Activating ZnO nanorods photoanodes in visible light by CdS surface sensitiser

Thin films of c-axis aligned uniform ZnO nanorods (NRs) were fabricated on to fluorine-doped tin oxide-coated soda lime glass substrate by a two-step chemical route. Thereafter ZnO NRs/CdS core shell structures were successfully synthesised by depositing CdS layer on top of vertically aligned ZnO NRs using less hazardous nanocrystal layer deposition technique. The presence of CdS in ZnO NRs/CdS core shell structures was confirmed by energy dispersive X-ray analysis. Examination of structure and morphology of the fabricated films by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed that both films have one-dimensional hexagonal wurtzite structure. Optical properties evaluated from ultraviolet-visible and photoluminescence spectra demonstrated better photo response of ZnO NRs/CdS core shell structure with respect to bare ZnO NR structure. Optical to chemical conversion efficiency of ZnO NRs/CdS photoanode was found to be similar to 1.75 times higher than bare ZnO NRs photoanode in photo electrochemical water splitting under visible light

Nanostructured ZnO thin film with improved optical and electrochemical properties prepared by hydrothermal electrochemical deposition technique

Zinc oxide (ZnO) thin films were grown on fluorine-doped tin oxide coated glass substrate by the hydrothermal electrochemical deposition (HTED) route using slightly acidic aqueous zinc acetate solution at 80°C and were characterised by various techniques. The deposited films showed n-type behaviour with improved carrier concentration. The steady state photocurrent densities were found to be 0.4 mA/cm2(under UV irradiation) and 8 μA/cm 2(under visible light illumination) at zero bias potential. Significant improvement of optical, electrochemical and photoelectrochemical properties of deposited films could be achieved using HTED technique

Low-temperature synthesis of strain sensor based on flexible ZnO nanowire-cellulose paper composite

ZnO nanowire was synthesised chemically at low temperature on a flexible three-dimensional and porous cellulose paper. The morphology and crystallography of the composite was characterised by field emission scanning electron microscope and X-ray diffraction. Performance of the developed ZnO nanowire-cellulose paper composite as strain sensor demonstrated good stability, high gauge factor and good repeatability. The results indicate the possible use of this sensitive and robust strain sensor in the fields of biomedical sciences, MEMS devices and structural health monitoring and other fields

Activating ZnO nanorods photoanodes in visible light by CdS surface sensitiser

Thin films of c-axis aligned uniform ZnO nanorods (NRs) were fabricated on to fluorine-doped tin oxide-coated soda lime glass substrate by a two-step chemical route. Thereafter ZnO NRs/CdS core shell structures were successfully synthesised by depositing CdS layer on top of vertically aligned ZnO NRs using less hazardous nanocrystal layer deposition technique. The presence of CdS in ZnO NRs/CdS core shell structures was confirmed by energy dispersive X-ray analysis. Examination of structure and morphology of the fabricated films by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed that both films have one-dimensional hexagonal wurtzite structure. Optical properties evaluated from ultraviolet–visible and photoluminescence spectra demonstrated better photo response of ZnO NRs/CdS core shell structure with respect to bare ZnO NR structure. Optical to chemical conversion efficiency of ZnO NRs/CdS photoanode was found to be ∼1.75 times higher than bare ZnO NRs photoanode in photo electrochemical water splitting under visible light

Effects of Mg% on open circuit voltage and short circuit current density of Zn1-xMgxO/Cu2O heterojunction thin film solar cells, processed using electrochemical deposition and spin coating

Zn1-xMgxO/Cu2O/Ag solar cells were fabricated upon fluorine doped tin oxide coated soda lime glass substrate with varying percentage of Mg mol% doping in zinc oxide (ZnO) layer. Short circuit current density & open circuit voltages of the fabricated cells were investigated. Optimum doping with Mg improved the transparency of ZnO layer which helped in increasing the short circuit current density of solar cells. An enhancement of open circuit voltage was observed with increase in x, which was investigated using X-ray photoelectron spectroscopy and the results revealed that with increase in x, there was a decrease in conduction band offset between Zn1-xMgxO and cuprous oxide layers. From UV-Visible transmittance spectra, it was observed that with Mg doping in ZnO nanostructure, optical losses were reduced which resulted in increase in Short circuit current density. The objective of this study was to investigate and develop a technology for fabrication of solar cells that is both cost effective and easy to produce

Understanding osteomyelitis and its treatment through local drug delivery system

Chronic osteomyelitis is a major challenge in bone surgery. Conventional use of antibiotics is not an effective way to control the malaise due to so many reasons. Determination of optimal treatment strategy becomes difficult for the orthopaedic surgeons and as a consequence, the patients suffer not only from therapeutic failure but also due to adverse side effects of antibiotics and financial loss due to additional stay at hospitals. A wide application of carrier systems, as a medium for local delivery of antibiotics, is being used experimentally and clinically for the treatment of osteomyelitis. This kind of delivery system provides sustained higher concentration of antibiotics at the infection site with reduced possibility of toxicity. This review highlight etiology and pathophysiology of osteomyelitis, current therapeutic options with their limitations, and potentiality of biomaterial based carrier materials impregnated with antibiotics as local delivery approach. (C) 2016 Elsevier Inc. All rights reserved

