Thermo-Responsive Single-Chain Cyclized/Knotted Polymers for Cell Encapsulation

Abstract

Spinal cord injury (SCI) is a traumatic condition that results in the loss of motor and sensory functions. Mesenchymal stem cells (MSCs) have the potential to enhance the inflammatory microenvironment after SCI and promote nerve regeneration. However, maintaining long-term enrichment and sustained release of stem cells around the injured area remains a significant challenge. In this study, we synthesized a series of thermo-responsive single-chain cyclized/knotted polymers (SCKPs) using reversible addition-fragmentation chain transfer (RAFT) polymerization. By adjusting the types and ratios of monomers, we were able to tune the lower critical solution temperature (LCST) to approximately 37°C. Importantly, SCKPs formed a half-interpenetrating polymer network (H-IPN) with thiolated hyaluronic acid (HA-SH), effectively encapsulating stem cells while maintaining high cell viability. This novel H-IPN shows great promise as a carrier for stem cell therapy in the treatment of SCI.