IMPACT OF CRYSTALLINE-ENGINEERED BIOACTIVE GLASS ON BIOLOGICAL CHARACTERISTIC OF POLYMER REINFORCED COMPOSITE SCAFFOLDS

In this research, the bioactive glass (BG) with different microstructure was compounded with poly-l-lactic acid (PLLA) by freeze drying method to fabricate composite scaffold. The CaOP2O5- SiO2-ZnOglass powder was first produced by sol-gel method followed by heat-treatment processing at 500, 700 and 900 C and analyzed by Thermal Gravimetric (TG), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM) and X-ray analysis, and also the scaffolds were characterized by energy dispersive X-ray analysis (EDXA) and scanning electron microscopy (SEM). It was observed that the increasing in heat-treatment temperature of BG powder has reduced the amorphous to crystalline phase ratio. In composite scaffolds, there is70 to 80 vol.% interconnected open pores with 50 to 200 mu m size and reinforced powder well distributed in their structure. The ion exchange (degradation/re-precipitation) properties of different scaffolds were assessed in Simulated Body Fluid (SBF) after 45 days of immersing and it was found that the weight of scaffold reduced about 25 wt% and the pH of media changedabout0.6 unit. The re-precipitation products were assessed and it can be understood that the increasing of BG crystallinity structure can reduce the amount of biological apatite product and change its chemical composition. Osteoblast culture analysis was performed and observed that the cells could attach and spread well with high alkaline phosphatase activity. These results prove that using of crystalline-engineered BG in polymer matrix as composite scaffold control the biological interaction of tissue engineering scaffolds.