Healing Pattern in Calvarial Bone Defects Following Bone Regenerationin Rats Guided by Chitosan Scaffold and Adipose Tissue-DerivedMesenchymal Stem Cells

摘要

Cell-based tissue engineering using scaffolds provides a promising option for the repair of bone tissue damagecaused by trauma or aging-related degeneration such as osteoporosis. In this study, a porous 3D scaffold was used tosupport the differentiation process of rat adipose -derived stem cells (ADSCs) into osteoblasts in vitro. The scaffold wasmade with chitosan, gelatin and chondroitin. In addition, the scaffold was crosslinked by glutaraldehyide. The osteogenicdifferentiation of ADSCs was improved in 3D culture as shown by the cell viability assay (MTT) and analyses of, alkalinephosphatase activity (ALP), and collagen production during three weeks of culturing. During the 2nd and 3rd weeks ofculturing, bone markers, such as osteopontin and osteocalcin, were detected by the PCR analysis. In vivo biocompatibilitywas evaluated subcutaneously in rats. A mild inflammatory response was observed during the 5 weeks. Reduction of thematrix fibers by reabsorptive cells and formation of new blood vessels were observed during this period. However, noinflammation was observed. Five weeks after the implants were placed in the calvaria -defects, a small amount of bonerepair was observed. In addition, immunohistochemistry revealed the presence of EGFPs ADSCs in the newly formedextracellular matrix. These findings indicated that the chitosan–gelatin–chondroitin 3D structure enhances cellularproliferation, which may be useful in the development of biomaterials for the stimulation of adult stem cells in bone tissueengineering.