The effect of bone surface mimicked magnetic particle embedded pdms membranes on human osteoblast cell behavior

Cell microenvironment can be defined as all biophysical, biochemical, biomechanical properties that affect cell behaviour and cell fate. These factors include surface topography, roughness, stiffness along with the extracellular matrix (ECM) and presence of other soluble factors. Changes in the microenvironment are directly or indirectly converted into signalling pathways inside the cell and affect cellular metabolism. In this thesis, effects of surface topography and surface chemistry were investigated by synthesizing magnetic particle embedded (MP) (0.5%w/w) bone surface mimicked (BSM) polydimetylsiloxane (PDMS) membranes on osteoblast behavior. Bone tissue microenvironment were imitated by chemically modifying membrane surfaces with extracellular matrix proteins Fibronectin (FN) and type-I Collagen (Col-I). Human fetal osteoblast cells (hFOB) were seeded on these magnetic particle embedded bone surface mimicked scaffolds in order to observe potential differences in osteoblast behavior. Material characterization for these plain, bone surface mimicked (BSM), magnetic particle embedded PDMS (mpPDMS) membranes were done using Water Contact Angle (WCA) measurements, Vibrating Sample Magnetometry (VSM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). Cellular behaviour on these membranes were investigated using alamarBlue cell proliferation assay, indirect MTT assay, actin and nuclear fluorescent stainings. Results of these study indicated that the protein modifications and surface topography resulted from bone surface pattern transfer to membrane surfaces have increased osteoblast adhesion and proliferation. Additionally, cell morphologies were natural and consistent with previous findings but further experimentations are required to understand possible effects of embedded magnetic particles (Fe3O4) on mechanotransductive and intracellular signalling pathways.