Efficient green silver nanoparticles-antibiotic combinations against antibiotic-resistant bacteria.

Antibiotic-resistant bacterial strains and the consequent surge in infections caused by them have become major public health concerns. Silver nanoparticles (AgNPs) exhibit antibacterial properties and have wide applications in biomedical sciences. In this study, AgNPs were synthesized in the presence of antibiotics: Ceftazidime (Cft), Cefotaxime (Cef), Ceftriaxone (Cfx), and Cefepime (Cpm), along with the extract of Mentha longifolia. Mentha longifolia-based AgNPs were kept as the control for all experiments. The associated metabolites, structural properties, surface charges, and antibacterial activity of the AgNPs were also evaluated. Overall, a blue-shift of SPR peaks was observed for control AgNPs (λmax = 421 nm, 422 nm, 426 nm, and 406 nm for Cft-AgNPs, Cef-AgNPs, Cfx-AgNPs, and Cpm-AgNPs, respectively), compared to the control (λmax = 438 nm). Fourier-transform infrared spectroscopy showed that antibiotic-based AgNPs had distinct peaks that corresponded to the respective antibiotics, which were not observed in the control. XRD analysis showed that there were observed changes in crystallinity in antibiotic-based AgNPs compared to the control. TEM images revealed that all samples had spherical nanoparticles with different sizes and distributions compared to the control. The Zeta potential for extract-based AgNPs was - 33.6 mV, compared to -19.6 mV for Cft-AgNPs, -2 mV for Cef-AgNPs, -21.1 mV for Cfx-AgNPs, and - 24.2 mV for Cpm-AgNPs. The increase in the PDI value for antibiotic-based AgNPs also showed a highly polydisperse distribution. However, the antibiotic-AgNPs conjugates showed significantly higher activity against pathogenic bacteria. The addition of antibiotics to AgNPs brought significant changes in structural properties and antibacterial activities.

Nanomedicine as a potential novel therapeutic approach against the dengue virus.

Dengue is an arbovirus infection which is transmitted by Aedes mosquitoes. Its prompt detection and effective treatment is a global health challenge. Various nanoparticle-based vaccines have been formulated to present immunogen (antigens) to instigate an immune response or prevent virus spread, but no specific treatment has been devised. This review explores the role of nanomedicine-based therapeutic agents against dengue virus, taking into consideration the applicable dengue virus assays that are sensitive, specific, have a short turnaround time and are inexpensive. Various kinds of metallic, polymeric and lipid nanoparticles with safe and effective profiles present an alternative strategy that could provide a better remedy for eradicating the dengue virus.