Biomimetic surface modification of Three-dimensional printed Polylactic acid scaffolds with custom mechanical properties for bone reconstruction

3D printing has recently emerged as an innovative fabrication method to construct critical-sized and patient-specific bone scaffolds. The ability to control the bulk geometry of scaffolds in both macro and micro-scales distinguishes this technology from other fabrication methods. In this study, bone tissue-specific scaffolds with different pore geometries were printed from polylactic acid (PLA) filaments at three given infill densities ranging from 20 to 30%. A hybrid hydrogel made of synthetic biphasic calcium phosphate (BCP) and collagen was applied to coat 3D printed well-structured triangular samples with 30% infill density. The coating process changed the surface texture, increased the average strand diameter and average pore size, and decreased the open porosity of samples, all of which increased the mechanical strength of biomimetic-coated scaffolds. According to matrix mineralization staining and osteo-related gene expression, the coating of scaffolds significantly facilitates metabolic activity and osteogenic differentiation of dental pulp-derived mesenchymal stem cells (DPSCs). Taken together, these results indicated that the biomimetic coating is a highly promising approach that could be taken into consideration in the design of a porous scaffold for bone tissue engineering.