Synthesis and characterization of pH-sensitive nanocarrier based chitosan-g-poly(itaconic acid) for ciprofloxacin delivery for anti-bacterial application.

This study aims to develop pH-sensitive and controlled release of ciprofloxacin from ciprofloxacin-loaded grafted chitosan-coated zinc oxide nanoparticles (Cip@Gchit/Zn-NPs) for the treatment of bacterial infections in the human colon. For this aim, first, the chitosan-g-poly(itaconic acid) [Chit-g-poly (Itac)] was synthesized via grafting of itaconic acid onto chitosan in the presence of cerium ammonium nitrate (CAN) under an inert atmosphere using conventional methods, while zinc oxide nanoparticles (Zn-NPs) were prepared via sol-gel technique. Characterization of the synthesized Cip@Gchit/Zn-NPs was analyzed using XRD, FT-IR, SEM, TGA, and zeta potential analysis. The antibacterial efficacy of Cip@Gchit/Zn-NPs against three pathogenic bacteria, namely Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, was superior to that of tetracycline reference drugs, as evidenced by larger inhibition zones. Cytotoxicity assessment of Cip@Gchit/Zn-NPs on the human chondrocyte cell line C28/I2 via MTT assay revealed 100 % cell viability at a concentration of 500 µg/mL. The loading efficiency of ciprofloxacin into Gchit/Zn-NPs was evaluated at various ratios, demonstrating lower loading efficiency; however, sustained release of ciprofloxacin from Cip@Gchit/Zn-NPs was excellent, with 98.13 % release observed at pH 7.2 over 10 h. Kinetic analysis of ciprofloxacin release followed the first-order kinetic models.

Review on emerging trends and challenges in the modification of xanthan gum for various applications.

This review explores the realm of structural modifications and broad spectrum of their potential applications, with a special focus on the synthesis of xanthan gum derivatives through graft copolymerization methods. It delves into the creation of these derivatives by attaching functional groups (-OH and -COOH) to xanthan gum, utilizing a variety of initiators for grafting, and examining their diverse applications, especially in the areas of food packaging, pharmaceuticals, wastewater treatment, and antimicrobial activities. Xanthan gum is a biocompatible, biodegradable, less toxic, bioactive, and cost-effective natural polymer derived from Xanthomonas species. The native properties of xanthan gum can be improved by cross-linking, grafting, curing, blending, and various modification techniques. Grafted xanthan gum has excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing ability. Owing to its remarkable properties, such as biocompatibility and its ability to form gels resembling the extracellular matrix of tissues, modified xanthan gum finds extensive utility across biomedicine, engineering, and the food industry. Furthermore, the review also covers various modified derivatives of xanthan gum that exhibit excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing abilities. These applications could serve as important resources for a wide range of industries in future product development.

The effects of cesium lead bromide quantum dots on the performance of copper phthalocyanine-based organic field-effect transistors.

Highly luminescent all-inorganic cesium lead bromide (CsPbBr3) perovskite quantum dots (QDs) have been extensively used as a photosensitizer in optoelectronic devices, while p-type small-organic-molecule copper phthalocyanine (CuPc) is also widely used as a photoactive material in solar cells, organic field-effect transistors (OFETs), etc. In this paper, we report the preparation of a CsPbBr3-QDs/CuPc heterostructure to study the effect of CsPbBr3-QDs on CuPc. The optical properties of both CuPc and the QDs/CuPc heterostructure were compared and contrasted using UV-vis absorbance and photoluminescence (PL) measurements. Furthermore, to study their electronic and charge transfer features, we fabricated field-effect transistors (FETs) on both pristine CuPc and QDs/CuPc heterostructure thin films and studied their photoresponsive electrical characteristics. Both pristine and QDs/CuPc-based FETs showed an enhancement in current and carrier mobility under illumination. The enhancement in the current and carrier mobility of the QDs/CuPc-based FETs is due to a large number of photoexcited charge carriers. We also observed that the current and carrier mobility in the QDs/CuPc heterostructure-based FET were lower than those of the pristine CuPc-based FET. This can be explained by the n-type doping effect of CsPbBr3 QDs on CuPc, which reduces the accumulation of holes in the active p-channel near the insulating layer and causes charge to be transferred from the QDs to the CuPc. Thus, we have observed a charge transfer effect in the CsPbBr3 QDs/CuPc heterostructure, which can be used in optoelectronic devices.

A review on the synthesis of graft copolymers of chitosan and their potential applications.

