Fabrication and characterization of magnetic scaffolds in bone tissue engineering
Date of Issue2018-06-18
School of Chemical and Biomedical Engineering
Magnetic scaffolds gained much popularity for tissue repair in the recent years. Here we focus on magnetic nanocomposite scaffolds made of poly-(caprolactone) (PCL), tri- calcium phosphate (TCP) and Iron Oxide magnetic nanoparticles (MNPs) for bone repair. The chemical, thermal, and mechanical properties of the scaffolds and the in vitro cell responses were examined comprehensively to investigate their effectiveness for use as bone scaffolds. The scaffolds were fabricated with a solvent free and efficient method known as cryomilling, resulting in homogeneous distribution of MNPs and TCP in PCL matrix. Chemical properties of PCL, TCP and MNP were all retained in the composite. Thermal properties of the scaffold were not significantly different from pure PCL, an FDA approved biomaterial. The mechanical stiffness increased significantly with the addition of TCP and MNPs, but lies within the Young Modulus range of cortical bone. For in vitro studies, pre-osteoblast cells (MC3T3-E1) were used. The cell proliferation of magnetic scaffolds (5%MNPs) with the exposure to PEMF had a 25.5% higher proliferation than the same scaffold composition with no exposure to PEMF. Cell differentiation at 2.5%MNP was significantly higher than PCL/TCP scaffold with PEMF exposed, revealing the osteogenic property of MNPs. Even at day 28, both 2.5%MNP and 5%MNP scaffolds have a significantly higher cell differentiation with PEMF exposed. Cell mineralization, as assessed by the quantification of calcium deposits, was significantly enhanced particularly on 1%MNP scaffolds. FESEM images of cell interaction suggests that PEMF provided a microenvironment suitable for differentiation as cell morphology resembles that of osteocytes. The results are indicative of the excellent physical properties and biocompatibility of PCL-TCP-MNP scaffolds as well as PEMF-induced enhanced bone healing, suggesting potential use of the magnetic scaffolds and PEMF for bone repair and regeneration.
Final Year Project (FYP)
Nanyang Technological University