Facile synthesis and characterization of chitosan/zinc oxide nanocomposite for enhanced antibacterial and photocatalytic activity

Phytofabrication of biocompatible chitosan-based ZnO nanocomposite aided by Cissus quadrangularis extract enriched with antimicrobial and antioxidant potential

A dynamic chitosan-based ZnO nanocomposite (NC) was fabricated via a cost-effective formulation and an eco-friendly procedure utilizing Cissus quadrangularis (CQ) plant extract. This study investigates the antimicrobial and antioxidant properties, together with the cytocompatibility aspects of chitosan-incorporated ZnO nanocomposite (CS-ZnO/CQE). The formation and structural morphology of the nanocomposites were examined using FTIR, UV-Vis, XRD, XPS, BET, TGA, SEM, and TEM techniques. The antibacterial test results demonstrated the greatest inhibitory zone diameter against S. aureus (19 ± 1.00 mm) and E. coli (17 ± 1.05 mm), assessed through agar well diffusion method. Also, the composite exhibited a DPPH inhibition rate of 78.7 ± 0.34 %, indicating its high effectiveness in neutralizing free radicals. In addition, the nanocomposite exhibited less toxicity towards human erythrocytes, HDF and HEK-293 cells as a result of the biocompatibility exhibited by CS, ZnO, and CQ plant extract. Likewise, it has exceptional cell migratory capacity and possesses biodegradability factors. These observations strongly suggest the potential of CS-ZnO/CQE as a cutting-edge antibacterial and antioxidant agent to be implemented in the medical sector.

Medicinal and chemosensing applications of chitosan based material: A review

Chitosan (CTS), has emerged as a highly intriguing biopolymer with widespread applications, drawing significant attention in various fields ranging from medicinal to chemosensing. Key characteristics of chitosan include solubility, biocompatibility, biodegradability and reactivity, making it versatile in numerous sectors. Several derivatives have been documented for their diverse therapeutic properties, such as antibacterial, antifungal, anti-diabetic, anti-inflammatory, anticancer and antioxidant activities. Furthermore, these compounds serve as highly sensitive and selective chemosensor for the detection of various analytes such as heavy metal ions, anions and various other species in agricultural, environmental and biological matrixes. CTS derivatives interacting with these species and give analytical signals. In this review, we embark on an exploration of the latest advancements in CTS-based materials, emphasizing their noteworthy contributions to medicinal chemistry spanning the years from 2021 to 2023. The intrinsic biological and physiological properties of CTS make it an ideal platform for designing materials that interact seamlessly with biological systems. The review also explores the utilization of chitosan-based materials for the development of colorimetric and fluorimetric chemosensors capable of detecting metal ions, anions and various other species, contributing to advancements in environmental monitoring, healthcare diagnostics, and industrial processes.

Cobalt oxide-chitosan based nanocomposites: Synthesis, characterization and their potential pharmaceutical applications

This research aimed to prepare, characterize, and investigate the biological efficacy of chitosan‑cobalt (II) oxide hybrid nanocomposites against a variety of micrograms. Analytical methods, FTIR, SEM, XRD, and EDX, were utilized to thoroughly characterize the produced CS-CoO nanocomposite. In FTIR spectra, the presence of the chitosan peaks in addition to that of CoO at 681 and 558 cm-1 confirmed that CoO molecules interact with the chitosan backbone. Moreover, in the XRD measurements, significantly less chitosan crystallinity was observed. Due to the incorporation of a larger amount of cobalt oxide within the polymer matrix. Applying the Debye-Sherrer calculation, the crystallite size was obviously reduced from 48.24 nm (5 wt %) to 19.27 nm (20 wt %) for the obtained nanocomposites. Furthermore, SEM measurements showed a transformation in the chitosan surface with the physical adsorption of CoO molecules on the surface active sites of chitosan that were visible in SEM graphs. Additionally, EDX determined the amount of Co element within the chitosan, with the sample of 20 wt % weight being found to be 19.26 wt %. The variable dose well-diffusion method was utilized to assess the efficacy of the CS-Co nanocomposite against a wide range of bacteria and fungi. CS - CoO nanocomposite is more effective than chitosan alone as an antibacterial agent against both Gram-positive and Gram-negative bacteria. Moreover, the MTT approach was employed to measure the cytotoxicity based on the cell viability of different cancer cell lines under different UV expositions. The proportion of the destroyed cells elevated due to the easy diffusion of CS - CoO nanocomposite into cancer cells as UV-free anticancer activity. UV exposition has stimulated the anticancer activity, which was attributed to an increase in ROS generation caused by the increased dose of the chitosan and its CS - CoO nanocomposites. Furthermore, the antioxidant capacities of the prepared nano-composites thin films were validated using the DPPH free radical scavenging method and showed good antioxidant activities with the DPPH radical compared with standard vitamin C. It has been noticed that by increasing the content of CoO nanoparticles from 5 to 20 wt %, the biological activity of the prepared nanocomposites was enhanced.

