Improved physical properties and in vitro biocompatibility of chitosan composite scaffolds incorporated with a green filler on bone cells

Scaffolds to facilitate three-dimensional bone ingrowth have been widely researched for bone regeneration. Fish scale can serve as a green filler for the reinforcement of chitosan scaffolds as it contains type I collagen and hydroxyapatite (HAp) which will promote osteoblastic functions. In the current study, chitosan scaffolds were incorporated with fish scale at a weight percent (wt%) range of 12–20. The composite scaffolds with interconnected pore and porosity of 26–142 μm and 58.2–76.1%, respectively, exhibited an improved compressive modulus ranging from 0.905 to 1.1 MPa. The improved mechanical property of chitosan–fish scale (C–FS) scaffolds was also coupled with reduced degradation rates of 9.3–14.3%. Fluorescence microscopic observation showed that the cell adhesion was peaked on the C–FS scaffold with 18 wt% of fish scale at the density of 1.05 ± 0.39 cells/mm². Subsequently, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the cell proliferation on C–FS scaffolds was significantly higher (p < 0.05) than that of control cells. Furthermore, the early differentiation of MG63 measured using alkaline phosphatase assay revealed the highest peak at 14-day culture on the scaffolds. These findings clearly signified the potential incorporation of fish scale at 18 wt% into chitosan scaffolds for reinforcement purpose by promoting the highest osteoblastic adhesion, proliferation and early differentiation.