Reversibly Adhesive, Anti-Swelling, and Antibacterial Hydrogels for Tooth-Extraction Wound Healing.

Oral wound treatment faces challenges due to the complex oral environment, thus, sealing the wound quickly becomes necessary. Although some materials have achieved adhesion and sterilization, how to effectively solve the contradiction between strong adhesion and on-demand removal remains a challenge. Herein, a reversibly adhesive hydrogel is designed by free radical copolymerization of cationic monomer [2-(acryloyloxy) ethyl] trimethylammonium chloride (ATAC), hydrophobic monomer ethylene glycol phenyl ether acrylate (PEA) and N-isopropylacrylamide (NIPAAm). The cationic quaternary ammonium salts provide electrostatic interactions, the hydrophobic groups provide hydrophobic interactions, and the PNIPAAm chain segments provide hydrogen bonding, leading to strong adhesion. Therefore, the hydrogel obtains an adhesion strength of 18.67 KPa to oral mucosa and can seal wounds fast within 10 s. Furthermore, unlike pure PNIPAAm, the hydrogel has a lower critical solution temperature of 40.3 °C due to the contribution of ATAC and PEA, enabling rapid removal with 40 °C water after treatment. In addition, the hydrogel realizes excellent anti-swelling ratio (≈80%) and antibacterial efficiency (over 90%). Animal experiments prove that the hydrogel effectively reduces inflammation infiltration, promotes collagen deposition and vascular regeneration. Thus, hydrogel as a multi-functional dressing has great application prospects in oral wound management.

Glucose and pH Dual-Responsive Polymersomes with Multilevel Self-Regulation of Blood Glucose for Insulin Delivery.

Smart insulin delivery systems now play essential roles in diabetes treatment, whereas most existing systems suffer from insufficient regulation against blood glucose. Here, a glucose and pH dual-responsive insulin delivery system with multilevel self-regulation of blood glucose was constructed. Photocross-linked dual-responsive polymersomes were prepared by the self-assembly of the diblock copolymer methoxyl poly(ethylene glycol)-b-poly[3-acrylamidophenylboronic acid-co-2-(diethylamino)ethyl methacrylate-co-2-hydroxy-4-(methacryloyloxy)benzophenone] (mPEG-b-P(AAPBA-co-DEAEMA-co-BMA)) synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT), where insulin and glucose oxidase (GOx) were co-encapsulated inside. It is worth noting that the polymersomes with tunable membrane permeability are the first glucose-responsive platform consisting of both PBA and GOx. According to the pH change produced by gluconic acid, the pH-sensitive monomer DEAEMA endowed the polymersome membrane with multilevelly tunable and self-regulative permeability, further controlling the release behavior of insulin. This multilevel tunability was reflected directly in in vitro insulin release tests and was proven by the self-regulation of blood glucose in vivo. Promisingly, the polymersomes have great potential to be applied for the self-regulation of blood glucose in the treatment of diabetes.