Naphthalene derived Schiff base as a reversible fluorogenic chemosensor for aluminium ions detection.

Schiff base (HNPD) was achieved by reacting 2-hydroxy-1-naphthaldehyde with N-phenyl-o-phenylenediamine in enthanol medium. The spectroscopic analyses were done to establish the formation of Schiff base apparently. Further, synthesized Schiff base conjugate was successfully used as a fluorogenic chemosensor to detect aluminium ions (Al3+) with high fluorescence amplification among the other interfering various metal ions. The limit of detection of 0.0248 × 10-6 M and a binding constant of 6.19 × 103 M-1 were obtained by the receptor HNPD for Al3+ detection. A high influence of intramolecular charge transfer kinetics was established to realize the selective responsiveness towards Al3+ ions. Density functional theory approximation formulated the band energy modulation and localization and delocalization of electron density for the HNPD and Al3+ complexation. The developed sensor ultimately inspected on the real soil and water samples and ascertained the practical ability of Al3+ ions detection of HNPD chemosensor.

Fabrication of chitosan/fibrin-armored multifunctional silver nanocomposites to improve antibacterial and wound healing activities.

A wound healing substitute promotes rapid tissue regeneration and protects wound sites from microbial contamination. The silver-based antiseptic frequently moist skin stains, burns and irritation, penetrates deep wounds and protects against pathogenic infections. Thus, we formulated a novel fibrin/chitosan encapsulated silver nanoparticle (CH:F:SPG-CH:SNP) composites bandage accelerating the polymicrobial wound healing. Electrospinning method was employed to form the nano-porous, inexpensive, and biocompatible smart bandages. The structural, functional, and mechanical properties were analyzed for the prepared composites. The biological capacity of prepared CH:F:SPG-CH:SNP bandage was assessed against NIH-3 T3 fibroblast and HaCaT cell lines. In vitro hemolytic assays using red blood cells were extensively studied and explored the low hemolytic effect (4.5 %). In addition, the improved drug delivery nature captured for the CH:F:SPG-CH:SNP composite bandage. Antibacterial experiments were achieved against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Lactobacillus bulgaricus using zone inhibition method. Moreover, in-vivo wound healing efficacy of fabricated smart bandage was evaluated on the albino Wistar rats which revealed the significant improvement on the postoperative abdomen wounds.

Nanomaterials for detection of biomolecules and delivering therapeutic agents in theragnosis: A review.

Nanomaterials are emerging facts used to deliver therapeutic agents in living systems. Nanotechnology is used as a compliment by implementing different kinds of nanotechnological applications such as nano-porous structures, functionalized nanomaterials, quantum dots, carbon nanomaterials, and polymeric nanostructures. The applications are in the initial stage, which led to achieving several diagnoses and therapy in clinical practice. This review conveys the importance of nanomaterials in post-genomic employment, which includes the design of immunosensors, immune assays, and drug delivery. In this view, genomics is a molecular tool containing large databases that are useful in choosing an apt molecular inhibitor such as drug, ligand and antibody target in the drug delivery process. This study identifies the expression of genes and proteins in analysis and classification of diseases. Experimentally, the study analyses the design of a disease model. In particular, drug delivery is a boon area to treat cancer. The identified drugs enter different phase trails (Trails I, II, and III). The genomic information conveys more essential entities to the phase I trials and helps to move further for other trails such as trails-II and III. In such cases, the biomarkers play a crucial role by monitoring the unique pathological process. Genetic engineering with recombinant DNA techniques can be employed to develop genetically engineered disease models. Delivering drugs in a specific area is one of the challenging issues achieved using nanoparticles. Therefore, genomics is considered as a vast molecular tool to identify drugs in personalized medicine for cancer therapy.

Development of chitosan-based cerium and titanium oxide loaded polycaprolactone for cutaneous wound healing and antibacterial applications.

