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A flexible, lightweight and efficient nanohybrid of poly(vinylidene fluoride) and functionalized graphene oxide is prepared through an optimized electrospinning process for energy harvesting. Nanohybrids yield good quality fibers upon the incorporation of functionalized graphene oxide. The addition of nanofillers leads to a decrease in the fibre diameter arising from better interaction of the nanoparticle with the polymer matrix. An electroactive phase of ∼88% is achieved upon the addition of nanoparticles which leads to better piezoelectric materials for energy harvesting applications. The transformation of the electroactive phases from the non-piezoelectric part is confirmed through spectroscopic and thermal studies. The developed scaffold is fabricated into a nanogenerator device for electro-mechanical responses. The fabricated device from the nanohybrid of PVDF and functionalized graphene oxide produces a better electromechanical response of 62 V (peak-to-peak) and 48.3 μW cm−2 power generation using finger tapping as compared to 20 V and 23.4 μW cm−2 power generation from pristine PVDF fibres. These devices have the capability to generate a considerable amount of power from various human body movements like walking, foot tapping and bending. These devices have been used to power LEDs from various real life waste mechanical resources like opening and closing of drawers and walking over door mats.

Herein, we demonstrate a template directed route for the synthesis of self-supported cobalt-iron based Prussian blue analogues (PBAs). The PBAs are electrochemically transformed into layered double hydroxides to produce excellent water oxidation and hydrogen evolution activity, while the overall water splitting is attained at a cell voltage of 1.58 V to reach 20 mA cm-2 current density.

1,7Phenanthroline based bisboron dipyrromethenes (bisBODIPYs) B1 and B2 obtained via small substitutional changes (Cl/SCH3) have been described. The effect of RIR in emission enhancement in a viscous solvent (glycerol) has been studied besides vital role of intermolecular interactions scrutinized by Xray single crystal studies. The efficiency of intersystem crossing (ISC) in generation of singlet oxygen (ΦΔ∼ 19.2% and 56.7%) by photoirradiation using visible light along with distinct photostability has been investigated by 1,3-diphenylisobenzofuran (DPBF) titration studies. The 1O2 generation quantum yield and photosensitizing durability of the bisBODIPYs have been investigated by photooxidation of 1,5-dihydroxynaphthalene (DHN) in presence of B1 and B2 as photosensitizers. The pseudo-first-order rate constants for photooxidation reactions and consumption rates of DHN reflected appreciable 1O2 generation quantum yields (ΦΔ: B1, 29.0; B2, 57.8%). Density functional theory (DFT) studies showed distri...

The present work is focused on the synthesis of morphology-controlled vertically aligned Zinc oxide (ZnO) nanosheets (NSs) using a high power low-temperature sonochemical process. The synthesis process is a facile and low-temperature process, which can be able to produce large-area, homogeneously-grown, vertically-aligned ZnO NSs with high surface to volume ratio. Also, using the same process, we have developed a low-temperature in-situ method of the magnesium (Mg), doped ZnO NSs with identical structure and morphology. The process is versatile, scalable and can be adopted for synthesizing various other doped morphology controlled nanosheets synthesis. The morphology and structure were confirmed using X-ray diffraction technique, FESEM, TEM/HRTEM while surface composition, bonding and doping were confirmed using XPS and UV–VISIBLE spectroscopy. We obtained 2D few layered thick ZnO nanosheets of flake size 2–5 μm with bandgap ∼3.38 eV, which was increased to ∼3.7 eV due to the Mg doping. Furthermore, we demonstrated the comparative photocatalytic activity of the as-synthesized pristine and doped ZnO nanosheets and found that Mg-doping promotes the faster catalytically active redox reaction, hence; the dye degradation time was 15 min faster compared to the pristine ZnO NSs under identical conditions. We believe that the rate-enhancement in photocatalytic dye degradation of Mg-doped ZnO NSs is obtained due to the faster hole transport properties and low recombination rate.

Nanohybrid scaffolds of chitosan have been designed for controlled drug delivery and bone regeneration. Sulfonated graphene oxide has been used to develop the nanohybrids. Nanohybrid scaffolds show highly hydrophilic character and greater mechanical strength as compared to pure chitosan. Nanohybrid scaffolds show an interconnected uniform porous network structure exhibiting sustained release kinetics of the antibacterial drug, tetracycline hydrochloride. Nanohybrids are found to be highly biocompatible in nature and are able to support and proliferate MG63 osteoblast cells and thereby induce bone tissue regeneration. The in-vivo bone healing study shows that the developed nanohybrid scaffolds have the potential to regenerate the bone faster without any side effects as compared to pure scaffolds. Hence, the developed nanohybrid scaffold has good potential as a controlled drug delivery vehicle and in bone tissue engineering for faster healing.

The use of cationic polymer based gene delivery vectors has several limitations such as low transfection efficiency, high toxicity, and inactivation by serum. The present work provides an inorganic based nanocarrier for efficient gene delivery and a method for preparing the same through a facile coprecipitation technique. The vehicle showed high loading capacity of DNA and can release the loaded DNA in a controlled pH-responsive manner. The developed gene delivery vehicle offers remarkable protection against DNase I and also provides protection against thermal damage. This vehicle also demonstrated efficient cellular uptake performance. Transfection and expression of plasmid gene encoding GFP proteins is achieved successfully by this LDH based vehicle. More interestingly, the developed Li-Al LDH efficiently induces GFP-p53 mediated apoptosis in HeLa cells exclusively sparing the normal tissue cells like NIH-3T3. The study demonstrates the potential of the developed inorganic based nanocarrier as a promising nonviral gene vector for tumor treatment.

