Grafting of chitosan-acrylamide hybrid on the wool: Characterization, reactive dyeing, antioxidant and antibacterial studies

Modified chitosan: Insight on biomedical and industrial applications

Chitosan (CS), a by -product of chitin deacetylation can be useful in a broad range of purposes, to mention agriculture, pharmaceuticals, material science, food and nutrition, biotechnology and of recent, in gene therapy. Chitosan is a highly desired biomolecule due to the existence of many sensitive functional groups inside the molecule and also because of its net cationicity. The latter provides flexibility for creating a wide range of derivatives for particular end users across various industries. This overview aims to compile some of the most recent research on the bio-related applications that chitosan and its derivatives can be used for. However, chitosan's reactive functional groups are amendable to chemical reaction. Modifying the material to show enhanced solubility, a greater range of application options and pH-sensitive targeting and others have been a major focus of chitosan research. This review describes the modifications of chitosan that have been made to improve its water solubility, pH sensitivity, and capacity to target chitosan derivatives. Applying the by-products of chitosan as antibacterial, in targeting, extended release and as delivery systems is also covered. The by-products of chitosan will be important and potentially useful in developing new biomedical drugs in time to come.

Selective Modifications of Sheep Wool Usable in Non-Textile Applications

The traditional textile use of wool as a valuable renewable material needs alternative applications in order to, besides sheep milk and meat, valorize currently unnecessary wool. Each type of product containing sheep wool requires wool with customized properties. Finding suitable physical and chemical modifications needed to develop new products while minimizing harmful side effects is a challenge for scientists. The presented review provides a brief overview of works published over the last decade associated with innovative wool scouring, dyeing, antifelting, and modification of its structure without the ambition to present complete, detailed data.

A novel removal of Ni2+ ions from water solutions using dispersive solid-phase extraction method with nano Fe3O4/chitosan-acrylamide hydrogel

The effluent release containing heavy metals as Ni2+ ions has drastic risks to both the natural environment and human health. In this research, the nano Fe3O4/chitosan-acrylamide hydrogel was prepared as a novel nano sorbent for dispersive solid-phase extraction of Ni2+ ions and applied to the water sample solution. The pH, amount and type of elution solvent, the extraction time, etc. were optimized to improve the efficiency of the proposed method. Analytical parameters such as concentration factor and relative standard deviation (%) were achieved as 33.3 and 1.8%, respectively. The capacity in equilibrium sorption was calculated at 22.54 mg g-1. Furthermore, to estimate the adsorption mode, Freundlich, Langmuir, and Temkin models were fitted with experimental isotherm data. Besides, to check the basic process of the metal adsorption mechanism, pseudo-first-order, pseudo-second-order, and Roginsky-Zeldovich models were investigated and the results were fitted with the pseudo-second-order model. The value of change in entropy (⊿S) obtained is -65.24 (J(mol K)-1). Negative values of change in enthalpy, ⊿H in (kJ mol-1) is -24.45 (kJ mol-1) which indicates both physical and chemical adsorptions involved in the process of adsorption. Finally, the nano Fe3O4/chitosan-acrylamide hydrogel exhibited high performance to remove the Ni2+ ions from water sample solution.

Fabrication of Chitosan-Loaded Multifunctional Wool Fabric for Reactive Dye Digital Inkjet Printing by Schiff Base Reaction

Improving the development of high-value multifunctional wool fabrics was essential to satisfy diverse needs. Considering the various characteristics of chitosan macromolecules, herein, a padding-cross-linking process was adopted and then multifunctional wool fabrics with outstanding printing effects, shrink resistance, and antibacterial properties were fabricated. The test results showed that chitosan macromolecules loaded successfully on the wool fiber surface by Schiff base reaction. Wool fabrics changed from hydrophobic to hydrophilic due to the existence of chitosan macromolecules. The color strength (K/S value) of the reactive dye inkjet-printed wool fabric was greatly increased from 20.48 to 26.6. The area shrinkage of final samples was 2.53%, which was exceedingly lower than that of the original wool (10.96%). Moreover, the chitosan macromolecules with reactive amino groups endowed wool fabrics with certain antibacterial properties against E. coli and S. aureus. Generally, this study provided guidance for manufacturing multifunctional digital inkjet-printed wool products in mass production.