Chitosan is an antimicrobial, biodegradable and biocompatible natural polymer, commercially derived from the partial deacetylation of chitin. Currently modified chitosan has occupied a major part of scientific research. Modified chitosan has excellent biotic characteristics like biodegradation, antibacterial, immunological, metal-binding and metal adsorption capacity and wound-healing ability. Chitosan is an excellent candidate for drug delivery, food packaging and wastewater treatment and is also used as a supporting object for cell culture, gene delivery and tissue engineering. Modification of pure chitosan via grafting improves the native properties of chitosan. Chitosan grafted copolymers exhibit high significance and are extensively used in numerous fields. In this review, modifications of chitosan through several graft copolymerization techniques such as free radical, radiation, and enzymatic were reported and the properties of grafted chitosan were discussed. This review also discussed the applications of grafted chitosan in the fields of drug delivery, food packaging, antimicrobial, and metal adsorption as well as dye removal.

Detection and classification of ECG noises using decomposition on mixed codebook for quality analysis.

In this Letter, a robust technique is presented to detect and classify different electrocardiogram (ECG) noises including baseline wander (BW), muscle artefact (MA), power line interference (PLI) and additive white Gaussian noise (AWGN) based on signal decomposition on mixed codebooks. These codebooks employ temporal and spectral-bound waveforms which provide sparse representation of ECG signals and can extract ECG local waves as well as ECG noises including BW, PLI, MA and AWGN simultaneously. Further, different statistical approaches and temporal features are applied on decomposed signals for detecting the presence of the above mentioned noises. The accuracy and robustness of the proposed technique are evaluated using a large set of noise-free and noisy ECG signals taken from the Massachusetts Institute of Technology-Boston's Beth Israel Hospital (MIT-BIH) arrhythmia database, MIT-BIH polysmnographic database and Fantasia database. It is shown from the results that the proposed technique achieves an average detection accuracy of above 99% in detecting all kinds of ECG noises. Furthermore, average results show that the technique can achieve an average sensitivity of 98.55%, positive productivity of 98.6% and classification accuracy of 97.19% for ECG signals taken from all three databases.

Synthesize and characterization of binary grafted psyllium for removing toxic mercury (II) ions from aqueous solution.

Acrylamide and acrylonitrile were grafted on psyllium employing ceric ammonium nitrate (CAN) as initiator under N2 atmosphere to get an adsorbent of mercury ions. The synthesized adsorbent was optimized by varying synthetic parameters viz. monomer concentration, reaction time, temperature, initiator concentration, etc. to obtain the maximum yield of the grafted product as well as maximum adsorption of ionic mercury. The synthesized adsorbent was characterized by FT-IR, SEM, XRD, zeta potential and thermal techniques. The effect of various process parameters such as pH, time, adsorption dose and temperature on Hg (II) adsorption was investigated. The maximum Hg (II) adsorption (96%) was achieved at temperature (30 °C), dose (30 mg), pH (6), time (60 min) and initial concentration of mercury with 100 ppm. The Hg(II) adsorption on Psy-g-Poly (Am-co-An) was confirmed by XPS study. The isotherm data of the adsorption experiments obeyed the classical Langmuir adsorption isotherm. On the other hand, the kinetic data followed the second-order kinetics, indicating the chemisorption mechanism.

Synthesis and characterization of crosslinked chitosan for effective dye removal antibacterial activity.

A novel binary crosslinked material based on chitosan [chit-cl-Poly (AA-co-Am)] has been synthesized through crosslinking employing ceric ammonium nitrate (CAN) initiator under N2 atmosphere for the effective removal of methyl orange dye as well as antibacterial studies. The synthesized adsorbent was characterized by FT-IR, SEM, XRD and TGA techniques. The effect of various process parameters such as pH, time, adsorption dose, and temperature on the removal of methyl orange was investigated. The isotherm data of the adsorption experiments obey the classical Freundlich adsorption isotherm while the kinetic data followed the pseudo-second-order kinetics. The antibacterial behavior of optimized samples was evaluated by the determination of maximum inhibitor growth of bacteria such as Escherichia coli (E. coli), Staphylococcus aureus and (S. aureus) Pseudomonas aeruginosa (P. aeruginos). The present study provides substantial evidence to prove beyond doubt that material based on chitosan [chit-cl-Poly (AA-co-Am)] seems to have the potential for effective removal of dyes from aqueous streams which can be extended to systems of significant importance.

Novel binary grafted chitosan nanocarrier for sustained release of curcumin.