Magnetic materials with high specific loss power (SLP) are desirable for magnetic hyperthermia to minimise the amount of material required to obtain the therapeutic temperature (42–46 °C) to destroy the cancer cells. The exchange coupled core-shell structure and the nanoclusters of magnetic nanoparticles having high SLP values are the most suitable candidates for this purpose. Herein, a simple method has been demonstrated for the synthesis of exchange coupled magnetic nanoflowers consisting of γ-Fe2O3 magnetic grains grown over the surface of MnFe2O4 core. The aqueous ferrofluid of nanoflowers displayed higher SLP values than single phase MnFe2O4 core. The intrinsic loss parameter for the nanoflowers was 3.30 nH m2 Kg−1 at an applied magnetic field of amplitude 250 Oe and frequency 113 kHz, which was significantly higher than the commercially available ferrofluids. The cytotoxicity of the nanoflowers were studied with HeLa cells. The magnetic hyperthermia treatment for 30 min with 0.75 mg/mL ferrofluid of the nanoflowers demonstrated a temperature rise to 46 °C and decreased the cell viability to 17% for HeLa cells. These nanoflowers (size around 40–60 nm) showed better magnetic properties viz. higher saturation magnetisation, initial susceptibility and lower coercivity, making them a suitable candidate for biomedical applications.

Fluorescence probe has attracted significant attention for biomedical imaging in recent years due to their high resolution at the cellular level. Organic-based fluorescent probes with high quantum yield are widely applied in bioimaging, but most of them suffer from a serious obstacle called aggregation-caused quenching in cellular systems. New fluorophore has been designed through functionalization of graphene oxide which emphatically exhibits aggregation-induced emission along with pH-responsive nanoprobe. Significantly higher emission of this material in slightly acidic media helps to detect tumor cell by creating a sharp contrast with the image of normal cells. The reason for pH-induced enhanced emission phenomenon is revealed through aggregation of sulfonated species in acidic media. Furthermore, the biocompatible nature of the newly developed material is found to be suitable for its application in biomedical imaging for cancer detection with better accuracy at lower cost. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1917-1924, 2019.

Despite 60% oral absorption, high first-pass metabolisms resulted in 2% oral bioavailability of raloxifene and also suffer poor water solubility. In this study, we developed the penetration enhancer rich hydrogel containing raloxifene-loaded solid lipid nanoparticles (RL-SLNs) for transdermal route. Interestingly, SLN offers higher solubility and thermodynamic activity due to amorphization of drug and evasion of first-pass metabolism by transdermal route. Cumulative effect will contribute to enhanced permeation flux, controlled drug release and enhanced bioavailability. Nanoparticles were synthesized using solvent emulsification–evaporation method and evaluated further for various physicochemical properties, ex vivo permeation and hydration studies. RL-SLN3 with particle size 227.9 ± 12.6 nm, polydispersity index 0.283 ± 0.021, zeta potential 15.4 ± 1.7 mV and entrapment efficiency 77.04 ± 5.08% was selected for further studies as optimized formulation. Differential scanning calorimetric method revealed that 54.75% of RL had changed to amorphous state adding to enhanced solubility. Furthermore, the results of ex vivo permeation studies on human skin elucidated that 10% d-limonene in combination with RL-SLN had excellent permeation flux (7.24 ± 0.49 µg/cm2 h) compared to RL-SLN alone and other penetration enhancers tested. Thus, the output of above studies suggested that transdermal delivery of RL-SLN using d-limonene as penetration enhancer can be a promising approach to evade the first-pass metabolism and increase the systemic bioavailability of RL.

Templated nanofibers of poly(vinylidene fluoride) have been designed on top of two dimensional nanoclay platelets for energy harvesting application. Dimension of nanofiber has been varied using different nanoclay content prepared through optimized electrospinning. The alteration in structure (electroactive phase) and morphology has been worked out as a function of nanoclay concentration. Nearly 90% piezoelectric active phase has been stabilized in presence of minimum quantity of nanoclay. Hybrid nanofiber is found to be tougher (300%) and stiffer by design, which in turn suitable for device application. Unimorph using hybrid nanofiber exhibits power generation up to 100 ms against less than 50 ms tenure using pristine fiber. Device has been fabricated using various nanofibers and demonstrates very high output voltage (70 V) and power density (68 μW cm−2) from the device made of hybrid nanofiber. Various modes of body movements e.g. bending, twisting, walking, foot and finger tapping can generate considerable power using the hybrid device and are able to transform waste mechanical energy to useful electric power. Underlying mechanism of charge separation in template system has been revealed which explain the high conversion of energy using the hybrid device.

