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

Abstract

Cell microenvironment can be defined as all biophysical, biochemical, biomechanicalpropertiesthataffectcellbehaviourandcellfate. Thesefactorsincludesurface topography, roughness, stiffness along with the extracellular matrix (ECM) and presenceofothersolublefactors. Changesinthemicroenvironmentaredirectlyorindirectly convertedintosignallingpathwaysinsidethecellandaffectcellularmetabolism. Inthis 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 microenvironmentwereimitatedbychemicallymodifyingmembranesurfaceswithextracellular matrix proteins Fibronectin and Collagen-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 all 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. 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.|Keywords : PDMS, Bone Surface Mimicking, Magnetic Particle, Protein Modification.