Progress in Research of Chitosan Chemical Modification Technologies and Their Applications

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has excellent biological activities such as antibacterial, antioxidant, and hemostasis. In recent years, the demand has increased significantly in many fields and has huge application potential. Due to the poor water solubility of chitosan, its wide application is limited. However, chemical modification of the chitosan matrix structure can improve its solubility and biological activity, thereby expanding its application range. The review covers the period from 1996 to 2022 and was elaborated by searching Google Scholar, PubMed, Elsevier, ACS publications, MDPI, Web of Science, Springer, and other databases. The various chemical modification methods of chitosan and its main activities and application research progress were reviewed. In general, the modification of chitosan and the application of its derivatives have had great progress, such as various reactions, optimization of conditions, new synthetic routes, and synthesis of various novel multifunctional chitosan derivatives. The chemical properties of modified chitosan are usually better than those of unmodified chitosan, so chitosan derivatives have been widely used and have more promising prospects. This paper aims to explore the latest progress in chitosan chemical modification technologies and analyze the application of chitosan and its derivatives in various fields, including pharmaceuticals and textiles, thus providing a basis for further development and utilization of chitosan.

Application of Achillea millefolium extract as a reducing agent for synthesis of silver nanoparticles (AgNPs) on the cotton: antibacterial, antioxidant and dyeing studies

The phyto-synthesis of silver nanoparticles and cotton dyeing with natural colorants can reduce the environmental impact of the process considerably. In this study, the extraction of natural colorants from Achillea millefolium petals was optimized by ultrasound technique. The AMP extract was applied for synthesis of silver nanoparticles (Ag NPs) on the cotton fabrics. The dyeing, antibacterial and antioxidant characteristics of cotton samples were investigated to optimize the process and evaluate its efficiency. The AMP extract had good substantivity towards cotton fabrics and the presence of tannic acid, as an environmentally-friendly mordant, further improved the absorption of AMP dye. The antibacterial and antioxidant activities of the dyed samples with AMP extract of were 50%and 60%, respectively. The addition of TA and Ag enhanced the antibacterial and antioxidant activities on the cotton samples to over 99%.

Attachment of Tragacanth gum on polyester fabric through the synthesis of iron oxide gaining novel biological, physical, and thermal features

This study focuses on polyester fabric modification to produce environmentally-friendly multifunctional fabrics for varied applications. The nanoparticles of iron oxide were achieved from ferrous sulfate solution under alkaline conditions and applied to Tragacanth gum to form an efficient layer on the polyester surface. The synthesis of Fe₃O₄ nanoparticles with a crystal size of 12 nm was approved in the XRD spectra and iron oxide/Tragacanth gum nanocomposites with an agglomerated size of about 62 nm were confirmed by the SEM and EDX techniques. The formation of hydroxyl and iron oxide bands was observed in the FTIR and XPS patterns. The superparamagnetic behavior of treated samples exhibited by VSM with a magnetic saturation of 0.86 emu/g. The products showed an antibacterial activity (95 and 91%) toward Gram-positive and -negative bacteria. The absorbance intensity of methylene blue decreased from 2.6 to 1.6 by the treated sample. The synthesized nanoparticles on the treated surface indicated a lower release of iron ions and cell toxicity. The rate of cell duplication increased under a magnetic field with 60 Hz and 0.5 mT for 20 min/day. The product color changed from white to a brownish hue and the wetting capacity and thermal ability increased.

Synthesis, characterization and application of chitosan-N-(4-hydroxyphenyl)-methacrylamide derivative as a drug and gene carrier

