Photoresponsive Polypeptide-Glycosylated Dendron Amphiphiles: UV-Triggered Polymersomes, OVA Release, and In Vitro Enhanced Uptake and Immune Response

Abstract

Efficient therapeuic proteins’ delivery into mammalian cells and subcellular transport (e.g., fast escape from endolysosomes into cytoplasm) are two key biological barriers that need to be overcome for antigen-based immunotherapy and related biomedical applications. For those purposes, we designed a novel kind of photoresponsive polypeptide-glycosylated poly­(amidoamine) (PAMAM) dendron amphiphiles (PGDAs), and their synthesis, UV-responsive self-assembly, and triggered ovalbumin (OVA) release have been fully investigated. The highly anisotropic PGDA4 with a glycosylated second-generation PAMAM dendron self-assembled into stable polypeptide vesicles (polymersomes) within 20–50 wt % water, which exhibited UV-responsive reassembly, dynamic binding with a lectin of concanavalin A, and an accelerated OVA release in vitro. Moreover, upon 365 nm UV irradiation, the self-assembled polymersomes of those glycopolypeptides were transformed into micellar aggregates in aqueous solution at pH 7.4 but disassembled completely at pH 5. The OVA-loaded polymersomes could efficiently deliver OVA into RAW264.7 cells and achieve enhanced endolysosomes escape upon UV irradiation, as revealed by flow cytometry and confocal laser scanning microscopy (CLSM). Furthermore, the enzyme-linked immunosorbent assay (ELISA) showed that the blank sugar-coated polypeptidosomes activated a high level of tumor necrosis factor α (TNF-α) of 468 pg/mL, playing a better role of immune adjuvant for activating the macrophages. Upon the UV irradiation with a dose of 3 J/cm2, the OVA-loaded polymersomes could further stimulate RAW264.7 and enhance the TNF-α level by about 45%. Consequently, this work provides a versatile platform to construct photosensitive and sugar-coated polymersomes of glycopolypeptides that have potential applications for protein delivery, immune adjuvant, and antigen-based immunotherapy.

Light-Triggered Polymersome-Based Anticancer Therapeutics Delivery

“…Spectrophotometric and chromatography methods are valuable tools for confirming the amphiphilic copolymer’s structure and quantifying encapsulated cargo by selecting a specific wavelength [ 197 ] or a chromatographic column, solvent, or condition. 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 ].…”

“…Song and collaborators developed UV-responsive photocleavage polypeptide-glycosylated poly-(amidoamine) (PAMAM) dendron amphiphiles (PGDAs), obtained by copper(I)-catalyzed azide-alkyne cycloaddition chemistry. It enabled the assembly of sugar-coated polypeptide vesicles (polymersomes) while delivering ovalbumin (OVA) antigen into mammalian cells [ 198 ], which could escape from endolysosomes into macrophage cytoplasm, activating the cellular immune response. Thus, glycosylated polypeptides presented carbohydrate residues located in the terminal ends or side chains, useful for cell recognition, adhesion, and binding, among others, through structures such as lectins, including concanavalin A.…”

Photocleavage‐based Photoresponsive Drug Delivery†

“…Light irradiation at 980 nm could initiate the cleavage of PPGs and the disassembly of micelles (82)(83)(84). In addition to the micelles, similar design was also used in polymersomes and tubisomes for light-induced dissociation of nanoparticles (85)(86)(87). Hydrophobic-to-hydrophilic switch is mainly used for the release of hydrophobic drugs.…”

Thermoresponsive Carbohydrate-b-Polypeptoid Polymer Vesicles with Selective Solute Permeability and Permeable Factors for Solutes

“…, electrical charge, stimuli-responsiveness, and membrane thickness) by tuning the chemical structure of the polymers. , Distinct from molecular assemblies such as micelles, polymer vesicles have an inner aqueous phase and can encapsulate hydrophilic substancessuch as small-molecule drugs, DNA, and proteinsin the inner aqueous compartment. Given their stability and functionality, polymer vesicles are suitable for biomedical applications, for example, as carriers for drug delivery systems. − …”

“…Another application of polymer vesicles is as compartments for nano-/microreactors that encapsulate enzymes to transform substrates into desired products. In particular, the concept of nanofactories has recently attracted much attention as therapeutic nanoreactors. ,− Nanofactories are based on enzyme-loaded vesicles that accumulate at target disease sites and transform prodrugs into native drugs. − However, because the solute permeability of polymer vesicles is extremely low , and because substrates negligibly penetrate into the interior of the vesicles, the permeability of the bilayer membranes must be enhanced. − …”