Bone surface microenviroment mimicked biodegredable scaffolds for osteogenic stem cell differentiation

Abstract

The change of the surface roughness, topography and stiffness as well as the chemical and/or biochemical components of the surfaces; might affect the cell-surface, cell-scaffold interface characteristics and may influence cellular behavior, which are important to investigate new bioprosthesis for tissue engineering applications. Thereby, in this thesis, mimicking bone surface microenvironment was aimed. Firstly, to produce a mould, bovine femur surface was mimicked by using Polydimethylsiloxane (PDMS). A biodegradable polymer, Poly (L-Lactic acid) was poured on the mould to obtain bone surface mimicked (BSM) scaffolds. Then, Bone Morphogenic Protein-2(BMP-2) was loaded on the scaffolds and its release profile was examined in-vitro conditions with Enzyme-Linked ImmunoSorbent Assay (ELISA). BSM scaffolds was modified either with hydroxyapatite (HA) or collagen type-I (Col-I) to construct these scaffolds, similar to the bone‘s natural micro- environment. Modified scaffolds were characterized with Water Contact Angle (WCA) measurements, Scanning Electron Microscope (SEM), X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Characterization studies were followed by cell culture studies. To analyze cell viability on the scaffolds, MTT was performed. To examine cell proliferation on the scaffolds, Alamar Blue was performed. The effect of the modifications on the controlled and directed osteogenic differentiation in in-vitro conditions was evaluated by using Alkaline Phosphatase Activity analysis, Alizarin Red and SEM EDAX tests.|Keywords : Biomimetic, Bone microenvironment, Bone tissue engineering, Stem cell.