To synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis. The current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses. The synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae. The endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

Medical nanotechnology is surfacing as a challenging arena covering new biomedical applications, such as drug delivery, treatment, nano diagnosis, controlled drug release, regenerative medicine, and disease prevention. The recent developments in the field of Nanotechnology have enabled the nanostructures to overcome the problems associated with drug delivery making them the promising agents for site-specific drug delivery with reduced side effects and the best treatment outcome. These nanodrug delivery systems are designed in such a way that they can breach the biological barrier and deliver the drug in a site-specific manner. They enhance the effectiveness of drugs by increasing the stability and water solubility of drugs and by increasing the rate at which these nano drug complexes are taken up by the cells and tissues. Dendrimers, nanocrystals, nano-polymer NPs, and liposomes are futuristic nano-based drug delivery systems. Smart polymers are future drug-delivery systems with cutting-edge precise technology that are employed in effective cellular targeting based on temperature, pH, photoresponsive, conductive and magnetic responsive smart polymers. This review provides a comprehensive view of various nanostructures and their application in drug delivery.