In vitro degradation and bioactivity of composite poly-l-lactic (PLLA)/bioactive glass (BG) scaffolds: comparison of 45S5 and 1393BG compositions

The objective of this study was to compare the effect of two bioglass (BG) compositions 45S5 and 1393 in poly-l-lactic composite scaffolds in terms of morphology, mechanical properties, biodegradation, water uptake and bioactivity. The scaffolds were produced via thermally induced phase separation starting from a ternary polymer solution (polymer/solvent/non-solvent). Furthermore, different BG to polymer ratios have been selected (1, 2.5, 5% wt/wt) to evaluate the effect of the amount of filler on the composite structure. Results show that the addition of 1393BG does not affect the scaffold morphology, whereas the 45S5BG at the highest amount tends to appreciably modify the scaffold architecture interacting with the phase separation process. Bioactivity tests confirmed the formation of a hydroxycarbonateapatite-layer in both types of BGs (detected via scanning electron microscopy, X-ray diffractometry and Fourier Transform Infrared Spectroscopy). Overall, the results showed that 1393BG composition affects the experimental preparation protocol to a minimal extent thus allowing a better control of the scaffold's morphology compared to 45S5BG.