Fabrication and characterization of chitosan based collagen/ gelatin composite scaffolds from big eye snapper Priacanthus hamrur skin for antimicrobial and anti oxidant applications.

In this study, for developing a scaffold for tissue engineering from fish processing wastes, a hierachial collagen/gelatin/chitosan novel porous scaffold was fabricated using blends of collagen and gelatin extracted from the skins of Marine big eye snapper Priacanthus humrur. Scaffolds were developed by mechanical spinning of chitosan and by mixing of collagen and gelatin solutions followed by freeze drying and subsequent crosslinking of polymers. The scaffolds were evaluated for rheological properties - porosity, apparent density and swelling capacity to assess their mechanical property.Gelatin/chitosan composition shown very high porosity(81.02%) and incorporation of collagen shown higher density in Collagen/gelatin/chitosan scaffolds (0.0522g/cm3) and collagen/chitosan scaffolds (0.0468 g/cm3).Morphology of the prepared scaffolds were analyzed by Scanning Electron Microscopy which showed reduced pore size of 10 to 20µ in Collagen/gelatin/Chitosan composite, 5 to 10µ in gelatin/chitosan composites and 2-5µ in collagen/chitosan composites. FTIR analysis showed intense peaks ranging 1120 -11267 cm-1 in the three different scaffolds that are denoted as CH groups. In-vitro antioxidant investigation through DPPH assay showed that the composite 3 in 1 mg/ml concentration exhibited higher antioxidant potential (70%). In contrast, ABTS scavenging assay identified composite1 in 1 mg/ml had good antioxidant activity with highest percentage of inhibition (29.5%). The scaffolds were also evaluated for anti microbial properties through disc diffusion assay. The results showed maximum inhibition- 14 mm, 12 mm and 14 mm for 200 µg of the sample for collagen/chitosan, gelatin/chitosan and collagen/gelatin/chitosan scaffolds respectively towards E.Coli and 20 mm, 20 mm and 24 mm towards S.aureus. The zone of inhibition against E. coli and S. aureus for the three scaffolds was comparatively lower and that could be due to the presence of chitosan. The findings of the study indicates that the bioscaffolds are expected to have wide application in tissue engineering.

GC-MS analysis of bioactive components and biosynthesis of silver nanoparticles using Hybanthus enneaspermus at room temperature evaluation of their stability and its larvicidal activity.

Green synthesis of silver nanoparticles (AgNPs) using Hybanthus enneaspermus extract at room temperature that act as a reducing agent as well as capping agent has been investigated. The synthesized AgNPs were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), zeta potential, and dynamic light scattering (DLS) transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX). The silver surface plasmon resonance was observed at 420 nm in the UV-visible spectrum. XRD peaks were observed at 2θ values in 38.20°, 44.40°, 64.60°, and 77.50° which are indexed as (111), (200), (220), and (311) bands of face-centered cubic (fcc) structures of silver. FTIR revealed the AgNPs were capped with plant compounds of alcohol, phenols, carbonyl, amines, and amide functional groups. TEM image shows that the particles were of spherical, hexagonal, and triangular in shape, and the size range was 16-26 nm. Further, DLS exhibits the average size of 25.2 nm and the zeta values were measured (-27.1 mV) which proves the stability of the AgNPs. The conversion of Ag(+) ions into Ag(0) was calculated using inductively coupled plasma atomic emission spectroscopy (ICP-MS) and was found to be 96 %. The biosynthesized AgNPs showed the larvicidal activity with the LC50 values of 17.24 and 13.12 mg/L against the fourth-instar larvae of Anopheles subpictus and Culex quinquefasciatus, respectively. The GC-MS analysis of the plant extract showed that 39 bioactive phytochemical compounds have been found to possess a wide range of activities, which may help in the protection against incurable diseases.

An investigation on cytotoxic effect of bioactive AgNPs synthesized using Cassia fistula flower extract on breast cancer cell MCF-7.

A single step protocol to produce biofunctionalized silver nanoparticles (AgNPs) using the aqueous extract of Cassia fistula flower as "natural factory" was investigated. The reaction between silver ions and aqueous flower extract after the bioreduction process has resulted in the formation of reddish brown color colloidal solution. XRD pattern showed the face centered cubic crystalline structure of AgNPs and exhibited spherical morphology as characterized by FE-SEM. FTIR studies identified different functional groups involved in effective capping of AgNPs. The zeta potential affirmed the phytoreduced AgNPs possess good stability and the size of the particle was measured by DLS. The synthesized AgNPs displayed effective cytotoxic potential against MCF7 and the inhibitory concentration (IC50) was recorded at 7.19 µg/mL. The apoptotic effects of the AgNPs were also confirmed by AO/EB staining. The investigation presents preliminary evidence that biosynthesized AgNPs can be used in the development of novel anticancer drugs.

