Rabia Javed

ZnO nanostructure fabrication in different solvents transforms physio-chemical, biological and photodegradable properties

Zinc oxide (ZnO) nanostructures are synthesized in various organic solvents (acetone, chloroform, ethyl acetate, ethanol and methanol) and water via coprecipitation process using zinc acetate as precursor. The resultant ZnO nanoparticles, nano rods and nano sheets are characterized by UV-vis spectrophotometric analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDX). The variable size and geometry of nanoparticles depend upon medium used for synthesis. The synthesized ZnO nanostructures exhibit minor to moderate antioxidative (DPPH based free radical scavenging activity, total antioxidative potential and total reducing power) response. Mild to moderate antibacterial and antifungal activities, excellent antileishmanial potential (IC50 up to 3.76), and good cytotoxic perspective (LD50 up to 49.4) is also observed by the synthesized ZnO NPs. The nanoparticles also exhibit moderate α-amylase inhibition response. Furthermore the nanostructures are evaluated for methylene blue photodegradation response within 60min time period. It is found that organic solvent alters shape, size and other physio-chemical properties of ZnO that ultimately modulate the biological, chemical, and environmental properties.

PVP and PEG doped CuO nanoparticles are more biologically active: Antibacterial, antioxidant, antidiabetic and cytotoxic perspective

Search for biologically active nanoparticles is prerequisite for biomedical applications. CuO nanoparticles synthesized by co-precipitation method are capped by polyethylene-glycol (PEG) and polyvinyl-pyrrolidone (PVP) on the surface by simple adsorption. Physical and chemical properties carried out by SEM, XRD and FTIR confirm nanometer in size and efficient capping of PVP and PEG on CuO NPs. Biological assays reveal higher activities of CuO-PEG and CuO-PVP as compared to the uncapped CuO nanoparticles. CuO-PEG shows better antitumor activity against Streptomyces as compared with CuO-PVP and CuO NPs. Both the capped NPs are significantly active for α-amylase inhibition assay. CuO-PVP demonstrates significantly better activity against bacterial strains followed by CuO-PEG and uncapped CuO. PVP coated CuO NPs also shows strong DPPH based free radical scavenging activity, total reducing power potential, total antioxidative potential and also carries flavonoid and phenolics properties determines to querecetin and gallic acid equivalence, respectively. It can be concluded that PVP and PEG capped CuO NPs are more capable to be used in biomedical applications as drug and diagnostic carrier molecules.

Wound healing applications of biogenic colloidal silver and gold nanoparticles: recent trends and future prospects

Nanotechnology has emerged as a prominent scientific discipline in the technological revolution of this millennium. The scientific community has focused on the green synthesis of metal nanoparticles as compared to physical and chemical methods due to its eco-friendly nature and high efficacy. Medicinal plants have been proven as the paramount source of various phytochemicals that can be used for the biogenic synthesis of colloidal silver and gold nanoparticles as compared to other living organisms, e.g., microbes and fungi. According to various scientific reports, the biogenic nanoparticles have shown promising potential as wound healing agents. However, not a single broad review article was present that demonstrates the wound healing application of biogenic silver and gold nanoparticles. Foreseeing the overall literature published, we for the first time intended to discuss the current trends in wound healing via biogenic silver and gold nanoparticles. Furthermore, light has been shed on the mechanistic aspects of wound healing along with futuristic discussion on the faith of biogenic silver and gold nanoparticles as potential wound healing agents.

Differential effects of plant growth regulators on physiology, steviol glycosides content, and antioxidant capacity in micropropagated tissues of Stevia rebaudiana

Abstract Plants naturally produce secondary metabolites on exposure to abiotic/biotic stress. Production of secondary metabolites, like phenols or flavonoids, is a defence mechanism against different stresses. This study explores the influence of plant growth regulators (PGRs) on the growth and secondary metabolites of in vitro grown tissues of zero calorie sweetener, Stevia rebaudiana. An efficient regeneration of this valuable plant under the influence of PGRs was conducted, and quantification of physiology parameters, steviol glycosides (SGs) and various antioxidant activities in callus, shoots and regenerated plants was performed. Significantly highest explant response was achieved by 2 mg/L of 6-benzyl aminopurine (BAP) and 0.5 mg/L of 2,4-dichlorophenoxy acetic acid (2,4-D) combination in case of callogenesis, while shoot and root organogenesis was best illustrated by control and 0.5 mg/L of indole acetic acid (IAA) treatment, respectively. Regarding SGs formation in leaves, significantly greater content (2.07% and 0.93%) was obtained by control in case of rebaudioside A (Reb A) and 2 mg/L of BAP in case of stevioside (ST). Leaves of rooted-shoots produced significantly highest Reb A (4.21%) and ST (2.22%) content in case of 1 mg/L of IAA and 0.25 mg/L of IAA inoculation in Murashige and Skoog growth medium, respectively. Similarly, differential effects of PGRs were elucidated in case of all in vitro grown tissues on antioxidant properties. The study concludes that secondary metabolites can be efficiently produced in in vitro culture so can be employed in bioreactors.