Search

A glucose-responsive and biodegradable copolymer, poly(e-caprolactone)-b-poly(2-phenylboronic ester-1,3-dioxane-5-ethyl)methylacrylate (PCL-b-PPBDEMA), was synthesized by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The diblock copolymer could be easily prepared as a membrane containing insulin via a solution casting approach. The crystalline behaviour and thermal properties were investigated by POM and DSC. The results indicated that the PPBDEMA segments could destroy the crystallizability of the PCL segments. Glucose molecules could react with PPBDEMA, which led to the breakage of the phenylboronic acid molecules from the PBDEMA groups. PCL-b-PPBDEMA copolymer membranes as intelligent carriers could realize controlled insulin release via adjusting the glucose concentration. At the physiological pH, the membrane revealed a higher release rate of insulin after immersion in glucose solutions with high concentrations than that in glucose solutions with lower concentrations. In vitro cytotoxicity assays showed that the membrane is almost noncytotoxic.

Reduction and temperature dually responsive poly(2-(2-methoxyethoxy)ethylmethacrylate-co-oligo(ethylene glycol) methacrylate)-b-poly(e-caprolactone)-SS-poly(e-caprolactone)-b-poly(2-(2-methoxyethoxy)ethylmethacrylat-co-oligo(ethylene glycol) methacrylate) (P(MEO2MA-co-OEGMA)-b-PCL-SS-PCL-b-P(MEO2MA-co-OEGMA)) was synthesized by the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The copolymer can self-assemble into spherical micelles. After loading doxorubicin (DOX) and photothermal agent Indocyanine green (ICG), the micelles were endowed with synergistic effect of chemotherapy and photothermal therapy to cancer through reduction and temperature dually triggered size-shrinkage and drug release. The micelles showed good reduction and temperature responsiveness due to the presence of disulfide bond and thermoresponsive segments in copolymer. Under reducing conditions, the disulfide bond broke and the micelles were converted into micelles with half the original size, which was conducive to drug release. Near Infrared light (NIR) promoted the photothermal conversion of ICG, so that the micelle underwent a temperature response transition and further promoted the release of drugs. The micelles showed drug release rate, high photothermal conversion efficiency, highly cytotoxic to cancer cells and excellent synergistic photothermal-chemotherapy effect.

To obtain efficient oil-water separation materials with responsiveness, cellulosic porous materials with switchable wettability in response to pH changes were developed by reacting cellulose acetoacetate sponges with alkylamines of varying carbon chain length via dynamic covalent enamine bonds. The resulting sponges reversibly changed between being superhydrophilic (θwater = 0°) and highly hydrophobic (maximal θwater = 146°) under suitable pH conditions while maintained the favorable porous structures. Notably, the functionalized sponges exhibited high and selective oil absorption capacity (40–80 g/g) and satisfying desorption ability of 80%, and could efficiently separate oil-water mixtures and emulsions with extremely high efficiency (> 99%) in a controllable manner. With the three-dimensional micro/nano porous structure, switchable wettability and intrinsic environmentally friendliness, the pH responsive cellulosic sponges developed here hold great potential in controllable oil-water separation and oily wastewater purification.