Biocompatibility and Efficacy of Collagen/Gelatin Sponge Scaffold with Sustained Release of Basic Fibroblast Growth Factor on Vocal Fold Fibroblasts in 3-Dimensional Culture

Objective: Treatment of vocal fold scarring remains challenging. We have previously reported the therapeutic effects of local injection of basic fibroblast growth factor (bFGF) in animal models and humans. A novel collagen/gelatin sponge (CGS) is capable of sustained release of bFGF, which compensates for its quick absorption in vivo, avoiding multiple injections. This study aimed to evaluate the biocompatibility and efficacy of the CGS in rat vocal fold fibroblasts prior to human trials. Methods: Fibroblasts extracted from Sprague-Dawley rat vocal folds were seeded onto a CGS and then cultivated with bFGF at concentrations of 0, 10, and 100 ng/mL. Vocal fold fibroblast morphology, adhesion, proliferation, and gene expression were measured under these 3-dimensional conditions. Results: Cells adhered to the CGS from day 1. Although no significant differences in cell morphology were detected, cell proliferation was accelerated by bFGF administration. Expression of endogenous bFGF and hepatocyte growth factor was significantly up-regulated at 10 ng/mL bFGF. The expression of procollagen I and procollagen III was significantly suppressed, whereas HAS-1 and HAS-2 were up-regulated at 10 and 100 ng/mL bFGF. Conclusion: The collagen/gelatin sponge is biocompatible with vocal fold fibroblasts and may be useful as a bFGF drug delivery system for the treatment of scarred vocal folds.