3D-bioprinted poly(lactic acid)/β-TCP/mesoporous β-TCP/mesoporous silica scaffolds: An investigation on in-vitro bioactivity and osteogenesis characteristics

The current work aims to formulate novel bioactive and biocompatible 3D printed poly (L L-lactic acid)/Beta tri calcium phosphate composite scaffolds reinforced with different types of mesoporous silica materials [PLA/ (3-TCP/MSMs] for bone regeneration application, which is not envisaged earlier. The bioink encompassing 30 % organic content (PLA) and 70 % inorganic content ((3-TCP and MSMs) is formulated and their rheological characteristics are evaluated. Optimization of process conditions for 3D printed PLA composite scaffolds was done and pneumatic extrusion is performed. The physico-chemical properties as well as in vitro biological characteristics were assessed for 3D printed PLA/(3-TCP/MSMs based composite scaffolds. The existence of (3-TCP and MSMs incorporated into PLA matrix was observed to fasten the formation of hydroxyapatite, as evidenced by in vitro bioactivity assessment. The in vitro cytocompatibility analysis revealed that the 3D printed PLA/(3-TCP/ MSMs composite scaffolds exhibit suitable biocompatible behaviour and osteogenic potential. The calcium mineralization and ALP expression were also noticed in higher levels for 3D printed PLA/(3-TCP/MSMs composite scaffolds. Gene expression analysis confirmed the expression of COL1, OCN, BMP-2 and RUNX2 on 3D printed PLA/(3-TCP/MSMs composite scaffolds. The results speculate that this novel formulation closely resembling the composition of natural bone might have promising applications in terms of in vivo bone tissue engineering.