Usage of 3D printed PLA scaffolds for small molecule induced bone regeneration

Bone is a tissue that has the ability to repair itself. However, critical bone damage that may occur as a result of trauma, tumor, disease, or infection cannot heal naturally. Developed 3D-printed scaffolds used in bone repair and regeneration applications stand out in this context. Chitosan nanoparticles increase the biocompatibility of synthetic polymer scaffolds as they support cell adhesion while also inducing bone differentiation of stem cells. On the other hand, bone tissue engineered structures were found to fail after implantation, usually due to insufficient vascularization. In tissue engineering, media and factors that enable endothelial cells to migrate to the region are used to support vascularization. In this study, poly (lactic acid) scaffolds produced with a 3D printer were used for bone regeneration. The ideal pore sizes of the scaffolds were determined at 370–460 μm. The scaffolds were alkali treated with 0.5 M NaOH for 4 hours, and the surfactant groups were exposed. Within the scope of the study, DIPQUO and GS4012 small molecules were encapsulated in chitosan nanoparticles to induce bone formation and vascularization, respectively. The surfaces of the scaffolds were coated with these nanoparticles. Mesenchymal stem cells isolated from rat bone marrow were seeded on the scaffold, and differentiation into bone tissue was achieved with controlled release of small molecules. Peripheral blood endothelial cells isolated in vitro from rat blood were used to test vascularization success. The designed system was tested in vitro in terms of osteogenesis and angiogenesis properties, and bone tissue formation was investigated. It was observed that bone differentiation was high in DIPQUO-containing groups (D-NP and DG-NP), while cell proliferation increased with vascularization in group containing GS4012 (G- NP). With this study, the bioactivity of the scaffold was increased by the encapsulation of small molecules, and the failure rate due to insufficient vascularization encountered in bone tissue engineering studies was reduced. Finally, the patient's recovery period was shortened by accelerating the healing process of bone injuries.