such as prostate, lung, and melanoma cancer cells, in vitro. The potential mechanism of these antitumour activities is that BPs could mediate apoptosis and the cell cycle arrest, which suggests synergistic therapeutic effects with anticancer agents . Among aAlendronate, a second-generation BP, has been used as a bone-targeting agent in treating metastatic lung cancer , breast Zoledronic acid, a third-generation BP, has been proven to be a cost-effective solution in treating bone resorptive diseases, such as osteoporosis and osteoporotic fractures . The admNanoparticles have been under investigation for a few decades because of their capability to alter the drug’s pharmacokinetics. The introduction of nanoparticles can solve the poor solubility of some hydrophobic drugs and reduce the metabolism, thus preventing the drug compounds from being degraded in the microenvironment ,84. The The surface of the nanoparticles can be modified as needed to achieve specific requirements of different disease conditions . Decorat2+ coordination polymer particles coated with alendronate-conjugated polyethylene glycol (PEG). The nanoparticle (DSP-Zn@PEG-ALN NP) had an average size of about 55 nm, which endowed the nanoparticles the ability to penetrate the slits (80 nm) of the bone sinusoidal capillaries and successfully transfer to the metastasis. Results from the in vitro HA binding test suggested that targeted DSP-Zn@PEG-ALN NPs had higher binding potency to the bone than non-targeted nanoparticles and free cisplatin [To deliver cisplatin prodrug (DSP) to BC bone metastatic lesions, He and co-workers developed Znisplatin . In in vMoreover, the administration of DSP-Zn@PEG-ALN NPs could suppress the growth of tumour and decrease bone destruction in a mouse BC bone metastasis model induced by intra-tibia injection of MDA-MB-231 cells. Importantly, researchers assessed the analgesic effects of DSP-Zn@PEG-ALN NPs in the mice group treated with these NPs. These mice showed significantly less duration of paw lifting and number of flinches, which suggested that the targeted NPs could effectively reduce the pain caused by metastasis to bone and potentially improve the quality of life. Moreover, the in vitro release assay result indicated that the release of DSP-Zn@PEG-ALN NPs was promoted as the pH reduced compared to the physiological pH (pH = 7.4). Thus, combining the pH-sensitive properties and specific release of NPs in the acidity of the bone microenvironment and the bone targeting capability, the utilisation of DSP-Zn@PEG-ALN NPs could prevent other organs from cisplatin toxicity .Huang and co-workers reported an alendronate-modified nanoparticle (DZ@ALN) loaded with a cisplatin prodrug and zoledronate. Apart from high affinity for the bone, DZ@ALN could also mediate the activation of the osteoclasts both in vitro and in vivo. Furthermore, compared to the combination of free cisplatin prodrug and zoledronate, DZ@ALN could significantly inhibit tumour growth in vivo in a bone metastasis tumour model induced by intra-tibia injection of MDA-MB-231 cells, relieve bone pain, and prevent bone destruction, which further breaks the ‘‘vicious cycle’’ of BC bone metastasis .Bortezomib is a protease inhibitor widely investigated in treating various cancers, such as myeloma, prostate, and lung cancers. Wang and co-workers developed a tripeptide RGD-targeted dendrimer for the delivery of bortezomib to metastatic tumour sites. With a boronate-catechol linkage, the dendrimer was endowed with pH-responsive properties. The result from in vitro targeting assay indicated that the conjugation of RGD could successfully lead the dendrimers to the MDA-MB-231 cells. Besides, the X-ray and micro-CT results showed that the bone destruction of the tibias in the RGD-targeted nanoparticle treated group was the lowest while the bone volume and trabecular number were the highest compared to the control groups. These results suggested that the RGD-targeted dendrimer could suppress the osteolysis caused by BC cells .Zhu and co-workers developed alendronate-modified bortezomib-catechol loaded prodrug micelles. The bortezomib-catechol-loaded ALN-NPs showed better release in an acidic environment (pH = 5.0) compared to the physiological pH. They also observed an enhanced affinity to the bone compared to the control groups, which could result in reduced systemic toxicity. In vivo, the drug-loaded alendronate-NPs could significantly repress tumour growth and tumour-induced bone destructions among female MDA-MB-231 cell bearing BALB/c-nu mice .Redox-sensitive alendronate targeting micelles loaded with curcumin (ALN-oHA-S-S-CUR) was formulated by conjugating the hydrophobic curcumin  to hydrophilic oligosaccharides hyaluronan (oHA) via disulphide bonds. oHA is a hydrophilic polysaccharide that can selectively bind to the CD44 receptor, which is overexpressed in different tumour cells. In vitro, ALN-oHA-S-S-CUR showed higher uptake and cytotoxicity in MDA-MB-231 cells than in MCF-7 cells because the latter cell line has a lower expression of CD44 receptor. In a spheroid model mimicking the tumour in vivo, ALN-oHA-S-S-CUR showed a deeper penetration in the multicellular 3D MDA-MB-231 cell spheroid than in the non-targeted group. . The resAlendronate-targeted nanoparticles composed of poly  acid (PLGA) loaded with curcumin and bortezomib were designed by Thamake and co-workers. In vitro bone targeting studies indicated that these targeted nanoparticles had increased affinity to the bone tissues. Furthermore, the alendronate conjugated nanoparticles could localise at a significantly higher rate and quantities with a more prolonged accumulation at the tumour site than the control groups in a bone metastasis model induced by intra-tibia injection of MDA-MB-231 model in vivo. Furthermore, the targeted nanoparticles could inhibit the process of bone resorption and tumour growth in vivo. However, the combination of curcumin and bortezomib did not exert any synergistic effect in the anti-osteoclastogenic activities in the bone .CL) loaded with doxorubicin. These nanoparticles were based on hyaluronic acid (HA) for specific binding to CD44 receptors expressed in BC cancer cells, and poly (aspartic acid) (PASP) DOX@ALN-(HA-PASP)CL showed enhanced bone affinity compared to the non-targeted nanoparticles in in vitro and in vivo assays. In an anti-bone resorption study in in vitro 3D model of breast cancer bone metastasis, the number of bone lacunas and osteoclasts induced by MDA-MB-231 cells at the calvarial sites were significantly decreased in DOX@ALN-(HA-PASP)CL -treated groups compared to the control groups, which indicated the anti-bone resorption ability of these two nanoparticles. Among MDA-MB-231 bearing mice, the administration of DOX@ALN-(HA-PASP)CL could repress tumour growth and significantly increase the ratio of bone volume to tissue volume, which is an indicator of less bone resorption [Zhao and co-workers designed a pH, and redox dual sensitive core crosslinked nanoparticle (DOX@ALN-(HA-PASP)sorption .Pham et al. fabricated a doxorubicin-loaded, alendronate-modified DDS based on PLGA, which showed significant bone targeting, antitumour and anti-bone resorption . A graphWu et al. developed an alendronate and low molecular weight heparin functionalised liposome (A-L-DOX-Lip) to achieve the selective delivery of doxorubicin. The low molecular weight heparin could increase the blood circulation time and exert anti-metastasis activity. With the combination of alendronate and heparin, A-L-DOX-Lip could significantly reduce the tumour volume at bone metastatic sites in a bone metastasis model induced by intra-femoral injection of 4T1 cells, decrease the toxicity of doxorubicin, and reduce bone resorption .Another alendronate-modified, doxorubicin-loaded, pH-sensitive DDS (ALN-PEG/C18/HYD-DOX-g-PASPAM) was reported by Lim et al., which could reduce the tumour volume in vivo in a mouse tumour model induced by subcutaneous injection of MDA-MB-231 cells compared to free doxorubicin and non-targeted particles .An alendronate-functionalised amphiphilic triblock micelle based on PEG, polyglutamic acid, and polyphenylalanine (PEG-PGlu-PPhA) (ALN-m/DTX) was prepared to deliver docetaxel to