The study deals with the synthesis and characterization of chitosan-g-Poly (Acrylic acid-co-Acrylamide) [chit-g-Poly (AA-co-Am)] for sustained release of curcumin. The formation of chit-g-Poly (AA-co-Am) was ascertained through various spectral, thermal, microscopic methods and zeta potential. The potential of chit-g-Poly (AA-co-Am) for drug delivery applications were investigated through pH regulated kinetic models, in vitro antibacterial assay and molecular docking studies. The study reveals antibacterial activity of chit-g-Poly (AA-co-Am) against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa along with enhanced binding with bacterial receptors. In this study, nanoparticle of curcumin drug with grafted chitosan (NpCGC) was developed as effective nano therapeutic drug delivery system. Kinetic data of NpCGC reveals that the enhanced release of curcumin from NpCGC has been occurred at pH 5.4. The present study provides an economical and eco-friendly approach towards the preparation of chit-g-Poly (AA-co-Am) for sustained drug delivery applications.

Binary grafted chitosan film: Synthesis, characterization, antibacterial activity and prospects for food packaging.

The antimicrobial binary grafted chitosan film [chit-g-Poly (An-co-Am)] was prepared by grafting of acrylonitrile and acrylamide on to chitosan via microwave initiated graft copolymerization. The grafting of acrylonitrile and acrylamide onto chitosan backbone was confirmed by FTIR, XRD, SEM and TGA/DTA/DTG analytical techniques. The binary grafted chitosan film possessed efficient antimicrobial activity against three tested strains, i.e. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The prepared binary grafted chitosan film was tested for packaging apple and guava to prevent microbial infection and extend their shelf life. The biodegradability study of binary grafted chitosan film was also done and all the results were positive.

Microwave assisted synthesis of binary grafted psyllium and its utility in anticancer formulation.

A binary grafted copolymer of Psyllium mucilage (Psy) with acrylic acid (AA) and acrylonitrile (An) has been successfully synthesized under microwave conditions for in vitro drug release study. The grafting was confirmed by FTIR spectroscopy, XRD, SEM, EDX, TGA analytical techniques and the intrinsic viscosity study. The swelling behavior of grafted material has been studied in solution of different pH and time. We also prepare Psy-g-Poly (AA-co-An) based beads with anti-cancer drug [(2-Chloro-3-(4-hydroxyphenylamino) naphthalene-1, 4-dione)]. The drug release behavior of Psy-g-Poly (AA-co-An) based beads has been determined in aqueous medium at different pH. It has been observed that highest drug release at pH 1.6. The drug release kinetics was analysed using the different models. This study demonstrates that the release of drug depends on the composition of beads and pH of release medium. Kinetics of drug release from beads is best fitted by zero order and first order model.

Synthesis and characterization of modified chitosan via microwave route for novel antibacterial application.

Herein we report the synthesis of novel antibacterial graft [Chit-g-Poly (AA-co-An)] and crosslink [Chit-cl-Poly (AA-co-An)] copolymer, consisting of acrylic acid (AA), acrylonitrile (An) and chitosan by using the microwave route, and it has been observed that grafting and crosslinking copolymers possess excellent antimicrobial properties. Studies of antibacterial activities of graft and crosslink samples were carried out against gram positive [Staphylococcus aureus (S. aureus)], gram negative [Escherichia coli (E. coli) and Pseudomonas aeroginosa (P. aeroginosa)] bacteria. The graft [Chit-g-Poly (AA-co-An)] and crosslink [Chit-cl-Poly (AA-co-An)] copolymers were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD) techniques etc to study structural characteristics of synthesised chitosan derivatives. The graft [Chit-g-Poly (AA-co-A)] copolymer showed excellent antibacterial activities against E. coli, P. aeroginosa and S. euros 30, 31 and 26mm zone inhibition, respectively, while [Chit-cl-Poly (AA-co-A)] showed antibacterial activities against E. coli, P. aeroginosa and S. euros 26, 36 and 21mm zone inhibition respectively.

A Review on the Modification of Polysaccharide Through Graft Copolymerization for Various Potential Applications.

INTRODUCTION: Graft copolymerization is one of the most promising technique uses to modify the properties of naturally available polymers with a minimum loss in their native characteristics. METHODS AND MATERIALS: Graft copolymerization is a very significant technique to add hybrid properties in backbone of polymers. The grafting generally initiated through the formation of free radical centers on the polymer backbone as well as monomer. RESULTS: Grafted polysaccharides have various applications in different important scientific areas such as drug delivery, pharmaceutical field, plastic industry, waste water treatment, tannery effluent treatment, textile industry, agriculture area, etc. all of this fascinated us to summarize the major research articles over the last two decades outlining different methods of grafting, surface modification, graft copolymerization of synthetic and natural polymers. CONCLUSION: Various redox initiator systems viz. Ceric ammonium nitrate, per sulfate, Irradiation, FAS-H2O2etc. is also explored for grafting of vinyl through conventional and non-conventional techniques.