Fabrication of chitosan nanocomposites loaded with biosynthetic metallic nanoparticles and their therapeutic investigation

The present research demonstrates the formation of zinc oxide nanoparticles facilitated by Cissus quadrangularis (CQ-ZnONPs) and subsequent synthesis of chitosan-conjugated nanocomposites (CQ-CS/ZnONCs) along with their biological assessment. The biosynthesized nanoparticles and nanocomposites were physicochemically characterized and therapeutically assessed for their antioxidant, antibacterial, and antidiabetic potential. The formation of CQ-ZnONPs and CQ-CS/ZnONCs was preliminarily validated by the change in color and subsequently by UV-visible spectroscopic analysis. The crystalline peaks associated with the CQ-ZnONPs in CQ-CS/ZnONCs were established by XRD analysis. Morphological evaluation of CQ-ZnONPs and CQ-CS/ZnONCs was carried out through FE-SEM and HRTEM studies. The particle size of the CQ-ZnONPs and CQ-CS/ZnONCs was 243.3 nm and 176.6 nm, with a PDI of 0.188 and 0.199, respectively. Nanoparticles and nanocomposites expressed Zeta potential of -15.7 mV and -16.2 mV, respectively. The CQ-ZnONPs and CQ-CS/ZnONCs showed good radical effectiveness with various in-vitro assays. The formulated nanoparticles and nanocomposites displayed significant antibacterial activity against the selected bacterial pathogens. CQ-CS/ZnONCs presented noteworthy α-amylase and α-glucosidase inhibitory effects compared to CQ-ZnONPs with IC50 of 73.66 ± 1.21 μg/mL and 87.59 ± 1.29 μg/mL, respectively. Moreover, the synthesized CQ-CS/ZnONCs demonstrated 98.92 ± 0.39% and 99.58 ± 0.16% wound contraction (at 7 and 14 mg, respectively), significantly (p < 0.05) higher than the standard and CQ-ZnONPs. Thus, the CQ-ZnONPs and CQ-CS/ZnONCs could effectively develop promising drug delivery systems to inhibit pathogens and chronic tissue repair.

Fabrication of silver nanoparticles immobilized on magnetic lignosulfonate: Evaluation of its catalytic activity in the N-acetylation reactions and investigation of its anti-cutaneous squamous cell carcinoma effects

Due to the non-optimal response of most types of cancer to various treatment methods and their rapid progress, research continues in the field of producing drugs with less toxicity and greater efficiency. There are many nanocomposites with diverse biological activities that include part of anticancer drugs in new pharmacological science. The present investigation describes a green procedure for the in situ support of Ag nanoparticles (NPs) over sodium lignosulfonate (NaLS) modified magnetic nanoparticles (Fe3O4@NaLS/Ag) and its subsequent biological and chemical performance. FT-IR, TEM, FE-SEM, EDS, ICP, VSM and XRD techniques were used to characterize the synthesized Fe3O4@NaLS/Ag. The catalytic efficacy of the desired composite was applied in the N-acetylation of various amines in the presence of Ac2O under solvent-free conditions. The Fe3O4@NaLS/Ag catalyst was recovered by an external magnet and reused for nine runs without a significant decrease in the activity. The cytotoxic and anti-cutaneous squamous cell carcinoma potentials of biologically synthesized Fe3O4@NaLS/Ag nanocomposite against PM1 and MET1 cells were determined. The anti-cutaneous squamous cell carcinoma properties of the Fe3O4@NaLS/Ag nanocomposite could significantly remove PM1 and MET1 cells. The IC50 of Fe3O4@NaLS/Ag nanocomposite was 288 and 270 μg/mL against PM1 and MET1 cells, respectively. Also, Fe3O4@NaLS/Ag nanocomposite presented a high antioxidant potential according to the IC50 value. According to the above results, the recent nanocomposite can be used in treating cutaneous squamous cell carcinoma after doing clinical trial studies.

