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Local delivery of anticancer agents via injectable hydrogels could be a promising method for achieving spatiotemporal control on drug release as well as minimizing the disadvantages related to the systemic mode of drug delivery. Keeping this in mind, we report the development of N,O-carboxymethyl chitosan (N,O-CMCS)-guar gum-based injectable hydrogels for the sustained delivery of anticancer drugs. The hydrogels were synthesized by chemical crosslinking of multialdehyde guar gum (MAGG) and N,O-CMCS through dynamic Schiff base linkages, without requiring any external crosslinker. Fabrication of injectable hydrogels, involving N,O-CMCS and MAGG via Schiff base crosslinking, is being reported for the first time. The hydrogels exhibited pH-responsive swelling behavior and good mechanical properties with a storage modulus of about 1625 Pa. Due to the reversible nature of Schiff base linkages, hydrogels displayed excellent self-healing and thixotropic properties. Doxorubicin (Dox), an anticancer agent, was loaded onto these hydrogels and its release studies were conducted at pH 7.4 (physiological) and pH 5.5 (tumoral). A sustained release of about 67.06% Dox was observed from the hydrogel after 5 days at pH 5.5 and about 32.13% at pH 7.4. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay on the human embryonic kidney cell line (HEK-293) and the hemolytic assay demonstrated the biocompatible nature of the hydrogels. The Dox-loaded hydrogel exhibited a significant killing effect against breast cancer cells (MCF-7) with a cytotoxicity of about 72.13%. All the data presented support the efficiency of the synthesized N,O-CMCS/MAGG hydrogel as a biomaterial that may find promising applications in anticancer drug delivery.

Magnesium ferrite (MgFe2O4) nanorods and magnesium ferrite/polythiophene (MgFe2O4/PTh) composites have been fabricated by sol–gel and in-situ emulsion polymerization approach to investigate EMI (electromagnetic interference) shielding activity in the X-band region. The encapsulation of MgFe2O4 nanorods by conducting PTh decreased the coercivity and improved the conductivity of the composites. The composite with a maximum loading of MgFe2O4 nanoparticles (MP-21; MgFe2O4:PTh = 2:1) displayed superior magnetic moment (23.27 emu/gm) and coercivity (0.023 kOe). In addition, the composite (MP-21) exhibited the highest SE (shielding effectiveness) of − 40.17 dB at 10.29 GHz by 1 mm thick pellet for X-band region (8.2–12.4 GHz). The excellent shielding behavior of the composite is attributed to the synergistic effect of these two moieties resulting in the high dielectric and magnetic loss. Moreover, the porous and rod-like morphology of these composites further induces microwave absorption ability. These results revealed that MgFe2O4/PTh composite showed the maximum EMI shielding property, which can find potential application as a lightweight, high-performance EMI shielding material.

Gum arabic with multialdehyde groups (GAMA) was synthesized and utilized as a naturally derived macromolecular and nontoxic cross-linker to develop biocompatible and smart succinic anhydride-modified chitosan (SCS)-based injectable hydrogels for the first time. Aqueous solutions of GAMA and SCS were mixed at 37 °C to obtain hydrogels through pH-responsive, dynamic, and biodegradable Schiff base linkages. The effect of concentration of GAMA on hydrogel stiffness, swelling, morphology, and drug release behavior was investigated. These hydrogels exhibited outstanding self-healing and mechanical properties. Nanocurcumin as a chemotherapeutic agent was synthesized and loaded into these hydrogels for release studies carried out at pH 7.4 and 5.5. MTT assay revealed that these hydrogels are nontoxic to human embryonic kidney cell line (HEK-293). Loaded hydrogels demonstrated significant cytotoxicity against breast cancer cell line (MCF-7). Thus, the present strategy may find promising application for controlled delivery of anticancer drugs for treating locally accessible cancers.

The present study reports the formulations of biocompatible nanocomposite hydrogels using chitosan (CH), poly(vinyl alcohol) (PVA), oleo polyol, and fumed silica (SiO2) via a free radical polymerization method for anti-cancer drug delivery. Structural, morphological, and mechanical analyses were conducted using FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, and rheological techniques. The effect of SiO2 concentration on mechanical strength, swelling ratios, morphological, and drug delivery behavior was investigated. The incorporation of SiO2 nanoparticles in hydrogels resulted in a significant enhancement in its properties. MTT assay of human embryonic kidney (HEK-293) and human colon (HCT116) cancer cell lines was conducted for up to 48 h to evaluate biocompatibility and cytotoxicity. These studies confirmed the biocompatible nature of nanocomposite hydrogels. Cisplatin-loaded nanocomposite hydrogels exhibit sustained release as compared to free cisplatin at pH 4.0 an...

The electronic and communication devices such as mobile, laptop, and radio ease our day-to-day life. However, these devices emit harmful radiation, which affects human health and the environment. Therefore, to prevent such radiation-based pollution and provide a safer working environment, viable and promising EMI shielding materials have been investigated. Keeping this in mind, the present work reports the relatively low-temperature synthesis of bismuth-doped barium ferrite (BaBixFe12−xO19, Bi-BFO) nanoparticles and their nanocomposite via sol–gel and in situ emulsion polymerization approaches for their application in EMI shielding material. The influence of Bi-doping on phase purity, morphology, structure, and thermal behavior has been explored. The EMI shielding properties of these materials have been investigated in the X-band (8.2–12.4 GHz) region. The composite (Bi-BFO:PT = 2:1 Bi-BFO/PTh-21) with 1 mm thickness exhibited maximum shielding effectiveness (SE) of − 47.12 dB in the X-band region. The high shielding activity is mainly due to the efficient complementarities between the magnetic and dielectric loss. The doping of Bi in barium ferrite results in the increase in electrical polarization that led to the high dielectric loss, causing higher absorption of electromagnetic (EM) waves. These studies suggest that the nanocomposite may find its scope as an excellent microwave absorber for a wide frequency region.

