Preparation and mechanical behavior of PLGA/nano-BCP composite scaffolds during in-vitro degradation for bone tissue engineering

In this paper, the yield strength and elastic modulus of Poly (lactide-co-glycolide) (PLGA) and PLGA/nano-biphasic calcium phosphate (nBCP) composite scaffolds, before and during in-vitro degradation, have been evaluated. Composite scaffolds were made by using PLGA matrix and 10-50 wt.% nBCP powder as the reinforcement material. All scaffolds, with more than 89% porosity, were fabricated by thermally-induced phase separation (TIPS). During in-vitro degradation (0-8 weeks), the PLGA/nBCP scaffolds showed both more weight loss and better mechanical properties as compared to neat PLGA scaffolds. The PLGA/nBCP scaffolds with 30 wt.% nBCP illustrated the highest value of yield strength among the composite scaffolds, before and after degradation, until 6 weeks. After 8 weeks, the yield strength values were very poor and close to each other. The values of elastic modulus for all samples were less than the half of their initial values after 6 weeks. However, after 8 weeks, the elastic moduli of all samples reduced to negligible values.