Preparation of novel clay/chitosan/ZnO bio-composite as an efficient adsorbent for tannery wastewater treatment

This study focuses on the preparation of an activated clay/chitosan/ZnO bio-composite using solvent casting method. Clay was activated through microwave radiation using 1 M H2SO4 at a minimum liquid to solid ratio (L/S). Chitosan was extracted from waste prawn shell and ZnO nanoparticles (ZnO-NPs) were synthesized from zinc acetate di-hydrate (Zn (CH3CO2)2·2H2O) using the sol-gel method. The produced bio-composite were characterized using FT-IR, TGA, XRD and SEM. Response surface methodology (RSM) was used for experimental design to find out the optimum conditions, e.g., pH of the solution, dosage of adsorbent and contact time for the removal of methylene blue (MB) and Cr (VI) using MINITAB 18.1 software. The optimum conditions obtained for the highest removal of MB were pH 9.57, dosage 55.44 mg and contact time 114.09 min. Similarly, for the highest removal of Cr (VI) the optimum conditions were pH 3.75, dosage 67.42 mg and contact time 111.27 min. Applying these optimum conditions, the highest removal efficiency for MB and Cr (VI) was obtained at 84.21 % and 82.67 % with 9.57 mg g-1 and 10.45 mg g-1 of adsorption capacity respectively. The adsorption data were studied for both Langmuir and Freundlich isotherm. The value of maximum Langmuir sorption was (qm) 17.346 mg g-1 and 17.621 mg g-1 for MB and Cr (VI) respectively.

Novel photo and bio-active greyish-black cotton fabric through air- and nitrogen- carbonized zinc-based MOF for developing durable functional textiles

This study explores the potential of using the carbonization of Zn-based metal-organic frameworks (Zn-MOF-5) under N2 and air to modify zinc oxide (ZnO) nanoparticle for the production of various photo and bio-active greyish-black cotton fabrics. The MOF-derived ZnO under N2 demonstrated a significantly higher specific surface area (259 m2g-1) compared to ZnO (12 m2g-1) and MOF-derived ZnO under air (41.6 m2 g-1). The products were characterized using various techniques, including FTIR, XRD, XPS, FE-SEM, TEM, HRTEM, TGA, DLS, and EDS. The tensile strength and dye degradation properties of the treated fabrics were also investigated. The results indicate that the high dye degradation capability of MOF-derived ZnO under N2 is likely due to the lower ZnO band gap energy and improvement in electron-hole pair stability. Additionally, the antibacterial activities of the treated fabrics against Staphylococcus and Pseudomonas aeruginosa were investigated. The cytotoxicity of the fabrics was studied on human fibroblast cell lines using an MTT assay. The study findings demonstrate that the cotton fabric covered with carbonized Zn-MOF under N2 is human-cell compatible while showing high antibacterial activities and stability against washing, highlighting its potential for use in developing functional textiles with enhanced properties.