metastatic sites of BC. In in vitro studies, ALN-m/DTX could exert a potent cytotoxic effect in a 4T1 cell model that was mimicking the bone microenvironment with hypercalcemia. Those micelles also showed an improved capability for binding to the bone and inhibiting the progress of osteoclastogenesis, bone resorption, and tumour-induced macrophage migration both in vitro and in vivo. In addition, the development of bone metastasis was delayed, and the weight loss was significantly controlled after the administration of ALN-m/DTX in a mouse BC bone metastasis model induced by injecting 4T1 cells into the left cardiac ventricle of female BALC/c mice .Another amphophilic phospholipid polymer functionalised with alendronate (PMBA-DTX) was developed to carry docetaxel. The targeted nanoparticles showed antitumour activity among various BC cell lines (MDA-MB-231. MCF-7 and 4T1) in vitro and an enhanced accumulation at bone tissue in vivo .PEG-ylated polybutyl cyanoacrylate (PBCA) based zoledronic acid decorated nanoparticles (PBCA-PEG-ZOL) were formulated by Monkkonen’s group as a carrier of docetaxel. PBCA-PEG-ZOL could significantly increase the number of apoptotic cells compared to the docetaxel control group among MDA-MB-231 and BO2 cell lines, indicating an improved cytotoxic activity of docetaxel in these nanoparticles .Being a good target for treating BC bone metastasis, ανβ3 integrin can be targeted by ligands other than RGD peptide. A quinolone nonpeptide ligand specific for ανβ3 integrin was developed and conjugated to phospholipid/polysorbate 80 micelle nanoparticles (ανβ3-MPs) to deliver docetaxel-prodrug to metastatic bone sites. In vivo, ανβ3-MPs showed a 6.5-fold higher affinity for bone tissue compared to non-targeted MPs. Furthermore, after the administration of ανβ3-MPs/DTX-PD, the tumour volume and tumour-induced bone loss were significantly reduced with less hepatotoxicity compared to the docetaxel-treated group .A PLGA-based DDS with two targeting agents was designed, alendronate (A) for bone targeting and folic acid (FA) for targeting cancer cells that overexpress the folate receptors. Paclitaxel was loaded in the hydrophobic pocket of D-α-tocopheryl polyethylene glycol succinate (TPGS), and different targeted NPs were fabricated. Considering the HA binding test results, in vitro cellular up-taking test, and in vitro cytotoxicity test, the PTX-AFTPNs (A to F ratio: 0.67) showed the best dual-targeting potency and was further studied in vivo. Although both mono (A) and dual (AF) targeted NPs, i.e., ATPNs and AFTPNs (A:F = 0.67), were localised in bone lesions more than the control groups, mono-targeting nanoparticles (ATPNs) exhibited higher affinity to the bone than AFTPNs (A:F = 0.67). This effect was probably due to the presence of FA that decreases the percentage of alendronate on the surface of nanoparticles. PTX-AFTPNs showed the highest antitumour activity at the metastatic bone sites of 4T1 tumour-bearing mice, the best survival rate and an improved bone morphological integrity .A novel alendronate-targeted paclitaxel-loaded pullulan (Pull) delivery system (Pull-(GGPNle-φ-PTX)-(PEG-ALN)) developed and showed robust affinity to bone tissue in vitro. In addition, these nanoparticles could also inhibit the proliferation of BC cells (MDA-MB-231 and 4T1) and suppress BC cell migration and angiogenesis .In another study, a glutamic oligopeptides-RGD peptide derivative (Glu6-RGD) was designed as a targeting agent for conjugation to paclitaxel-loaded liposomes to enhance the biodistribution to the bone in BC bone metastasis. In vivo studies showed that the paclitaxel concentration in the bone metastatic lesions of targeted liposome treated mice was significantly higher than in free paclitaxel treated mice. Moreover, the liposome accumulated significantly more in metastatic bone lesions compared to normal bones .Apart from the traditional anticancer compounds, alendronate-functionalised nanoparticles could also be an effective carrier for specific inhibitors of transcription factors. A small molecular inhibitor of transcription factor Gli2 (an upregulator of PTHrP), GANT58, was encapsulated in alendronate-conjugated amphiphilic diblock copolymer-based nanoparticles (GANT58-BTNPs). It was reported that 10% of alendronate (based on molar ratios) in the hydrophilic polymer block gave rise to the best balance between systemic pharmacokinetics and bone affinity. This amount of alendronate resulted in the highest bone to live biodistribution ratio. The administration of GANT58-BTNPs could significantly inhibit tumorigenesis and bone resorption in a mouse intracardiac model of bone metastasis. The bone volume fraction in the tibiae of the GANT58-BTNPs treated group was significantly higher than drug-free alendronate-conjugated nanoparticles, indicating that alendronate and GANT58 could exert dual beneficial therapeutic effects .Bisphosphonates such as zoledronic acid have also been used for the selective delivery of immunostimulatory agents. Pang and co-worker designed zoledronic acid-modified bone targeting metal-organic framework (MOF) nanoparticles loaded with immunostimulatory cytosine-phosphate-guanosine (CpG) (BT-isMOF). Both results from in vitro and in vivo studies indicated that BT-isMOF nanoparticles had a robust capability of targeting the metastatic bone lesions, leading to a significant reduction in the osteoclast-mediated bone resorption and simultaneous induction of macrophage polarisation to the M1 pro-inflammatory phenotype. This phenotype is known for the secretion of pro-inflammatory cytokines, which may also play a role in the antitumour activities .Bisphosphonate-conjugated nanoparticles loaded with contrast agents could play a role in diagnosing BC bone metastasis. Qiao et al. developed zoledronic acid-conjugated gadolinium (Ⅲ) upconversion nanoparticles (PUCZP) by encapsulating plumbagin and poly (acrylic acid) (PAA) inside bimodal mesoporous silica. With the existence of gadolinium (Ⅲ), a contrast agent in T1-MRI, PUCZP could help to detect early bone metastasis, which is generally hard to diagnose by standard radiography. With the help of PAA, the nanoparticles could release in a pH-sensitive mode in the osteoclast acidity (pH = 4.5~5.5). Furthermore, PUCZP could inhibit the expression of RANKL and further suppress the osteocyte-induced osteoclast formation and weaken the invasive properties of MDA-MB-231 and 4T1 cells in vitro. In addition, UPCZP could repress tumour growth and osteoclastogenesis in a mouse intracardiac model of BC bone metastasis .Photothermal therapy (PTT) is a method that converts absorbed photon energy to heat by utilising photo-absorbing materials and killing the cancer cells under a near-infrared (NIR) laser. According to relevant studies, PTT is capable of antitumour activity by itself and could increase the sensitivity of tumour cells to anticancer compounds, which further improves the efficacy of chemotherapy . In addiNanoparticles conjugated with zoledronic acid were designed by encapsulating gold nanorods in mesoporous silica (Au@MSNs-ZOL). The Au@MSNs-ZOL showed great affinity for bone both in vitro and in vivo. In in vitro studies, the Au@MSNs-ZOL could promote the differentiation of osteoblasts and inhibit the formation of osteoclast-like cells. Furthermore, combining with NIR, Au@MSNs-ZOL could significantly reduce the volume and weight of the tumour among MDA-MB-231 bearing mice, which could relieve bone pain and reduce the bone resorption at the metastatic bone lesions .3O4) and indocyanine green (ICG)-loaded PLGA nanoparticles (ICG/Fe3O4@PLGA-ZOL) were prepared, on which zoledronic acid was conjugated as a targeting agent. In vitro, the group with magnet and laser showed less cell viability than the group without a magnet at the bottom of the plate. More nanoparticles were engulfed by the cells and killed under irradiation. In this DDS, both zoledronic acid and Fe3O4 play the targeting role, which results in a high affinity to bone and great anti-tumorigenic potency [Superparamagnetic iron oxide (Fe potency .Photodynamic therapy (PDT) is a non-invasive, safe, and selective therapeutic approach widely studied in treating various kinds of cancers. With a combination