Effects of the controlled-released basic fibroblast growth factor from chitosan-gelatin microspheres on human fibroblasts cultured on a chitosan-gelatin scaffold

To provide for prolonged, site-specific delivery of basic fibroblast growth factor (bFGF) to the grafted skin in a convenient manner, biodegradable chitosan-gelatin microspheres containing bFGF were fabricated and incorporated into a porous chitosan-gelatin scaffold in this study. The microspheres are an integral part of the porous three-dimensional scaffolds, and their incorporation does not significantly affect the scaffold porosity and the pore size. The release kinetics of bFGF showed a fast release (23.7%) at the initial phase in the first 2 days, and the ultimate accumulated release was approximately 71.8% by day 14, indicating an extended time course for complete release. Human fibroblasts seeded on chitosan-gelatin scaffolds with and without bFGF-loaded chitosan-gelatin microspheres (bFGF-MS) were incubated in vitro for 2 weeks and showed that, compared to chitosan-gelatin scaffolds alone, the scaffolds with bFGF-MS significantly augmented the proliferation and glycosaminoglycan (GAG) synthesis of human fibroblasts. Moreover, real-time reversed transcribed polymerase chain reaction (RT-PCR) analysis for fibroblast-related extracellular matrix (ECM) gene markers demonstrated that the transcript level of laminin was markedly upregulated by about 9-fold. These results suggest that chitosan-gelatin scaffolds with bFGF-MS possess a promising potential as a tissue engineering scaffold to improve skin regeneration efficacy and to promote vascularization.