Wound healing efficacy of curcumin-loaded sandalwood bark-derived carbon nanosphere/PVA nanofiber matrix.

The present investigation deals with the evaluation of the wound healing efficacy of sandalwood bark-derived carbon nanospheres loaded with curcumin-embedded polyvinyl alcohol (PVA) nanofiber membranes (NF). Carbon nanospheres (CNS) were prepared by pyrolyzing sandal wood bark powder at 750 °C. The morphology was confirmed by field emission scanning electron micrographs and a rich amount of carbon was confirmed by the energy dispersive X-ray technique. Curcumin, an active wound healing drug was loaded onto synthesized CNS and confirmed by ATR-IR studies. Drug-loaded CNS were anchored in a PVA matrix via electrospun nanofiber fabrication. The fabricated nanofiber membranes were characterized and evaluated for wound healing efficiency. The cytotoxicity assay proved the non-toxic nature of the prepared PVA/CNS-curcumin-loaded NF. Membranes with active CNS/drug showed better antimicrobial activity against S. aureus and E. coli, which was estimated using the zone of inhibition (ZOI) test. The in vitro scratch wound healing assay of prepared PVA/CNS-curcumin nanofibers was efficient enough and showed 92 to 98% wound closure, which was greater than the control (without drug) nanofiber membranes. The PVA nanofiber matrix with interconnected structure and carbon nanostructures together enhanced the wound healing efficacy of the considered wound healing membrane, which is a promising novel approach for future wound healing patches.

Physisorption of trichloroethylene and tetrachloroethylene on novel zeta arsenene nanotubes - A first-principles study.

The structural stability of novel ζ-arsenene nanotubes (ζ-AsNT) is studied based on the density functional theory framework and is used as a base material for the detection of trichloroethylene and tetrachloroethylene vapours. The formation energy of ζ-AsNT is found to be -4.321 eV/atom and the energy band gap is 0.304 eV. Besides, the changes in the electronic properties of ζ-AsNT are explored with regard to the projected density of states, charge transfer, and electron density difference. The bandgap energy decreases for hollow site orientation to 0.205 and 0.204 eV for trichloroethylene and tetrachloroethylene vapours and increases for the valley and top site orientations. The adsorption energies were maximum for the valley site orientation of target molecules onto ζ-AsNT (01.165 and -1.513 eV for trichloroethylene and tetrachloroethylene, respectively). Moreover, the target vapours trichloroethylene and tetrachloroethylene are physisorbed on ζ-AsNT enabling the recycling of base substrate for continuous operation. The average energy gap changes vary from 18 to 32.9% depending on adsorption sites. The variation in the average energy gap owing to adsorption of trichloroethylene and tetrachloroethylene indicates the chemo-sensing nature of ζ-AsNT. The current report lays the inroads in the development of a new sensing element for the detection of chloroethylene molecules.

Multidentate ligand approach for conjugation of perovskite quantum dots to biomolecules.

Building compatible surface on perovskite quantum dots (PQDs) for applications like sensing analytes in aqueous medium is highly challenging and if achieved by simple means can revolutionize disease diagnostics. The present work reports the surface engineering of CsPbBr3 QDs via "simple ligand exchange process" to achieve water-compatible QDs towards detection of biomolecules. The monodentate oleic acid ligand in CsPbBr3 QDs is exchanged with dicarboxylic acid containing (bidentate) ligands such as folic acid (FA), ethylenediamine tetra-acetic acid (EDTA), succinic acid (SA) and glutamic acid (GA) to develop an efficient water-compatible PQD-ligand system. optical and theoretical studies showed the existence of a stronger binding between the perovskite and succinic acid ligand as compared to oleic acid (OA) and all other ligands. Replacement of OA with SA and retention of crystal structure is validated using spectroscopic and microscopic tools. It is observed that SA ligands facilitate better electronic coupling with PQDs and show significant improvement in fluorescence and stability. Further N-Hydroxy succinimide (NHS), which is a well-known compound to activate carboxyl groups, is used to bind onto SA PQDs as multidentate ligand, to form water stable PQDs. SA PQDs react with NHS (in water) to form multidentate ligand passivated PQDs that show very high photoluminescence (PL) as compared to OA PQDs in toluene. This also results in the formation of an NHS ester that allows bioconjugation with PQDs. This simple probe in water is further utilized for sensing a highly hydrophilic bovine serum albumin (BSA) protein as a model target to demonstrate the potential and effectiveness of this process to create compatible QDs for the successful conjugation of biomolecules. Although the focus of this work is to demonstrate bioconjugation and not achieving higher sensitivity levels, the intrinsic sensing level of these compatible QDs towards BSA shows a detection limit of 51.47 nM, which is above par with other reports in literature.

