Synthesis of drug conjugated magnetic nanocomposite with enhanced hypoglycemic effects.

In the present study, a magnetic nanocomposite (magnetite Fe3O4 and hematite Fe2O3) has been successfully synthesized by the sol-gel method and coated with polyvinyl alcohol (PVA) followed by conjugation of anti-diabetic drug metformin. Detailed structural and microstructural characterization of the nanocomposite (NP) and drug conjugated nanocomposite (NP-DC) are analyzed by the Rietveld refinement of respective XRD patterns, FTIR analysis, UV-Vis spectroscopy, SEM and TEM results. SEM and TEM image analyses reveal the spherical morphology and average size of NP, PVA coated nanoparticles (NP-PVA) and NP-DC samples, indicating a suitable size to be a nanocarrier. The biocompatibility of NP and NP-DC was carried out in NIH/3T3 and J774A. 1 cells. The enhanced activity of the drug, when conjugated with nanocomposite, is confirmed after the treatment of both the pure drug and NP-DC sample on the 18 h fasted normoglycemic and hyperglycemic mice. The blood glucose level of the mice is effectively decreased with the same concentration of the pure drug and NP-DC sample. It proves the increased activity of the NP-DC sample, as only 5 wt% drug is present that shows the same efficiency as the pure drug. This study suggests excellent biocompatibility and cytocompatibility of NP and NP-DC besides the critical property as a hypoglycemic agent. It is the first time approach of conjugating metformin with a magnetic nanocomposite for a significant increment of its hypoglycemic activity, which is very important to reduce the side effect of metformin for its prolonged use.

Enhanced antifungal activity of fluconazole conjugated with Cu-Ag-ZnO nanocomposite.

Cu-Ag-ZnO nanocomposite (NC) has been successfully synthesized by mechanical alloying the Cu, Zn and Ag powder mixture under Ar atmosphere within 4 h of milling. The nanocomposite is then conjugated with the antifungal drug fluconazole by adding 5 wt% powdered drug to the NC and mechanical alloying the total powder mixture for one more hour. The Rietveld refinement of XRD data and FTIR spectrum analyses reveal the detailed structural and microstructural characterizations of the nanocomposite-drug conjugate (NC-DC). Presence of Cu, Ag, ZnO and drug in the 5 h milled powder are confirmed by analyzing TEM images and FESEM-EDS spectrum. Results obtained from FESEM and TEM images reveal the measure of particle size of the nanocomposite-drug conjugate and it agrees well with the crystallite size obtained from the Rietveld refinement. A significant antifungal activity of NC-DC against Candida sp. fungi has been revealed using disk agar diffusion method. Minimum inhibitory concentration (MIC) test confirms that NC-DC with only 5 wt% fluconazole produces similar antifungal activity of the pure (100 wt%) and conventional fluconazole. Thus, the conjugation of conventional drug to a nanocomposite results in enhancement of drug efficiency by a factor 20 folds. This is very important, particularly, for those antibiotics which are very effective in controlling several epidemic diseases but show intense side effects when used at higher dose and/or for a longer duration.