Oleo polymer coatings provide a paradigm shift in traditional corrosion control. Herein, the present work provides new insight on solventless Tung oil Polyetheramide-Cerium oxide (UTOPETA-CeO2) nan...

Present study reports a facile synthesis of surface-active antimicrobial hyperbranched polyurethane coatings using oleo-ethers of boric acid (BA) as branching and biocidal moiety (BHPU). The antimicrobial branching center was synthesized via polycondensation reaction of BA and vegetable oil-based diol. The structural characterization of synthesized BHPU and its linear counterpart was investigated using Fourier-transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 11B NMR) spectroscopy techniques. The cured coatings were examined by physico-mechanical, thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). The antimicrobial behavior of these polymers against Gram-positive and Gram-negative bacteria was carried out by well diffusion technique. The appearance of zone of inhibition (ZOI) in case of BHPU confirmed its antimicrobial activity, which arisen due to the presence of cationic moiety in its structure. These investigations showed that the utilization of oleo-ethers of BA as branching agent in synthesis of BHPU coatings induced prominent effect on its physico-mechanical, thermal, and biocidal properties. In addition, soil burial study for 210 days was conducted on BHPU film to confirm its contact-killing mechanism against soil-borne bacteria. These results suggest the potential scope of BHPU in various applications such as long-term antimicrobial surface-active coatings for medical devices, packaging industry, paints, etc. Keywords: Boric acid, Hyperbranched, Polyurethane, Antimicrobial coating, Sustainable polymers

Tung oil monoglyceride (TMG), 4,4′-diaminodiphenylsulfone modified (DDS-TO-alkyd) polypyrrole enveloped cerium oxide (PPy-PSCeO2) nanofiller dispersed alkyd nanocomposites (alk-DDS-PPy-PSCeO2-x) were synthesized using pyromellitic dianhydride through an eco-friendly, solvent-less and in situ approach. Structural elucidation was carried out using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H, 13C NMR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques while morphological studies were performed using a scanning electron microscope (SEM/EDX), dynamic light scattering (DLS) and optical micrographs. Physico-chemical and physico-mechanical studies were tested to ASTM standards with a hydrophobic study measured by CA values. Further, the anticorrosive performance of the plain alkyd (alk-Pl) and alk-DDS-PPy-PSCeO2-x nanocomposite-coatings were experimentally studied using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and salt spray studies (SST). These studies revealed that nanocomposite (alk-DDS-PPy-PSCeO2-1.5) coatings synthesized by the green and solvent-less approach exhibit higher physico-mechanical properties, hydrophobicity, adhesion and superior corrosion protective performance under acidic and saline environments in comparison to reported oleo-alkyds and other oleo-polymer nanocomposite coatings. The proposed oleo-alkyd nanocomposite-coatings are found to be ecologically reliable and thermally more stable and can be safely used up to 213 °C.

The present research highlights the synthesis of new polymer Polyborozirconia(o-toluidine) (PBOT-Z): a novel nanoconducting polymer via a green, easy and scalable approach. This method was free of the template and harmful surfactant, leading PBOT-Z nanoparticles of uniform size c.a. 120–130 nm of well-defined shape. Successively, PBOT-Z incorporated epoxy nanocomposites were prepared which revealed that coatings exhibited outstanding anti-corrosive properties as compared to other nanocomposite coatings. This was corroborated to Boron(B) and Zirconia(Zr) in POT, both of which acted as a smart filler, dynamic cross-linkers as well as compatible modifiers.

The enormous demand of energy and depletion of fossil fuels has attracted an ample interest of scientist and researchers to develop materials with excellent electrochemical properties. Among these materials carbon based materials like carbon nanotubes (CNTs), graphene (GO and rGO), activated carbon (AC), and conducting polymers (CPs) have gained wide attention due to their remarkable thermal, electrical and mechanical properties. On this account, the present review article summarizes the history of ESDs and the basic function of various types of ESDs. Further, the various nanomaterials used in energy storage devices for the past few years have also been discussed in detail. In addition, the future trend in the development of highly efficient, cost-effective and renewable energy storage materials have also been highlighted. Keywords: Batteries, Capacitor, Conducting polymer, Graphene, Energy devices

Herein, a facile route was employed for the construction of novel dual-functional boronated (hybrid) hyperbranched polyurethane composite (HPUC) coatings using covalently functionalized reduced graphene oxide (FRGO) as chain extender and reinforcing agent. The FRGO exhibited excellent compatibility with the boronated HPU matrix that resulted in the chemical, structural and surface transformation of FRGO-HPUC coatings. The electrochemical corrosion studies were employed to confirm the protective performance of these composite coatings. The presence of electron deficient centres (tri-coordinated B) and electron rich FRGO restricted the diffusion of electrons through the coating network, which altered the mechanism of corrosion protection. In addition, the antimicrobial surface activity of these composites were investigated to ascertain their permanent contact killing properties.

Waterborne polyurethanes (WPUs), owing to their environmental friendliness and non-flammability, are considered as a green class of materials for a wide spectrum of applications, like adhesives, co...

The chemically oxidized gum arabic was prepared and used as a naturally derived nontoxic and pH-responsive cross-linker to develop smart polyvinyl alcohol (PVA)-based hydrogels for the first time. The formulated hydrogels exhibited high mechanical properties, good porosity, and pH sensitivity, which facilitated their application as promising biomaterials for sustained delivery of folic acid. Further, the synthesized cross-linked PVA hydrogels displayed no cytotoxicity toward the human embryonic kidney cell line and exhibited higher blood compatibility. The hydrolytic degradation study confirmed their biodegradable nature. While the sustained delivery along with photoprotective properties of these hydrogels confirmed their multifunctional characteristics, these results suggest that these hydrogels may act as an efficient photoprotective material and find their application in the field of drug delivery.

