Preparation and evaluation of an Arg-Gly-Asp-modified chitosan/hydroxyapatite scaffold for application in bone tissue engineering.

Bone tissue engineering has become a promising method for the repair of bone defects, and the production of a scaffold with high cell affinity and osseointegrative properties is crucial for successful bone substitute. Chitosan (CS)/hydroxyapatite (HA) composite was prepared by in situ compositing combined with lyophilization, and further modified by arginine‑glycine‑aspartic acid (RGD) via physical adsorption. In order to evaluate the cell adhesion rate, viability, morphology, and alkaline phosphatase (ALP) activity, the RGD‑CS/HA scaffold was seeded with bone marrow stromal cells (BMSCs). The osseointegrative properties of the RGD‑CS/HA scaffold were evaluated by in vivo heterotopic ossification and in vivo bone defect repair. After 4 h culture with the RGD‑CS/HA scaffold, the adhesion rate of the BMSCs was 80.7%. After 3 days, BMSCs were fusiform in shape and evenly distributed on the RGD‑CS/HA scaffold. Formation of extracellular matrix and numerous cell‑cell interactions were observed after 48 h of culture, with an ALP content of 0.006 ± 0.0008 U/l/ng. Furthermore, the osseointegrative ability and biomechanical properties of the RGD‑CS/HA scaffold were comparable to that of normal bone tissue. The biocompatibility, cytocompatibility, histocompatibility and osseointegrative properties of the RGD‑CS/HA scaffold support its use in bone tissue engineering applications.