of different factors, including a photosensitiser, an appropriate wavelength, and molecular oxygen, PDT could generate reactive oxygen species (ROS), leading to cell necrosis or apoptosis ,113. Sig2+ levels increased, resulting in excessive endoplasmic reticulum stress leading to the inhibition of tumour cell proliferation [An alendronate-functionalised DDS (BTZ@ZnPc-ALN) was developed for the selective co-delivery of bortezomib and a photosensitiser Zinc phthalocyanine to achieve the chemo-PDT of BC bone metastasis. In vivo studies showed that BTZ@ZnPc-ALN could reduce the tumour volume by 85% compared to the control group in MDA-MB-231 bearing mice, which was realised by inducing ROS-induced mitochondrial damage. In addition, the expression of GRP78 protein and the cytosolic Caferation . DetaileAs the most common site of metastasis, bone metastasis seriously affects BC patients’ survival rate and quality of life and remains a challenging clinical condition. Therefore, we need effective treatments to avoid the devastating impacts of BC bone metastasis on patients. One way to achieve this could be the development of targeted DDSs. Nanotechnology-based delivery systems have shown several advantages in treating BC bone metastasis compared to the conventional therapies, including: (1) solve the challenges associated with poor physicochemical properties of the payloads such as low solubility of hydrophobic drugs; (2) increase the therapeutic index of drugs; (3) enhance the metabolic stability and plasma circulation times of the payloads; (4) promote passive targeting through the EPR effect and mediate active targeting to the bone using different targeting moieties; (5) enable triggered release of the payloads. With the conjugation of a targeting agent, these DDSs can specifically deliver payloads to the bone metastatic lesions, which can greatly reduce the side effect of the cytotoxic anticancer reagents. This review highlighted the research involving DDSs relevant to the targeted treatment of BC bone metastasis, suggesting promising therapeutic options for this unmet condition. However, being in their early preclinical stages of development, there are still challenges for the future translation of these technologies to the clinic. Some of those include optimising the fabrication process for upscaling to achieve clinical translation and designing and conducting studies that inform about the fate of DDSs in vivo and their interaction with blood, healthy and diseased tissues, and cells, as well as intracellular compartments. Furthermore, lessons from previous drug developments in the area of nanomedicine have shown that those DDSs with more complex designs face additional challenges in their optimisation and characterisation that leads to lower reproducibility in the production processes. To fully uncover the potential of nanotechnology-based DDSs in BC bone metastasis, it is necessary to understand the nanomaterials’ properties and the metastasis itself. This allows more in-depth investigations on the interaction between these DDSs and the BC bone metastasis.


Positron emission tomography (PET) molecular imaging is a powerful tool for interrogating physiological and biochemical processes to understand the biology of disease and advance therapeutic developments. Near-infrared fluorescence (NIRF) optical imaging has become increasingly popular for intraoperative staging to enable cellular resolution imaging of tumor margins during surgical resection. In addition, engineered antibody fragments have emerged as promising molecular imaging agents given their exquisite target selectivity, rapid systemic clearance and site-selective chemical modification. We report a tri-functional platform for construction of a modular antibody fragment that can rapidly be labeled with radionuclides or fluorophores for PET or NIRF molecular imaging of prostate stem cell antigen (PSCA). To provide a universal approach towards the targeted delivery of PET and optical imaging agents, we have developed a tri-functional platform (TFP) for the facile construction of modular, target-specific tracers. These modalities offer complimentary data, with PET enabling whole-body functional information about disease localization and potential metastasis while the optical component provides fluorescent-guided intraoperative staging.in vivo.4 Advances in antibody engineering techniques to reduce immunogenicity, modify pharmacokinetics and improve clearance have facilitated the development and translation of antibody fragments to be utilized as molecular imaging probes.5 Recombinant antibody fragments called cys-diabodies  contain a C-terminal cysteine that forms a disulfide bridge to stabilize dimerization which can be preferentially reduced to unveil free thiols for well-defined, site-specific conjugation.5 Importantly, the cysteine modification is located away from the antigen-binding site to preserve immunoreactivity of the protein conjugate. These constructs are particularly powerful imaging agents due to their small size, high tumor uptake, thiol-specific conjugation and fast blood clearance which results in high tumor to background ratios within 2 hours of probe injection.6 Labeled with positron-emitting radionuclides , recombinant diabody/cys-diabody constructs have been employed as immunoPET probes for a variety of tumor types including breast, pancreatic, prostate and colorectal cancers as well as for tumor-infiltrating CD8+ T cells.5 In addition, fluorescently labeled antibody fragments have been evaluated in vivo for their potential use as targeted optical imaging probes in xenograft models.8Antibody-based PET (immunoPET) is a versatile platform for the development of molecularly targeted, sensitive and quantitative imaging of cell-surface protein expression via a highly efficient (4+2) cycloaddition reaction to incorporate either fluorine-18 or a near-infrared fluorescent dye. This robust strategy leverages the tetrazine-trans-cyclooctene ligation which has been gaining interest for the selective introduction of fluorine-18 into biologically relevant molecules.9 The remarkable speed of this ligation is well suited for 18F-labeling of proteins, where the short radioactive half-life and stringent conditions demand the need for rapid, efficient chemistry.10To provide a universal approach towards the targeted delivery of PET and optical imaging agents, we have developed a tri-functional platform (TFP) for the construction of modular cys-diabodies. This novel platform rapidly yields a site-specific bioconjugate with improved pharmacokinetic properties that can be readily labeled in vivo information on cell-surface protein expression for any target-specific construct.For proof-of-concept, a cys-diabody against prostate stem cell antigen (PSCA) was conjugated to the tri-functional platform and immunoPET and optical imaging were performed to access whole-body biodistribution as well as tumor targeting potential in mice carrying prostate cancer xenografts. This model demonstrates not only the capability of the platform to afford molecular imaging tracers that provide high-contrast images against PSCA-positive cells, but also reveals the potential of this approach to provide 11 The inherent nature of the inverse electron demand Diels–Alder (IEDDA) cycloaddition12 between tetrazine and trans-cyclooctene – catalyst-free, extremely rapid, highly selective, modular, robust – make it an attractive reaction for protein labeling applications and provided the rationale to incorporate it into the tri-functional platform design and construction.13Exploiting strain-energy to facilitate molecular reactivity has been established as a highly effective strategy, prompting the discovery and applications of promising bioorthogonal reactions.in vivo which is considerably longer than the 3–7 h circulating half-life of a cys-diabody.14,5 The rapid pharmacokinetics of cys-diabodies permit bioconjugation via maleimide-based synthons and is well established in molecular imaging applications.7The maleimide synthon is a powerful tool for site-specific bioconjugation, and perhaps the most common functional group for selective modification of proteins. Fast kinetics and remarkably high