Preparation and characterization of highly porous ceramic-based nanocomposite scaffolds with improved mechanical properties using the liquid phase-assisted sintering method

摘要

Recent advances in the field of biomaterials have led to the development of ceramic-matrix nanocomposites with enhanced mechanical properties, which is essential for hard tissue scaffolds. In this study, the improvement in mechanical and biological properties of beta-tricalcium phosphate reinforced with 45S5 bioactive glass under different sintering conditions was studied. In order to improve the thermal stability and biological responses, beta-tricalcium phosphate was doped with 5 mol% strontium ions. Highly porous nanocomposites, with different weight ratios of Sr-tricalcium phosphate/bioactive glass (75/25, 50/50, 25/75), were fabricated through the foam replication method by sintering samples under various thermal conditions (1200-1250 celcius/0-1 h). The effects of bioactive glass content and sintering parameters on microstructure and mechanical behaviors of the nanocomposites were assessed. The obtained results showed that increasing 45S5 bioactive glass content, sintering temperature, and dwelling time gradually improved the mechanical properties of final products which were ascribed to the improved ceramic densification. The composites with the optimal compressive strength were selected to apply in further characterization and cell culture experiments. The selected scaffolds showed excellent bioactivity since a continuous layer of minerals covered the entire surface of composites after immersion in simulated body fluid solution for two weeks. Moreover, the cell culture studies demonstrated that the composite scaffolds could well support the attachment and proliferation of MG-63 osteoblast-like cells. This investigation clearly concluded that the appropriate incorporation of 45S5 bioactive glass into the beta-tricalcium phosphate matrix can effectively promote the mechanical behavior, bioactivity, and biocompatibility of the resultant composite scaffolds.