Light‐Responsive Serinol‐Based Polyurethane Nanocarrier for Controlled Drug Release

Abstract

In the present work, a new and facile strategy for the synthesis of light‐responsive polyurethanes (LrPUs) based on serinol with o‐nitrobenzyl pendent groups is developed. Stable monodisperse nanoparticles from these LrPUs can be formulated reproducibly in a simple manner, which is shown by dynamic light scattering (DLS) measurements. Upon irradiation with UV light, both polymers and nanoparticles undergo rapid degradation, which is investigated by DLS, scanning electron microscopy, size exclusion chromatography, and UV–vis spectroscopy. The nanoparticles are also employed for the encapsulation of the model drug Nile Red, and by exposure to UV light, a burst release of the payload is detected via fluorescence spectroscopy. This strategy can be easily applied to the straightforward synthesis of various new serinol‐based monomers with different stimuli‐responsive properties and therefore expand the family of biodegradable polymers.

L‐glutamic acid as a versatile platform for rapid synthesis of functional polyesters via facile Passerini multicomponent polymerization

“…Inspired by previous works of serinol‐based stimuli‐responsive self‐immolative polycarbonates reported by Hedrick, 27 Li, 28,29 and Kuckling, 30,31 herein, taking advantages of the P‐3CP including high atom economy, no by‐products, no catalyst and mild polymerization conditions, we have designed and synthesized a series of novel pH‐responsive self‐immolative polyesters by using l ‐GA as biorenewable raw material via P‐3CP as eco‐friendly polymerization method (Scheme 1). First, the polymerization conditions were optimized using GA1 with adipaldehyde and tert ‐butyl isocyanide (IC1) by varying molar feed ratios of [GA1]: [adipaldehyde]: [IC1] as well as screening organic solvents.…”

“…It has been known that serinol‐based polycarbonates exhibit self‐immolative ability. After deprotection, the reactive amine side groups are able to react with carbonate bonds in polymer backbone to form cyclic carbamate moieties via intramolecular cyclization and degrade polymers automatically into small molecules or oligomers 28–31 . The reason for the self‐degradation property is that the five‐membered cyclic carbamate is thermally stable and kinetically preferred to form.…”

Recent Advances in Stimuli‐Responsive Commodity Polymers

“…Photo‐responsive PURs have been widely used to fabricate nanoparticles/nanocarriers/micelles for photo‐controllable drug release. [ 134,135 ] For example, hydrophilic‐hydrophobic‐hydrophilic triblock copolymers can be synthesized with incorporation of the photocleavable oNB units into the backbone of the hydrophobic block repeatedly to prepare light‐breakable micelles, which undergoes fast UV‐induced disintegration.…”

Backbone-Degradable (Co-)Polymers for Light-Triggered Drug Delivery

“…Polymers exhibiting a change in the polarity, solubility, or structure as a response to internal or external stimuli, like pH, , temperature, redox conditions, , or light − have been of great interest in recent years. One reason for this interest is the broad field of possible applications of such polymers, which include catalyst immobilization, sensors, , and patterning , as well as tissue engineering, , drug delivery, − and tissue adhesives .…”

“…Polycarbonates − (PCs) and polyurethanes − (PUs) are generally considered excellent materials for biomedical applications because of their biodegradability, low toxicity, and biocompatibility. A versatile route for the synthesis of polyurethanes is the polyaddition of diols and diisocyanates using organotin catalysts, which also enables end-group functionalization. , Common approaches for the synthesis of polycarbonates are the ring-opening polymerization (ROP) of cyclic carbonates, like trimethylene carbonate (TMC), , and the polycondensation of diol monomers. , While ROP typically leads to PCs with narrow dispersity and a defined architecture, the synthesis of cyclic carbonate monomers is often expensive and, due to the polymerization mechanism, restricted to diols of certain carbon chain lengths . On the contrary, numerous different diols can be utilized for polycondensation with, e.g., dimethyl carbonate (DMC) or diphenyl carbonate (DPC) employing organocatalysts or alkali-metal catalysts, even in large-scale approaches. − We reported the synthesis of polycarbonates with light-cleavable pendant groups for the application as photosensitizer-loaded controlled release systems for the photodynamic therapy (PDT) of gastrointestinal tumors. ,,, Upon irradiation, the polymers showed degradation by a nucleophilic “backbiting” of the liberated amine groups, which led to an increased release of photosensitizer compared to standard polylactic- co -glycolic acid (PLGA) nanoparticles.…”