chemoselectivity towards cysteine residues account for its persistent popularity in protein labeling. Despite susceptibility of the succinimidyl thioether linkage to hydrolysis and retro-Michael reactions, the half-life of a maleimide-protein linkage is ∼60 h via a succinimidyl thioether linkage; (2) a tetrazine for rapid labeling of the immunoconjugate via a (4+2) cycloaddition reaction; and (3) a hydrophilic side chain to improve the in vivo biodistribution profile and favor renal clearance (via rapid (4+2) cycloaddition with a broad range of TCO-modified tags without the need for further optimization of reaction conditions. Ultimately, the power of this approach lies in its modularity; it enhances the versatility of a single cys-diabody, potentially of any desired specificity, without compromising affinity to its molecular target, and facilitates facile labeling with radionuclides and fluorophores.The tri-functional platform consists of three key moieties: (1) a maleimide for site-specific conjugation to the cys-diabody learance . Traditiin vivo. However, imaging is also impacted by the catabolism and the clearance/retention of subsequent radiometabolites, which are strongly influenced by properties such as lipophilicity and charge. Much has been learned from pharmacokinetics and biodistribution studies on radiolabeled peptides, which have been modulated by chemical moieties such as aspartate residues,15 histidine/glutamic conjugates,16 succinic acid,17 glycosylation18 and the metal chelator DOTA.19 Increasing negative charge or incorporating chemical groups such as these has resulted in increased plasma clearance20 and diverted tracer or metabolite clearance in favor of renal over hepatobiliary.18A critical challenge in the development of molecular imaging agents is the image contrast between signal and background. Radiolabeled antibodies and their fragments can display exquisite target affinity, with predictable kinetics and clearance routes 21 With a molecular weight of ∼53 kDa, below the threshold for first-pass renal clearance, the initial clearance route for the bioconjugate was via the kidneys. Radiometabolites were reabsorbed and ultimately routed through the hepatobiliary system, resulting in extended blood pool activity and retention in the liver, kidneys and gastrointestinal tract (GI), presumably due to high lipophilicity of tracer radiometabolites.21 Size, structure and charge distribution are key properties that influence renal retention of radiolabeled metabolites.22 As a result of this study, the tri-functional platform was designed to preserve kidney retention of radiometabolites, reduce liver and GI activity and provide a clean background in the lower abdomen by incorporating an anionic moiety to decrease lipophilicity. We chose to incorporate a DOTA for its ease of synthetic installation and its potential for chelation of therapeutic radioisotopes towards the future development of theranostic tools. The rationale for our platform design is strengthened by a recent report that biodistribution of an 18F-labeled peptide tracer could be significantly modulated by installation of a metal-free DOTA appendage.19Previously, our group reported a dual-modality linker for conjugation to a cys-diabody for imaging PSCA expression.3 was prepared in four steps starting from commercially available N-boc-l-lysine  was site-specifically conjugated to the tri-functional platform (3) and utilized for PET and NIR optical imaging. The construction process starts with mild reduction of the cys-diabody to cleave the disulfide bridge and provide two free thiols (Prostate stem cell antigen (PSCA) is a cell surface protein expressed by prostate, pancreatic and bladder cancers with low expression in normal tissues and no expression in bone or lymph nodes, primary sites of cancer metastasis.e thiols .via a Michael addition between the sulfhydryl and maleimide group, producing the modular cys-diabody TFP-cDb. Excess reagents were separated from the protein conjugate using a gel filtration column and the modular cys-diabody TFP-cDb was analyzed by polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography (SEC)  Fig. S3. To affoectively . The mod18F]fluoroethoxy TCO was automated on the ELIXYS FLEX/CHEM radiochemical synthesizer (Sofie Biosciences) as described previously.28 For 18F-labeling, reformulated [18F]fluoroethoxy TCO (37 MBq) was added to TFP-cDb  and the mixture was incubated for 10 minutes at room temperature  and determined to be 63% and 98% respectively. The immunoreactive fraction (63%) was well within the previously reported range for A2 cys-diabody based immunoPET tracers (40–80%) (21Synthesis of [perature . Purific(40–80%) .21via the hepatobiliary route, resulting in high liver signal which hinders the ability to visualize liver metastasis. In order to maintain low background signal in the liver and generate high contrast images, renal clearance is highly desirable for PET molecular imaging probes. To evaluate in vivo imaging and biodistribution, 18F-cDb  was injected via the tail vein into male nude mice (n = 4) and microPET/CT scans were acquired. ex vivo biodistribution analysis which confirm that 18F-cDb demonstrated rapid clearance from circulation within 2 h followed by renal metabolism and retention of radiometabolites in the kidneys, enabling high contrast images within a few hours after probe injection  bearing PSCA-positive (right shoulder) and PSCA-negative (left shoulder) subcutaneous xenografts were intravenously injected with 18F-cDb  and imaged at 2 and 4 h post injection (p.i.)  . At 4 h,ol tumor . Represeol tumor .et al. using a VLA-4 radiopeptide.19 Likewise, in the case of the radiopeptide study, a DOTA moiety reduced GI accumulation by 10-fold to 4.5% ID g−1 in tumor-bearing mice.19 Analogous findings for both peptide and small protein-based imaging tracers reinforces the critical influence of hydrophilic, anionic chemical moieties, such as DOTA, on tracer biodistribution and performance. Additionally, in a radionuclide therapy application of our construct, long retention times of radiometabolites causing renal toxicity could be counteracted by infusion of basic amino acids  or polygelines (e.g. Gelofusine®) to block tubular reabsorption.22These results independently confirm the influence of a DOTA moiety to reduce GI tract accumulation and to redirect clearance to the kidneys over liver, which was recently demonstrated by Roxin Fluorescence image-guided surgery allows for real-time tumor delineation. Optical imaging agents that use fluorescence to identify cancerous cells offers the potential advantage of intraoperative imaging, ultimately improving surgical margins and reducing incidence of cancer recurrence. To evaluate our platform for utility in image-guided surgery, the modular cys-diabody was labeled with a near infrared fluorescent dye, sulfo-cyanine 5. SulfoCy5 TCO (20 mM in DMF) was added to TFP-cDb  at room temperature and, after 10 minutes, the (4+2) cycloadduct sCy5-cDb was obtained . SDS-PAGn = 3) bearing human prostate cancer xenografts, each with PSCA-positive cells implanted in the right shoulder and PSCA-negative cells implanted in the left shoulder, were used for the in vivo optical imaging experiment. Reformulated sCy5-cDb (20 μg) was injected via tail vein and mice were sacrificed 4 h after probe injection. Optical imaging performed post mortem with skin removed around the tumors allowed ready visualization of the antigen-positive tumors (Ex vivo analysis of major organs revealed strong autofluorescence from the stomach and intestines and to a lesser extent the liver and spleen (30 and can be adapted to the current modular platform to enable rapid optimization of fluorescent dyes to identify the ideal fluorophore to utilize, which may be dependent on multiple variables. Taken together, this study demonstrates that the tri-functional platform can efficiently afford modular immunoconjugates for PET and optical imaging that maintain favorable in vivo biodistribution profiles and high affinity to the cell-surface protein of interest.Male nude mice (e tumors . Considee tumors . Ex vivod spleen . As exped spleen . sCy5-cDtrans-cyclooctene, site-specific protein labeling was successfully accomplished to rapidly afford two molecular imaging constructs. ImmunoPET and NIRF optical imaging in mice bearing PSCA-positive subcutaneous tumors confirmed in vivo targeting and revealed specific tracer uptake and remarkable contrast in antigen-positive tumors. As envisioned, the DOTA moiety of the tri-functional platform favorably influenced 18F-cDb biodistribution and metabolite clearance to significantly diminish non-specific GI uptake. We anticipate that our approach will provide a straightforward path towards the development and clinical translation of immunoPET and optical imaging tracers based on antibody fragments of desired specificity.In summary, we have synthesized a tri-functional platform and constructed a modular antibody fragment that targets PSCA, a well-established prostate and pancreatic cancer biomarker. Using the robust and rapid inverse electron demand Diels–Alder reaction between tetrazine and A. M. Wu is a shareholder and consultant to ImaginAb, Inc.SC-011-C9SC05007H-s001


