XXXX Coated Upconversion Nanoparticles: A Versatile Platform for the Development of Efficient Theranostics.

@entity5 @entity2733 @entity3758 @entity3440 @entity1473
UNASSIGNED: Next generation theranostic devices will rely on the smart integration of different functional moieties into one system. These individual chemical elements will have a variety of desired chemical and physical properties and will need to behave in a multifunctional manner. Researchers have used upconversion nanoparticles (UCNPs) as a basis for superior imaging probes to locate cancerous lesions. The features of these nanoparticles, such as large anti-Stokes shifts, sharp emission bands, long-lived luminescence, and high resistance to photobleaching, have produced versatile probes. One way to improve these probes is to add a layer of dense or mesoporous @entity3440 to the outer surface of UCNPs (UCNP@ @entity3758 ). These modified UCNPs are chemically stable and much less cytotoxic than the original UCNPs. In addition, their surface can be easily modified to introduce various functional groups (e.g., - @entity2733 , - @entity1473 , -SH) via silanization, which facilitates conjugations with various biological molecules for multimodal imaging or synergetic therapeutics. This versatility makes UCNP@ @entity3758 particles excellent platforms for the construction of efficient theranostics. In this Account, we provide a comprehensive summary of recent progress in the development of UCNP@ @entity3758 nanocomposites for theranostics in the hope of speeding their translation into the clinic. We first discuss the major design principles and protocols for engineering various nanocomposites based on UCNP@ @entity3758 structures including those coated with dense @entity3440 , mesoporous @entity3440 , or hollow mesoporous @entity3440 . Next we summarize several representative efforts that probe the relaxivity mechanisms of these nanostructures as a way to optimize magnetic resonance sensitivity, multimode @entity5 imaging, near-infrared light-triggered chemotherapy, photodynamic therapy, and synergetic therapy (the combination of radiotherapy with chemotherapy, thermotherapy, or photodynamic therapy) using UCNP@ @entity3758 -based theranostics. By rational integration of a wide range of features that convey multiple functions (such as imaging and therapy) into the structure or onto the surfaces of UCNP@ @entity3758 , the constructed theranostics show promise for multimodal @entity5 imaging, biosensing, and effective @entity5 therapy. Finally, we discuss the limitations of UCNP@ @entity3758 nanostructures, the difficulties in the design of smart theranostics, and their potential role in clinical @entity5 research.
