Development, characterization, and in vitro bioactivity studies of sol-gel bioactive glass/poly(L-lactide) nanocomposite scaffolds

Developing materials combining the advantages of synthetic polymers and bioactive glass nanoparticles can provide an efficient bone engineering scaffold. In this study, sol-gel bioactive glass (SG) nanoparticles were synthesized by quick alkali-mediation; Sol-gel derived bioactive glass/Poly(L-lactide) nanocomposite scaffolds were then developed. The influence of the glass content on the porosity of nanocomposite scaffolds was evaluated by SEM. The results showed that the neat polymer scaffold (PLA) has a highly interconnected porous structure with a maximum pore size of about 250 urn. For the composite scaffold containing 25 wt.% glass (SGP25). the decrease in the maximum pore size, (to about 200 pm) was not significant while for the SGP50 composite scaffold containing 50 wt.% glass it was a significant decrease (to about 100 pm). The apparent porosity of the scaffolds was 56.56% +/- 7.15, 54.14% +/- 3.84, and 53.11% +/- 3.99 for PLA, SGP25, and. SGP50 respectively. FF-IR, TGA. and XRD results revealed some interaction of the glass filler with the polymeric matrix in the scaffolds. The degradation study showed that, by increasing the glass content in the scaffolds, the water absorption decreased, the weight loss increased. and the cumulative ion concentrations released from them also increased. This indicates the possibility of modulating the degradation rate by varying the glass/polymer ratio. At the end of the incubation period, the weight losses were around 5.44% +/- 0.96, 32.50% +/- 2.73, and 41.47% +/- 3.02 for the PLA. SGP25. and SGP50, respectively. Moreover. the water uptake reached 119.65% +/- 18.88 and 93.39% +/- 13.01 for SGP25 and SGP50. respectively. The addition of the SG to the scaffolds was found to enhance their in vitro bioactivity. Therefore, these nanocomposite scaffolds have a potential to be applied in bone engineering. All data are expressed as mean +/- standard deviation (n = 3). (C) 2009 Elsevier B.V. All rights reserved.