Sustainable development requires greener modifications of petro-based polymers and environment benign alternatives. Here we report, formulation of sustainable vegetable (soy) oil based epoxy polymer blends (ESODG), and their green colored nickel oxide (NiO) based organic-inorganic hybrid (ESODG-PA-NiO) nanocomposites (NCs). Along with additional improvements over generic shortcomings of DGEBA epoxies, the polymeric NC formulation can substitute up to 50% of synthetic epoxy polymer. ESODG-PA-NiO imbibes various value added properties of synthetic polymers but the use of ESO and reduction in the use of organic solvents lead to a sharp decrease in volatile organic components (VOCs). The incorporation of NiO and formulation of stable NCs were confirmed by Fourier transform infrared (FT-IR), 1H and 13C nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA). Further, the anticorrosive performance of these coatings have been investigated using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and salt (5 wt.% NaCl vapors) mist techniques. It was observed that with the increased NiO concentration in NC improved, the thermal stability, physicochemical/mechanical properties, hydrophobicity, lowering of current density (Icorr), and higher pore resistance (3.5 wt.% NaCl and HCl solutions) values. The excellent anticorrosive performance of ESODG-PA-NiO hybrid is mainly governed by the electrostatic interaction between NiO and ESODG-PA, which provide additional locking/sealing effect and rectified polymeric artifacts and can be used as a surface decorative/protective anticorrosive coating.

Surface functionalized tri-metallic strontium magnesium ferrite (Sr0.3Mg0.7Fe2O4, SMF) nanoparticles were synthesized by using facile solvent less green oleo polyol method. Various analytical techniques (XRD, XPS, FT-IR, TEM, SEM, BET, and VSM) were used for the investigation of the crystal lattice, surface functionalization, morphology, surface area, and magnetic properties of these nanoparticles. SEM and TEM analysis revealed that the nanoparticles exhibit mesoporous morphology with cubic structure. These mesoporous nanoparticles have been exploited for the removal of toxic organic pollutant (Congo red, CR) from the aqueous solution. Detailed investigations on the adsorption of CR dye by these nanoparticles have been conducted via the rate kinetics study using various adsorption isotherms (Freundlich, Langmuir, Temkin, etc.). These studies revealed that the mesoporous SMF nanoparticles with the high surface area (21.85 m2g−1), have exhibited superior adsorption capacity (>90% within 30 min) and fast separation ability under the influence of external magnetic field along with good recyclability (∼93%). The adsorption analysis of magnetic SMF revealed pseudo-second order dye removal kinetics and follow Freundlich isotherms. These properties of magnetic SMF nanocubes provide an extra edge over other such reported systems and may find its potential as a cost-effective magnetic adsorbent for water treatment application.

Barium ferrite encapsulated polythiophene (BaFe12O19/PTh) nanocomposite has been synthesized to analyse electromagnetic interference (EMI) shielding. The morphological analysis of the synthesized composites has been investigated by scanning electron microscopy (SEM), which confirmed the encapsulation of BaFe12O19 nanoparticles by PTh forming a core-shell structure. Highest loading of BaFe12O19 in composite (NC-100 i.e. BaFe12O19:PTh = 1:1) exhibits excellent magnetic properties with a magnetic moment and coercivity of 25.78 emu/gm and 2.5 kOe, respectively. Microwave shielding behaviour of the nanocomposite samples has been tested in X-band region by vector network analyser. Highest −43.27 dB shielding effectiveness at 11.65 GHz has been obtained in NC-100 composite. The excellent shielding effectiveness is due to the synergistic effect of dielectric and magnetic loss of the nanocomposite. These results suggest that the BaFe12O19/PTh nanocomposite (NC-100) exhibited superior EMI shielding properties and find wider application as low cost, high performance, lightweight microwave absorbing material.

Inhibition of electrochemical and microbial corrosions is one of the prominent importance in both industrial and environmental applications. Therefore, we have designed a sustainable surface-active bi-functional (antimicrobial/anticorrosive) polyurethane nanocomposite (PUC) coating by means of synergistic effects of π-π interaction and in situ incorporation of graphene oxide (GO) for the first time. The PUC was synthesized using Pongamia oil, acrylic acid (to induce π-π interaction), GO (biocidal and reinforcing agent), and toluene diisocyanate (TDI) via one-pot addition polymerization. These interactions improved GO distribution, which influenced the structure and segmental dispersion within the PUC network. Further, it was observed that the properties (physical, mechanical, thermal, barrier, and adhesion) of the synthesized PUC coating were significantly improved. The electrochemical studies confirmed that upon addition of small amount of GO (0.5 wt.%) the anticorrosive behavior of PU nanocomposite coating was increased, exhibiting high corrosion potential (Ecorr= -0.179 V), low corrosion current density (Icorr = 2.3 × 10−11 A. cm-2), and enhanced impedance modulus at low frequency (|Z|0.01 Hz = 3.6 × 1010 Ω cm2) even after 21 days of immersion (5% NaCl solution). Besides, the surface activity of the PUC coating was confirmed by its strong contact-killing effect against Gram-positive and Gram-negative bacteria. Based on these results, present work provides a facile route towards the development of high-performance dual-functional coatings that may find a wider scope of applications in various industries like maritime, food, fuel and healthcare.