In this current scenario, there is a broad range of use of resins in both domestic and industrial applications. Especially the importance of resins for adhesive in the wood industry is inevitable. But most of the commercially available resins for adhesive application are prepared of formaldehyde or fossil fuel-based resources which possess serious health issues. Henceforth, development of environmentally friendly resin from renewable resources through a cost-effective technique is a challenging task. Motivated by these facts and prospects, we present a novel technique for addressing non-renewability difficulties while also improving adhesive strength of the material. In this study, lignin-based composite resin with enhanced sustainability and adhesion strength have been achieved by a simply mixing of high concentration of poly (itaconic acid)-functionalized-lignin (P(IA)-f-Lignin) and aqueous emulsion of polyvinyl acetate. The P(IA)-f-Lignin was synthesized by in-situ free radical polymerization of partly neutralized IA in the presence of aqueous lignin dispersion at 90 °C using ammonium persulfate as initiator. The formation of P(IA)-f-Lignin was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), field emission scanning electron microscope (FESEM) and thermogravimetric analysis (TGA). Here, we have been fabricated 20, 30, 40, 50, and 60 wt% of P(IA)-f-Lignin containing composite resin with desired amount of aqueous emulsion of polyvinyl acetate (PVAc). The changes in physico-chemical interactions were established by FTIR analysis. Various properties like viscosity, thermo-stability, and adhesive properties of all the formulated composite resin were inspected thoroughly. The composite containing 40 wt% of P(IA)-f-Lignin shows excellent improvement of adhesion strength from 3.32 ± 0.12 MPa to 7.83 ± 0.45 MPa. These fabricated composite resin with a high concentration of bio-based P(IA)-f-Lignin content and strong adhesion strength is very promising for fabrication of biobased adhesives with improved sustainability. publishedVersion

The polymer–particle matrix structure has attracted great interest for daytime radiative cooling due to its various advantages; however, cost-effective fabrication process development and proper material selection are crucial tasks. Herein, we illustrate the selection of fabrication process and materials based on development, characterization, and experimental performance. The initial selection is based on solar radiation backscattering and isotropic thermal emission properties of polymers and particles. Among potential polymers (PMMA, PVDF, and PU), PMMA is experimentally found more suitable for radiative cooling because of negligible absorption in the solar radiation spectrum. Among the selected particles (CaCO3, BaSO4, ZnO, and SiO2), the experimental performance of BaSO4 in the polymer matrix is found to be excellent. Furthermore, the optimum particle volumetric concentration is found at 70%, with an optimum thickness of 500 μm for the substrate independent radiative cooler. Spray-coating is found to be a better option for fabrication as compared to drop casting. The performance evaluation was carried out at Varanasi, India for over two months to investigate the environmental parameters' effect on performance. For an optimized structure, the observed maximum temperature drop from the ambient is 6 °C (17 °C lower than bare roof surface) during noontime and 9 °C during the evening. At ambient temperature, the recorded cooling power is 35 W/m2 at noon (solar peak) and 78 W/m2 in the evening for the experimentally optimized structure.

Cationic polymer-based gene delivery vectors suffer from several limitations such as low DNA-loading capacity, poor transfection, toxicity, environmental degradations, etc. Again, very limited works are available addressing the binding interactions in detail at the atomic level explaining the loading capacity, protection ability against harsh environments, and controlled release behavior of the DNA-encapsulated vehicles. Here, a poly(l-lactide) (PLA) nanoparticle-based controlled DNA release system is proposed. The developed vehicle possesses a high DNA-loading capacity and can release the loaded DNA in a controlled manner. Spectroscopic, physicochemical, and molecular simulation techniques (AM1 and atomistic molecular dynamics) have been employed to understand the binding interactions between PLA and DNA molecules enabling high DNA loading, protection against external harsh environments, and controlled DNA release behavior. Methyl thiazolyl tetrazolium (MTT) assay experiments confirm the biocompatible nature of the vehicle. Cellular uptake efficiency and endo-lysosomal escape capabilities have been investigated against HeLA cells. This study, therefore, demonstrates the development of a promising nonviral DNA delivery vector and includes a detailed investigation of the atomic-level interaction behavior between PLA and DNA molecules.

Surface functionalization of graphene oxide with sulfonate group and subsequent grafting with polyurethane chains leads to the significant improvement in the properties of polymer and modified graphene as a filler. Modification of graphene oxide is revealed through spectroscopy while grafting of polymer chain over sulfonated graphene is confirmed through 1H NMR and other techniques. Higher order of self-assembly phenomena is observed in nanohybrids as compared to pure polymer through greater interaction between polymer chain and sulfonated graphene. Significant improvement in corrosion inhibition phenomena is observed using nanohybrids at low concentration as compared to pure polymer indicating its superior efficiency as a corrosion inhibitor. Nanohybrids also exhibit better biocompatible nature in lower concentration of filler with considerable sustained release of drug vis-a-vis pure polymer suggest its potential to use as a biomaterial for tissue engineering applications.

Passive radiative cooling is an emerging field and needs further development of material. Hence, the computational approach needs to establish for effective metamaterial design before fabrication. The finite difference time domain (FDTD) method is a promising numerical strategy to study electromagnetic interaction with the material. Here, we simulate using the FDTD method and report the behavior of various nanoparticles (SiO2, TiO2, Si3N4) and void dispersed polymers for the solar and thermal infrared spectrums. We propose the algorithm to simulate the surface emissive properties of various material nanostructures in both solar and thermal infrared spectrums, followed by cooling performance estimation. It is indeed found out that staggered and randomly distributed nanoparticle reflects efficiently in the solar radiation spectrum, become highly reflective for thin slab and emits efficiently in the atmospheric window (8–13 µm) over the parallel arrangement with slight variation. Higher slab thickness and concentration yield better reflectivity in the solar spectrum. SiO2-nanopores in a polymer, Si3N4 and TiO2 with/without voids in polymer efficiently achieve above 97% reflection in the solar spectrum and exhibits substrate independent radiative cooling properties. SiO2 and polymer combination alone is unable to reflect as desired in the solar spectrum and need a highly reflective substrate like silver.