Improved cotton fabrics properties using zinc oxide-based nanomaterials: A review

Zinc oxide nanoparticles (ZnO NPs) have gained significant attention in the textile industry for their ability to enhance the physicochemical properties of fabrics. In recent years, there has been a growing focus on the development of ZnO-based nanomaterials and their applications for cotton and other fabrics. This review paper provides an overview of the synthesis and diverse applications of ZnO-based nanomaterials for textile fabrics, including protection against UV irradiation, bacteria, fungi, microwave, electromagnetic radiation, water, and fire. Furthermore, the study offers the potential of these materials in energy harvesting applications, such as wearable pressure sensors, piezoelectric nanogenerators, supercapacitors, and human energy harvesting. Additionally, we discuss the potential of ZnO-based nanomaterials for environmental cleaning, including water, oil, and solid cleaning. The current research in this area has focused on various materials used to prepare ZnO-based nanocomposites, such as metals/nonmetals, semiconductors, metal oxides, carbon materials, polymers, MXene, metal-organic frameworks, and layered double hydroxides. The findings of this review highlight the potential of ZnO-based nanomaterials to improve the performance of textile fabrics in a range of applications, and the importance of continued research in this field to further advance the development and use of ZnO-based nanomaterials in the textile industry.

Structural regulatory mechanism of phosphotungstate acid decorated graphene oxide quantum dots-chitosan aerogel and its application in ciprofloxacin degradation

Chitosan modified AGQD (amine modified graphene oxide quantum dots) and then combined with H₃PW₁₂O₄₀ to obtain CS_x@AGQD-HPW₁₂ via facile process and applied for CIP removal through pre-adsorption and photocatalytic processes. The application of chitosan could regulate the morphology and photoelectric properties effectively. CS_0.5@AGQD-HPW₁₂ was found to have the optimal CIP removal performance among all the products, the corresponding adsorption removal efficiency and pre-adsorption photocatalysis process were 72.1 % and 98.8 %, respectively. Results of toxicity assessment confirmed photocatalytic degradation process could mitigate the ecotoxicity of CIP effectively. The optimal TOC (total organic carbon) removal efficiency was about 52.1 %. Possible pathways for CIP degradation and reaction mechanism were proposed based on the results of intermediates analysis and trapping experiments. This demonstrated a novel approach to chitosan application and an eco-friendly way to remove CIP by adsorption-photocatalysis process.

The use of chitosan-based composites for environmental remediation: A review

The presence of hazardous pollutants in water sources as a result of industrial activities is a major environmental challenge that impedes the availability of safe drinking water. Adsorptive and photocatalytic degradative removal of various pollutants in wastewater have been recognized as cost-effective and energy-efficient strategies. In addition to its biological activity, chitosan and its derivatives are considered as promising materials for the removal of various pollutants. The abundance of hydroxyl and amino groups in the chitosan macromolecular structure results in a variety of concurrent pollutant's adsorption mechanisms. Furthermore, adding chitosan to photocatalysts increases the mass transfer while decreasing both the band gap energy and the amount of intermediates produced during photocatalytic processes, improving the overall photocatalytic efficiency. Herein, we have reviewed the current design and preparation of chitosan and its composites, as well as their applications for the removal of various pollutants by adsorption and photocatalysis processes. Effects of operating variables such as the pH, catalyst mass, contact time, light wavelength, initial pollutant's concentration, and catalyst recyclability, are discussed. Various kinetic and isotherm models are presented to elucidate the rates, and mechanisms of pollutant's removal, onto chitosan-based composites, and several case studies are presented. Additionally, the antibacterial activity of chitosan-based composites has been discussed. This review aims to provide a comprehensive and up-to-date overview of the applications of chitosan-based composites in wastewater treatment and put forward new insights for the development of highly effective chitosan-based adsorbents and photocatalysts. Finally, the main challenges and future directions in the field are discussed.

Metal-Polymer Nanocomposites: A Promising Approach to Antibacterial Materials

There has been a new approach in the development of antibacterials in order to enhance the antibacterial potential. The nanoparticles are tagged on to the surface of other metals or metal oxides and polymers to achieve nanocomposites. These have shown significant antibacterial properties when compared to nanoparticles. In this article we explore the antibacterial potentials of metal-based and metal-polymer-based nanocomposites, various techniques which are involved in the synthesis of the metal-polymer, nanocomposites, mechanisms of action, and their advantages, disadvantages, and applications.

