Magnetic Mechanotransduction of Mesenchymal Stem Cells via a Highly Fluorescent Magnetic Micro Patterned Anti-Microbial Composite Scaffold

摘要

Mesenchymal stem cells differentiates into different phenotype in the process of development or repair different organs in presence of various signals including physical stimulus. Osteogenesis is a complex process which involves not only growth factors like BMP-2 and RunX-2 but also requires physical stimuli like mechanical stretch. However, it is difficult for a tissue engineering scaffold to be mechanically stimulated especially in an in vivo system. In this context a micropattemed nanocomposite scaffold is fabricated which incorporated highly luminescent magnetic iron oxide nanoparticles and nanosilver doped hydroxyapatite nanoparticles. The nanoparticles were synthesized in hydrothermal route and characterized via TEM, SEM, EDX, FTIR, Raman, XPS, UV Vis spectroscopy, fluorescence spectroscopy and SQUID. The scaffold preparation was characterized via SEM, rheology, AFM and mechanical testing measurement. The final fabrication was a 3d printed lattice structured scaffold. The cell culture evaluation was performed in vitro via rat bone marrow derived stem cells using MTT assay, fluorescence microscopy, SEM, ALP assay, DNA quantification assay, o-cresolphthalein Ca deposition assay and PCR based gene expression study. The antimicrobial activity study was conducted against S aureus and E Coli. Cell cultured scaffolds were implanted subcutaneously on albino rats on different time intervals. Post sacrifice the sections were evaluated for bone growth via histology and immuno histochemistry study. In all the biological study 1 mT rare earth magnets were used to provide static magnetic field.