Advances in Functionalized Photosensitive Polymeric Nanocarriers

Abstract

The synthesis of light-responsive nanocarriers (LRNs) with a variety of surface functional groups and/or ligands has been intensively explored for space-temporal controlled cargo release. LRNs have been designed on demand for photodynamic-, photothermal-, chemo-, and radiotherapy, protected delivery of bioactive molecules, such as smart drug delivery systems and for theranostic duties. LRNs trigger the release of cargo by a light stimulus. The idea of modifying LRNs with different moieties and ligands search for site-specific cargo delivery imparting stealth effects and/or eliciting specific cellular interactions to improve the nanosystems’ safety and efficacy. This work reviews photoresponsive polymeric nanocarriers and photo-stimulation mechanisms, surface chemistry to link ligands and characterization of the resultant nanosystems. It summarizes the interesting biomedical applications of functionalized photo-controlled nanocarriers, highlighting the current challenges and opportunities of such high-performance photo-triggered delivery systems.

Light-Triggered Polymersome-Based Anticancer Therapeutics Delivery

“…Although nanocarrier surfaces can be functionalized with a high ligand density due to their high surface-area-to-volume ratio, the density needs to be carefully tuned to optimize the balance between diffusion, uniform distribution, penetration depth, and binding affinity [ 32 ]. Functionalization can be achieved by various conjugation methodologies recently reviewed by our group [ 58 ]. Conventionally, the ligands used for active targeting are specific to bind to overexpressed receptors in tumor cells compared to healthy cells (a mechanism known as active tumor targeting).…”

“…To cite an example, click chemistry conjugation involves generating building blocks by adjoining small units with heteroatom links (C–X–C) in between [ 164 ] Other functionalization strategies employ different functional groups, such as thiol and vinyl sulfone [ 165 ], hydroxyl and amine [ 166 ], and aldehyde [ 167 ], present on the targeting ligand of the polymersome surface. For more details, please refer to our recent review on the functionalization of photosensitive nanocarriers [ 58 ].…”

“…Fourier transform infrared spectroscopy (FTIR) has been employed to corroborate the chemical structure of the amphiphilic copolymers and the presence of functional groups through the presence of their characteristic peaks [ 198 , 199 ]. UV-Vis spectroscopy and chromatography can, thus, be employed as a quantification strategy according to the cargo characteristics to quantify the cargo encapsulation efficiency (EE) and loading capacity (LC) [ 58 ]. Alternatively, UV-vis spectroscopy has straightforwardly monitored the photocleavage [ 80 ] and photoisomerization [ 200 ] properties in light-triggered polymersomes by evaluating the spectra evolutions upon light irradiation.…”

Polymeric Micro/Nanocarriers and Motors for Cargo Transport and Phototriggered Delivery

“…Nanocarriers are synthesized with free functional groups with a positive or negative net charge, porosity, and adsorption characteristics on their surface for functionalization, targeting biomolecules via covalent linking, adsorption, and π-π interaction strategies, promoting specific interactions with the target cells [242][243][244]. Fernández and Orozco summarized different chemistries for functionalizing photosensitive nanocarriers in a recent review [245].…”

Biocompatible Nanocarriers for Enhanced Cancer Photodynamic Therapy Applications

“…The polymer-based nanocarriers are more often considered as carrier molecules for various drug delivery applications, including PDT. Polymer-based nanocarriers can alter their surface chemistry to functionalize the specific targeting moieties (ligands or antibodies), which helps to facilitate site-specific or targeted drug delivery to the site of action [37,38]. Li et al (2021) recently reported the use of biocompatible nanocomplex for cancer therapy-the synthesized 5,10,15,20-tetrakis (4-aminophenyl) porphyrin (TAPP) and Fe3 + -loaded PEGylated polygalacturonic acid nanocomplex increased the 1 O 2 upon 760 nm laser irradiation, and exhibited cytotoxic effects in B16 melanoma cells [39].…”