Titanium dioxide (TiO2) nanostructures are one of the most plentiful compounds that have emerged in various fields of technology such as medicine, energy and biosensing. Various TiO2 nanostructures (nanotubes [NTs] and nanowires) have been employed in photoelectrochemical (PEC) biosensing applications, greatly enhancing the detection of targets. TiO2 nanostructures, used as reinforced material or coatings for the bare surface of titanium implants, are excellent additive materials to compensate titanium implants deficiencies-like poor surface interaction with surrounding tissues-by providing nanoporous surfaces and hierarchical structures. These nanostructures can also be loaded by diversified drugs-like osteoporosis drugs, anticancer and antibiotics-and used as local drug delivery systems. Furthermore, TiO2 nanostructures and their derivatives are new emerging antimicrobial agents to overcome human pathogenic microorganisms. However, like all other nanomaterials, toxicity and biocompatibility of TiO2 nanostructures must be considered. This review highlights recent advances, along with the properties and numerous applications of TiO2-based nanostructure compounds in nano biosensing, medical implants, drug delivery and antibacterial fields. Moreover, in the present study, some recent advances accomplished on the pharmaceutical applications of TiO2 nanostructures, as well as its toxicity and biocompatibility, are presented.

This review presents an overview of recent progress in the development of bio-nano hybrid materials based on the photoactive protein bacteriorhodopsin (bR). The interfacing of bR with various nanostructures including colloidal nanoparticles (such as quantum dots and Ag NPs) and nanoparticulate thin films (such as TiO2 NPs and ZnO NPs,) has developed novel functional materials. Applications of these materials are comprehensively reviewed in two parts: bioelectronics and solar energy conversion. Finally, some perspectives on possible future strategies in bR-based nanostructured devices are presented.

Dye-sensitized solar cells (DSSCs), which are proposed as a substitute for silicon crystalline solar cells, have received considerable attention in the recent decade. They could be produced from inexpensive materials through low-cost processes. In the current work, a bio-sensitized solar cell is designed using abundant, cheap, and nontoxic materials. Bacteriorhodopsin and bacterioruberin are two natural biomolecules found in the cytoplasmic membrane of Halobacterium salinarum. These two pigments were immobilized on nanoporous titanium dioxide films successfully and employed as molecular sensitizers in DSSC with efficient photocurrent generation. The photovoltaic performance of DSSCs based on bacteriorhodopsin and bacterioruberin sensitizers was investigated. Under AM1.5 irradiation a short-circuit current of 0.45mAcm(-2), open circuit voltages of 0.57V, fill factor of 0.62, and an overall energy conversion efficiency of 0.16% are achieved by employing a mixture of biomolecules as a sensitizer.

IJMM 1394; 9(3): 48-53 Background and Aim: H5N1 influenza viruses may acquire the ability to transmit between humans. thus, there is the possibility of a pandemic event. HA1 protein has been shown to play a major role in binding the virus to its target cell and the main neutralizing antibody responses elicit against this region. Bacillus subtilis has been identified as a free endotoxin host for expression and secretion of heterologous proteins with immunological activity. Although the bacteria is not capable of making glycosylated proteins, it has been shown that glycosylation of HA is not much necessary for its immunogenicity. Here we produced secretory recombinant HA1 protein in B. subtilis.