Dear Editor:uninfected. Regarding conjunctival swabs, all tested eyes yielded virus-negative results. Clearly, this is important empirical information in regard to infection risks for ophthalmologists and medical staff in tertiary eye care centers, including the handling of human corneal donor tissue — always provided that patients or donors are not infected.In a prospective study, Rokohl and colleagues looked into the possibility that SARS-CoV-2 may hide in the eyes of pre-screened asymptomatic patients in a tertiary eye care center . The autinfected individuals, viz., COVID-19 patients, survivors, or asymptomatic carriers, and virus material persistence in immune-privileged sites of the eye and elsewhere?We compliment the authors for taking this initiative and call for research regarding hiding places of SARS-CoV-2 to be expanded: What about infected individuals may be(come) of interest, in 1967 a virus reservoir in sperm was proposed in the course of discovering the Marburg virus (MV) [To exemplify why “secret” hiding sites in rus (MV) . Carefulrus (MV) ) spermatrus (MV) . That Ebrus (MV)  — in semrus (MV)  — conveyRegarding SARS-CoV-2, investigating virus materials in semen of COVID-19 cases in acute and recovery phases yielded ambiguous results. The question of whether virus material may persist in the privileged immunity site of the testes remains open . In cont


Nature Communications 10.1038/s41467-022-28487-2, published online 23 February 2022.Correction to: The original version of this Article contained an error in the Reference section (Ref. 46), which was previously incorrectly given as‘Neuromorphic tactile system encompassing healable materials and memristive elements to perform proof-of-concept edge tactile sensing, demonstrated in a prosthetic application.’The correct version states‘Neuromorphic tactile system encompassing healable materials and memristive elements to perform proof-of-concept edge tactile sensing, demonstrated in a robotic task that is further applicable to prosthetic applications.’This has been corrected in both the PDF and HTML versions of the Article.


Exploration of tumor immunity leads to the development of immune checkpoint inhibitors and cell-based immunotherapies which improve the clinical outcomes in several tumor types. However, the poor clinical efficacy of these treatments observed for other tumors could be attributed to the inherent complex tumor microenvironment (TME), cellular heterogeneity, and stemness driven by cancer stem cells (CSCs). CSC-specific characteristics provide the bulk tumor surveillance and resistance to entire eradication upon conventional therapies. CSCs-immune cells crosstalk creates an immunosuppressive TME that reshapes the stemness in tumor cells, resulting in tumor formation and progression. Thus, identifying the immunological features of CSCs could introduce the therapeutic targets with powerful antitumor responses. In this review, we summarized the role of immune cells providing CSCs to evade tumor immunity, and then discussed the intrinsic mechanisms represented by CSCs to promote tumors’ resistance to immunotherapies. Then, we outlined potent immunotherapeutic interventions followed by a perspective outlook on the use of nanomedicine-based drug delivery systems for controlled modulation of the immune system. Medical scientists have developed diversified treatments for cancer therapy; nonetheless, cancer mortality remains one of the biggest problems for humans worldwide. Tumor immunogenicity is induced by the antitumor activities of dendritic cells (DCs) and macrophages which activate the tumor-associated antigens (TAAs)-specific T cells resulting in the production of necessary cytokines and engagement of γδ T cells, natural killer (NK) cells, and B cells, all providing antitumor cytotoxicity . InspireHowever, the genetic and cellular heterogeneity of the surrounding tumor microenvironment (TME) complicated the clinical efficacy of those treatments, which requires further understanding of the multiple aspects of tumor biology . Along wThe tumor site-infiltrated immune cells are expected to target and eradicate cancer cells. However, the failure of immune responses and switching from immunosurveillance to tumor surveillance occurs due to increased niche complexity and emerged immunosuppressive TME is produced by CSCs alone or in cooperation with other non-cancerous cells including tumor-supportive immune cells , 9. Repr+DCs recruiting to the tumor site in Wnt/β-catenin-dependent pathway [+ DC impairing CD8+T cell activity or rising the resistance to anti-PD1 treatment [+ CSCs-derived extracellular vesicles (EVs) carry a soluble type of MHC-I, HLA-G (sHLA-G), which act as a ligand for immunoglobulin-like transcript (ILT) inhibitory receptors and thus impair monocyte differentiation into mature DCs through IL-6–STAT3 signaling pathway [+ colon cancer cells with high metastatic ability [Mature dendritic cells (DCs) are major antigen-presenting cells (APCs) which present TAAs on MHC-I molecules plus overexpress costimulatory molecules resulting in activate antigen-specific T cells-directed immune responses . However pathway , and  program and these cells, in turn, promote hepatocellular carcinoma (HCC) invasion and metastasis [The interaction between normal tissue-resident stem cells (SCs) and macrophages is essential for organ development, tissue homeostasis, and regenerative medicine . This intastasis .Alternatively, TAMs induce the overexpression of CD47 ligand on pancreatic CSCs , HCC CSC+CD14–CD33+ and they secrete cytokines and chemokines in TME providing immunosuppressive niche and thus, reducing the efficacy of immunotherapy [+CSCs have been shown to recruit the immunosuppressive MDSCs in the tumor site [Human myeloid-derived suppressor cells (MDSCs) are myeloid-originated progenitor cells that are classified into two subsets; monocytic MDSCs (M-MDSCs) and polymorphonuclear MDSCs (PMN-MDSCs). MDSCs are defined by CD11botherapy . Mammaliotherapy . During mor site   the modulation of RNA interference such as upregulation of piRNA-823 to induce NANOG, OCT4, and SOX2 expression , (ii) thl cancer . These f+T cells into Tregs [Regulatory T cells (Tregs) are a T cells-originated subset that has been shown to crosstalk with CSCs in several mechanisms to promote an immunosuppressive TME  Fig. 1dd1d. CSCsto Tregs . In hypoto Tregs . Moreoveto Tregs .