Resveratrol is a polyphenolic nutraceutical that exhibits pleiotropic activities in human subjects. The efficacy, safety, and pharmacokinetics of resveratrol have been documented in over 244 clinical trials, with an additional 27 clinical trials currently ongoing. Resveretrol is reported to potentially improve the therapeutic outcome in patients suffering from diabetes mellitus, obesity, colorectal cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The polyphenol is reported to be safe at doses up to 5 g/d, when used either alone or as a combination therapy. The molecular basis for the pleiotropic activities of resveratrol are based on its ability to modulate multiple cell signaling molecules such as cytokines, caspases, matrix metalloproteinases, Wnt, nuclear factor-κB, Notch, 5'-AMP-activated protein kinase, intercellular adhesion molecule, vascular cell adhesion molecule, sirtuin type 1, peroxisome proliferator-activated receptor-γ coactivator 1α, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, Ras association domain family 1α, pAkt, vascular endothelial growth factor, cyclooxygenase 2, nuclear factor erythroid 2 like 2, and Kelch-like ECH-associated protein 1. Although the clinical utility of resveratrol is well documented, the rapid metabolism and poor bioavailability have limited its therapeutic use. In this regard, the recently produced micronized resveratrol formulation called SRT501, shows promise. This review discusses the currently available clinical data on resveratrol in the prevention, management, and treatment of various diseases and disorders. Based on the current evidence, the potential utility of this molecule in the clinic is discussed.

Toxicity, biodegradability, biocompatibility and complex synthesis techniques are the major challenges in development for self-powered piezoelectric nanogenerators for biomedical applications. Here, we report a novel bio-waste hybrid with polymer for self-powered nanogenerator by using abundantly available natural self-aligned collagen fibrous fish scale as an efficient energy harvester. Fish scale induces the electroactive phase over its surface through synergism. Structure and morphology confirm the uniform distribution of scale particle in PVDF matrix and γ-phase formation in the presence of the filler. Energy harvesting performance of the bio-waste based hybrid device exhibit very voltage of 22 V and high energy density of 28.5 μW/cm 2, considerably higher value than the existing waste based device. Compressive stress by the human finger is sufficient to drive the bio-waste hybrid to generate energy along with other modes of naturally occurring vibration like twisting, bending, walking, foot tapping etc.

Novel biocompatible and brush copolymers have been developed for cancer treatment using its controlled drug-release potential. Polyurethane graft on linear dextrin has been synthesized to control the hydrophilic–hydrophobic balance for regulated drug delivery. The properties of the graft copolymers have been tuned through graft density. The prepared grafts are thermally stable and mechanically strong. An injectable hydrogel has been developed by embedding the drug-loaded brush copolymers in methyl cellulose to better control the release for a prolonged period, importantly by keeping the drug release at a constant rate. Cellular studies indicate the biocompatible nature of the brush copolymers whose controlled and slow release of drug exhibit significant cytotoxic effects on cancer cells. Endocytosis of drug tagged contrast agent indicates greater transport of biologically active material inside cell as observed through cellular uptake studies. In vivo studies on melanoma mice exhibit the real efficacy of the controlled drug release from the injectable hydrogel with significant melanoma suppression without any side effects as opposed to severe toxic effects observed in conventional chemotherapy. Special application method of drug-loaded hydrogel just beneath the tumor makes this system incredibly effective through confinement. Thus, brush copolymer injectable hydrogel is a promising vehicle for control release of drug for cancer treatment in future.

A novel, water-soluble, luminescent anthracene-bridged AA-type bi-arm poly(N-vinylpyrrolidone) (ATC-PNVP) was synthesized using a click reaction between alkyne-terminated PNVP and 9,10-bis(azidomethyl)anthracene. The resultant anthracene-bridged PNVP (ATC-PNVP) was characterized using 1H NMR, FTIR, UV-Vis, and fluorescence spectroscopic methods and GPC analysis. ATC-PNVP showed effective fluorescence properties in an aqueous medium. It showed highly selective "turn off" sensing behaviour towards picric acid, a common nitro-aromatic explosive, with a wide linear range of detection of 0.01-0.3 mM and LOD value of 0.006 mM in water. ATC-PNVP-based paper sensors also showed very effective detection of picric acid in the concentration range 0.001-1.0 mM. Its binding with bovine serum albumin (BSA) was studied using steady-state, synchronous and 3D fluorescence spectroscopy and this study showed effective quenching of the intrinsic fluorescence of BSA and occurrence of a FRET-type interaction. Furthermore, this luminescent ATC-PNVP was efficiently used as a fluorescence microscopy labelling agent in NIH-3T3 and HeLa cells, and showed greater uptake and hence better fluorescent labelling in the cytosols of the tested cells than free 9,10-bis(azidomethyl) anthracene. The cell viability study also showed a very good biocompatible and non-toxic nature of ATC-PNVP at lower working concentrations towards each of the types of cells tested.