Evaluation of zinc oxide nanoparticles toxicity on marine algae chlorella vulgaris through flow cytometric, cytotoxicity and oxidative stress analysis.

The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnO NPs) was investigated in Marine algae Chlorella vulgaris (C. vulgaris). High zinc dissociation from ZnONPs, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONPs toxicity. To examine the mechanism of toxicity, C. vulgaris were treated with 50mg/L, 100mg/L, 200mg/L and 300 mg/L ZnO NPs for 24h and 72h. The detailed cytotoxicity assay showed a substantial reduction in the viability dependent on dose and exposure. Further, flow cytometry revealed the significant reduction in C. vulgaris viable cells to higher ZnO NPs. Significant reductions in LDH level were noted for ZnO NPs at 300 mg/L concentration. The activity of antioxidant enzyme superoxide dismutase (SOD) significantly increased in the C. vulgaris exposed to 200mg/L and 300 mg/L ZnO NPs. The content of non-enzymatic antioxidant glutathione (GSH) significantly decreased in the groups with a ZnO NPs concentration of higher than 100mg/L. The level of lipid peroxidation (LPO) was found to increase as the ZnO NPs dose increased. The FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (FESEM and CM).

The Green synthesis of gold nanoparticles using an aqueous root extract of Morinda citrifolia L.

In the present work, we describe the synthesis of gold nanoparticles using an aqueous root extract of Morinda citrifolia. UV-vis spectroscopy, XRD, FTIR, FE-SEM, EDX and TEM were performed to characterize the formation of gold nanoparticles. The synthesized gold nanoparticles were characterized by a peak at 540 nm in the UV-vis spectrum. The XRD peaks at 38°, 44°, 64° and 77° can be indexed to the (111), (200), (220) and (311) Bragg's reflections of cubic structure of metallic gold, respectively. The FTIR result showed that extract containing protein might be responsible for the formation of the nanoparticles and may play an important role in the stabilization of the formed nanoparticles. FESEM images revealed that the particles were triangle and mostly spherical in shape. TEM images clearly revealed the size of the nanoparticles were 12.17-38.26 nm in size.

Biosynthesis, characterization and cytotoxic effect of plant mediated silver nanoparticles using Morinda citrifolia root extract.

Silver has been used since time to control bodily infection, prevent food spoilage and heal wounds by preventing infection. The present study aims at an environmental friendly method of synthesizing silver nanoparticles, from the root of Morinda citrifolia; without involving chemical agents associated with environmental toxicity. The obtained nanoparticles were characterized by UV-vis absorption spectroscopy with an intense surface plasmon resonance band at 413 nm clearly reveals the formation of silver nanoparticles. Fourier transmission infra red spectroscopy (FTIR) showed nanopartilces were capped with plant compounds. Field emission-scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM) showed that the spherical nature of the silver nanoparticles with a size of 30-55 nm. The X-ray diffraction spectrum XRD pattern clearly indicates that the silver nanoparticles formed in the present synthesis were crystalline in nature. In addition these biologically synthesized nanoparticles were also proved to exhibit excellent cytotoxic effect on HeLa cell.

1,25-dihydroxyvitamin D3 receptor is upregulated in aortic smooth muscle cells during hypervitaminosis D.

Several studies have demonstrated that excess of vitamin D3 is toxic particularly to vascular tissues. A notable pathological feature is arterial calcification. The nature of the toxic metabolite in hypervitaminosis D and the pathogenesis of arterial calcification are not clearly understood. The present study was undertaken to explore whether arterial calcification is a sequel of increased calcium uptake by arterial smooth muscle mediated by up regulation of vitamin D receptor in the cells in response to elevated circulating levels of vitamin D3 in serum. The experimental study was performed in 20 New Zealand white female rabbits aged 6 months. Animals in the test group were injected 10,000 IU of cholecalciferol intramuscularly twice a week for one month. Six control animals were given intra-muscular injections of plain cottonseed oil. Animals were sacrificed and aortas were examined for pathological lesions, 1,25-dihyroxyvitamin D3 (1,25(OH)2 D3) receptor levels and 45Ca uptake in smooth muscle cells. Serum samples collected at intervals were assayed for levels of 25-OH-D3 and calcium. The results showed that in animals given injections of cholecalciferol, serum levels of 25-OH-D3 were elevated. In four of these animals calcification and aneurysmal changes were seen in the aorta. Histological lesions comprised of fragmentation of elastic fibers as well as extensive loss of elastic layers. 1,25(OH)2 D3 receptor levels were up regulated and 45Ca uptake enhanced in aortas of animals which were given excessive vitamin D3. The evidences gathered suggest that excess vitamin D is arteriotoxic and that the vitamin induces arterial calcification through up regulation of 1,25(OH)2D3 receptor and increased calcium uptake in smooth muscle cells of the arteries.

