Biocompatibility of a chitosan-based injectable thermosensitive hydrogel and its effects on dog periodontal tissue regeneration

We evaluated the biocompatibility of an injectable chitosan-based thermosensitive hydrogel, which was prepared from chitosan and quaternized chitosan (HTCC) containing α,β-GP (CS-HTCC/GP). The ability of the CS-HTCC/GP thermosensitive hydrogel to partake in periodontal tissue regeneration was investigated. The CS-HTCC/GP thermosensitive hydrogel was found to have no toxic effects and could promote alkaline phosphatase (ALP) activity in human periodontal ligament cells (HPDLCs) in vitro. An extract of the CS-HTCC/GP thermosensitive hydrogel had no obvious influence on the ultrastructure of HPDLCs. The CS-HTCC/GP solution was injected into the rumps of rats resulting in a non-specific inflammation reaction. CS-HTCC/GP thermosensitive hydrogel loading with basic fibroblast growth factor (CS-HTCC/GP-bFGF) more effectively enhanced new periodontal support tissues in dogs. All results indicated that the CS-HTCC/GP thermosensitive hydrogel exhibited excellent biocompatibility and had potential as an injectable local drug delivery vehicle and tissue-engineering scaffold for periodontal disease therapy.