Nonwoven fabric supported, chitosan membrane anchored with curcumin/TiO2 complex: Scaffolds for MRSA infected wound skin reconstruction.

Use of biomaterial scaffolds as drug carriers for infected wounds treatment is of wide scope. A series of curcumin/TiO2 complex loaded chitosan scaffolds are fabricated for the same. Synthesized wound dressing material is screened for their morphology, water absorption capacity; in vitro drug release patterns, in vitro antibacterial studies against gram +ve and a gram -ve bacteria, cell viability for 3T3-L1 cell lines as well as in vivo MRSA infected wound healing capability. Formation of curcumin/TiO2 complex was confirmed by X-ray diffraction studies, the anchoring pattern of them on the chitosan scaffold was analyzed by FESEM and EDS mapping. All membranes showed a better performance towards in vitro antibacterial and in vivo wound healing properties than the control ones in 14 days. The bacterial count on wound for a regular time period was measured and the scaffold with higher amount of curcumin in its complex is found to give the better performance, along with skin regeneration due to synergistic effect of curcumin and TiO2.

Membranes for dehydration of alcohols via pervaporation.

Alcohols are the essential chemicals used in a variety of pharmaceutical and chemical industries. The extreme purity of alcohols in many of such industrial applications is essential. Though distillation is one of the methods used conventionally to purify alcohols, the method consumes more energy and requires carcinogenic entertainers, making the process environmentally toxic. Alternatively, efforts have been made to focus research efforts on alcohol dehydration by the pervaporation (PV) separation technique using polymeric membranes. The present review is focused on alcohol dehydration using PV separation technique, which is the most efficient and benign method of purifying alcohols that are required in fine chemicals synthesis and developing pharmaceutical formulations. This review will discuss about the latest developments in the area of PV technique used in alcohol dehydration using a variety of novel membranes.

Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample.

Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by CN bond to enhance the hydrophilicity. 1H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56l/m2h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.

Photoactive titania float for disinfection of water; evaluation of cell damage by bioanalytical techniques.

A photoactive float was fabricated with the modified titania to cause a feasible disinfection of water, contaminated with E. coli. The commercially available titania was doped with neodymium by pulverization technique to enhance its activity in sunlight and a multiapproach technique was used to evaluate the extended efficiency of the doped sample. X-ray diffraction patterns depicted the retention of anatase phase on doping and the existence of neodymium was confirmed by the energy dispersive atomic X-ray analysis and the X-ray photoelectron spectroscopy. Transmission electron microscopy and Bruner-Emmett-Teller analysis depicted a marginal increase in the particle size and a decrease in the surface area, respectively. Doping induces semiconductor behavior with lower band energy that could respond to visible light and exhibit better disinfection activity. The "f" and "d" transitions of the lanthanide in doped sample caused new electronic behavior of trapping/detrapping effect together with bandgap narrowing. The amount of malondialdehyde, protein, DNA and RNA released on destruction of E. coli was observed to be 0.915 × 10(-3) µg mL(-1), 859.912 µg mL(-1), 20.173 µg mL(-1) and 1146.073 µg mL(-1), respectively. The above analytical methods along with standard plate count method substantiated the enhanced disinfection efficiency of the doped sample in sunlight.