The aim of this study was to develop a green method to fabricate a novel CS modified N-(4-hydroxyphenyl)- methacrylamide conjugate (CSNHMA) and to evaluate its biomedical potential. CSNHMA has been prepared by a simple method via aza Michael addition reaction between CS and N- (4-hydroxyphenyl)-methacrylamide (NHMA) in ethanol. Its structural and morphological properties were characterized by various analysis techniques. The obtained results confirmed that a highly porous network structure of CSNHMA was successfully synthesized via aza Michael addition reaction. Consequently, it was analyzed as a drug and gene carrier. CSNHMA/pGL3 showed an enhanced buffering capacity due to the presence of NHMA moiety leading to higher transfection efficiency in all cancer cells (A549, HeLa and HepG2) as compared to native CS and Lipofectamine®. Therefore, these findings clearly support the possibility of using CSNHMA as a good transfection agent. For in vitro drug release study, we prepared CSNHMA nanoparticles (NPs) and curcumin loaded CSNHMA NPs of size <230 nm respectively via the non-toxic ionic gelation route and the encapsulation efficiency of drug was found to be 77.03%. In vitro drug release studies demonstrated a faster and sustained release of curcumin loaded CSNHMA NPs at pH 5.0 compared to physiological pH.

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.

Eco-friendly synthesis of functionalized chitosan-based nanoantibiotic system for potential delivery of linezolid as antimicrobial agents

To obtain a healthy human being with beneficial microflora against different pathogenic infections, classical antibiotics with nanosized biomaterials were used to inhibit the growth of bacterium by their potent synergistic effect. Hence, this study planned to load an oxazolidinone antibiotic named linezolid (LD) onto functionalized chitosan (CN) with 3, 5- dinitrosalyslic acid (DA) via microwave synthesis without harsh condition. The exploring synergistic effect of linezolid (LD) with CN/DA controllable nanostructure was compact efflux-mediated methicillin-resistant Staphylococcus aureus (MRSA) burden and other selected bactericide Gram-positive ((S. aureus), Gram-negative (E. coli), Fungi (C. albicans), Yeast (A. niger), and E. faecalis. The obtained results showed that LD was incorporated into both the internal and external surface of the aggregated CN/DA nanosystem with an average diameter of 150 nm ± 4 hints of the drug loading. Owing to the nature of functionalized CN, the release efficiency attains 98.4% within 100 min. The designed LD@CN/DA exhibited inhibition zone 54 mm, 59 mm, 69 mm, 54 mm, 57 mm, and 24 mm against the tested microbes respectively rather than individual LD. The major target of the current research is achieved by using LD@CN/DA as a nanoantibiotic system that has exceptional consistently active against multi-resistant pathogens, in between MRSA which resist LD. Also, cell viability was performed even after three days of direct cell culture on the surface of the designed nanoantibiotic. The mechanism of microbial inhibition was correlated and rationalized to different charges and the presence of oxygen species against microbial infections. Our findings provide a deep explanation about nanostructured antibiotics design with enhanced potentially pathogen-specific activity.

Enhanced thermal stability, hydrophobicity, UV radiation resistance, and antibacterial properties of wool fabric treated with p-aminobenzenesulphonic acid

Wool fibre is a popular fibre for the manufacture of apparel and floor coverings, but it does not have adequate thermal stability, antistatic, UV resistance, and antibacterial properties that are required for some applications, such as outerwear and hospital gowns. In this work, a wool fabric was treated with para-aminobenzenesulphonic acid (ABSA) by the oxidative polymerisation method and its effect on the thermal stability, UV radiation resistance, electrical conductivity and antibacterial properties of the treated fabric was systematically evaluated. It was found that the ABSA treatment had synergistic effects on the various functional properties of the treated fabric. The ABSA treatment not only made the fabric antibacterial but also enhanced its UV radiation absorption capability, surface hydrophobicity, electro-conductivity, tensile strength, and thermal stability. The maximum degradation temperature of the wool fibre increased from 339.5 °C to 349.6 °C and the UV-B transmission through the fabric at 290 nm reduced to 1.5%. The surface hydrophobicity of the treated fabric samples also improved as the surface contact angle of the fabric increased from 119.5° for the untreated to 131.7° for the fabric treated with 4% ABSA. The surface electrical resistance decreased from 1200 × 10⁹ to 484 × 10⁹ Ohm cm⁻¹, and the treated fabric also showed excellent antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. The developed treatment could be used in the textile industry as an energy-efficient process for the multi-functionalisation of wool and other polyamide fibres.

The treatment with para-aminobenzenesulphonic acid produced a multifunctional wool fabric with enhanced hydrophobicity, thermal stability, UV resistance, and antibacterial properties.