Temperature-Responsive Biodegradable Injectable Polymers Having Tissue Adhesive Properties for Biomedical Materials

Abstract

Injectable polymers (IPs) exhibiting in situ hydrogel formation have attracted attention as vascular embolization and postoperative adhesion prevention materials. When using them for such purposes, attribution of tissue adhesion property to the hydrogel is important. We previously reported a temperature-responsive biodegradable IP system using triblock copolymers of poly(ε-caprolactone-co-glycolic acid) and poly(ethylene glycol) (tri-PCGs). Recently, we developed IP systems containing acrylate-capped tri-PCG (tri-PCG-Acryl) and polythiol compound (DPMP)-loaded tri-PCG. This IP system exhibit temperature-responsive gelation, where chemical cross-links were formed via thiol-ene reaction. The duration of gel state under physiological conditions and its physical properties could be controlled by changing the content of tri-PCG-Acryl and DPMP in the system. In this study, the addition of aldehyde-modified Pluronic (PL-CHO) was investigated for attributing tissue adhesive properties to the IP system. This IP system containing PL-CHO showed high tissue adhesive properties by Schiff base formation between the aldehyde groups and the biological tissue surface. We evaluated the possibility of using IP system as vascular embolization materials and postoperative adhesion prevention materials. The IP system showed good embolization performance in blood vessels, resisting pressure. The IP hydrogel remained at the administration site in the abdominal space for 2 days and showed effective adhesion prevention performance.