+ T cells activation to target the CSC-neoantigens generating through tumor-specific somatic mutations [Normally, T cells recognize overexpressed TAAs in the form of MHC/peptide complexes on the APCs surface. However, CSCs-TAAs have shown low immunogenicity which is related to their sharing with normal tissues and the presence of tolerogenic T lymphocytes recognizing these antigens. In addition, CSCs escape immunosurveillance and recognition by antitumor immunity through (i) suppressing T-cell activation , (ii) thutations . EMT/β-cutations . In the utations .high CSCs are located in the front of invasive tumors and provide a physical shield against the infiltration of CD8+ T cells to support immune evasion [CSCs also express other immune checkpoint molecules such as CD276, CTLA4 (cytotoxic T lymphocyte antigen-4), and Galectin-3  as an ECM glycan-binding protein. During HNCC development and metastasis, the CD276 evasion . TGFβ de evasion . In anot evasion .Thanks to CSC plasticity, another strategy for evading CSCs from the immunosurveillance is developing the slow-cycling or quiescent CSCs supporting long-term survival and maintaining tumor-initiating potential in these cells . Quiesce+CD44+CSCs/CICs expressing NKG2DL [+CSCs expressing NKp30 and NKp44 [NK cells expressing activator NKG2D ligands, NKG2DL, or activating receptors  are able to kill MHC-1-negative CSCs in an APC-independent manner . Compareg NKG2DL , and MHCnd NKp44 . Howevernd NKp44  and renand NKp44  have beend NKp44 . Moreovend NKp44 . The depnd NKp44 . TherefoAlthough clinical evidence has demonstrated the efficiency of anti-CTLA-4 and anti-PD-1/PD-L1 antibodies in targeting bulk tumor cells, a large number of patients still do not derive benefit from them. A deeper understanding of the unique interactions between CSCs and the immune system can contribute to developing efficient immunotherapies capable of targeting pathways responsible for CSCs acquiring immune evasion as summarized below.± AML stem cells have shown high expression of poly-ADP-ribose polymerase 1 (PARP1) which is responsible for the repression of NKG2DL. This subset of NKG2DL-negative cells mediates evasion from NK cells clearance, and thus inducing genetic or pharmacologic inhibition of PARP1 leading to re-expression of NKG2DLs on the AML stem cells surface and re-sensitizing them to NK cells [Resistant CSCs overexpress metabolic vulnerabilities that can be targeted by immunomodulators or drugs directed to CSCs-associated pathways. MHC-Ib-expressing CSCs are vulnerable to NK cell-mediated cytotoxicity in an NKG2DL-dependent mechanism , wherebyNK cells .+CSCs exhibited upregulation of NKp30/NKp46 ligands and downregulation of MHC-I molecules making them sensitive to NK-cell-mediated cell lysis [The low infiltration of injected NK cells in the solid tumors may contribute to the development of targeting circulating CSCs in the bloodstream . The melll lysis . The intll lysis . Additioll lysis ; the benll lysis . Similarll lysis . Couplinll lysis , 67. TheRegarding CAR NK cells, epidermal growth factor receptor (EGFR) as breast CSCs-TAA was eliminated in vivo in mice model using EGFR-CAR NK-92 cells, and its therapeutic efficacy was improved when combined with FDA-approved oncolytic herpes simplex virus (oHSV) . MetastaNonetheless, the downregulation of TAA in CSCs  and expr+ CSCs to CD8+ T cell-mediated cytotoxic activities and inhibits the cancer growth in vivo [The DCs-based vaccines have been developed as a promising and effective strategy to facilitate CSC eradication, and in two examples, DCs loaded with CSCs-lysate  or CSCs- in vivo .Fig. 2ImRegarding immune checkpoints molecules Fig. , the comThe T cells suppressor and CSCs supportive effects of Tregs-derived COX-2 and its product, PEG-E2 , could b+ T-cells killing in an MHC-restricted manner in vivo [+ U373 glioma xenograft mouse model and the results indicated that CARs with a short spacer had significantly greater antitumor activity, which could be augmented by transgenic expression of cytokines to counteract the immunosuppressive TME [Regarding adoptive cell therapy (ACT), IFN-γ has been shown to upregulate the MHC-I molecules in HLA class I-defective CSCs and thus, make sensitive their neoantigen reorganization by T cells to efficiently target CSCs populations . Further in vivo . Similar in vivo . Ephrin sive TME . Promisisive TME . Howeversive TME .Immunosuppressive TME contributes to the development of immunotherapeutic interventions for the eradication of malignant diseases . TargetiEncouraging results directed CAR-T cell therapy against CSCs in other clinical studies Fig. c. HoweveImmunotherapies could be combined with CSCs-targeted nano agents/carries with potentials to both debulk the original tumor and eradicate the emerging resistant CSCs . Indeed,Without the use of toxic transfection reagents, the co-delivery of both antigen and adjuvant in such nanovaccines leads to targeting the same APCs maximizing the benefits of the intended vaccinal effect. Nanovaccines provide the intranuclear and intracellular delivery of DNA and mRNA vaccines, respectively Fig. a while iLymph nodes (LNs) are the micrometastasis sites of migrating CSCs first reenter hereafter circulating, and further, CSCs induce lymphangiogenesis-supporting tumor metastasis . On the Primary CSCs are located in the center of primary solid tumors with restricted cytotoxic lymphocyte infiltration , 93, and+ T cell immune responses, provided long-lasting therapy, and decreased the risk of adverse systemic toxicity in vivo [Immunomodulatory antibodies target CSCs expressing CTLA-4 or CD276 promoting robust antitumor immune responses, but the induction of off-tissue effects is reported in clinical settings , 48. To  in vivo .+ T cells (or NKG2D-CAR T cells) to the TME of unresectable solid tumors using polymeric alginate scaffolds encapsulated bioactive adjuvants  and functionalized with anti- CD3, CD28, and CD137 antibodies, and adhesion peptides  [Inefficient migration and expansion of T cells into solid tumors containing CSCs can be addressed by local delivery of CD8T cells) . The scaT cells) . These fAs stated above, CSCs impair DCs recruitment and maturation, , downregIn summary, our literature surveys the mechanisms through which CSCs and individual immune cells create an immunosuppressive TME-supporting tumor progression and relapse that will help guide the next generation of immunotherapies. Additionally, the CSCs' TAA and CSC-supportive TME can be a target of potent immune agents as monotherapy or in combination with approved drugs to overcome the resistant mechanism in immune evader CSCs. Owing to the shared tumor-initiating and immune evasion properties of CSCs with non-CSCs, CSC's key neoantigens and stemness transcription factor can be targeted by specific immunotherapies. Next, strengthening preclinical studies can accelerate CSC-targeted CAR CIK/T/NK cells in cancer treatment and establish safety in the clinic, ensuring their applications in future clinical cancer treatment. Finally, the nano delivery platforms provide a means to improve the local or systemic delivery of immunotherapies to cancer cells. However, future works and innovations may enable us to adjust nano-immunotherapy as curative approaches to target CSCs with the same efficacy in different tumors.


CCG-1423 is a Rho A pathway inhibitor which has been reported to inhibit Rho/SRF-mediated transcriptional regulation. SRF and SRF cofactors, which include ternary complex factors (TCFs) and myocardin-related transcription factor (MRTF), regulate various cellular functions. The Rho/SRF signaling pathway also regulates the sirtuin 2 (SIRT2) gene that contains a classic serum response element (SRE) sequence. Current research on CCG-1423 focuses on gene expression levels of SRF in response to CCG-1423 and how SRF levels affect the cells; the studies are focused on cell morphology, migration, viability/reproduction, and overall function. The pathways of this inhibitor have yet to be fully elucidated, but several have been suggested with good evidence. Our goal is to study the effect of CCG-1423 on mitochondrial function and gene expression of cells. In this work C2C12 myoblast cells have been used as an in-vitro model to study cellular bioenergetics and variations in gene expressions induced by CCG-1423. The effect of CCG-1423 on mitochondrial function was determined by measuring the mitochondrial oxygen consumption rate and glycolysis rate after treating C2C12 cells with varying concentrations of CCG-1423 overnight. In C2C12 myoblast cells, CCG-1423 treatment significantly reduced mitochondrial oxygen consumption rate (OCR) in a dose-dependent manner. However, treatment of C2C12 cells with CCG-1423 overnight increased the extracellular acidification rate (ECAR) in a dose-dependent manner. By indicating that CCG-1423 represses mitochondrial respiration via the Rho-SRF signaling pathway, the results of this study may enable a better understanding of the bioenergetics of the cell in the aging body.


