Biocompatibility and bioactivity of gelatin hydrogel sponges incorporating bioactive glasses capable of controlled release of basic fibroblast growth factor.

This study aimed to evaluate the in vivo biocompatibility and bioactivity of gelatin hydrogel sponges incorporating bioactive glasses (BG), with or without impregnation of basic fibroblast growth factor (bFGF), as a potential scaffold for dentin-pulp complex regeneration. H.E. staining showed inflammatory cell infiltration in gelatin hydrogel sponges not incorporating BG (Gel-BG(0)) at 1 week, with blood vessels in the bFGF group (Gel-BG(0)-bFGF). Gelatin hydrogel sponges incorporating 10 wt% BG (Gel-BG(10)) and 50 wt% BG (Gel-BG(50)) retained their structure without inflammation. At 2 weeks, Gel-BG(0)-bFGF was no longer present, while Gel-BG(10) and Gel-BG(50) showed fragmentation and fibroblast infiltration. At 6 weeks, extracellular matrix-like structures were observed in Gel-BG(10) and Gel-BG(50). Masson's trichrome staining confirmed collagen deposition, and von Kossa staining revealed calcification. SEM-EDX analysis demonstrated Ca and P deposition throughout the implanted Gel-BG(10) and Gel-BG(50), with minimal Si and no co-localization of Ca and C. The co-localization of Ca and P indicates in vivo hydroxyapatite formation derived from BG. Gelatin hydrogel sponges incorporating BG and impregnated with bFGF demonstrated excellent biocompatibility, collagen matrix formation, and in vivo mineralization. These findings support their potential application in dentin-pulp regeneration and bone tissue engineering.