Herein, we present the synthesis of CD, polycarbazole (PCz), and CDs encapsulated in PCz (CD@PCz) nanofillers. These nanofillers were dispersed in a safflower oil polyurethane (PU) matrix to formulate nanocomposite coatings. The structures, morphologies, and thermal behaviors of these coatings were investigated using Fourier transform infrared (FTIR) spectroscopy, solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The anticorrosive performance was evaluated using acid resistance, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and salt spray tests. The results showed that the PU nanocomposites had superior corrosion resistance performance with a very small loading amount (0.5%) of nanofiller (CD, PCz, and CD@PCz). The CD@PCz/PU nanocomposite coatings exhibited excellent corrosion resistance performance, with a low icorr value (1.15 × 10−11 A cm−2), a high Ecorr value (0.05 V), and the highest protection efficiency (99.999%) compared with other coating systems. The superior anticorrosive performance of these coatings was attributed to the excellent barrier properties, strong filler–matrix interactions, and the formation of a stabilized passive layer at the coating-metal interface. These results suggested that the proposed nanocomposite coatings (CD@PCz/PU) have potential for the development of a new generation of multicomponent anticorrosive coatings with high performance.

A waterborne polyesteramide (WBPEA) and its nanocomposites (WBPEA–RGO) were synthesized using soya oil, diethanol amine, phthalic anhydride and RGO nanoparticles. Ethanolic solutions of RGO nanoparticles were dispersed in WBPEA via sonication (WBPEA–RGO) and simultaneously both (WBPEA) and (WBPEA–RGO-x) were cured with 80 phr poly(melamine-co-formaldehyde) isobutylated solution (PMF). Their coatings (WBPEA–PMF-80 and WBPEA–PMF-80–RGO-x) were formulated on finally polished carbon steel strips. The structural elucidation of these materials was performed by FT-IR and NMR spectroscopic analysis. The physico-chemical, physico-mechanical, thermal and anticorrosive properties of these coatings were investigated, which revealed that the nanocomposite coatings possess remarkably good physico-mechanical [impact resistance (150 lb per in.), scratch resistance (11.5 kg), bend tests (flexibility retained up to 1/8 inch)] properties. The nanocomposite coatings show far superior anticorrosive performance (impedance = 107 ohm cm2 and phase angle = 85.6°) in comparison to those of WBPEA–PMF-80 (impedance = 106 ohm cm2 and phase angle = 82°) and other such reported coatings.

Graphene oxide (GO) reinforced Polyvinyl chloride (PVC)-Waterborne Castor Alkyd (WCA) nanocomposites (PVC/WCA/GO) films were processed through solution blending technique. TGA showed that the thermal stability of PVC/WCA/GO-0.5 films was better than that of PVC/WCA blend film. With incorporation of 0.5 wt.% GO, the tensile strength and elastic modulus of the blend nanocomposite have significantly improved by about 260% and 185%, respectively, compared with neat polymer. The physico-mechanical properties of these films suggest that the PVC/WCA/GO nanocomposite films may have a potential scope for their application in packaging industries. The results are supported by characterizations like FTIR, XRD, TEM and FESEM.

Nanocomposite hydrogels have found a wide scope in regenerative medicine, tissue engineering, and smart drug delivery applications. The present study reports the formulations of biocompatible nanocomposite hydrogel films using carboxymethyl cellulose-hydroxyethyl cellulose-acrylonitrile-linseed oil polyol (CHAP) plain hydrogel and Na-montmorillonite (NaMMT) dispersed CHAP nanocomposite hydrogel films (NaCHAP) using solution blending technique. The structural, morphological, and mechanical properties of resultant nanocomposite hydrogel films were further investigated to analyze the effects of polyol and NaMMT on the characteristic properties. The synergistic effect of polyol and nanofillers on the mechanical strength and sustained drug-release behavior of the resultant hydrogel films was studied, which revealed that the increased cross-link density of hydrogels enhanced the elastic modulus (up to 99%) and improved the drug retention time (up to 72 h at both pHs 7.4 and 4.0). The release rate of cisplatin in nanocomposite hydrogel films was found to be higher in CHAP-1 (83 and 69%) and CHAP-3 (79 and 64%) than NaCHAP-3 (77 and 57%) and NaCHAP-4 (73 and 54%) at both pHs 4.0 and 7.4, respectively. These data confirmed that the release rate of cisplatin in nanocomposite hydrogel films was pH-responsive and increased with decrease of pH. All nanocomposite hydrogel films have exhibited excellent pH sensitivity under buffer solution of various pHs (1.0, 4.0, 7.4, and 9.0). The in vitro biocompatibility and cytotoxicity tests of these films were also conducted using 3-(4,5-dimethylthiazole-2-yl-2,5-diphenyl tetrazolium bromide) assay of human embryonic kidney (HEK-293) and human breast cancer (MCF-7) cell lines up to 48 h, which shows their biocompatible nature. However, cisplatin-loaded nanocomposite hydrogel films effectively inhibited the growth of human breast MCF-7 cancer cells. These studies suggested that the proposed nanocomposite hydrogel films have shown promising application in therapeutics, especially for anticancer-targeted drug delivery.

Pemphigus Vulgaris (PV) is a life-threatening autoimmune disease manifested with blisters in the skin and mucosa and caused by autoantibodies against adhesion protein desmoglein-3 (Dsg3) expressed in epithelial membrane linings of these tissues. Despite many studies, the pathogenesis of PV remains incompletely understood. Recently we have shown Dsg3 plays a role in regulating the yes-associated protein (YAP), a co-transcription factor and mechanical sensor, and constraining reactive oxygen species (ROS). This study investigated the effect of PV sera as well as the anti-Dsg3 antibody AK23 on these molecules. We detected elevated YAP steady-state protein levels in PV cells surrounding blisters and perilesional regions and in keratinocytes treated with PV sera and AK23 with concomitant transient ROS overproduction. Cells treated with hydrogen peroxide also exhibited augmented nuclear YAP accompanied by reduction of Dsg3 and α-catenin, a negative regulator of YAP. As expected, transfection of α-catenin-GFP plasmid rendered YAP export from the nucleus evoked by hydrogen peroxide. In addition, suppression of total YAP was observed in hydrogen peroxide treated cells exposed to antioxidants with enhanced cell-cell adhesion being confirmed by decreased fragmentation in the dispase assay compared to hydrogen peroxide treatment alone. On the other hand, the expression of exogenous YAP disrupted intercellular junction assembly. In contrast, YAP depletion resulted in an inverse effect with augmented expression of junction assembly proteins, including Dsg3 and α-catenin capable of abolishing the effect of AK23 on Dsg3 expression. Finally, inhibition of other kinase pathways, including p38MAPK, also demonstrated suppression of YAP induced by hydrogen peroxide. Furthermore, antioxidant treatment of keratinocytes suppressed PV sera-induced total YAP accumulation. In conclusion, this study suggests that oxidative stress coupled with YAP dysregulation attributes to PV blistering, implying antioxidants may be beneficial in the treatment of PV.