Sunlight-driven antibacterial activity of a novel zinc oxide quantum dot and its optimization using Box-Behnken design-A medicament for communicable disease protective wearables

The current study focuses on microwave-assisted zinc oxide quantum dots synthesis (ZnO-QDs) from zinc oxide bionanocomposite (ZnO-BC) preparation. The novelty lies in the preparation of ZnO-QDs, since the natural elements present in ZnO-BC itself acted as a surface penetration enhancer without using any chemical agent. Under ultraviolet (UV) light ZnO-QDs emitted a blue glow, confirming the fluorescence property. Using Box-Behnken design, the experimental factors of ZnO-QDs were optimized, yielding a positive response of 350 nm absorbance and these results also matched with the UV-visible spectroscopy characterization studies of ZnO-QDs. Using Escherichia coli, the antibacterial activity of ZnO-BC in comparison to ZnO-QDs was determined using the well diffusion method and an inhibition zone ranging from 11 to 23 mm and in the broth assay the OD values were reduced by almost seven and 10 times for ZnO-BC and ZnO-QDs, respectively, when compared to the control (untreated). The antibacterial activity demonstrated that our newly prepared BC and its QDs have superior activity when compared to the standard antibiotics such as ampicillin. This type of nanomaterial can be used as a new bioactive natural material with light-assisted activity for antibacterial coatings in the manufacture of personal protective equipment.

Engineered Zn-based nano-pesticides as an opportunity for treatment of phytopathogens in agriculture

People's desire for food has never slowed, despite the deterioration of the global agricultural environment and the threat to food security. People rely on agrochemicals to ensure normal crop growth and to relieve the existing demand pressure. Phytopathogens have acquired resistance to traditional pesticides as a result of pesticdes' abuse. Compared with traditional formulations, nano-pesticides have superior antimicrobial performance and are environmentally friendly. Zn-based nanoparticles (NPs) have shown their potential as strong antipathogen activity. However, their full potential has not been demonstrated yet. Here, we analyzed the prerequisites for the use of Zn-based NPs as nano-pesticides in agriculture including both intrinsic properties of the materials and environmental conditions. We also summarized the mechanisms of Zn-based NPs against phytopathogens including direct and indirect strategies to alleviate plant disease stress. Finally, the current challenges and future directions are highlighted to advance our understanding of this field and guide future studies.

Chitosan-based Dy2O3/CuFe3O4 bio-nanocomposite development, characterization, and drug release kinetics

Chitosan (CS)/metal oxide (MO) nano-carriers have recently attracted attention due to their great integration into several biomedical applications. Herein, CS and dysprosium oxide based bio-nanocomposites (Dy₂O₃/CuFe₃O₄/CS) were prepared using a citrate sol-gel route for biomedical settings at large and drug delivery, in particular. The chemical structure, average crystallite size, and surface morphology of Dy₂O₃/CuFe₃O₄/CS bio-nanocomposites were characterized using spectroscopic techniques, including FT-IR, PXRD, and SEM. The prepared nano composite's drug loading or release kinetics were investigated by FT-IR, zeta potential (ZP), and ultraviolet-visible spectroscopy (UV-Vis). In the FT-IR spectrum, the peaks in the range of 800-400 cm^-1 confirmed the formation of meta-oxides, while amide bands at 1661 and 1638 cm^-1 revealed the existence of CS in the bio-nanocomposite. The peaks at 2θ = 35.46 and 28.5, 39.4 indicated the presence and chemical interaction of Dy₂O₃ and CuFe₃O_4, respectively. The crystallite size was <20 nm. The model drug used in the loading and in vitro release assays was ciprofloxacin hydrochloride. Ciprofloxacin's CF stretch caused a modest peak to be seen at 1082 cm^-1 and changed in zeta potential value from 7.90 mV to 8.88 mV endorsing that the drug had been loaded onto the nanomaterial. The loading efficiency (%) of CIP onto the composite was from 25 to 30 %, calculated from optical density measurements. Different kinetic models, such as zero-order, first-order, Higuchi, Hixon-Crowell, and Korsmeyer-Peppas, were determined to confirm the drug release mechanism. The percent (%) of drug release from the surface of Dy₂O₃/CuFe₃O₄/CS in PBS (pH 7.4), acidic (pH 2.2) and basic (pH 9.4) dissolution media were found to be 70, 28 and 20 %, respectively. Drug kinetics showed that mainly the release is fickian type followed "Fick's law of diffusion", slightly deviated from fickian release (dissolution-dependent system). Korsmeyer-Peppas (R² 0.9773, n < 0.4) and Higuchi's (R² 0.9846) models were the best for fitting controlled drug release data. The results revealed that the Dy₂O₃/CuFe₃O₄/CS bio-nanocomposite has good potential for a controlled drug delivery system.

