BIOMIMETIC SYNTHESIS, CHARACTERIZATION AND EVALUATION OF ANTIOXIDANT, ANTIMICROBIAL EFFICACY OF SILVER NANOPARTICLES USING ANDREDERA CORDIFOLIA LEAF EXTRACT

Objective: The present study is focussed on the biosynthesis of silver nanoparticles using aqueous extract of Andredera cordifolia and to investigate the free radical scavenging potential, antimicrobial activity of the nanoparticles against different human pathogens.Methods: The formation of silver nanoparticles was indicated by the colour change from colourless to reddish brown. Biosynthesized nanoparticles was characterised using several techniques, viz- UV-Vis spectroscopy, FT-IR, XRD, TEM, SEM and EDAX analysis. The free radical scavenging potential was measured by DPPH, FRAP assay, antimicrobial activity against six microorganisms was tested using disc diffusion method.  Results: UV-Vis spectral analysis showed silver Surface Plasmon Resonance band at 426 nm.  The crystalline morphology and size of the nanoparticles were determined by TEM, SEM, and X-ray diffraction studies which showed the average size of the nanoparticles in the range 40 –60nm.  The biologically synthesized nanoparticles efficiently inhibited pathogenic organisms such as E. coli, Staphylococcus aureus, Klebsiella Pneumonia, Pseudomonas aeruginosa and Proteus vulgaris.  The biosynthesized nanoparticles might serve as a potent antioxidant as revealed by DPPH assay and FRAP assay. Conclusion: The biosynthesis of silver nanoparticles had several advantages in pharmaceutical applications as well as large scale commercial production.Key Words: Silver nanoparticle, Andredera cordifolia leaf, SEM,TEM,XRD,antioxidant, antimicrobial,etc

SERUM LIPID LEVELS IN PERIODONTITIS PATIENTS: A CASE-CONTROL STUDY

Objective: We aimed to evaluate serum lipid levels in periodontitis patients and compared with healthy subjects.Methods: A case-control study was conducted among 30 participants in the age group of 35-60 y, including 15 subjects in case group with community periodontal index (CPI) score of ≥2 and 15 subjects in the control group with a CPI score of ≤ 1 based on their periodontal status. Fasting blood samples were taken for measurement of lipid profiles, including total cholesterol, triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) using an enzymatic method. Odds ratio and independent t-test at *p=0.05 significance level were calculated.Results: Periodontitis patients were 4.1 times at risk to have high triglyceride, 1.3 times at risk to have high total cholesterol and 0.3times at risk to have higher HDL. Independent t-test showed higher total cholesterol/HDL ratio (*p=0.033) and lowered HDL levels (*p=0.027) in periodontitis patients.Conclusion: Periodontitis group has significantly higher total cholesterol/high-density lipoprotein ratio and lower high-density lipoprotein levels when compared to the healthy group

Structural, morphological, optical, and photoluminescence properties of nanocrystalline PbS thin films grown by chemical bath deposition

The transparent and nanocrystalline lead sulfide (PbS) thin films were prepared by the chemical bath deposition (CBD) technique onto glass substrates deposited at 80 °C using aqueous solution of lead acetate and thiourea. The X-ray diffraction pattern proves the crystallinity of deposited films that crystallize in the orthorhombic structure and preferred orientation. The energy band-gap and refractive index were estimated using UV–visible absorption spectra. The variation in band-gap with grain size showed blue-shift typical of electron quantum confinement. The effect of crystal ordering on refractive index was also evident by the linear increase of the refractive index with grain size. The PbS thin films were characterized by XRD, optical and SEM analysis

Preparation of nanocrystalline Cd-doped PbS thin films and their structural and optical properties

PbS and Cd-doped PbS nanocrystalline thin films prepared by the chemical bath deposition technique was deposited onto glass substrates at 80 °C. The aqueous solution containing Cd2+ and Pb2+ precursors was used to obtain good quality film deposits at optimized preparative parameters. The characterization of these films was performed using X-ray diffraction, optical absorption, photoluminescence properties, scanning electron microscopy and energy dispersive X-ray analyses to explore the properties of the PbS and Cd-doped PbS films. The prepared films were adherent to the substrate and well crystallized according to the cubic structure, which displayed a preferred orientation. According to the X-ray diffraction analysis, the crystallite size of the films decreased from 74 nm to 64 nm with increasing Cd doping. The optical properties were determined from ultraviolet-visible spectroscopy measurements in the absorbance energy range from 300â1200 nm. The UV-visible analysis shows that the band gap value of the PbS thin films increased from 2.12 eV to 2.65 eV by doping with Cd. Morphological analysis showed that the shape of the grains over the substrate surface was changed from a regular random orientation to an irregular shape with Cd doping. The energy dispersive X-ray analysis showed that the film contains Cd, Pb and S elements without any other impurities. Keywords: Thin films, Chemical synthesis, X-ray diffraction, Optical propertie

A facile green synthesis of silver nanoparticles using the medicinal plant Leucas aspera and their antibacterial activity

The junction of nanotechnology and biomedical sciences unfasten the possibility for a wide range of biological research topics and medical uses at the molecular and cellular level. In the present study silver nanoparticles were synthesized by using Leucas aspera leaf extract support of biological process. The extract incubated with 1mM AgNO3 solution showed gradual change in the color of the extract from greenish to reddish brown. Reduction of silver ions by the leaf extract was examined by UV-visible spectroscopic technique. Further, it was confirmed by Fourier Transformations Infrared spectroscopic (FTIR) analysis. The purity of the synthesized silver nanoparticles was examined through X-Ray Diffraction (XRD) analysis. The nanoparticles were examined for the antibacterial activities of antibiotic (Tetracycline), silver nanoparticles and the combined effect of both antibiotic and nanoparticles against the multi drug resistant human pathogens

Enhanced protein delivery by multi-ion containing eggshell derived apatitic-alginate composite nanocarriers

Abstract not availableT.S. Sampath Kumar, K. Madhumathi, B. Rajkamal, S. Zaheatha, A. Rajathi Malar, S. Alamelu Ba