The growth and proliferation of pathogenic microbes and bacteria on various surfaces have caused an ever-increasing awareness, necessitating scientists of diverse realm to develop potential antimicrobial materials. Among various methods of prevention, the application of biocidal polymer films and coatings has played a vital role. Generally such polymers are developed by the incorporation of antimicrobial moieties within their matrices. The design and formulation of polymer nanocomposite (PNC) films and coatings with biocidal property, have gained higher interest due to the exceptional reinforcing abilities of nanomaterials compared to other biocides. From this perspective, the aim of the present chapter is to discuss the approaches used for the fabrication and processing of surface-active, selective, leaching and nonleaching antimicrobial PNCs along with their mechanism of action. The chapter also covers the importance of naturally derived precursors for the construction of eco-friendly and cost-effective antimicrobial PNCs. Further the advantages, limitations, and the future scope of such functional PNCs have been discussed.

Biodegradable and biocompatible hydrogels are a fairly imperative class of biomaterials, which find applications for drug delivery. The blending of natural biopolymers and synthetic polymers has introduced exceptional characteristics in hydrogels for diverse biomedical applications. Here, we report a novel class of pH responsive, hydrophobically modified chitosan based hydrogels using methylmethacrylate (MMA) and sustainable polyol. The polyol derivatized hydrogels were characterized using FT-IR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The biodegradability studies were carried out in soil and water. The in vitro equilibrium swelling behavior in different buffer solutions of pH values (4 and 7.3), including some physiological solutions were also evaluated. The potential of these hydrogels in drug delivery was demonstrated by preliminary biocompatibility assessment in different human sera for 24 hours. No significant changes in the values of various components present in sera before and after test procedures were found.

The susceptibility for corrosion, poor mechanical/chemical stabilities, and adhesion of polymers under corrosive environments hamper their application as anticorrosive coatings. The microporous structure of polymers provides passage for the penetration of corrosive ions at coating–metal interface, which led to their poor serviceability. To overcome these drawbacks, advanced structural modifications such as copolymers, hybrid polymers, and polymer nanocomposites have been made. Among these, polymer nanocomposites (PNs) have enormously attracted the attentions of corrosion technologists because of their significant role in providing the enhanced service life and improved physicomechanical and anticorrosive properties. Thus, this chapter briefly discusses the history of anticorrosive PN coatings (PNCs), use of various nanofillers in polymers, processing and formulation of anticorrosive PNCs, characterization techniques, and an overview on the utilization of sustainable precursors. The advantages and shortcomings of PNCs along with the definition of technical words and future prospects have also been discussed.

The frequent use of electrical equipment and devices has raised a serious threat to the environment and society in the form of electromagnetic interference (EMI), which not only decreases the competency of instruments but also affects the human health badly. Therefore, to reduce the effect of EMI, materials with high shielding effectiveness (SE) need to be designed. Conducting polymers (CPs) such as polyaniline, polypyrrole, polythiophene, etc., provide high conductivity and dielectric properties and are found to be promising for EMI shielding applications. Further, to enhance its SE, composites based on CPs have been widely studied. In view of this, the present chapter highlights the recent developments in CP composites in EMI shielding. The synthesis and properties of such materials are also discussed in detail. Further, the future scope of CP-based EMI shielding materials has also been discussed in detail.

The waterborne soya alkyd (WSA) and its RGO dispersed nanocomposites (WSA-RGO) were synthesized via ex situ polymerization using a solvent-less green approach. The soya oil monoglyceride was used as precursor for waterborne alkyd. The synergistic effect of nanofillers and poly melamine coformaldehyde isobutylated solution modified organic matrix (WSA) on physicomechanical and corrosion inhibition of these coatings on finally polished carbon steel (CS) was investigated. Their physicochemical, physicomechanical, and thermal properties were analyzed using standard protocols. The electrochemical corrosion measurements of these coatings were performed using Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy. The aforementioned studies revealed that the nanocomposite coatings exhibit promising corrosion protection performance which is evident from the icorr, Ecorr, impedance and phase angle values of coatings (i.e., icorr 7.736 × 10–9 Acm–2, Ecorr −0.191 V, impedance ∼107 Ω cm2, and phase a...

The work reports the synthesis of nano Poly(borophenyldiammine) PBPDA: a novel nanoconducting polymer via easy, scalable and eco-friendly green approach. The method is template less and surfactant less, ensuing PBPDA nanospheres of uniform size c.a. 120–130 nm of high solubility, conductivity, surface area, crystallinity and well-defined shape. More interestingly, PBPDA nanoparticles dispersed epoxy nanocompsites were prepared using DMSO, as an alternative non-toxic solvent, considering the extreme present urgency for clean environment. Our findings revealed that coatings exhibited outstanding anti-corrosive properties as compared to other conducting polymer based coatings, which is corroborated to B in PDA, which acted as a filler, cross linker and modifier.

