In vitro bioactivity and biocompatibility assessment of PCL/PLA–scaffolded mesoporous silicate bioactive glass: Role of boron activation

Abstract

Bioactive glasses with rapid biodegradation and efficient biomineralization for damaged bone tissue repair remain deficient. Based on this fact, some new types of boron-activated mesoporous Bioactive silicate glasses (BMSGs) were made to determine the feasibility of achieving their improved mechanical strength, structure, porosity, biodegradability and bone healing performance. Four samples of the form xB2O3 – (80–x) SiO2 – 15CaO – 5P2O5 with x is 0, 5, 10, and 15 mol% were prepared using a unified sol-gel/evaporation induced self-assembly (SG-EISA) process. Furthermore, the solvent casting/partial leaching method was used to Scaffold the proposed BMSGs by polycaprolactone/polylacticacid (named as BMSG-PPS). The role of boron concentration fine-tuning in modifying the glasses morphology, structure, Bioactivity and Biocompatibility was assessed in vitro by immersing them in simulated body fluid (SBF) at various durations. Intense XRD peak at 31.7° confirmed the existence of crystalline hydroxyl carbonate apatite (HCA) in the glasses. Glass made with 10 mol% of boron (BMSG-PPS10) showed the strongest crystalline peak of HCA amongst all the studied samples. FESEM image of the Scaffold surface also revealed the presence of HCA agglomeration after 168 h of immersion in the SBF. The boron-free sample (BMSG-PPS0) showed strong agglomeration of HCA and Ca to P ratio (1.78±0.01) close to bone. After 168 h of immersion in the SBF solution, the symmetric stretching of PO43–and CO32–bands in the glass became more prominent. After 168 h of immersion in the SBF, the samples’ weight loss and solution pH correspondingly varied in the range of 5.66–7.37 % and 6.80–7.02. In addition, ICP–OES analyses of the glasses verified an increase of Si release in the SBF from the silicate network, indicating their rapid biodegradation. Briefly, the proposed BMSG–PPS with improved Bioactivity and Biocompatibility may be beneficial for various bio-medical implant coating applications.