Nisha Yadav

Bio: Nisha Yadav is an academic researcher from Shiv Nadar University. The author has contributed to research in topics: Cardanol & Graphene. The author has an hindex of 9, co-authored 16 publications receiving 239 citations. Previous affiliations of Nisha Yadav include Royal Institute of Technology.

Graphene Oxide-Coated Surface: Inhibition of Bacterial Biofilm Formation due to Specific Surface–Interface Interactions

Abstract: Graphene oxide (GO) is a promising and remarkable nanomaterial that exhibits antimicrobial activity due to its specific surface–interface interactions. In the present work, for the first time, we have reported the antibacterial activity of GO-coated surfaces prepared by two different methods (Hummers’ and improved, i.e., GOH and GOI) against bacterial biofilm formation. The bacterial toxicity of the deposited GO-coated surfaces was investigated for both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) models of bacteria. The mechanism of inhibition is different on the coated surface than that in suspension, as determined by measurement of the percentage inhibition of biofilm formation, Ellman’s assay, and colony forming unit (CFU) studies. The difference in the nature, degree of oxidative functionalities, and size of the synthesized GO nanoparticles mitigates biofilm formation. To better understand the antimicrobial mechanism of GO when coated on surfaces, we were able to demonst...

Sustainable Framework of Chitosan–Benzoxazine with Mutual Benefits: Low Curing Temperature and Improved Thermal and Mechanical Properties

Abstract: Polybenzoxazines (PBzs) are emerging as a highly promising and superior class of thermoset polymers for a variety of applications. However, it remains a significant challenge to substantially lower the ring-opening polymerization (ROP) temperature with an ease in processability. On the other hand, biomacromolecule chitosan (CS) is explored extensively, but its practical applications have been precluded by poor thermal and mechanical properties. Here, we developed a fully biobased copolymer of vanillin benzoxazine (V-fa) monomer with CS, which is effective in providing mutual benefits, effective lowering in ROP temperature of benzoxazine (70 °C), and an enhanced thermal stability of CS (by 85 °C, and with char yield of ∼32%). To understand this unusual lowering in ROP temperature, we investigated the structural interaction mechanism between solvated CS and V-fa using in situ NMR studies. The analysis of fully intercalated co-structure demonstrated that there is a strong preference for ROP over Schiff base ...

Stable Dispersions of Covalently Tethered Polymer Improved Graphene Oxide Nanoconjugates as an Effective Vector for siRNA Delivery.

Abstract: Conjugates of poly(amidoamine) (PAMAM) with modified graphene oxide (GO) are attractive nonviral vectors for gene-based cancer therapeutics. GO protects siRNA from enzymatic cleavage and showed reasonable transfection efficiency along with simultaneous benefits of low cost and large scale production. PAMAM is highly effective in siRNA delivery but suffers from high toxicity with poor in vivo efficacy. Co-reaction of GO and PAMAM led to aggregation and more importantly, have detrimental effect on stability of dispersion at physiological pH preventing their exploration at clinical level. In the current work, we have designed, synthesized, characterized and explored a new type of hybrid vector (GPD), using GO synthesized via improved method which was covalently tethered with poly(ethylene glycol) (PEG) and PAMAM. The existence of covalent linkage, relative structural changes and properties of GPD is well supported by Fourier transform infrared (FTIR), UV–visible (UV–vis), Raman, X-ray photoelectron (XPS), el...