The biodegradability of electrospun Dextran/PLGA scaffold in a fibroblast/macrophage co-culture

Fibroblast and macrophage are 2 dominant cell types respond cooperatively to degrade implanted biomaterials. Using an electrospun Dextran/Poly-lactide-co-glycolide (PLGA) scaffold as a model, an in vitro fibroblast/macrophage co-culture system was developed to investigate the degradability of implantable biodegradable materials. SEM showed that both fibroblasts and macrophages were able to degrade the scaffold, separately or cooperatively. Under the synergistic coordination of macrophages and fibroblasts, scaffolds showed faster degradation rate than their counterparts incubated with a single type of cells as well as in PBS or cell culture medium. Lysozyme, non-specific esterase (NSE), gelatinase, hyaluronidase-1 and alpha-glucosidase were up-regulated in the presence of the scaffold, suggesting their roles in the cell-mediated scaffold degradation. In addition, the expressions of cell surface receptors CD204 and Toll like receptor 4 (TLR4) were elevated 1 week after cell seeding, implying that these receptors might be involved in scaffold degradation. The results of in vivo subdermal implantation of the scaffold further confirmed the biodegradability of the Dextran/PLGA scaffold. The fibroblast/macrophage co-culture model adequately mimicked the in vivo environment and could be further developed into an in vitro tool for initial biomaterial evaluation.