Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Post-fabrication surface modification of 3D-printed PCL scaffolds using gallic acid-grafted chitosan (GA-g-CS) and baghdadite (BAG) to enhance the osteogenic differentiation of human adipose-derived mesenchymal stem cells (hASCs).

ABSTRACT
In this study, we provided a post-fabrication modification process to resemble the organic and mineral phases of natural bone by employing gallic acid-grafted chitosan (GA-g-CS) and baghdadite (BAG), respectively. We hypothesized that the simultaneous employment of GA-g-CS and BAG could improve the osteogenic differentiation potency of human adipose mesenchymal stem cells (hASCs), cultured on 3D-printed scaffolds. For this purpose, GA-g-CS was prepared by a free radical reaction. The 1HNMR, FTIR, and Folin–Ciocalteu analyses confirmed the successful and effective grafting of gallic acid on the chitosan structure. Furthermore, the successful formation of BAG, synthesized by a sol–gel method, was confirmed by XRD, EDX, and FTIR analyses. Four 3D-printed samples, fabricated in this study, were pure PCL and PCL-coated samples, named GA-g-CS, BAG, and GA-g-CS/BAG. The morphology and elemental analysis of fabricated scaffolds were evaluated by SEM and EDX-MAP. Although % porosity was not changed by adding GA-g-CS or BAG, the %water absorption and hydrolytic degradation were enhanced in the presence of GA-g-CS or BAG. Despite the PCL and BAG groups, there was an acceptable % DPPH inhibition in samples containing GA-g-CS. The results of the biological assessments revealed that GA-g-CS/BAG can be a promising candidate for bone tissue engineering applications.