Biomimetic collagen-sodium alginate-titanium oxide (TiO2) 3D matrix supports differentiated periodontal ligament fibroblasts growth for periodontal tissue regeneration

Fabrication of biomaterial that mimics a suitable biological microenvironment is still a major challenge in the field of periodontitis treatment. Hence, in this report, we presented for the first time the fabrication of a novel biomaterial 3D matrix using collagen combined with sodium alginate and titanium oxide (TiO₂) to recreate the in-vivo microenvironment and to act as a platform for the culture of human periodontal ligament fibroblasts (HPLF) towards osteogenic differentiation. Further, we explored the changes of differentiated and undifferentiated HPLF cells in morphological and cellular level comparing 2D (standard culture plates) and 3D cell culture systems. The physicochemical parameters such as stiffness, water binding capacity, swelling, shrinkage factor, porosity and in-vitro biodegradation show the suitability of this 3D matrix to act as a scaffold for in-vitro periodontal regeneration. The differentiated HPLF cells in the 3D matrix secrete high levels of collagen, osteocalcin, alkaline phosphatase compared to the conventional 2D cell culture. Morphological analysis revealed the structural changes of HPLF cells before and after differentiation in 2D and 3D cell culture. In this study, we find that the level of osteocalcin secretion towards osteogenic differentiation was enhanced in HPLF cells by 3D matrix as compared with 2D cell culture, which demonstrates the osteogenic stimulatory potential of 3D matrix. Overall, the fabricated 3D matrix supports the differentiation of the HPLF cells into osteoblastogenic lineage cells in-vitro and is a promising approach for further investigations in in-vivo treatment of periodontal tissue impairment.