Biogenic Preparation, Characterization, and Biomedical Applications of Chitosan Functionalized Iron Oxide Nanocomposite

Chitosan (CS) functionalization over nanomaterials has gained more attention in the biomedical field due to their biocompatibility, biodegradability, and enhanced properties. In the present study, CS functionalized iron (II) oxide nanocomposite (CS/FeO NC) was prepared using Sida acuta leaf extract by a facile and eco-friendly green chemistry route. Phyto-compounds of S. acuta leaf were used as a reductant to prepare CS/FeO NC. The existence of CS and FeO crystalline peaks in CS/FeO NC was confirmed by XRD. FE-SEM analysis revealed that the prepared CS/FeO NC were spherical with a 10–100 nm average size. FTIR analyzed the existence of CS and metal-oxygen bands in the prepared NC. The CS/FeO NC showed the potential bactericidal activity against E. coli, B. subtilis, and S. aureus pathogens. Further, CS/FeO NC also exhibited the dose-dependent anti-proliferative property against human lung cancer cells (A549). Thus, the obtained outcomes revealed that the prepared CS/FeO NC could be a promising candidate in the biomedical sector to inhibit the growth of bacterial pathogens and lung cancer cells.

Facile synthesis, characterization, antioxidant activity, and antibacterial activity of carboxymethyl inulin salt derivatives

A series of novel carboxymethyl inulin derivatives bearing thiosemicarbazide salts, aminoguanidine salts, and aniline salts were prepared via a facile method and employed to evaluate in vitro antioxidant activity and antibacterial activity. Their structures were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The characterization results confirmed the successful synthesis of carboxymethyl inulin salt derivatives. The in vitro antioxidant activity evaluation results presented a significant improved superoxide radical scavenging ability, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and reducing ability of carboxymethyl inulin salt derivatives as compared to inulin and carboxymethyl inulin. In particular, the series of carboxymethyl inulin derivatives containing thiosemicarbazide salts and aminoguanidine salts showed remarkable free radical scavenging ability and reducing ability. Moreover, the carboxymethyl inulin derivatives containing thiosemicarbazide salts and aniline salts displayed potential antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. The cytotoxicity assay was also carried out on L929 cells by CCK-8 method, and all samples showed weak cytotoxicity. Furthermore, hemolysis results showed no hemolytic activity of most prepared inulin derivatives. In summary, the inulin derivatives containing thiosemicarbazide salts exhibited outstanding antioxidant activity, antibacterial activity, and biocompatibility, and the all-inclusive properties highlighted their potential use in food and medical applications.

Microbial approaches for sustainable remediation of dye-contaminated wastewater: a review

The coloured effluents produced from different industries, such as textile, plastics, printing, cosmetics, leather and paper, are extremely toxic and a tremendous threat to the aquatic organisms and human beings. The removal of coloured dye pollutants from the aqueous environment is a great challenge and a pressing task. The growing demand for low-cost and efficient treatment approaches has given rise to alternative and eco-friendly methods, such as biodegradation and microbial remediation. This work summarizes the overview and current research on the remediation of dye pollutants from the aqueous environment by microbial bio-sorbents, such as bacteria, fungi, algae, and yeast. In addition, dye degradation capabilities of microbial enzymes have been highlighted and discussed. Further, the influence of various experimental parameters, such as temperature, pH, and concentrations of nutrients, and dye, has been summarized. The proposed mechanism for dye removal by microorganisms is also discussed. The object of this review is to provide a state-of-the-art of microbial remediation technologies in eliminating dye pollutants from water resources.