SILVER NANOPARTICLES OF MORINGA OLEIFERA – GREEN SYNTHESIS,CHARACTERISATION AND ITS ANTIMICROBIAL EFFICACY

Abstract : The traditional medicinal plant Moringa oleifera is an integral part of the Indian diet and has notable beneficial effects in its leaves, stems, flowers, roots, bark and seeds. It has reported properties like antimicrobial, anti inflammatory, ant diabetic, anti oxidative, anti tumorogenic amongst many other properties. In the present study we have devised a new green method of synthesis of silver nanoparticles to evaluate its antimicrobial efficacy using the aqueous plant extract as the reductant as well as the stabilizer. A cold method of synthesis of silver nanoparticles using silver nitrate solution is performed. After the synthesis step, the nanoparticles are characterised using UV VIS spectroscopy, scanning electron microscopy and transmission electron microscopy. The results show the incorporation of the silver ions in the extract and also the reduction of the particle size to the nano range. The antimicrobial potential of these nanoparticles synthesized is tested against various gram positive and gram negative strains of bacteria keeping streptomycin as the standard positive control antibiotic. The antibiotic assay is performed using agar well diffusion method and comparable results are obtained in comparison to the standard antibiotic. It is seen that the nanoparticles have good antibacterial efficacy against the tested strains. Hence nanoparticles of Moringa oleifera aqueous extracts can be used as a potential alternative to traditional antibiotics using this non toxic safe way of green synthesis. Keywords: Moringa oleifera, silver nanoparticles, antimicrobia

Bioactive Silver Phosphate/Polyindole Nanocomposites

Materials capable of releasing reactive oxygen species (ROS) can display antibacterial and anticancer activity, and may also have anti-oxidant capacity if they suppress intracellular ROS (e.g. nitric oxide, NO) resulting in anti-inflammatory activity. Herein we report silver phosphate (Ag3PO4)/polyindole (Pln) nanocomposites which display antibacterial, anticancer and anti-inflammatory activity, and have therefore potential for a variety of biomedical applications

Fabrication of PVA-Silver nanoparticle composite film for elimination of microbial contaminant from effluent

The effluent contains many harmful microbes which should be eliminated before it is discharged into a water body. Silver nanoparticles (AgNPs) being high-quality significance and have a great impact on this research field as it inhibits microbial proliferation and infection. Therefore, it may use for Bioremediation purposes, our laboratory is fascinated by the production of polymer matrix entrapment silver nanoparticles for in situ bio-remediation purposes. The AgNPs was prepared from sawdust by decoction method. The yellowish solution turns into dark brown colour indicating the formation of AgNPs. A sharp SPR (Surface Plasmon Resonance) band formation in UV-vis spectroscopy scan establishes the formation and stability of silver nanoparticles in an aqueous solution. SEM microphotograph indicated roughly spheroidal structure with (63±3) nm average diameters of newly synthesized AgNp. Polyvinyl alcohol (PVA) is eco-friendly and non-toxic to the environment was chosen for the preparation of polymeric matrix. The non-toxic concentration (1 μg/mL) of AgNp was dispersed into PVA solution followed by cross-linked with maleic acid. PVA- maleic acid is cross-linked by the formation of an ester bond, whereas silver nanoparticles physically entrap into the cross-linked matrix. The silver nanoparticles were released from the matrix nearly after 10 min of swelling of the composite film. In a microbial assay using E. coli agar medium, PVA-AgNp composite film shows the significant killing of microorganisms. Microbial elimination is measured indirectly by pH measurement and dissolved oxygen concentration measurement of the effluent in situ against RO- water, taken as control. The dissolved oxygen concentration from RO water and effluent water was measured on Day “0” followed by treatment and incubation at the BOD chamber. The treatment with PVA-AgNp composite film reduced the BOD Level and increase dissolved oxygen level simultaneously increasing the quality of water

VapC12 ribonuclease toxin modulates host immune response during Mycobacterium tuberculosis infection

