Green in situ immobilization of gold and silver nanoparticles on bacterial nanocellulose film using Punica granatum peels extract and their application as reusable catalysts.

In this study, Punica granatum peels extract induced in situ deposition was applied to prepare Au and Ag nanoparticles on bacterial nanocellulose film. Bacterial nanocellulose provided as an eco-friendly and excellent support for the interaction of P. granatum peel biomolecules and further reduction of Au and Ag ions. Meanwhile, a possible in situ growth mechanism of Au and Ag on bacterial cellulose by P. granatum peel extract biomolecules was presented. Further, the metal nanoparticles incorporated bacterial cellulose films were used to catalyze the reduction of 4-nitrophenol. The results of the present study indicated excellent catalytic reduction properties of Au and Ag nanocellulose films for 4 consecutive cycles. In addition, Au and Ag incorporated cellulose nanofiber films exhibited superior antioxidant activity and improved mechanical properties compared to pristine cellulose nanofiber film. The findings of this study may provide new insights and broad application of bacterial cellulose and green synthesis method for the development of various metal-cellulose composites.

The electrochemical immunosensor for detection of prostatic specific antigen using quince seed mucilage-GNPs-SNPs as a green composite.

Prostatic specific antigen (PSA) is known as a biomarker of prostate cancer. In males, prostate cancer is ranked second as leading cause of death out of more than 200 different cancer types1. As a result, early detection of cancer can cause a significant reduction in mortality. PSA concentration directly is related to prostate cancer, so normal serum concentrations in healthy means are 4 ng and above 10 ng as abnormal concentration. Therefore, PSA determination is important to cancer progression. In this study, a free label electrochemical immunosensor was prepared based on a new green platform for the quantitative detection of the PSA. The used platform was formed from quince seed mucilage containing green gold and silver nanoparticles and synthesized by the green method (using Calendula officinalis L. extract). The quince mucilage biopolymer was used as a sub layer to assemble nanoparticles and increase the electrochemical performance. This nanocomposite was used to increase the antibody loading and accelerate the electron transfer, which can increase the biosensor sensitivity. The antibodies of the PSA biomarker were successfully incubated on the green platform. Under the optimal conditions, the electrochemical impedance spectroscopy (EIS) was proportional to the PSA biomarker concentration from 0.1 pg mL-1 to 100 ng mL-1 with low limit of detection (0.078 pg mL-1). The proposed green immunosensor exhibited high stability and reproducibility, which can be used for the quantitative assay of the PSA biomarker in clinical analyses. The results of real sample analysis presented another tool for the PSA biomarker detection in physiologic models.

Biogenic synthesis, characterization of gold and silver nanoparticles from Coleus forskohlii and their clinical importance.

In modern era, the great interest and demand among chemists and researchers for metal nanoparticles is increasing in the application of biomedical fields, textiles, cosmetics and various sectors. Consequently, the present study reports an eco-friendly, cost-effective, rapid and easy method to produce environment-friendly metal nanoparticles to prevent exhaustion of metal resources. In this context, gold and silver metal nanoparticles were green synthesized using the Root Extract of Coleous forskohlii (RECo) as capping and reducing agent. The synthesized gold (GNPs) and silver nanoparticles (SNPs) were characterized using UV-Visible spectrophotometer, High-resolution transmission electron microscopy (HR-TEM), Particle size analysis (PSA), Fourier-transform infrared spectroscopy (FT-IR) and X-Ray Diffractometer (XRD). Their clinical importance was analysed using anti-oxidant assay (DPPH - 2,2-diphenyl-1-picrylhydrazyl and Phosphomolybdenum PMA) and cytotoxicity (MTT assay) against HEPG2 (liver cancer cell lines). Further, the antimicrobial activity against two microorganisms were tested using disc diffusion method against Proteus vulgaris pathogen and Micrococcus luteus pathogen. RECo-GNPs and SNPs were found to be stable in aqueous medium for a longer time and exhibited favorable anti-oxidant, anti-bacterial and anti-cancer activity. The phytoconstituents present in the root extract of Coleous forskohlii was elucidated using GC-MS analysis.

Green synthesis, characterization of gold and silver nanoparticles and their potential application for cancer therapeutics.

In the present article, we demonstrate the delivery of anti-cancer drug to the cancer cells using biosynthesized gold and silver nanoparticles (b-AuNP & b-AgNP). The nanoparticles synthesized by using Butea monosperma (BM) leaf extract are thoroughly characterized by various analytical techniques. Both b-AuNP and b-AgNP are stable in biological buffers and biocompatible towards normal endothelial cells (HUVEC, ECV-304) as well as cancer cell lines (B16F10, MCF-7, HNGC2 & A549). Administration of nanoparticle based drug delivery systems (DDSs) using doxorubicin (DOX) [b-Au-500-DOX and b-Ag-750-DOX] shows significant inhibition of cancer cell proliferation (B16F10, MCF-7) compared to pristine drug. Therefore, we strongly believe that biosynthesized nanoparticles will be useful for the development of cancer therapy using nanomedicine approach in near future.

Anti-cancer studies of noble metal nanoparticles synthesized using different plant extracts.

Biofunctionalized gold and silver nanoparticles synthesized using different plant extracts of guava and clove in vitro anti-cancer efficacy against four different cancer cell lines human colorectal adenocarcinoma, human kidney, human chronic myelogenous, leukemia, bone marrow, and human cervix have been studied and reported. The present experimental study suggests that flavonoids functionalized gold nanoparticles synthesized using aqueous clove buds extract are more potential than guava leaf extract towards anti-cancer activities. The microscopic and 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assay infer that the functionalized irregular shaped gold nanoparticles synthesized with aqueous clove bud extract showed a satisfactory anti-cancer effect on all the cell lines. The silver nanoparticles synthesized using same extracts are devoid of anti-cancer activity. The XTT assay revealed dose-dependent cytotoxicity to cancer cell lines. The study revealed that the free radicals generated by gold nanoparticles are responsible for anti-cancer effect. To confirm the free-radical scavenging efficacy of gold nanoparticle, nitric oxide assay is followed. We observed that the gold nanoparticles swabbed the free radicals in dose-dependent manner. With continued improvements, these nanoparticles may prove to be potential anti-cancer agents.