Nanochannels were created in poly(vinylidene fluoride) and its nanohybrid films by bombarding with high-energy swift heavy ions. The nanochannel dimensions of the membranes varied from 80 to 100 nm using 5 × 107 ion fluence of SHIs. The walls of the nanochannels were grafted with the monomer 3-hexylthiophene using the free radicals generated by the swift heavy ions, which was followed by their sulphonation for better ion conduction. Organically modified nanoclay enhanced the electroactive β-phase in the polymer and its extent increased after irradiation, grafting and sulphonation, resulting in a better material for different electroactive applications. The semiconducting current–voltage characteristics of the functionalized nanochannels were studied through a parameter analyzer of the bulk film against the insulating behavior of the neat polymer. The current–voltage characteristic of the membrane exhibited strong dependency on functionalization and showed superior conduction in the functionalized nanohybrid membrane. The proton conductivity of the functionalized nanohybrid was 4.59 × 10−2 S cm−1 at 30 °C, while methanol permeability was drastically reduced as compared to that of standard Nafion 117; this indicated the higher values of the selectivity parameter, which is a key feature of the better performance of the fuel cell membrane: 1.02 × 105 S cm−3 s as opposed to the value of 0.73 × 105 S cm−3 s for Nafion 117. The membrane electrode assembly studies of the functionalized nanohybrid showed 0.76 V open circuit voltage, leading to power density of 92 mW cm−2 and current density of 252 mA cm−2, which were significantly higher than those of the functionalized pure polymer and standard Nafion 117 membrane, indicating its good potential for applications in fuel cells.

A bio-based piezoelectric egg shell membrane (ESM) is used for energy harvesting applications in the form of two and three-component nanohybrids. A bio-waste piezo-filler in a piezoelectric polymer matrix was designed through an induced β-phase nucleation in the matrix using an organically modified two-dimensional nanoclay. Structural alteration (α to β-phase) in the presence of the nanoparticles was also manifested by morphological changes over spherulite to a needle-like morphology; thus, these nanohybrid materials are suitable for energy harvesting applications. ESM-based nanogenerators were fabricated with local ordering of piezo phases, as revealed via atomic force microscopy, leading to the generation of mostly electroactive phases in the whole nanohybrid. The voltage outputs from the optimized device were measured to be ∼56 and 144 V in single and multiple stacks (five), respectively, with corresponding power densities of 55 μW cm−2 and 100 μW cm−2. The efficiency of the device was verified using a variety of body movements, e.g. bending, twisting, walking, and foot tapping, causing mechanical energy dissipation, which eventually transformed into energy storage. The underlying mechanism of high conversion of energy is explained by the synergistically induced piezo-phase in the polymer matrix together with the floppy piezo-filler. The mechanical stability, durability and repeated energy conversion of the hybrid device make it a robust nanogenerator. The biocompatibility of the nanogenerator was verified through cellular studies, demonstrating its appropriate use in powering biomedical devices/implants.

Biodegradable poly(e-caprolactone) (PCL) is developed as a controlled drug delivery vehicle of vancomycin (VMC) with the advantage of avoiding a second surgery. The PCL–VMC hybrid, prepared through a solution route, is used as a delivery vehicle for vancomycin for controlling MRSA osteomyelitis as well as healing the cavity simultaneously in an experimental study. An in vitro study is conducted to optimize vancomycin impregnation in the PCL–VMC hybrid. An in vitro study on drug release from the hybrid material is investigated in phosphate buffer saline showing steady and sustained release of the drug. The release kinetics is fitted with several models and a non-Fickian nature is established following the Korsmeyer–Peppas model. Spectroscopic techniques and morphology observations reveal the cause of sustained release to be the strong interaction between the drug and the polymer. The results of the antibacterial assay show that the loading of vancomycin into the PCL matrix is able to maintain the activity of the pure drug. For the in vivo study, a unicortical defect is created in the metaphysis of the distal femur in rabbits. After contaminating the defect with MRSA, the 1st group of rabbits were treated with pure polymer, the 2nd group of rabbits were treated with normal saline (PBS), the 3rd group of rabbits were treated with pure VMC and in the last group of rabbits PCL–VMC was placed. Rabbits are assessed by clinical, radiological, histological, gross examination and bacterial load assays. Infection persisted throughout the period of study for both the pure polymer and PBS treated rabbits while rabbits treated with the PCL–VMC hybrid do not show any sign of infection. The VMC treated group rabbits show mild infection for the 1st week of the study; however, the infection becomes gradually more severe with time. Serial histology confirms the formation of new bone without any inflammation and necrosis for the rabbits treated with PCL–VMC. Importantly, the PCL–VMC hybrid bioadsorbs after delivery of the drug and thereby avoids the second surgery to remove the conventional implant.

Latent tracks in pure polymer and its nanohybrid are fabricated by irradiating with swift heavy ions (SHI) (Ag+) having 140 MeV energy followed by selective chemical etching of the amorphous path, caused by the irradiation of SHI, to generate nanochannels of size ∼80 nm. Grafting is done within the nanochannels utilizing free radicals generated from the interaction of high-energy ions, followed by tagging of ionic species to make the nanochannels highly ion-conducting. The uniform dispersion of two-dimensional nanoparticles better controls the size and number density of the nanochannels and, thereby, converts them into an effective membrane. The nanoparticle and functionalization induce a piezoelectric β-phase in the membrane. The functionalized membrane removes the radioactive nuclide like 241Am+3 (α-emitting source) efficiently (∼80% or 0.35 μg/cm2) from its solution/waste. This membrane act as a corrosion inhibitor (92% inhibition efficiency) together with its higher proton conduction (0.13 S/m) ability. The higher ion-exchange capacity, water uptake, ion conduction, and high sorption by the nanohybrid membrane are explored with respect to the extent of functionalization and control over nanochannel dimension. A membrane electrode assembly has been fabricated to construct a complete fuel cell, which exhibits superior power generation (power density of 45 mW/cm2 at a current density of 298 mA/cm2) much higher than that of the standard Nafion, measured in a similar condition. Further, a piezoelectric matrix along with its anticorrosive property, high sorption characteristics, and greater power generation makes this class of material a smart membrane that can be used for many different applications.