Serum 25-hydroxyvitamin D3 levels are elevated in South Indian patients with ischemic heart disease.

Several lines of evidence point to a possible relationship between vitamin D and cardiovascular disease. Animal experiments and observational studies in humans suggest vitamin D to be arteriotoxic and an association of high intake of vitamin D with increased incidence of ischemic heart disease (IHD). The major source of vitamin D in adults is vitamin D synthesized in the skin through exposure to the sun. In tropical environment there is a possibility of high level of solar exposure and enhanced serum levels of vitamin D in the population. We explored the relation between serum level of 25-hydroxyvitamin D3 and IHD in a case-control study involving 143 patients with either angiographic evidence of coronary artery disease or patients with acute myocardial infarction and 70 controls, all men in the age group of 45-65 years. Fasting blood samples were collected, serum separated and serum levels of 25-hydroxyvitamin D3 was measured by protein binding radioligand assay. Serum levels of cholesterol, triglyceride, calcium, magnesium and inorganic phosphate were also determined. Prevalences of diabetes, hypertension and smoking history were noted. Statistical comparisons of variables between cases and controls were done using chi2-tests. Multivariate logistic regression analysis was done to examine the association of IHD with serum levels of 25-hydroxyvitamin D3 controlling for selected variables. Serum levels of 25-hydroxyvitamin D3, calcium, inorganic phosphate, total cholesterol, low density lipoprotein and triglycerides were elevated in a higher proportion of patients, compared to controls. Serum levels of 25-OH-D3 above 222.5 nmol/l (89 ng/ml) was observed in 59.4% of cases compared to 22.1% in controls (p < 0.001; unadjusted odds ratio (OR): 5.17; 95% confidence interval (CI): 2.62-10.21). When controlled for age and selected variables using the multivariate logistic regression, the adjusted OR relating elevated serum 25-hydroxyvitamin D3 levels (> or = 222.5 nmol/l, > or = 89 ng/ml) and IHD is 3.18 (95% CI: 1.31-7.73). Given the evidences for the arteriotoxicity of vitamin D, further investigations are warranted to probe whether the elevated serum levels of 25-hydroxyvitamin D3 observed in patients with IHD in a tropical environment has any pathogenic significance.

Magnesium levels in serum and erythrocytes of children from Kerala.

BACKGROUND: Magnesium is required in higher quantities, during the phase of rapid growth, in children. Its level in the ground water in Kerala is low. This can cause magnesium deficiency especially in children from the lower socio-economic groups who also suffer from nutritional insufficiency. METHODS: We compared the serum and erythrocyte magnesium levels of school children from high and low (agricultural labourers and fisherfolk) socio-economic groups. These levels were determined using atomic absorption spectrophotometry. Body mass indices and haemoglobin levels were used as indirect measures of nutritional status. RESULTS: Serum and erythrocyte magnesium levels were significantly lower in both boys and girls from low socio-economic groups who also had lower body mass indices. CONCLUSION: Nutritional insufficiency is prevalent in children from the low socio-economic groups and is associated with low serum and erythrocyte magnesium levels.

Nutritional status of children in Kerala.

Nutritional status of children in two poor communities was studied using conventional anthropometric techniques. A total of 944 children, of which 246 boys and 242 girls in coastal area and 213 boys and 249 girls in the non-coastal area formed the study group. With measurements of height and weight, the prevalence of various forms of growth retardation was determined in two communities. Inspite of better food intake, the rural coastal children exhibited poorer nutritional status mainly because of environmental deprivation.

High morbidity and low mortality--the experience of urban preschool children in Kerala.

This study was undertaken to estimate the morbidity pattern in children under 3 years in urban Kerala. Two cohorts of 111 and 74 children were selected from contrasting areas in Trivandrum city, capital of Kerala, by systematic sampling. Morbidity information on each child was gathered for one year through weekly visits and recording of symptoms by trained investigators. The results showed: 1. very high incidence rates of all illness groups studied, with peak incidence being observed in the first 6 months and the lowest in the third year; 2. up to six times greater risk for many disease groups in the more environmentally deprived area; 3. no significant differences in risk between sexes; 4. no seasonal variation. We conclude that despite low infant and child mortality levels, morbidity load in Kerala, for 0-3-year-old children is very high and this is directly related to the quality of the environment.