Mechanistic understanding of antibiotic persistence is a prerequisite in controlling the emergence of MDR cases in Tuberculosis (TB). We have reported that the cholesterol-induced activation of VapC12 ribonuclease is critical for disease persistence in TB. In this study, we observed that relative to the wild type, mice infected with ΔvapC12 induced a pro-inflammatory response, had a higher pathogen load, and responded better to the anti-TB treatment. In a high-dose infection model, all the mice infected with ΔvapC12 succumbed early to the disease. Finally, we reported that the above phenotype of ΔvapC12 was dependent on the presence of the TLR4 receptor. Overall, the data suggests that failure of a timely resolution of the early inflammation by the ΔvapC12 infected mice led to hyperinflammation, altered T-cell response and high bacterial load. In conclusion, our findings suggest the role of the VapC12 toxin in modulating the innate immune response of the host in ways that favor the long-term survival of the pathogen inside the host

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Green Synthesis of Silver Nanoparticles Using Waste Tea Leaves

Green synthesis of silver nanoparticles has gained momentum since the demand to synthesize nanoparticles in an eco-friendly way has increased significantly. Here we report, economic and cost-effective biosynthesis of silver nanoparticles using waste of tea leaves (Camellia sinensis). The aim of the study was to biosynthesize silver nanoparticles and to assess its potential applications such as antibacterial activity, plant growth induction and dye degradation. Standardization studies were done using UV- Spectroscopy to determine the optimum synthesis condition for synthesis of silver nanoparticles. The optimum conditions were found to be pH 6.0, ambient temperature condition and 5mM AgNO3 concentration. Characterization studies using UV-Visible Spectroscopy, TEM and AFM analysis show nanoscale range of the particles. The silver nanoparticles showed maximum antibacterial activity against K. pneumonia followed by E. coli and minimum activity against C. diptheriae. The nanoparticles showed significant effect on the growth of Vigna radiata seeds at 50% concentration of nanoparticles. The particles immobilized on cotton cloth showed antibacterial activity against Gram positive organisms. Dye degradation studies showed that the nanoparticles are able to degrade phenol red and blue textile dye effectively

Ginseng used for bone tissue scaffold

696-701The scaffold based tissue engineering materialized for bone tissue therapy. Gelatin-glutaraldehyde cross linked scaffold was prepared by solvent casting -porogen leaching method. It was characterized by FTIR and SEM microphotograph analysis. Absence of peak at waves no. 1625 cm−1 in ATR-FTIR indicated formation of cross-linking. FE-SEM micrograph showed honeycomb pad like structure with high porosity. Methanolic extract of Withania somnifera (Ashwagandha) root extract induced MC3T3 E1 osteoblast cell adhesion and proliferation on porous gelatin scaffold. GC-MS analysis pointed out presence of 4-amino- 2-ethyl-3-methylquinoline, an active phyto-chemicals having tissue regeneration potential. High anti-oxidant capacity down regulates cell death mechanism by scavenging free radical. The biocompatible gelatin scaffold has RGD moiety that attune the MC3T3 E1 osteoblast cell adhesion. Withania somnifera root extract may boost up cell proliferation on scaffold. Therefore treatment with Withania somnifera root extract may be the new approaches for designing bone tissue scaffold for bone tissue therapy

Ginseng used for bone tissue scaffold

The scaffold based tissue engineering materialized for bone tissue therapy. Gelatin-glutaraldehyde cross linked scaffold was prepared by solvent casting -porogen leaching method. It was characterized by FTIR and SEM microphotograph analysis. Absence of peak at waves no. 1625 cm−1 in ATR-FTIR indicated formation of cross-linking. FE-SEM micrograph showed honeycomb pad like structure with high porosity. Methanolic extract of Withania somnifera (Ashwagandha) root extract induced MC3T3 E1 osteoblast cell adhesion and proliferation on porous gelatin scaffold. GC-MS analysis pointed out presence of 4-amino- 2-ethyl-3-methylquinoline, an active phyto-chemicals having tissue regeneration potential. High anti-oxidant capacity down regulates cell death mechanism by scavenging free radical. The biocompatible gelatin scaffold has RGD moiety that attune the MC3T3 E1 osteoblast cell adhesion. Withania somnifera root extract may boost up cell proliferation on scaffold. Therefore treatment with Withania somnifera root extract may be the new approaches for designing bone tissue scaffold for bone tissue therapy