The anionic membrane based on poly(vinylidene fluoride) (PVDF) has been successfully synthesized by grafting of vinyl benzyl trimethyl ammonium chloride. The chemical grafting has been confirmed through the spectroscopic techniques such as FTIR, NMR, and UV–visible. Morphological studies through the scanning electron microscope and atomic force microscope also indicate the changes in surface topography. Structural transformation was studied using XRD and DSC measurements, and the deconvolution analyses indicate the phase fraction of the functionalized membrane as compared with pristine PVDF. The polar/partial polar phase (β+γ), responsible for piezoelectricity, is found to be 64% for a functionalized membrane. The mechanical stability and glass transition temperature of the functionalized membrane are determined using dynamic mechanical measurement. Membrane characteristics such as water uptake (14.2%), ion exchange capacity (0.91 mmol/g), ion conductivity (0.52 mS/cmat 25 °C), and lower activation energy value of 28.31 kJ/mol of the functionalized membrane indicate the suitable electrolyte for alkaline fuel cells, and the creation of the piezoelectric phase indicates the possibility of a smart membrane for various technologies.

The presence of hydroxyl groups in cyclodextrin (CD) makes it highly hydrophilic and simultaneously allows its chemical modification to graft polyurethane to control the drug release for longer period of time by maintaining the hydrophobic-hydrophilic balance through varying extent of grafting. Grafting of polyurethane on CD is confirmed through 1 H NMR and molecular weight measurement while FTIR and UV visible studies further support grafting and emphasize the interaction among polymer chains as a whole. Degree of grafting is evaluated from the integrated peak area in NMR spectra. Thermal and mechanical measurements show improved stability and strength of the graft polymers with respect to pure CD. The conversion of particle nature of CD to strip-like morphology in graft copolymers is evident from atomic force microscopy. Sustained drug release has been achieved using graft copolymer against burst release from pure CD and specific interactions, as observed through spectroscopy and thermal measurements, are responsible for sustained release of drug. Biocompatibility of graft copolymers has been checked using cellular studies through MTT assay and cell adhesion. Importantly, the cell killing efficiency has been demonstrated by embedding anticancer drug in polymer matrices causing mortality rate of 75% using graft copolymer against scanty 25% using pure drug or drug embedded in CD and the result is understood from the sustained release of drug from the graft copolymer vis-a-vis burst release in other systems. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 434-444, 2019.

Electrospun scaffold has been developed using biodegradable polymer and age old herbal drug for efficient wound healing patch with much better patient compliance. Positively charged smaller particle size (40 nm) of the drug has been prepared for greater penetration through epidermal barrier to enhance the wound healing activity of drug. Controlled drug release has been understood in terms of interactions between the components through spectroscopic techniques and calorimetric studies. In-vivo study using albino rats shows better wound healing efficiency of scaffold in terms of higher wound area contraction, minimum inflammation, faster epithelialization and vascularization. Cellular studies also endorse the scaffold as better biomaterial. Clinical studies also demonstrate fast healing of different type of wounds in presence of all three wound dressing materials with histological evidences. The complete biodegradation of the patch confirms its green nature of the developed patch.

A hole conducting layer for quantum dot sensitized solar cell (QDSS) as a function of redox behavior has been reported. Polyurethanes, comprising hard and soft segments, have been functionalized fo...

Functionalization of poly(vinylidene fluoride-co-hexafluoro propylene) (HFP) is made to prepared membrane for its application in fuel cell. The sulphonation of HFP membrane is carried out under control condition to maintain its stiffness and toughness of the membrane. The evidence of functionalization (sulphonation) is confirmed through different spectroscopic techniques such as NMR, FTIR, EDS mapping and UV–visible measurement and the degree of sulphonation is calculated from the integral peak area. The structural change from the usually crystallized α-phase to piezoelectric γ-phase in functionalized membrane is established through XRD studies. Mechanical and thermal stabilities of the membrane are established through universal testing machine and thermogravimetric measurements. Suitability of proton exchange membrane has been verified through their high water uptake (12%), low fuel permeability (4.43 × 10−7 cm2 s−1) and thermal stability (up to 200 °C). The proton conductivity is found to be high in functionalized membrane while its low fuel permeability and high temperature stability is very good as compared to standard Nafion membrane. Efficiency of the membrane is reported in the form of selective parameter (ratio of conductivity and methanol permeability) of value 0.78 × 105 S cm−3.s for functionalized HFP against the value of 0.81 × 105 S cm−3.s for standard Nafion 117. Moderately high open circuit voltage (0.63 V) and power density of 48.34 mW/cm2 is reported indicating very good performance of the overall membrane for direct methanol fuel cell. Therefore, direct functionalization of a polymer is a better approach for the preparation of fuel cell membrane.

Poly(vinylidene fluoride) (PVDF) is processed at high temperature to generate energy from waste mechanical energy. The piezoelectric β-phase has been induced through uniaxial elongation of polymer films at high temperature. The extent of β-phase has been confirmed from a deconvoluted XRD pattern, found to be ∼75% of the electroactive phase, and able to demonstrate high piezoelectric effect as evident from the measured piezoelectric coefficient of −30 pC/N after a suitably processed and poled specimen. Bulk morphology and spectroscopic studies support the structural alteration. Following the direct piezoelectric effect, energy harvesting devices have been fabricated which show very high power output of 55.2 μW/cm2 using the processed and poled specimen. Thus, robust and easily processable polymeric material having very high energy conversion efficiency is demonstrated which is sufficient to power miniaturized devices.

