Banana fiber Cellulose Nano Crystals grafted with butyl acrylate for heavy metal lead (II) removal.

The present work deals with extraction of Cellulose Nano Crystals (CNCs) from Banana fiber using the steam explosion method. Extracted CNCs was grafted with butyl acrylate (BA) monomer with ceric ammonium nitrate (CAN) as an initiator. The prepared graft copolymer was analyzed using FTIR, XRD, SEM and EDAX. FTIR results indicate that the CH2 type of linkages was observed in the grafted copolymer showing effective formation of grafted copolymer. XRD results elucidate the changes in the crystalline behaviour of the prepared CNCs grafted butyl acrylate copolymer. SEM images of a prepared adsorbent was appeared to be heterogeneous and covered with clusters which will be suitable for adsorption. Batch adsorption studies was carried out for the removal of Pb(II) ions from the aqueous solution using the prepared copolymer. The parameters such as effect of pH, contact time, initial metal ion concentration and adsorbent dosage was investigated. From the observed results it was concluded that, the optimum pH: 5, contact time: 360 min, adsorbent dosage: 4 g/100 mL and initial metal ion concentration: 125 mg/L. The adsorption isotherm models of Pb(II) ions could be described very well by Freundlich model and the kinetic results revealed that pseudo-second-order kinetics showed a better fit.

Development of 3D scaffolds using nanochitosan/silk-fibroin/hyaluronic acid biomaterials for tissue engineering applications.

Bone tissue engineering put emphasis on fabrication three-dimensional biodegradable porous scaffolds that supporting bone regeneration and functional bone tissue formation. In the present work, we prepared novel 3D tripolymeric scaffolds of nanochitosan (NCS)/silk fibroin (SF)/hyaluronic acid (HA) ternary blends and demonstrating the synergistic effect of scaffolds and its use in tissue engineering applications. The physico-chemical characterization of the prepared scaffold was evaluated by FTIR, XRD and SEM studies. The FT-IR and XRD results confirmed the interfacial bonding interaction existing between polymers. SEM images showed good interconnected porous structure with rough surface morphology. The in vitro cytocompatibility tests carried out with osteoblast cells by the MTT assay demonstrated that the blended scaffold favors the early adhesion, growth and proliferation of preosteoblast MC3T3-E1 cells. The alizarin red assay indicated that the prepared scaffold can promote the osteogenic differentiation and facilitate the calcium mineralization of MC3T3-E1 cells. The alkaline phosphatase assay confirmed that the NCS/SF/HA scaffold provide conducive environment for osteoblast proliferation and mineral deposition. The bactericidal action of NCS/SF/HA scaffold reveals that the prepared sample has the potential to kill the microorganisms to a greater extent. Hence the overall findings concluded that the NCS/SF/HA scaffolds have better applications in tissue engineering.

Removal of toxic heavy metal lead (II) using chitosan oligosaccharide-graft-maleic anhydride/polyvinyl alcohol/silk fibroin composite.

The present work was aimed to investigate the efficiency of novel chitosan oligosaccharide-graft-maleic anhydride(COS-g-MAH)/Polyvinyl alcohol (PVA)/silk fibroin (SF) composite for removing the toxic heavy metal lead (II) ion from aqueous solution by batch adsorption studies. Initially the chitosan oligosaccharide-graft-maleic anhydride copolymer has been prepared by utilizing ceric ammonium nitrate as an initiator and the optimised graft copolymer was then used for synthesizing COS-g-MAH/PVA/SF composite. The prepared samples were analyzed through FTIR and XRD studies. The FTIR results indicate that the grafted chitosan oligosaccharide copolymer was mixed homogeneously with silk fibroin and polyvinyl alcohol through intermolecular hydrogen bonding. The XRD results elucidate the changes in the crystalline behaviour of the prepared COS-g-MAH/PVA/silk fibroin composite. Both FTIR and XRD results revealed a strong interaction among COS-g-MAH, PVA and silk fibroin components. To evaluate the adsorption potential of the synthesized composite, the parameters such as pH, adsorbent dosage, contact time and initial Pb(II)ion concentration was investigated. The adsorption isotherms of Pb(II) could be described very well by Langmuir model and the kinetic results revealed that pseudo second order kinetics shows a better fit. This work provides a practical and high-efficient method for water treatment at moderate concentration of toxic heavy metals.

Genetic variation of GSTM1, GSTT1 and GSTP1 genes in a South Indian population.

The glutathione S transferase (GST) family of enzymes play a vital role in the phase II biotransformation of environmental carcinogens, pollutants, drugs and other xenobiotics. GSTs are polymorphic and the polymorphisms in GST genes have been associated with cancer susceptibility and prognosis. Moreover, distinct ethnic differences have been observed in the type and frequency of GST gene polymorphisms. Hence, the present study was aimed to determine the frequencies of GSTM1, GSTT1 and GSTP1 polymorphisms in 255 healthy random volunteers from South India. The GSTM1 and GSTT1 genotypes were determined by PCR and GSTP1 by PCR-RFLP using peripheral blood DNA. The GSTM1 and GSTT1 null genotype frequencies were found to be 22.4% and 17.6% respectively. The GSTP1 allelic frequency was 0.78 for the Ile allele and 0.22 for the Val allele and the genotype frequency was 58.4% for Ile/Ile, 38.4% for Ile/Val, and 3.1% for Val/Val. Comparison of the frequencies of GST polymorphisms observed in the present study with other Indian and world populations revealed a distinctive nature of the South Indian population with respect to polymorphims at the GST gene loci. A better understanding of carcinogen metabolizing gene distribution should contribute to risk assessment of humans exposed to environmental carcinogens.