On bone defect repair with PLGA-HAP composite scaffolds biomaterials

Abstract:

Objective：To provide experimental basis for the further preparation of bioactive bone repair materials by detecting the biological behaviour of rat bone mesenchymal stem cells（BMSCs） in the PLGA-HAP composite scaffolds biomaterials. Methods：Hydroxyapatite（HAP） with different concentrations formed by biomimetic mineralization in vitro and deposited on polylactic-co-glycolic acid（PLGA） turned to PLGA-HAP scaffolds biomaterials（0 mmol/L，4.2 mmol/L，25 mmol/L）. Rat BMSCs were co-cultured into them to detect the effects of each group of materials on cell adhesion，proliferation and osteogenic differentiation. Results：In the cell proliferation experiment，the absorbance values of the control group on 1 d，4 d，and 7 d were 0.361±0.009，0.408±0.005，and 0.430±0.006，the values of PLGA-HAP（0 mmol/L） composite scaffolds on 1 d，4 d，and 7 d were 0.203±0.003，0.477±0.006，and 0.606±0.007，the values of PLGA-HAP（4.2 mmol/L） composite scaffolds at 1 d，4 d，and 7 d were 0.262±0.006，0.527±0.005，and 0.635±0.003，respectively，and PLGA-HAP（25 mmol/L） composite scaffolds at 1 d，4 d，and 7 d values were 0.270±0.002，0.575±0.004，and 0.667±0.005，respectively. The F value of the time factor was 10 632.000，that of the HAP concentration factor was 678.000，and that of the interaction factor was 732.600，all P=0.000. The data had statistical differences，indicating that the scaffold with relatively long time and high mineralization degree was more conducive to cell adhesion，growth and proliferation，and the influence of time factor was relatively positive. In the alkaline phosphatase（ALP） activity value test，the activity values of the composite scaffolds PLGA-HAP（0 mmol/L），PLGA-HAP（4.2 mmol/L），and PLGA-HAP（25 mmol/L） at 3 days were 0.088±0.015，0.122±0.016 and 0.125±0.008，the activity values at 7 days were 0.146±0.004，0.469±0.024 and 0.573±0.013，respec－tively. The F value of the time factor was 1 653.000，the F value of the HAP concentration factor was 400.900，and the F value of the interaction factor was 280.500，all P=0.000. The statistically different data showed that scaffold materials with different mineralization degrees could promote the repair of bone defects in a relative period of time. With the passage of time，the scaffold with higher HAP concentration，i.e. higher mineralization degree，was more conducive to the osteogenic differentiation of cells，and the influence of time was relatively positive. Conclusion：Hydroxyapatite-loaded PLGA composite scaffold can significantly promote cell adhesion，prolifer－ation and osteogenic differentiation. This study is an important experimental basis and foundation for further development of related bioactive bone repair materials.