Different hard segment content (HSC) polyurethanes (PUs) have been synthesized using linear (hexamethylene diisocyanate; HMDI) and alicyclic (isophorone diisocyanate; IPDI) diisocyanates to understand the effect on structure–property relationship and how it affects the shape memory behavior of PUs. Structural details have been elucidated through NMR and other spectroscopic techniques including the quantification of HSC. The nature of interactions between the polymer chains and their extent has been revealed. Thermal and mechanical properties as a function of the chemical structure and HSC indicate faster degradation in higher HSC. Layer-by-layer self-assembly through extensive hydrogen bonding has been established through XRD, small-angle neutron scattering, AFM, and optical images by capturing nanometer scale to micron scale inhomogeneities. The greater interaction in the HMDI system as compared to IPDI PUs leads to the crystallization of the hard segment. The differential shape memory effect has been re...

Correction for ‘Nanochannel conduction in piezoelectric polymeric membrane using swift heavy ions and nanoclay’ by Karun Kumar Jana et al., RSC Adv., 2013, 3, 6147–6159. DOI: 10.1039/C3RA23176C

Two major problems in chemotherapy, poor bioavailability of hydrophobic anticancer drug and its adverse side effects causing nausea, are taken into account by developing a sustained drug release vehicle along with enhanced bioavailability using two-dimensional layered double hydroxides (LDHs) with appropriate surface charge and its subsequent embedment in polymer matrix. A model hydrophobic anticancer drug, raloxifene hydrochloride (RH), is intercalated into a series of zinc iron LDHs with varying anion charge densities using an ion exchange technique. To achieve significant sustained delivery, drug-intercalated LDH is embedded in poly(ε-caprolactone) (PCL) matrix to develop intravenous administration and to improve the therapeutic index of the drug. The cause of sustained release is visualized from the strong interaction between LDH and drug, as measured through spectroscopic techniques, like X-ray photoelectron spectroscopy, infrared, UV-visible spectroscopy, and thermal measurement (depression of melting temperature and considerable reduction in heat of fusion), using differential scanning calorimeter, followed by delayed diffusion of drug from polymer matrix. Interestingly, polymer nanohybrid exhibits long-term and excellent in vitro antitumor efficacy as opposed to pure drug or drug-intercalated LDH or only drug embedded PCL (conventional drug delivery vehicle) as evident from cell viability and cell adhesion experiments prompting a model depicting greater killing efficiency (cellular uptake) of the delivery vehicle (polymer nanohybrid) controlled by its better cell adhesion as noticed through cellular uptake after tagging of fluorescence rhodamine B separately to drug and LDH. In vivo studies also confirm the sustained release of drug in the bloodstream of albino rats using polymer nanohybrid (novel drug delivery vehicle) along with a healthy liver vis-à-vis burst release using pure drug/drug-intercalated LDHs with considerable damaged liver.

We have described the ability of a newly synthesized fluorescent probe (LP1) to detect phosphatase activity in lysosomes in cancer cells. Probe LP1 displayed a 33-fold fluorescence intensity enhancement at λem 532 nm in the presence of phosphatase in HEPES buffer (pH 4.5). The quantum yield of probe LP1 was increased by ∼21-fold upon exposure to phosphatase at acidic pH. The probe LP1 is highly chemoselective toward phosphatase (ALP/ACP) and is insensitive to interference by ubiquitous biological analytes. The high cell adhesion property and cell viability of LP1 indicate that LP1 is biocompatible and nontoxic; these two characteristic features make it a suitable candidate for phosphatase tracking in living cells. LP1 dose-dependent fluorescence images in living cells suggested that the expression of phosphatase in cancer cells (HeLa) is 2-fold higher as compared to the normal NIH-3T3 cells. The colocalization images confirmed that LP1 was exclusively localized in lysosomes. We envision that LP1 could be a potential tool in clinical diagnosis for discriminating cancer cells from normal cells depending on the expression of phosphatase in lysosomes.

Single phase equi-atomic (Al0.2Co0.2Fe0.2Mn0.2Ni0.2)3O4 high-entropy oxide (HEO) having spinel structure was synthesised employing simple and cost effective microwave assisted co-precipitation technique, followed by calcination at 500 °C. The material obtained was highly crystalline and stable at higher temperatures. The uniformity in elemental distribution was apprehended through STEM-EDS elemental mapping. The X-ray photoelectron spectroscopy confirmed +3 ionic state for Fe and Al, while other elements oxidised to higher ionic states to maintain charge neutrality. Ferrimagnetic behaviour was confirmed for the obtained HEO through magnetic characterisations.

