The mechanisms for the heat-induced osteogenesis are not completely known and the thermal regulation of human mesenchymal stem cell (hMSC) differentiation is not well studied. In this study, the direct effects of mild heat shock (HS) on the differentiation of hMSCs into osteoblasts in self-assembling peptide hydrogel and on tissue culture plates were investigated. hMSCs isolated from human bone marrow were seeded in conventional culture plates (two-dimensional [2D] culture) and on the surface of three-dimensional (3D) PuraMatrix peptide hydrogel (3D culture), followed by 1 h HS at 41°C once a week during osteogenic differentiation. Alkaline phosphatase (ALP) activity was enhanced in both 2D and 3D cultures via periodic HS at early stage of differentiation; meanwhile, HS significantly increased the calcium deposition at day 19 and 27 of differentiation in both 2D and 3D cultures. The periodic HS also upregulated osteo-specific genes, osterix (OSX) on day 11, osteopontin (OP) on day 19, and bone morphogenetic protein 2 (BMP2) on day 25 in 2D culture. In 3D PuraMatrix culture, the runt-related transcription factor 2 (Runx2) was upregulated by HS on day 25 of differentiation. The heat shock protein 70 (HSP70) was significantly upregulated by HS in differentiated hMSCs analyzed at 24 h after HS. These results demonstrate that HS induced an earlier differentiation of hMSCs and enhanced the maturation of osteoblasts differentiated from hMSCs. Therefore, mild HS treatment may be potentially used to enhance the bone regeneration using hMSCs. Our data will guide the design of in vivo heating protocols and enable further investigations in thermal treatments of MSC osteogenesis for bone tissue engineering.

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This review is on current advancements in IL-mediated synthesis of TiO2, and the potential for future research in this area.

Magnesium ferrite nanoparticles (NPs) were synthesized by co-precipitation, sol-gel and solution combustion methods. Polyethylene glycol (PEG), urea and oxalyl dihydrazide (ODH) were used as fuels for the combustion. Various physicochemical techniques viz. X-ray diffraction (XRD), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FT-IR), BET surface analysis and transmission electron microscopy (TEM) were utilized to study the effect of synthetic methodology on the properties of synthesized NPs. Differences in crystallinity, surface area, particle size and magnetic parameters of the ferrite NPs synthesized by different methods were observed. XRD pattern of NPs obtained by sol-gel and combustion methods confirmed phase purity where as in co-precipitation method ?-Fe2O3 was detected as impurity phase which also resulted in greater value of physical density and lowering of magnetic parameters of the final thermolysis product. TEM micrographs indicated that ferrite NPs are spherical with average diameter of 12-25 nm. Presence of rectangular shaped crystallites of ?-Fe2O3 was clearly evident in the TEM images of the NPs synthesized by co-precipitation method.