Theranostics, a combination of therapy and diagnostics, is a field of personalized medicine involving the use of the same or similar radiopharmaceutical agents for the diagnosis and treatment of patients. Prostate-specific membrane antigen (PSMA) is a promising theranostic target for the treatment of prostate cancers. Diagnostic PSMA radiopharmaceuticals are currently used for staging and diagnosis of prostate cancers, and imaging can predict response to therapeutic PSMA radiopharmaceuticals. While mainly used in the setting of metastatic, castrate-resistant disease, clinical trials are investigating the use of PSMA-based therapy at earlier stages, including in hormone-sensitive or hormone-naïve prostate cancers, and in oligometastatic prostate cancers. This review explores the use of PSMA as a theranostic target and investigates the potential use of PSMA in earlier stage disease, including hormone-sensitive metastatic prostate cancer, and oligometastatic prostate cancer. A theranostic treatment both identifies suitable patients for treatment, provides a patient and cancer-specific treatment, and monitors response to treatment, all using the same or similar radiopharmaceuticals. Treatment typically involves the use of target-specific ligands that are bound to radioactive atoms. Depending on the physical properties of the radioisotope  and quantity of radiopharmaceutical administered to the patient (megabecquerel vs. gigabecquerel), these agents allow for diagnosis or subsequent disease treatment. While the term theranostics was only recently coined ,2, the ue tumors ; Radium-131I), treatment often involves a theranostic product pair. A theranostic product pair consists of two agents with the same targeting ligand, but different radionuclides. One part of the pair is specific for diagnostic imaging (predominantly gamma-ray emission suitable for SPECT or PET), while the other is specific for treatment . Thus, the theranostic product pair works together to identify suitable patients for treatment (diagnostic agent) or treat the patient (therapeutic agent) [While some radiometals directly target disease sites such as uptake of radioactive iodine within thyroid tissue, radiopharmaceuticals can also be designed to target cancer-specific receptors. The ideal theranostic target is both overexpressed in cancer cells and has minimal or no expression in normal tissues, thereby permitting high tumor dose with low toxicity to normal tissues. These agents typically have three distinct parts: a radionuclide (often conjugated by a chelator), a linker, and a ligand that binds with a targeted cancer cell receptor ,11. The c agent) ,11.Prostate-specific membrane antigen (PSMA) is a promising theranostic treatment target. PSMA is a 750 amino acid type 2 integral membrane glycoprotein with two monomers and an intracellular, transmembrane, and extracellular domain . The dis® [18F and 68Ga) have also been favored recently, enabling high-resolution and quantitative PET/CT imaging. Currently, the most common diagnostic agents are 68Ga-PSMA-11 and 18F-DCFPyl . These agents can localize areas of disease recurrence at very low levels of PSA, with tumor avidity being observed in the majority of patients with prostate cancer [Ga68 PSMA-11 PET/CT scans were more accurate in detecting lymph nodal and distant metastases than conventional imaging with a bone scan and a contrast-enhanced CT of the abdomen and pelvis for patients with newly diagnosed high-risk prostate cancer [18F-DCPyl-PET/CT scans and the lesion identified by central readers or pathology) in the setting of biochemical recurrence [Initial diagnostic imaging with PSMA used the same 7E11-C5 antibody (capromab pendetide), labeled with indium-111, and branded under the name ProstaScint® . Althoug® . More ree cancer ,24,25. Pe cancer . Likewiscurrence .177Lu) decays by beta emission (100%) with a half-life of 6.6 days [177Hf nucleus. The beta decay of 177Lu is relatively low energy , resulting in a mean range of 0.7 mm and a maximum range of 2.1 mm in soft tissues [177Lu allows for efficient delivery of therapeutic radiation to prostate cancer lesions. Although not particularly useful for therapy, the gamma emissions resulting from the decay of 177Lu allow for high-quality SPECT/CT imaging, thereby enabling image-based dosimetry following administration of the therapeutic radiopharmaceutical. These therapies tend to be given in multiple doses , which means that post-treatment dosimetry allows for adaptation in subsequent cycles of therapy based on absorbed dose to critical structures and tumor tissues [177Lu and 131I, 225Ac decays by alpha emission with a half-life of 10 days. Preliminary studies have shown potentially greater antitumor efficacy with reduced bone marrow toxicity with PSMA-targeted 225Ac agents, likely due to the short range associated with alpha particles (0.04–0.06 mm) [177Lu-PSMA-617 which carries the chelator DOTA for conjugation of various radiometals [Several radionuclides have been utilized for the therapeutic use of PSMA, including Lutetium-177, Iodine-131, and Actinium-225. The most common therapeutic nuclide in use  . In term0.06 mm) . Multipliometals .177Lu-based PSMA radioligands have shown promising results, including significant PSA declines and improvement in symptoms with PSMA. A meta-analysis of 177Lu-PSMA studies in MCRPC showed that 46% of patients had a greater than 50% PSA decline after treatment with Lu-PSMA, and 75% of patients had any PSA decline after therapy [177Lu-PSMA-617 in comparison with cabazitaxel resulted in higher PSA responses and fewer grade 3 or 4 adverse responses [177Lu-PSMA-617 or standard of care treatment demonstrated statistically significant improvements in progression-free survival (8.7 vs. 3.4 months) and overall survival (15.3 vs. 11.3 months) with 177Lu-PSMA-617 treatment [177Lu-PSMA-617 in the MCRPC setting, and this agent is currently under review by the FDA. In terms of treatment with alpha emitters, preliminary studies of 225Ac-PSMA-617 have also shown high response rates in terms of PSA declines both as an initial treatment and with progression following treatment with 177Lu-PSMA-617 [68Ga-PSMA-11 scans , thus allowing for selection of patients who are likely to respond to potential 177Lu-PSMA-617 therapy [Most clinical trials have focused on the use of PSMA radiotherapeutics for metastatic, castrate-resistant prostate cancers (MCRPC). The reason for the selection of this patient population is twofold: first, there is a current need for durable treatment options in this patient population, as chemotherapy and other systemic therapy responses are typically limited in duration, and second, PSMA expression is typically very high in this patient population. Initial trials with  therapy . In the esponses . The recreatment . The posPSMA-617 ,37,38,39 therapy ,36.225Actinium agents have demonstrated decreased hematologic toxicity, but higher rates of xerostomia [PSMA-targeted radioligands have a favorable toxicity profile. Common side effects include dry mouth or xerostomia (up to 30% of men), fatigue, and nausea, which correlate with areas of PSMA expression in normal tissues ,35,36,40rostomia . PSMA lirostomia . There hrostomia ,44. If Prostomia .177-Lu-PSMA-617 in the metastatic, hormone-sensitive (or hormone naïve) population [177Lu-PSMA-617 as compared to docetaxel alone in men with a new diagnosis of high-volume metastatic hormone-naïve prostate cancer [177Lu-PSMA-617 in combination with standard of care treatment (androgen deprivation therapy and androgen receptor-directed therapy) compared to standard of care treatment alone is also recruiting participants [While the focus of the majority of PSMA radioligand studies is in patients with MCRPC, high PSMA expression is also found in earlier disease stages, including in the high risk, recurrent, and oligometastatic settings. The traditional treatment of metastatic castrate-sensitive prostate cancer is the initiation of androgen deprivation, potentially in combination with chemotherapy or an androgen receptor inhibitor ,47. Howepulation ,49. The e cancer . A largeicipants ,49.11C-choline