Preparation and histological evaluation of biomimetic three-dimensional hydroxyapatite/chitosan-gelatin network composite scaffolds.

A novel biodegradable hydroxyapatite/chitosan-gelatin network (HA/CS-Gel) composite of similar composition to that of normal human bone was prepared as a three-dimensional biomimetic scaffold by phase separation method for bone tissue engineering. Changing the solid content and the compositional variables of the original mixtures allowed control of the porosities and densities of the scaffolds. The HA granules were dispersed uniformly in the organic network with intimate interface contact via pulverizing and ultrasonically treating commercial available HA particles. Scaffolds of 90.6% porosity were used to examine the proliferation and functions of the cells in this three-dimensional microenvironment by culturing neonatal rat caldaria osteoblasts. Histological and immunohistochemical staining and scanning electron microscopy observation indicated that the osteoblasts attached to and proliferated on the scaffolds. Extracellular matrices including collagen I and proteoglycan-like substrate were synthesized, while osteoid and bone-like tissue formed during the culture period. Furthermore, the cell/scaffold constructs had good biomineralization effect after 3 weeks in culture.

[Tissue engineering study on chitosan-gelatin/hydroxyapatite composite scaffolds--osteoblasts culture].

OBJECTIVE: To investigate the behavior of rat calvarial osteoblasts cultured on chitosan-gelatin/hydroxyapatite (CS-Gel/HA) composite scaffolds. METHODS: The rat calvarial osteoblasts (the 3rd passage) were seeded at a density of 1.01 x 10(6) cells/ml onto the CS-Gel/HA composite scaffolds having porosity 85.20%, 90.40% and 95.80%. Cell number was counted after cultured for 3 days, 1 week, 2 weeks and 3 weeks. Cell proliferation, bone-like tissue formation, and mineralization were separately detected by HE, von Kossa histological staining techniques. RESULTS: The CS-Gel/HA composite scaffolds supported the attachment of seeded rat calvarial osteoblasts. Cells proliferated faster in scaffold with higher porosity 90.40% and 95.80% than scaffold with lower porosity 85.20%. The osteoblasts/scaffold constructs were feasible for mineral deposition, and bone-like tissue formation in 3 weeks. CONCLUSION: This study suggests the feasibility of using CS-Gel/HA composite scaffolds for bone tissue engineering.