Dynamics in Controllable Stimuli-Responsive Self-Assembly of Polymer Vesicles with Stable Radical Functionality

Abstract

Self-assembled polymer vesicles have emerged as exciting and promising materials for their potential application in drug delivery, but the dynamics of stimuli-responsive polymers in these areas with pendant functionality in order to understand the structure–property relationship under different physicochemical conditions is still open to discussion. In this work, nitroxide radical-containing copolymers were synthesized and utilized to investigate local dynamics in their vesicular assemblies. Herein, electron paramagnetic resonance (EPR) spectroscopy was applied to reveal the smart supramolecular vesicular structure and polymer chain dynamics in stimuli-responsive controlled assemblies by considering molecular-level interactions. These interactions and dynamics were dependent on the microenvironment of the assemblies, which might be affected by physicochemical parameters such as radical concentration, pH, redox agent, polarity, and viscosity. These observations help to accomplish quantitative insights into the stimuli-responsive colloidal vesicular assemblies. The vesicles were used as an anticancer drug carrier, which showed high drug loading efficiency (63.65%). The reduction-responsive prompt disassembly accelerated the release. Furthermore, the biocompatibility and anticancer activity were examined by cellular experiments against normal fibroblasts (L929) and human cervical cancer (HeLa) cell lines, respectively. The results demonstrate that this effort provides an easy strategy for designing controllable stimuli-responsive polymer nanosystems which promotes their promising application in cancer treatment.

Co-assembly of Amphiphilic Triblock Copolymers with Nanodrugs and Drug Release Kinetics in Solution

“…According to previous studies, malignant tumor cells often lead to changes in biochemical properties such as lower pH, higher glutathione concentration, and temperature due to higher metabolic levels and accumulation of acidic substances. 58 In addition, specific parts such as the gastrointestinal tract often have lower pH. For example, the pH of the intestine is about 6.8, the pH of the stomach is 2−4, and the pH of the colonic is even lower.…”

“…al synthesized stable amphiphilic copolymers containing hydrophobic nitroxide radicals for selfassembly into polymeric vesicles and adjusted the hydrophobicity of the copolymer by changing the proportion of free radical moieties. 58 Nitroxide radicals will undergo a disproportionation reaction in acidic media, resulting in a decrease in the free radical concentration. In a highly reducing environment, hydrophobic nitroxide radicals are converted into hydrophilic hydroxylamine groups, which will destroy the hydrophobic-lipophilic balance.…”

In situ stimulus-responsive self-assembled nanomaterials for drug delivery and disease treatment

“…By adding fluorescent groups to generate functional polymers inside cells to manipulate and monitor cell behavior, the tedious synthesis and solution This journal is © The Royal Society of Chemistry 2023 processing procedures of block copolymers in traditional selfassembly strategies can be avoided. 146,147 Ocyanine-based photoacids are often used as light-responsive media. When exposed to visible light, the medium decreases its pH value and induces DNA triplex formation, leading to the spatial reconstruction of chiral plasma molecules.…”

“…By adding fluorescent groups to generate functional polymers inside cells to manipulate and monitor cell behavior, the tedious synthesis and solution processing procedures of block copolymers in traditional self-assembly strategies can be avoided. 146,147…”

Local Chain Dynamics in Polyelectrolyte Multilayers of Chitosan and Spin‐Labeled Poly(ethylene‐alt‐maleic acid)

“…Furthermore, inter‐polymer complexes of spin‐labeled poly(styrene‐co‐maleic acid) with polyethylene glycols were studied. [ 41 ] The spin‐label technique has been also used to study the dynamics of amphiphilic copolymers in self‐assembled polymer vesicles, [ 44 ] of poly(N‐isopropyl methacrylamide‐co‐acrylic acid)s in stimuli‐responsive self‐assembled nanostructures, [ 45 ] and of amphiphilic poly(methyl methacrylate‐co‐acrylic acid)s in self‐assembled smart nanoparticles. [ 46 ] Dendrimers were spin‐labeled to analyzes the interactions occurring between differently functionalized poly(amidoamine) (PAMAM) dendrimers and model membranes.…”