In near future, bio-based polymer coatings are expected to gradually replace the fossil oil based coating materials. However, extensive application of bio-based polymer is still a challenge because of its several limitations. The use of organic-inorganic hybrid cross linker is one of the interesting strategies used for the processing of highly crosslinked polymer coatings with improved mechanical and anticorrosive performance. Thus present work reports the preparation of organic-inorganic hybrid (OIH) cross linker using melamine formaldehyde (MF) and 3 isocynatopropyl triethoxy silane (IPTES). The structural characterization was carried out using various spectroscopic techniques, which provide ample evidence in favor of MF/IPTES cured alkyd formation. The impact of OIH cross linker on various properties like physico-mechanical, adhesion, thermal stability and anticorrosive properties was investigated systematically. The enhancement in aforementioned properties could be explained in terms of synergistic effect of s-triazine ring of melamine formaldehyde and IPTES.

Desmoglein 3 (Dsg3) plays a crucial role in cell-cell adhesion and tissue integrity. Increasing evidence suggests that Dsg3 acts as a regulator of cellular mechanotransduction, but little is known about its direct role in mechanical force transmission. The present study investigated the impact of cyclic strain and substrate stiffness on Dsg3 expression and its role in mechanotransduction in keratinocytes. A direct comparison was made with E-cadherin, a well-characterized mechanosensor. Exposure of oral and skin keratinocytes to equiaxial cyclic strain promoted changes in the expression and localization of junction assembly proteins. The knockdown of Dsg3 by siRNA blocked strain-induced junctional remodeling of E-cadherin and Myosin IIa. Importantly, the study demonstrated that Dsg3 regulates the expression and localization of yes-associated protein (YAP), a mechanosensory, and an effector of the Hippo pathway. Furthermore, we showed that Dsg3 formed a complex with phospho-YAP and sequestered it to the plasma membrane, while Dsg3 depletion had an impact on both YAP and phospho-YAP in their response to mechanical forces, increasing the sensitivity of keratinocytes to the strain or substrate rigidity-induced nuclear relocation of YAP and phospho-YAP. Plakophilin 1 (PKP1) seemed to be crucial in recruiting the complex containing Dsg3/phospho-YAP to the cell surface since its silencing affected Dsg3 junctional assembly with concomitant loss of phospho-YAP at the cell periphery. Finally, we demonstrated that this Dsg3/YAP pathway has an influence on the expression of YAP1 target genes and cell proliferation. Together, these findings provide evidence of a novel role for Dsg3 in keratinocyte mechanotransduction.

Desmoglein 3 (Dsg3), plays a crucial role in cell-cell adhesion and tissue integrity. Increasing evidence suggests that Dsg3 acts as a regulator of cellular mechanotransduction, but little is known about its direct role in mechanical force transmission. The present study investigated the impact of cyclic strain and substrate stiffness on Dsg3 expression and its role in mechanotransduction. A direct comparison was made with E-cadherin, a well-characterized mechanosensor, in human keratinocytes. Exposure of oral and skin keratinocytes to equiaxial cyclic strain promoted changes in expression and localization of junction assembly proteins. Knockdown of Dsg3 by siRNA blocked strain-induced junctional remodeling of E-cadherin and Myosin IIa. Importantly, the study demonstrated that Dsg3 regulates the expression and localization of YAP, a mechanosensor and an effector of the Hippo pathway. Furthermore, we showed that Dsg3 forms a complex with phospho-YAP and sequestered it to the plasma membrane, while Dsg3 depletion had an impact on both YAP and phospho-YAP in their response to mechanical forces, increasing the sensitivity of keratinocytes to both strain-or substrate rigidity-induced nuclear relocalization of YAP and phospho-YAP. We showed that PKP1 seemed to be the key in such a complex formation since its silencing resulted in Dsg3 disruption at the junctions with concomitant loss of pYAP in the peripheral cytoplasm. Finally, we demonstrated that this Dsg3/YAP pathway has an influence on the expression ofYAP1target genes as well as cell proliferation in keratinocytes. Together, these findings provide evidence of a novel role for Dsg3 in keratinocyte mechanotransduction.

This research work deployed free radical polymerization for the development of pH-responsive hybrid nanocomposite hydrogels (NCHs) with the formation of improved interpenetrating networks (IPN). The crosslinked biopolymeric system was composed of (chitosan (CH)/guar gum (GG)/polyol) and a nanofiller (Cloisite 30B). The study was aimed to investigate the role of Cloisite 30B as a nanofiller and linseed oil-derived polyol to induce stable interpenetrating networks in chitosan‒guar gum-based hydrogels. FT-IR analysis confirmed the formation of crosslinked networks with the formation of hydrogen bonds in the synthesized NCHs. Thermogravimetric analysis and differential scanning calorimetry revealed high thermal stability of the NCHs. The hydrolytic and soil burial degradation tests confirmed the biodegradability of the synthesized NCHs. An extraordinarily high swelling capacity in a buffer solution of pH 4.0 and 7.4 demonstrated their pH-responsive behavior. It has been demonstrated that even the minimal addition of polyol to the guar gum-based hydrogels has influenced the stability and characteristic features such as high swelling capacity owing to the formation of interpenetrating networks and the biodegradability of the hydrogels.

The conversion of micro lignin to lignin nanoparticles (LNP) and their application in engineering and technology are potential steps towards global sustainability because lignin is obtained from industrial and agricultural waste and can be used in green chemistry. In the present study, we report the high-yield synthesis of lignin nanoparticles in different media, i.e., castor oil (CO), ethylene glycol (EG) and water (W) and evaluate their effect on the size and morphology of the LNP. The syntheses of LNP cover 9 out of 12 of the green chemistry principles; the synthesis was carried out via acid precipitation in a polyol medium, which acts as a stabilizing agent. From the results of the TEM, DLS, and SEM studies, it was observed that ≈15–20 nm LNP were successfully formed and spherical morphologies were observed when EG and CO were used as solvents. Furthermore, the anticorrosive behaviour of these nanoparticles was evaluated; the LNP acted as anticorrosive nanofillers for the protection of carbon steel (CS) in stringent corrosive conditions and was dispersed in an epoxy matrix to formulate epoxy nanocomposite coatings. Physicomechanical and electrochemical impedance spectroscopy (EIS) studies suggest that LNP-dispersed epoxy coatings potentially protect the underlying materials and show better protection as compared to the bare epoxy coatings.