Cerium dioxide (CeO2) based nanomaterials have emerged as promising dermal equivalents, promoting fibroblast infiltration and tissues regeneration. To enhance the antibacterial and wound healing activity, herein chitosan (CS)-CeO2 combined nano titanium dioxide (TiO2) complex loaded polycaprolactone (PCL) nanohybrid (CS-CeO2/TiO2/PCL) scaffolds were prepared through casting method. The nanohybrid scaffolds' physiochemical, morphological, mechanical, and biological properties were evaluated using advanced analytical techniques. Fourier transform infrared spectroscopy spectrum evidently depicted the various intermolecular interactions on the nanohybrid scaffolds. The developed scaffold exhibited the high swelling behavior and good degradability and permeability which is beneficial for absorbing wound transudation to fasten the healing efficacy. Moreover, CS-CeO2/TiO2/PCL scaffolds owned the better antibacterial activity against bacterial strains E. coli and S. aureus. Also, MTT assay on fibroblast (NIH 3T3) cells and immortalized human keratinocytes (HaCaT) cells indicated improved cell viability and proliferation. In vivo results revealed that the fabricated scaffold full aid to complete wound closure after 14 days which showed CS-CeO2/TiO2/PCL as the significant wound dressing material with potential antibacterial immunity.

Synthesis of chitosan based reduced graphene oxide-CeO2 nanocomposites for drug delivery and antibacterial applications.

In this study, the unique characteristics of chitosan, reduced graphene oxide (rGO) and cerium oxide (CeO2) based hybrid bionano-composites make a carrier for various drug delivery and antimicrobial applications. The recent literatures shown that addition of biopolymers to rGO and CeO2 based nanocomposites exhibit excellent performance in design and development of biosensors, wound dressings, electrodes, microfluidic chips, drug delivery systems and energy storage applications. Chitosan (CS), reduced graphene oxide (rGO) mixed with cerium oxide (CeO2) to form CS-rGO and CS-rGO-CeO2 hybrid bionano-composites using precipitation method. The physiochemical characterization of casted nanocomposite sheet was done using FTIR, XRD, UV-Vis spectrum, SEM and TGA. The XRD results of CS-rGO-CeO2 revealed that the nanoparticle was found to be crystalline structure. FTIR revealed that nitrogen functionalities of CS interacted with rGO-CeO2 to form hybrid nanocomposites. The thermal gravimetric analysis (TGA) showed that the CS-rGO-CeO2 has better thermal stability up to 550 °C. The SEM confirms the surface morphology of CS-rGO-CeO2 has large surface area with smooth surface. Moreover, the antibacterial properties of nanocomposites exhibit excellent zone of inhibition against Staphylococcus aureus and Escherichia coli. The NIH3T3 cell line evaluations showed superior cell adhesion on hybrid nanocomposites. Hence bionano-composite based on CS, rGO and CeO2 are potential biomaterials for drug delivery and antibacterial applications.

Investigation of the one-step electrochemical deposition of graphene oxide-doped poly(3,4-ethylenedioxythiophene)-polyphenol oxidase as a dopamine sensor.

In this paper, we fabricated poly(3,4-ethylenedioxythiophene) (PEDOT)-graphene oxide-polyphenol oxidase (PEDOT-GO-PPO) as a dopamine sensor. The morphology of PEDOT-GO-PPO was observed using scanning electron microscopy. Cyclic voltammetry was conducted to study the oxidation-reduction characteristics of dopamine. To optimize the pH, potential and limit of detection of dopamine, the amperometric technique was employed. The found limit of detection was 8 × 10-9 M, and the linear range was from 5 × 10-8 to 8.5 × 10-5 M. The Michaelis-Menten constant (K m) was calculated to be 70.34 µM, and the activation energy of the prepared electrode was 32.75 kJ mol-1. The electrode shows no significant change in the interference study. The modified electrode retains up to 80% of its original activity after 2 months. In the future, the biosensor can be used for the quantification of dopamine in human urine samples. The present modified electrode constitutes a tool for the electrochemical analysis of dopamine.

