Polymethyl methacrylate (PMMA) grafted collagen scaffold reinforced by PdO-TiO2 nanocomposites

Abstract

In the past few decades, the design and fabrication of bio-scaffolds exhibiting structural stability in long-term and biocompatibility has received much attention in the field of tissue engineering application. In this direction, we have synthesized different mole ratio of PdO-TiO₂ nanocomposites (1:1, 2:1 and 3:1 of Pd:Ti, size 5-11nm, 7-16 nm and 9-22 nm) through a simple single step sol-gel method. The obtained nanocomposites of different sizes were assimilated into poly (methyl methacrylate) grafted collagen biopolymer (g-PMMA-Collagen), resulting in a PdO-TiO₂-g-PMMA-Collagen based scaffold. Physico-chemical properties and biocompatibility of g-PMMA-Collagen/PdO-TiO₂-g-PMMA-Collagen scaffolds were analysed by using various techniques such as XRD, FT-IR, TGA, DSC, Universal Testing Machine, MTT, Alkaline phosphatase, Alizarin Red S staining assay and the obtained results were compared against pure collagen scaffold. Our results suggest that the incorporation of 1:1 mol ratio PdO-TiO₂ nanocomposite (Size, 5-11 nm) offers a higher thermal stability (83.45 °C) and mechanical strength (Young's modulus 105.57 MPa) than the pure collagen scaffold (71.64 °C, 11.67 MPa). The PdO-TiO₂ endowed scaffolds were not toxic to MG 63 cells (human osteosarcoma) and enhanced the ALP activity on the scaffolds during in vitro osteogenic differentiation. This work provides a new approach for mechanical reinforcing and enhanced osteogenic activity of collagen scaffolds without affecting its conformation or biocompatibility, an aspect that possibly makes them ideal for bone tissue engineering applications.

Keywords: Bone tissue engineering; Collagen; Mechanical strength; PMMA; PdO–TiO(2) nanocomposite.