Recent advances in nano scaffolds for bone repair

Biomedical applications of nanomaterials are exponentially increasing every year due to analogy to various cell receptors, ligands, structural proteins, and genetic materials(that is, DNA). In bone tissue, nanoscale materials can provide scaffold for excellent tissue repair via mechanical stimulation, releasing of various loaded drugs and mediators, 3D scaffold for cell growth and differentiation of bone marrow stem cells to osteocytes. This review will therefore highlight recent advancements on tissue and nanoscale materials interaction.

Rapid and multimodal in vivo bioimaging of cancer cells through in situ biosynthesis of Zn＆Fe nanoclusters

Early diagnosis remains highly important for efficient cancer treatment, and hence, there is significant interest in the development of effective imaging strategies. This work reports a new multimodal bioimaging method for accurate and rapid diagnosis of cancer cells by introducing aqueous Fe^2＋ and Zn^2＋ ions into cancer cells （i.e., HeLa, U87, and HepG2 cancer cells）. We found that the biocompatible metal ions Fe^2＋ and Zn^2＋ forced the cancer cells to spontaneously synthesize fluorescent ZnO nanoclusters and magnetic Fe3O4 nanoclusters. These clusters could then be used for multimodal cancer imaging by combining fluorescence imaging with magnetic resonance imaging and computed tomography imaging. Meanwhile, for normal cells （i.e., L02） and tissues, neither fluorescence nor any other obvious difference could be detected between pre- and post-injection. This multimodal bioimaging strategy based on the in situ biosynthesized Zn＆Fe oxide nanoclusters might therefore be useful for early cancer diagnosis and therapy.

Titanium dioxide-tetra sulphonatophenyl porphyrin nanocomposites for target cellular bio-imaging and treatment of rheumatoid arthritis

Photodynamic therapy(PDT) is one of the latest biomedical technologies used for treatment of various neoplastic and non-neoplastic diseases. However, there still exist some well-known problems regarding its efficacy, e.g. effective concentration of the drug at the desired sites, the irradiation light dosimetry and biocompatibility of the photosensitizer. The introduction of nanotechnology and nanomaterial like biocompatible nano-titania(i.e., nano-TiO_2) may facilitate to solve some of these problems. In this study we have explored the possibility of combining tetra sulphonatophenyl porphyrin(TSPP) with nano-titania(PT) for efficient PDT with least adverse effects. The spectroscopic properties of these nano-composites were characterized by using fluorescence and UV-Vis absorption spectroscopic study. The singlet oxygen quantum yield was determined by using 2,5-diphenyl-3,4-benzofuran(DPBF), while the effect of nano TiO_2 with TSPP on the synovial fibroblast cells from human(HSC) and rat models(RSC) were investigated by confocal laser microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay. Our results suggest that nano TiO_2 with TSPP can be readily utilized for effective PDT treatment of Rheumatoid Arthritis(RA).

Highly sensitive electrochemical detection of living cells based on diamond microelectrode arrays

We designed boron-doped nanocrystalline diamond microelectrode arrays（BNCD-MEAs） with 16 channels for the bioanalysis of multicellular samples, which could be readily adapted for a highly sensitive detection of H2 O2[2_TD$IF]released from stimulated cells by ascorbic acid（AA）. Our observations demonstrated that the as-prepared diamond microelectrode arrays could be utilized to distinguish cancer cells from normal cells, and the amperometric study showed the considerable differences in the currents, indicating that the related Hep G2 cancer cells could release more H2 O2 than that of L02 normal cells. This supports the possibility to use diamond-based MEAs for rapid cancer cell detection in future clinic applications.