Fabrication of dual layered biocompatible herbal biopatch from biological waste for skin - tissue regenerative applications.

A dual layered herbal biopolymeric patch (biopatch) with enhanced wound healing efficiency and skin mimicking functions was fabricated for skin-tissue regenerative applications. In this study, hoof keratin (KE) extracted from biological waste and gelatin (GE) was employed for KE-GE biosheet fabrication using a simple casting method. Further, the top layer of the fabricated KE-GE biosheet was coated with bioactive Matricaria recutita (Chamomile flower) extract (CH) with gelatin through an electrospraying method. The optimized dual layered herbal biopatch (KE-GE/GE-CH) exhibits strong physiochemical (FTIR, XRD TG-DTA), mechanical (tensile strength) and biological (in vitro and in vivo) studies. Moreover, the morphology (SEM) of soft mimetic biopatch possesses excellent cell-material interaction and cell proliferation which accelerates the wound healing process. Biopatch demonstrates a proven degradation profile with good swelling features to achieve more than 80% herbal drug release in 96 h. Antimicrobial properties also reveal the potential activity of biopatch against bacterial microbes. In addition, in vitro cell viability using NIH 3T3 fibroblast cell lines and in vivo investigations revealed that the biopatch is non-cytotoxic, increases collagen deposition and shows rapid reepithelialization at the wound site as a potential wound dressing. We anticipated that the biological hoof keratin and bioactive herbal extract coated biopatch could serve as a desirable wound dressing candidate to suit various skin tissue regenerative applications.

Synthesis and Antibacterial Properties of Novel ZnMn2O4-Chitosan Nanocomposites.

The development of productive antibacterial agents from nontoxic materials via a simple methodology has been an immense research contribution in the medicinal chemistry field. Herein, a sol-gel one-pot reaction was used to synthesize hybrid composites of hausmannite-chitosan (Mn3O4-CS) and its innovative derivative zinc manganese oxide-chitosan (ZnMn2O4-CS). Fixed amounts of CS with different metal matrix w/v ratios of 0.5%, 1.0%, 1.5%, and 2.0% for Mn and Zn precursors were used to synthesize ZnMn2O4-CS hybrid composites. X-ray diffraction analysis indicated the formation of polycrystalline tetragonal-structured ZnMn2O4 with a CS matrix in the hybrids. Fourier-transform infrared spectroscopic analysis confirmed the formation of ZnMn2O4-CS hybrids. Detailed investigations of the surface modifications were conducted using scanning electron microscopy; micrographs at different magnifications revealed that the composites' surface changed depending on the ratio of the source materials used to synthesize the ZnMn2O4-CS hybrids. The antibacterial activity of the Mn3O4-CS and ZnMn2O4-CS composites was tested against various bacterial species, including Bacillus subtilis, Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa. The zone of inhibition and minimum inhibitory concentration values were deduced to demonstrate the efficacy of the ZnMn2O4-CS nanocomposites as antibacterial agents.

Synthesis of novel Sn1-xZnxO-chitosan nanocomposites: Structural, morphological and luminescence properties and investigation of antibacterial properties.

In recent times, metal oxide-organic nanocomposites have received great attention because of their feasibility to wide range applications such as super capacitors, antibacterial activity, biomedical sensors, battery applications and microfluidic devices. In this work, zinc oxide-chitosan (ZnO-CS) and their novel tin zinc oxide-chitosan (Sn1-xZnxO-CS) hybrid nanocomposites successfully synthesized by a simple one-pot sol-gel reaction. The equal metal oxide ratio such as 0.5, 1.0, 1.5 and 2.0% (W/V) for zinc and tin sources with constant weight of chitosan were used to prepare the Sn1-xZnxO-CS nanocomposites. Fourier transform infrared spectroscopy results proved the formation of Sn1-xZnxO-CS nanocomposites. X-ray diffraction patterns discovered the mixed phase polycrystalline nature of Sn1-xZnxO-CS nanocomposites. Optical and luminescence properties were extensively studied for nanocomposites by UV-Vis and photoluminescence spectroscopy, respectively. The surface modification elaborately discussed with scanning electron microscope images due to incorporation of SnOx with ZnO-CS matrix. The antibacterial properties of Sn1-xZnxO-CS were tested against Escherichia coli, Salmonella Typhi and Klebseilla Pneumoniae bacterial species.

