Formulation of Carica papaya latex-functionalized silver nanoparticles for its improved antibacterial and anticancer applications

In the present study, commercially important crop Carica papaya latex extract was used as potential bioreductant to fabricate high-stable silver nanoparticles (CPAgNPs). The reduction of Ag+ in Ag-0 nanostructures was initially observed with a color change from light to dark brown and further confirmed through SPR spectra at 410 nm in UV-vis spectroscopy. Fourier transform infrared spectroscopy (FTIR) analysis reveals that protein moieties present in the latex extract act as reducing/capping agent for nanoparticle synthesis. Interestingly, X-ray diffraction (XRD) study confirms that synthesized CPAgNPs were face centered cubic crystalline (fcc) in structure. High resolution transmission electron microscope (HRTEM) micrographs display polydispersed spherical CPAgNPs with an average size of 12 +/- 6 nm. The CPAgNPs display tremendous antibacterial activity against human pathogens such as Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae and Proteus mirabilis. On the other hand, in vitro anticancer studies were performed to assess the chemotherapeutic potential of formulating NPs against human breast carcinoma cell line (MCF-7). It was observed that fabricated CPAgNPs show excellent anticancer effect in a dose-dependent manner with the IC50 value 19.88 mu g/ml. These results clearly impelled that biogenic CPAgNPs can be used as promising nano-drug formulation to combat against bacterial infections and also for breast cancer chemotherapy. (C) 2016 Elsevier B.V. All rights reserved.