In Vitro and In Vivo Bone Regeneration Assessment of Titanium-Doped Waste Eggshell-Derived Hydroxyapatite in the Animal Model

Inthis work, a titanium-doped hydroxyapatite (HAp) scaffold wasproduced from two different sources (natural eggshell and laboratory-gradereagents) to compare the efficacy of natural and synthetic resourcesof HAp materials on new bone regeneration. This comparative studyalso reports the effect of Ti doping on the physical, mechanical,and in vitro as well as in vivo biological properties of the HAp scaffold.Pellets were prepared in the conventional powder metallurgy route,compacted, and sintered at 900 & DEG;C, showing sufficient porosityfor bony ingrowth. The physical-mechanical characterizations wereperformed by density, porosity evaluation, XRD, FTIR, SEM analysis,and hardness measurement. In vitro interactions were evaluated bybactericidal assay, hemolysis, MTT assay, and interaction with simulatedbody fluid. All categories of pellets showed absolute nonhemolyticand nontoxic character. Furthermore, significant apatite formationwas observed on the Ti-doped HAp samples in the simulated body fluidimmersion study. The developed porous pellets were implanted to assessthe bone defect healing in the femoral condyle of healthy rabbits.A 2 month study after implantation showed no marked inflammatory reactionfor any samples. Radiological analysis, histological analysis, SEManalysis, and oxytetracycline labeling studies depicted better invasionof mature osseous tissue in the pores of doped eggshell-derived HApscaffolds as compared to the undoped HAp, and laboratory-made samples.Quantification using oxytetracycline labeling depicted 59.31 & PLUSMN;1.89% new bone formation for Ti-doped eggshell HAp as compared toTi-doped pure HAp (54.41 & PLUSMN; 1.93) and other undoped samples. Histologicalstudies showed the presence of abundant osteoblastic and osteoclasticcells in Ti-doped eggshell HAp in contrast to other samples. Radiologicaland SEM data also showed similar results. The results indicated thatTi-doped biosourced HAp samples have good biocompatibility, new bone-formingability, and could be used as a bone grafting material in orthopedicsurgery

Synthesis and characterization of PCL-DA:PEG-DA based polymeric blends grafted with SMA hydrogel as bio-degradable intrauterine contraceptive implant

Presently available long-acting reversible female contraceptive implants are said to be an effective way of preventing unintended pregnancy. Unacceptable side effects attributed by these contraceptive implants act as a major drawback for the practitioners. These problems pave the way for the development of a new form of long acting non-hormonal female contraceptive implant, especially in the developing countries. PCL-DA: PEG-DA polymeric scaffold is grafted with Styrene Maleic Anhydride (SMA) based hydrogel, and their physicochemical, thermal and biological parameters are being explored for developing a bio-degradable form of the non-hormonal intrauterine contraceptive implant. With the fixed ratio of PEG-DA: PCL-DA polymer, SMA hydrogel was added at four different concentrations to determine the optimum concentration of SMA hydrogel for the development of a promising long-acting biodegradable intrauterine contraceptive implant. Structural elucidation of the polymers was confirmed using H-1 and C-13 NMR spectroscopic analyses. The physiochemical characterization report suggests that SMA hydrogel interacts with the PCL-DA: PEG-DA polymeric scaffold through intermolecular hydrogen bonding interaction. The in-vitro spermicidal activity of the polymeric scaffold increases when the concentration of SMA based hydrogel in the polymer samples is increased without showing any significant toxicological effects. From the study results, it may be concluded that SMA hydrogel grafted PCL-DA: PEG-DA scaffold can be developed as intra-uterine biodegradable non-hormonal female contraceptive implant due to its excellent bio-compatibility and spermicidal activity

Preparation and in vivo biocompatibility studies of different mesoporous bioactive glasses

A new generation of nanostructured glasses called mesoporous bioactive glasses (MBGs) exhibit superior surface texture, porosity and bioactive characteristics. The present study is carried out to develop and detailed characterize of ternary SiO2-CaO-P2O5 MBG structure, fabricated by three different variations using different surfactants, e.g., hexadecyltrimethylammonium bromide (CTAB), poly-ethylene glycol,(PEG) and Pluronic P123. After thorough physico-chemical characterization, MBG granules were investigated for in vivo bone regeneration in animal bone defect model (rabbit) where standard S53P4 bioactive glass was used as control. All the synthesized MBG powders showed nano-range median particle size of 80-120 nm (MBG-CTAB), 50-70 nm (MBG-PEG and MBG-P123) while their specific surface area as 473.2, 52.2 and 169.3 m(2)/g respectively. All MBGs showed mesoporous nature corroborating transmission electron microscopy (TEM) observation as well. Bone regeneration property was measured after 45 and 90 days post-implantation at distal epiphysis of rabbit femur by radiography, histology, fluorochrome labeling, micro computed tomography (micro-CT) and vital organ histology. Results from in vivo studies indicated that the MBG materials produce minimal toxicity to the body. Furthermore, the biocompatibility and biodegradability of the implant makes them more suitable for application in bone tissue engineering. Among various implants, MBG fabricated using suitable surfactant (CTAB) shown the best result compared to other implants. Nonetheless, all the materials are suitable for application in bone tissue engineering and have potential for bone regeneration and healing