Schiff base rare earth metal complexes: Studies on functional, optical and thermal properties and assessment of antibacterial activity.

We used the condensation chemistry with anthracene­9­carbaldehyde and 3,4­diaminopyridine to form Schiff base (SB) ligand, N2,N3­bis (anthracen­9­ylmethylene) pyridine­3,4­diamine incorporating Er, Pr and Yb rare earth metals to form a series of SB complexes. Surface, structure, thermal, and optical properties of the resulting complexes were investigated using a variety of tools. The characteristic luminescence properties were observed after rare earth metal inclusions in SB. Antibacterial studies were performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa in terms of zone of inhibition for SB complexes. The SB-Pr complexes showed better immune behavior against all the pathogens than the other SB metal complexes.

In vitro cytotoxicity activity of novel Schiff base ligand-lanthanide complexes.

A Schiff base ligand (SBL), N2, N3-bis (anthracen-9-ylmethylene) pyridine-2, 3-diamine, was synthesized through the condensation of 2,6-diaminopyridine and anthracene-9-carbaldehyde using a 1:2 ratio. 1H NMR spectra confirmed the observation of non-involvement aromatic carboxylic proton in SBL. A novel series of lanthanide (i.e., praseodymium (Pr), erbium (Er), and ytterbium (Yb))-based SBL metal complexes was successfully synthesized, and their functional groups were elaborately demonstrated using UV-visible, Fourier transform infrared (FT-IR), and fluorescence spectroscopy analyses. FT-IR spectral studies revealed that SBL behaved as a bidentate ligand and it was structured with metal ions by the two azomethine nitrogens. The synthesized SBL-based metal complexes were elaborately performed for cytotoxicity activity versus Vero, human breast cancer (MCF7), and cervical (HeLa) anticancer cell lines.

Evaluation of the Corrosion Resistance Properties of Electroplated Chitosan-Zn1-xCuxO Composite Thin Films.

Novel chitosan-zinc copper oxide (Zn1-xCuxO) composites were electrochemically synthesized through galvanostatic deposition. The prepared chitosan-based composite thin films were elaborately investigated to determine their structural, morphological, compositional, impedance, and corrosion properties. X-ray diffraction analysis was performed to reveal their structural orientation of composite thin films. Energy dispersive analysis by X-ray evidently confirmed the existence of Zn, Cu, and O in the composite thin films. Nyquist plots revealed that the chitosan-Zn1-xCuxO thin films had obvious semi-circular boundaries, and higher resistance was observed for chitosan-ZnO due to the grain boundary effect. Corrosion properties were evaluated using both an electrochemical method and the ASTM weight gain method, which revealed good corrosion rates of 34 and 35 × 10-3 mm/y, respectively, for chitosan-ZnO thin film.

One-Pot Facile Methodology to Synthesize Chitosan-ZnO-Graphene Oxide Hybrid Composites for Better Dye Adsorption and Antibacterial Activity.

Novel chitosan-ZnO-graphene oxide hybrid composites were prepared using a one-pot chemical strategy, and their dye adsorption characteristics and antibacterial activity were demonstrated. The prepared chitosan and the hybrids such as chitosan-ZnO and chitosan-ZnO-graphene oxide were characterized by UV-Vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The thermal and mechanical properties indicate a significant improvement over chitosan in the hybrid composites. Dye adsorption experiments were carried out using methylene blue and chromium complex as model pollutants with the function of dye concentration. The antibacterial properties of chitosan and the hybrids were tested against Gram-positive and Gram-negative bacterial species, which revealed minimum inhibitory concentrations (MICs) of 0.1 µg/mL.