PET/CT scan were randomized to surveillance or metastatic lesion-directed therapy (surgery or stereotactic body radiotherapy (SBRT) to all metastatic lesions) [In the setting of oligometastatic disease, it has been proposed that definitively treating patients with radiation therapy or surgery to the prostate or metastatic sites could improve overall survival and decrease or delay androgen deprivation therapy ,51. In alesions) . The medlesions) . Likewis177Lu, including the relatively short-range beta emissions, it is likely that 177Lu can effectively target small metastatic lesions [While definitive treatment of metastatic lesions by SBRT or metastasectomy in the oligometastatic setting can improve cancer-related outcomes, not all sites of metastases are in locations amenable to SBRT or surgical resection. In addition, while very small lesions may be seen on PSMA PET/CT scans, these lesions may not be feasibly targeted with SBRT due to their small size or difficulty ascertaining their location without the radiotracer. Treatment with PMSA-targeted radioligands could therefore be beneficial in this setting, by treating all lesions . Given the decay characteristics of  lesions .177Lu-PSMA-617 after the third recurrence of castrate-resistant prostate cancer in a pelvic lymph node [68Ga-PSMA-11 imaging revealed new uptake in a mediastinal lymph node and several infradiaphragmatic lymph nodes. He was treated with two administrations of 6 GBq of 177Lu-PSMA-617 , resulting in no detectable PSA for 5 months, and a slight rise in PSA following. A small pilot study of 10 patients with hormone-sensitive prostate cancer with fewer than 10 metastatic lesions , no curable treatment options , and tumor PSMA uptake higher than liver investigating the use of 177Lu-PSMA-617 showed promising results with response in terms of PSA decline [177Lu-PSMA-617 was found to be comparable to that seen in the treatment of high-volume MCRPC based on dosimetric analysis of tumor and normal tissues  [177Lu-PSMA-617 was observed [177Lu-PSMA-617 in the setting of oligometastatic disease currently recruiting patients [While there are few clinical trials investigating the use of theranostic PSMA agents in the setting of oligometastatic disease, these studies do showcase the potential promise of this agent in these settings . Von Eybmph node . The pat decline . All pat decline . The absy gland) . In addiobserved . There ipatients ,57.68Ga-PSMA expression [Of note, in addition to the oligometastatic setting, PSMA-targeted radiopharmaceuticals are also being investigated in the setting of high risk or intermediate risk localized prostate cancer with high pression .177Lu-PSMA therapy and treatment response have demonstrated an increased likelihood of response with increasing dose to tumors [Early studies investigating the relationship between tumor radiation absorbed dose from o tumors ,60. The o tumors  in patieWith the combination of diagnostic imaging and therapeutic treatment, theranostics allows for the selection of patients most likely to benefit from potential treatment. PSMA is a promising theranostic biomarker for the detection and treatment of prostate cancers. While the benefit of treatment has been mainly investigated in the setting of metastatic, castrate-resistant prostate cancers, PSMA-targeted radiopharmaceuticals may also be beneficial in a hormone-sensitive, metastatic prostate cancer setting, and with oligometastatic disease. Ongoing research studies will help to clarify the benefit of radiopharmaceuticals in an oligometastatic disease setting.


Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious and typically presents with respiratory complications. Non-respiratory etiology has been increasingly identified in the literature, including cardiac manifestations. Here, we discuss an atypical case recently treated for SARS-CoV-2 presenting with acute pericarditis. Our patient’s medical history of autoimmune disease and renal transplant further complicated her care. There is currently no standard of therapy for SARS-CoV-2-related pericarditis. We would like to highlight increased awareness of this rare complication as well as successful treatment regimens for acute management of the disease. Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is the pathogen responsible for the COVID-19 pandemic which has caused over 179 million cases and 3.8 million deaths around the world as of June 2021 [While SARS-COV-2 typically presents with respiratory symptoms like pneumonia, pathology in many other organ systems has been well documented. For example, cardiac complications of severe SARS-COV-2 have been increasingly identified in the literature. In a review of 11,500 hospitalized SARS-COV-2 patients, the myocardial injury was found in nearly a quarter of all cases [We present the case of a 71-year-old woman with a past medical history significant for systemic lupus erythematosus (SLE), focal segmental glomerulosclerosis, status post renal transplant 15 years prior, and type-2 diabetes mellitus. Her medications included tacrolimus and mycophenolate for pharmacologic immunosuppression following transplantation and sliding scale insulin.She initially presented to the emergency department for care following four days of progressively worsening cough, shortness of breath with generalized weakness, chest tightness, fever, and chills. She was diagnosed with SARS-COV-2 pneumonia which was managed with a one-week course of 6 mg daily dexamethasone and remdesivir. Her symptoms steadily improved and she was discharged to home care with rivaroxaban prophylaxis following completion of treatment.She represented to the emergency department the next day with shortness of breath, altered mental status, and chest pain which was exacerbated on inspiration. Her vitals on presentation were notable for a blood pressure of 172/81. Her physical examination was notable for an audible friction rub over her anterior chest wall and chest pain reproducibly improved by leaning forward. An electrocardiogram was obtained , sepsis, and acute kidney injury .There is a growing body of literature regarding cardiac complications from the virus. A recent prospective study conducted in Germany in non-selected participants found cardiac complications in 78% of recovered cases . These cCardiac injury or carditis in SARS-COV-2 positive patients can be measured through serial Troponin 1 (cTnI) in concordance with inflammatory markers, CMR, and RT-PCR viral load of SARS-CoV2 RNA . cTnI elInjury has been identified to take place through a variety of mechanisms, including direct viral binding to the angiotensin-converting enzyme 2 (ACE-2) receptor, overactive cytokine production, and pathologic activation of the innate immune system . The virSolid organ transplant recipients, such as the case presented above, are in a vulnerable and less studied population with regards to infectious diseases, such as SARS-COV-2. The immunocompromised status of transplant recipients adds uncertainty in prognosis and best practices. In their five-month review, Alfishawy et al. found 320 cases of SARS-COV-2 in transplant recipients to provide guidelines in treatment and immunosuppressive management . As noteCurrent frontline treatment for SARS-COV-2 in severe cases includes concomitant remdesivir, an RNA-dependent-RNA-polymerase inhibitor, and dexamethasone. Evidence to support dexamethasone’s use comes from the RECOVERY trial in which 28-day mortality was improved; evidence supporting the use of remdesivir comes from a documented decreased time to recovery and lesser incidence of serious adverse events ,12. TreaAcute pericarditis is a rare complication of SARS-COV-2. A high clinical suspicion should be noted in patients with recent SARS-CoV-2 positive assays in correlation with elevated troponins and EKG changes. Cardiac injury is hypothesized to occur secondary to immune response rather than direct toxicity. Treatment is currently case by case due to a lack of standardized therapy. Aggressive management including early hospitalization and adjuvant remdesivir, aspirin, and colchicine were successful for our patient.