Globular structured oleo alkyds possess low viscosity, good fluidity and play important role in the generation of volatile organic compound (VOC) free paints and coatings. Soya oil (SO), an abundant, inexpensive, renewable, and sustainable is one of the examples of such oleo alkyd precursor that meets the requirement of green chemistry. Present work reports the synthesis of hyperbranched soya alkyd based nanocomposite coatings and their corrosion inhibition efficiency. Hyperbranched alkyd (HBA) was synthesized using SO, pentaerythritol and phthalic anhydride. The magnetite (Fe3O4) nanoparticles were dispersed via sonication in butylated melamine formaldehyde (BMF) modified HBA (HBA-BMF) to formulate the nanocomposite (HBA-BMF-Fe3O4) anticorrosive coatings. The ASTM methods were used to evaluate structural, morphological, physico-mechanical, thermal, electrochemical and anticorrosive properties of these coatings. The HBA has a globular structure with the good degree of branching (DOB = 0.69). HBA-BMF and H...

With the endless efforts in the development of polymer composite materials, conducting polymer reinforced in polyurethane (CP/PU) composites are gaining tremendous attention of scientific community in the past few years. Conducting polymers as a reinforcement, offers exceptional properties when it combines with the thermoplastic polyurethane matrix. In view of this, we critically highlight the development of different types of conducting polymers reinforced in polyurethane composites, with a detailed discussion on their method of synthesis and various characterizations techniques. Furthermore, the promising applications of CP/PU composites have also been discussed. Finally, we attempted to assemble the existing challenges and the possible future perspectives.

In the present study, preparation, characterization and coating properties of plant oils based organic-inorganic hybrid materials [OIHM] are described. Polyols from Castor oil [CO], Linseed oil [LO] and tetraethoxyorthosilane [TEOS] serve as organic and inorganic constituents, respectively. OIHM are prepared by “hydrolysis-condensation” reactions. The hydroxyl groups of polyols condensed with TEOS, forming silica anchored polyol based OIHM which on addition reaction with isocyanate formed polyurethane hybrids [COHM-PU and LPOHM-PU]. In FTIR spectra of OIHM, absorption bands at 800 cm −1 (Si O Si sym str) and 1090.0 cm −1 (Si-O-Si assym str) confirmed the formation of nano silica, that occurred as unagglomerated and spherical particles as observed in TEM micrographs of OIHM. Thermogravimetric analysis showed the onset of degradation at 220 °C–225 °C. OIHM showed moderate to good antibacterial behavior against E.coli and S.aureus . OIHM coatings showed good corrosion rate and inhibition efficiency in 3.5 wt% NaOH, 3.5 wt% HCl and performed well in salt fog environment. The corrosion rate and IE% values for COHM-PU were found to be 1.534 × 10 −2 mm/yr and 94.208%, and 9.923 × 10 −3 mm/yr and 95.062% for LPOHM-PU, in 3.5 wt% NaOH for 0.5 mol loading of TEOS. In 3.5 wt% HCl, corrosion rate was 9.78 × 10 −3 mm/year for COHM-PU with IE% value as 91.90% and 7.98 × 10 −3 mm/year for LPOHM-PU with IE% value as 93.44%. OIHM were developed via a synergistic approach wherein plant polyols provide matrix for the production of SiO 2 ; the latter act as reinforcements improving the performance properties in hybrid polyurethane. OIHM may serve as platform chemicals for numerous industrial products such as paints and coatings.

Nano-sized CuO particles were prepared insitu via “one-pot, solvent-less” microwave-induced synthesis, by environmentally benign polyol process using polyol obtained from Linseed oil by (non-aqueous) condensation reaction, for the first time. Linseed polyol acts as solvent, base matrix providing functional groups, and stabilizer; the reaction is devoid of any additive, catalyst or solvent. In the prepared nanocomposites [LPE-CuO], CuO nanoparticles shaped somewhat like rods, assembled themselves in a “T-fashion”. The antifungal effects of synthesized particles were investigated against four clinical isolates of different Candida species. Results showed that the synthesized compound LPE-0.06 was found to be most effective, followed by LPE-0.05 and LPE-0.04. The rapid actions of the synthesized compounds on fungal cells suggested membrane-located targets. We investigated the effect of MIC90 values of these compounds on H+-ATPase mediated proton pumping by different Candida species. In the absence of glucose, the mean inhibition rate of H+ extrusion caused by MIC of LP was 28.09%, LPE: 33.04%, CuAc: 36.86%, LPE-0.04: 58.54%, LPE-0.05: 69.82% and LPE-0.06: 78.07%, respectively. Antifungal mechanism of action suggested that the synthesized compounds exert their antifungal activity by targeting H+-ATPase mediated proton pumping. Inhibition of H+-ATPase activity leads to intracellular acidification and consequently cell death. Results obtained in this study indicated strong antifungal activity of synthesized compounds against all the Candida species and suggest that the inhibition of fungal H+ ATPase is responsible for the antifungal activity of the test compounds. LPE-CuO can be employed as antifungal polyester and polyurethane coatings. The present work is consistent with the Principles (Principle 1,2,3,4,5,6,7,8, 12) of Green Chemistry.

