Objective(s): Silver nanoparticles have been widely used as new potent antimicrobial agents in cosmetic and hygienic products, as well as in new medical devices. Serious concerns have been expressed on the potential health risks of dermal applications of nanosilver containing consumer products (AgNPs), therefore regulatory health risk assessment has become necessary for the safe usage of AgNPs in biomedical products with special emphasis to their dermal toxicity potentials. We aimed in the present study to compare the dermal toxicity of three different AgNP containing disinfectantsin an albino rabbit model and tried to determine the role of size and other physicochemical properties on their possible dermal toxicity. Methods: After the characterization of all three samples by transmission electron microscopy (TEM), X-Ray Diffraction (XRD) and Dynamic Light Scattering (DLS) , corrosive and irritant potentials of AgNPs in three different sizes of three colloidal AgNPs were scored by the OECD 404 guideline with necessary modifications and were applied under the specified concentrations via nanosilver skin patches on the shaved skin of young female albino rabbits. All skin reactions were recorded in 3 min as well as in 1, 4, 24, 48 and 72 hours from the application and compared with the control group and followed up for 14 days. Results: Although short-term observations didn’t show any significant changes in the weight of animals and macroscopic variables, long-term histopathological abnormalities were seen in the skin of all test groups, which was not associated with the size and other physicochemical properties of AgNP samples. The toxicity manifestations were dry skin, scaling in doses lower than 100 ppm and erythema in higher doses up to 4000 ppm which was reversed. Conclusions: This finding creates a new issue in the possible dermal effects of all colloidal AgNPs, containing nano health products, which should be considered in future studies by focusing on other physicochemical properties of AgNPs and possible underlying mechanisms of toxicity by conducting cellular models.
The Western blot technique is a useful method for protein detection, but detection of small molecules of proteins or peptides is difficult. Nanotechnology makes peptide detection possible by making a metal-coated membrane of immobilin-polyvinylidene difluoride membranes. In this research, we used this technique for the diagnosis of avian influenza. Some immunodominant sequences of the nonstructural 1 protein of the avian influenza virus were selected with which to perform this technique for detection of antibodies in poultry sera. Gold nanoparticles were used to coat the immobilin-polyvinylidene difluoride membrane. This metal was able to bind to the functional groups of amino acids, such as the sulfhydryl group and the amine group, but it kept small molecules on the metal membrane and avoided diffusing peptides and small protein molecules to the metal-coated membrane during Western blotting. The size of the nonstructural 1 peptide was less than 2 kDa.
Objective(s): Folate-targeted liposomes have been well considered in folate receptor (FR) overexpressing cells including MCF-7 and 4T1 cells in vitro and in vivo. The objective of this study is to design an optimum folate targeted liposomal formulations which show the best liposome cell uptake to tumor cells.Material and Methods: In this study, we prepared and characterized different targeted formulations and a nontargeted form as a control. Physicochemical analysis showed that the liposomes had homogeneous population and appropriate size to accumulate to tumor sites through the enhanced permeation and retention (EPR) mechanism. Moreover, we compared the cell uptake of folate targeted liposomal docetaxel compared to nontargeted liposomes in vitro. Results: The in vitro drug release profile of the formulations at different time points showed none of the formulations did not has burst release. However, targeted liposomes accumulated in tumor tissue in vivo less than nontargeted formulations which could be attributed to their uptake by RES due to relatively greater size of targeted formulations. It is presumable that analyze the biodistribution process at longer time points and the molecular mechanisms behind the tissue accumulation could clear the issue. Conclusion: We conclude that success in vitro studies holds the promise of folate targeting strategy and in vivo study merits further investigations.
Recently convergence science was proposed and promoted in a large report from US National Science Foundation and Department of Commerce (NSF/DOC). The report was entitled "converging technologies for improving human performance. "It was dealing with converging of four technologies as: Nanotechnology, Biotechnology, Information technology and Cognitive science (NBIC). The report has gained tremendous popularity throughout the academia and scientific world. On Dec 2015 in a monthly meeting of the department of basic science of Iran Academy of Medical Science, the report of NSF/DOC on NBIC has been discussed. A working group has been established for more discussion and application in Iran. Several seminars in this regard have been performed, and presently this technology has been started as pilot in some technical universities in Iran. After US National Research Council (NCR) in the year 2014 and Massachusetts Institute of Technology (MIT) on convergence in biomedicine, the concept opened a new gate to approach solving medical and health care problems; the convergence technology in biomedical sciences has become interested and gained great popularity among the working group of convergence science in academy of medical science. This technology can lead to advances in fighting chronic diseases such as cancer, dementia, psychiatric disorders, disease of aging and others. The following is summary of proposed discussions in several gathered groups of scientists in this field.