Green silver nanoparticles for drug transport, bioactivities and a bacterium (Bacillus subtilis)-mediated comparative nano-patterning feature

Abstract

The ‘green’ synthetic aspects of functionally potent and biologically relevant nanomaterials are a crucial research objective. Pursuing this concept, we have investigated a green synthetic scheme for the sunlight-mediated generation of luminescent silver nanoparticles, which become stabilized via a supramolecular hydrogel (SHGel) network, as already reported by our group. In vitro and in vivo toxicity studies confirm the biologically relevant nature of SHGel-capped Ag NPs. Nontoxic SHGel-capped Ag NPs were intelligently used for the transport of drugs, including antifilarial and antibiotic agents, into cells. Apart from this activity, SHGel-capped Ag NPs and our previously reported nontoxic DNA hydrogel-capped Ag NPs are potent against pathogens and parasites. Most interestingly, the nanostructural patterns of SHGel- and DNA hydrogel-capped Ag NPs have been transformed into cotyledon- and flower bud-shaped forms of nanosilver, respectively, during their chemotherapeutic action against a particular bacterium, Bacillus subtilis. Transmission electron microscopy was used for the visualization of several patterns of nanosilver and the incorporation of Ag NPs into macrophages.