Recent reports on the magnetic nanoparticles (MNPs) as an efficient and alternative photothermal agent have excited the researchers worldwide. While MNPs have been explored well for high heating performance during magnetic hyperthermia (MHT), their full potential is yet to be explored as an efficient photothermal agent. In addition, the simultaneous exposure of alternating magnetic field (for MHT) and near infrared irradiation (for photothermal therapy PTT) can drastically enhance the heating behaviour of MNPs. In the present work we explored microwave assisted polyol method to get γ-Fe2O3 nanoflowers. The use of sodium acetate in varying amounts, as an alkali source, allowed the modification of structural and magnetic properties leading to the formation of nanoflower with high heating performance during MHT and PTT. Role of defects in γ-Fe2O3 nanoflowers were investigated using photoluminescence spectroscopy which highlighted distinct role of oxygen vacancies and surface states. The nanoflowers with better crystallinity and relatively higher coercive field performed well during MHT. The observed high intrinsic loss power value of 15.21 ± 0.34 nHm2Kg-as significantly higher than the commercially available ferrofluids and previously reported values for nanoflowers. During PTT, the therapeutic temperature of 42 °C was achieved for the aqueous suspension with a concentration as low as 100 µg/mL which demonstrates the superiority of γ-Fe2O3 nanoflowers as an efficient PTT agent.

The host–guest inclusion complex of meta-cresol (m-cresol, liquid at room temperature, guest molecule) is synthesized with β-cyclodextrin (β-CD, host molecule). The inclusion complex is characterized by various techniques like nuclear magnetic resonance, powder X-ray diffraction, field emission scanning electron microscopy and spectroscopic (steady state as well as time-resolved) techniques. To the best of our knowledge, no literature data is available on the photophysical properties (especially fluorescence upon photoexcitation) of m-cresol in liquid media till date. Our spectroscopic studies exhibit some interesting photophysical properties of m-cresol and its inclusion complex with β-CD in different liquid media. The present work is important in view of the various potential applications of m-cresol in science, technology and medicine.

Harvesting of energy, the continuous human effort throughout history, or reclaim energy from mechanical stress is presented in this work. Reduced graphene oxide, homogeneously dispersed in poly(vinylidene fluoride), induces the electroactive phases in the polar polymer. Good dispersion arising from better interactions between 2-D nanofiller and polymer chain is revealed through transmission electron microscopy and spectroscopic measurement. The induction of electroactive phases in polymer in the presence of nanofiller has been confirmed through structural, spectroscopy and thermal studies. Electroactive phases is confirmed through FTIR peaks at 840 cm −1 − 1 for β∕γ β ∕ γ phase and 884 cm −1 band for γ γ -peak in nanohybrid against 796, 876 and 975 cm −1 absorption peaks for α α -phase in pure PVDF. Morphological alteration (both surface and bulk) reaffirms the change of phases in the nanohybrid vis-a-vis pure polymer. Quantification of different phases has been made, in the presence of varying content of graphene, which is directly reflected in their properties. Greater mechanical and thermal stability of the nanohybrid help promoting this class of hybrid material for device application. Devices have been fabricated to understand the piezoelectric responses from the hybrid materials and output electrical signals (both voltage and current) are measured under mechanical stress applied from a motor driven mechanical setup. Both output voltage and current significantly increase either with greater applied load or graphene content in hybrid primarily due to higher strain produce or better induction of piezo phase, respectively. Moderately high electrical power density up to 14 μ μ W/cm 3 is measured from the device made of the hybrid material, suitable for a number of low power consuming electronic self-power devices and wireless sensors.

Thermoplastic polyurethane (TPU) nanohybrids have been prepared through melt extrusion using ester type PU and different concentrations of Indian origin organically modified nanoclay as filler. The level of dispersion of nanoclay in TPU is found to be good and considerable intercalation occurs due to strong interaction between polymer matrix and filler. The interaction is shown through spectroscopic measurement from the shifting of peak position in FTIR and UV–vis. absorption spectra. Nanoclay induces crystallization in polymer while the blob size, as measured through small angle neutron scattering, decreases in nanohybrid (1.5 nm) as compared to pure TPU (1.7 nm) obtained after fitting the initial data point to Debye-Bueche model. Mechanical responses are much superior in nanohybrid as compared to pure TPU and stiffness values continue to increase with nanoclay concentration while the toughness reach ata maximum value at an optimum concentration of 4 wt% of nanoclay. Uniaxial stretching lead to the crystallization of segments and ordering of hard segments as verified through sharp melting points in stretched TPU vis-a-vis predominant amorphous nature before stretching. Nanohybrid membranes are prepared to investigate the gas permeation across the membranes and very high gas barrier of nanohybrid (449 Barrer) is found as opposed to pure TPU barrier of 169 Barrer. Critical assessment of permeability is performed in presence of nanoclay in different concentrations with a plausible mechanism of gas barrier.

Bone cement has found extensive usage in joint arthroplasty over the last 50 years; still, the development of bone cement with essential properties such as high fatigue resistance, lower exothermic temperature, and bioactivity has been an unsolved problem. In our present work, we have addressed all of the mentioned shortcomings of bone cement by reinforcing it with graphene (GR), graphene oxide (GO), and surface-modified amino graphene (AG) fillers. These nanocomposites have shown hypsochromic shifts, suggesting strong interactions between the filler material and the polymer matrix. AG-based nanohybrids have shown greater osteointegration and lower cytotoxicity compared to other nanohybrids as well as pristine bone cement. They have also reduced oxidative stress on cells, resulting in calcification within 20 days of the implantation of nanohybrids into the rabbits. They have significantly reduced the exothermic curing temperature to body temperature and increased the setting time to facilitate practitioners, suggesting that reaction temperature and settling time can be dynamically controlled by varying the concentration of the filler. Thermal stability and enhanced mechanical properties have been achieved in nanohybrids vis-à-vis pure bone cement. Thus, this newly developed nanocomposite can create natural bonding with bone tissues for improved bioactivity, longer sustainability, and better strength in the prosthesis.