Mechanical stability, surface hydrophobicity, and thermal stability of anticorrosive polymeric coatings play a significant role in technological and industrial fields. In view of this, the present study demonstrates the design of transparent organic–inorganic hybrid nanocomposite coatings with improved mechanical strength and barrier properties. Herein, a suspension was formulated containing in situ grown titania (–O–Ti–O–) from titanium isopropoxide (TIP), diglycidyl ethers of bisphenol-A (DGEBA), and polyamide (PA). TIP simultaneously acts as a condensation agent, bridging agent (–O–Ti–O), as well as an inorganic surface modifier to epoxy resin and increases the water contact angle due to topographical improvement via optimum cross-linked surface density. The surface, morphological, thermal, and electrochemical techniques highlight broader application areas for these hybrid polymeric materials. The lowest Icorr value of 2.5211 × 10−10 for DGE–TiO2–PA hybrid coatings compared to those of DGE–PA (2.1029 × 10−7), CS (8.9131 × 10−5), and other reported coating systems in saline (3.5 and 5 weight% NaCl) environments projects DGE–TiO2–PA as a potential anticorrosive coating material.

Desmoglein-3 (Dsg3), the Pemphigus Vulgaris (PV) antigen (PVA), plays an essential role in keratinocyte cell–cell adhesion and regulates various signaling pathways involved in the progression and metastasis of cancer where it is upregulated. We show here that expression of Dsg3 impacts on the expression and function of p53, a key transcription factor governing the responses to cellular stress. Dsg3 depletion increased p53 expression and activity, an effect enhanced by treating cells with UVB, mechanical stress and genotoxic drugs, whilst increased Dsg3 expression resulted in the opposite effects. Such a pathway in the negative regulation of p53 by Dsg3 was Dsg3 specific since neither E-cadherin nor desmoplakin knockdown caused similar effects. Analysis of Dsg3−/− mouse skin also indicated an increase of p53/p21WAF1/CIP1 and cleaved caspase-3 relative to Dsg3+/− controls. Finally, we evaluated whether this pathway was operational in the autoimmune disease PV in which Dsg3 serves as a major antigen involved in blistering pathogenesis. We uncovered increased p53 with diffuse cytoplasmic and/or nuclear staining in the oral mucosa of patients, including cells surrounding blisters and the pre-lesional regions. This finding was verified by in vitro studies where treatment of keratinocytes with PV sera, as well as a characterized pathogenic antibody specifically targeting Dsg3, evoked pronounced p53 expression and activity accompanied by disruption of cell–cell adhesion. Collectively, our findings suggest a novel role for Dsg3 as an anti-stress protein, via suppression of p53 function, and this pathway is disrupted in PV.

Modification of Hyaluronic acid (HA) with Sodium metaperiodate (NaIO4) results in the formation of oxidized HA (OHA). OHA containing multiple aldehyde groups can easily react with the materials having amino functionality via formation of Schiff base linkage, resulting in the formation of OHA based hydrogel scaffolds. These hydrogels have recently attracted considerable attention as scaffolds for tissue engineering (TE) applications. Thus, the aim of the present review is to give an overview on OHA based hydrogels as scaffolds and their potential application in the field of TE along with the method of synthesis and important properties of OHA.

Kidney disease prevalence increases with age, with a common feature of the disease being defects in the epithelial tight junctions. Emerging evidence suggests that the desmosomal adhesion protein Desmoglein-3 (Dsg3) functions beyond the desmosomal adhesion and plays a role in regulating the fundamental pathways that govern cell fate decisions in response to environmental chemical and mechanical stresses. In this study, we explored the role of Dsg3 on dome formation, reactive oxygen species (ROS) production and transepithelial electrical resistance (TER) in MDCK cells, a kidney epithelial cell model widely used to study cell differentiation and tight junction formation and integrity. We show that overexpression of Dsg3 constrained nuclear ROS production and cellular doming in confluent cell cultures and these features coincided with augmented TER and enhanced tight junction integrity. Conversely, cells expressing dominant-negative Dsg3ΔC mutants exhibited heightened ROS production and accelerated doming, accompanied by increased apoptosis, as well as cell proliferation, with massive disruption in F-actin organization and accumulation, and alterations in tight junctions. Inhibition of actin polymerization and protein synthesis was able to sufficiently block dome formation in mutant populations. Taken together, these findings underscore that Dsg3 has a role in controlling cellular viability and differentiation as well as the functional integrity of tight junctions in MDCK cells.

A facile, one-pot oxidative polymerization approach was used to synthesize polydiphenylamine (PDPA) and polydiphenylamine/vanadium pentoxide (PDPA/V2O5) composite using APS as an oxidizing agent. The reactions were carried out in two different reaction media (i.e. aqueous and acidic). The influence of these two mediums on molecular structure, morphology and thermal stability was investigated using FTIR spectroscopy, X-ray diffraction, SEM–EDS and thermogravimetric analysis. The temperature dependent electrical conductivity and dielectric properties (dielectric loss and dielectric constant) of these materials were also conducted. These studies revealed that in aqueous medium PDPA/V2O5 composite has formed however, in acidic medium only the PDPA polymer formed, suggesting different nature of V2O5 in these two medium. The results also showed that the PDPA/V2O5 composite has higher yield, good electrical conductivity, charge transport, dielectric losses and thermal properties as compared to that of PDPA. Furthermore, the electrochemical properties were evaluated by cyclic voltammetry, and electrochemical impedance spectroscopy and found that PDPA/V2O5 composite shows good electrochemical properties.

Conducting polymers nanocomposites have been emerged as one of the most enthralling members of a polymer family. Their spectacular resourceful properties make them useful in every field of research in varying arenas such as supercapacitors, sensors, electronic materials, drug release, biosensors, tissue engineering, and stimuli-responsive and biomimetic polymeric materials. The chapter discusses the role of conducting polymers (CPs) with their vast applications as nanocomposites and their profound impact as green nanofillers in corrosion protection paints, coatings as well as inhibitors area. The work would significantly highlight CPs contribution in materials science and engineering as well as their prospects in coming years.

Nanocomposite coatings with synergistic properties hold a potential in long-term corrosion protection for carbon steel. Polydiphenylamine (PDPA) and vanadium pentoxide (V2O5) have rarely been used ...