Preparation and characterization of antibacterial, antioxidant, and biocompatible p-coumaric acid modified quaternized chitosan nanoparticles

Regulatory effects of different spacer alkyl chains on the in vitro antioxidant and antibacterial activities of chitosan quaternary ammonium/phosphonium salt derivatives

In this study, three chitosan quaternary phosphonium salts and three chitosan quaternary ammonium salts with varying spacer chain lengths were synthesized. Structure characterization of the obtained products was conducted using Fourier-transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis, and elemental analysis. Additionally, the in vitro scavenging efficiency of these derivatives against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals, as well as their antibacterial activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), were evaluated. The results indicated that the scavenging efficiency of the chitosan quaternary phosphonium salt at a concentration of 1.6 mg/mL ranged from 36.9 % to 48.7 % for DPPH free radicals and from 48.3 % to 66.3 % for superoxide free radicals, outperforming that of the chitosan quaternary ammonium salt with long alkyl chains. Furthermore, an increase in the length of the spacer alkyl chain was associated with enhanced antibacterial activities of the corresponding chitosan derivatives. At a concentration of 1.0 mg/mL, the synthesized chitosan derivatives demonstrated antibacterial rates exceeding 90 % against both E. coli and S. aureus. Notably, the CCK-8 assay confirmed that these derivatives are non-toxic to 293 T cells. Among the six derivatives, TPPBOC and DMDOC, characterized by longer spacer alkyl chains, demonstrated superior antioxidant and antibacterial activities. This research establishes a robust theoretical foundation for the development of more effective and safer antioxidants and antibacterial agents, thereby enriching the knowledge base in chitosan chemistry and functional materials, and paving new pathways for the innovation of novel antioxidant and antibacterial materials.

Stabilization of chitosan-based nanomedicines in cancer therapy: a review

Chitosan (CS), a versatile and alkaline polysaccharide, has gained significant attention in nanomedicine due to its biocompatibility and biodegradability. In recent years, its applications in cancer therapy, particularly for the delivery of chemotherapeutic drugs, diagnostic agents, and genes, have advanced considerably. However, many CS-based nanomedicines suffer from poor stability in biological fluids, especially under physiological conditions. The neutral pH and the presence of electrolytes in physiological environments reduce the charge density of CS, which can account for this application limitation of CS-based nanomedicines. To improve the stability and prevent dissociation or aggregation of these nanomedicines before reaching the target sites, this review summarizes common stabilization strategies including hydrophilic or hydrophobic modification of CS, as well as incorporation with metal ions (e.g. Fe3+ or Zn2+), complexation with anionic cross-linkers (e.g. TPP) or anionic polymers. Additionally, the review highlights the application of stabilized CS-based nanocarriers in drug delivery, with a particular focus on cancer therapy. The challenges and future perspectives for accelerating the clinical translation of these nanomedicines are also discussed.

Water-soluble chlorogenic acid-chitosan and polydatin-chitosan conjugates: antibacterial activity and inhibition of lipid and protein oxidation

BACKGROUND

Chitosan (CS), an abundant alkaline polysaccharide, is valued for its biocompatibility, non-toxicity, and antibacterial properties. However, its limited solubility and modest antioxidant activity constrain its utility. Grafting polyphenols onto chitosan through the use of grafting reactions can enhance both the solubility and bioactivity of chitosan. Among the techniques employed, the free radical grafting method is favored for its simplicity, environmental sustainability, and its effectiveness in preserving biological activity.

RESULTS

In this study, chlorogenic acid (CGA) and polydatin (PLD) were conjugated successfully to chitosan by a Vc/H2O2 redox system. Analytical techniques such as ultraviolet-visible (UV-visible) spectroscopy, fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and proton nuclear magnetic resonance (1H NMR) were employed to confirm the formation of covalent bonding between the polyphenol molecules and the chitosan backbone. The novel conjugates displayed superior antioxidant properties in comparison with pristine chitosan, as evidenced by their enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, and hydroxyl radical scavenging capacities, and Fe2+ reducing power. Both CGA-CS and PLA-CS exhibited excellent lipid and protein oxidation inhibition capabilities. Furthermore, the conjugates were shown to have significant antibacterial effects against four common pathogenic bacteria: Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas putida, and Staphylococcus aureus (P < 0.05).

CONCLUSION

The newly synthesized water-soluble polyphenol-chitosan conjugates demonstrated remarkable biological activity, particularly CGA-CS. This study offers new insights and a strong theoretical foundation for developing natural food preservation materials with potential applications in the food industry. © 2024 Society of Chemical Industry.

Synthesis and application of chitosan nanoparticles for bone tissue regeneration

Bone defects, resulting from trauma, tumor removal, infection, or congenital anomalies, are increasingly prevalent in clinical practice. Progress in bone tissue engineering has significantly advanced bone regeneration techniques. Chitosan-based nanoparticles (ChNPs) have emerged as a promising drug delivery system due to their inherent ability to enhance bone regeneration. These nanoparticles can extend the activity of osteogenic factors while ensuring their controlled release. Common synthesis methods for ChNPs include ionic gelation, complex coacervation, and polyelectrolyte complexation. ChNPs have demonstrated effectiveness in bone regeneration by delivering osteogenic agents, including DNA/RNA, proteins, and therapeutics. This review provides a comprehensive analysis of recent studies on ChNPs in bone regeneration, sourced from the PubMed database. It examines their synthesis techniques, advantages as drug delivery systems, incorporation into scaffold materials, and the challenges that remain in the field.

Diverse applications of versatile quaternized chitosan salts: A review

In the ever-evolving world of materials science, modifying natural polymers has garnered significant attention across diverse industries, driven by their inherent availability and cost-effectiveness. Among these, chitosan, a pseudo-natural cationic polymer, has emerged as a versatile player, finding applications in medical, pharmaceutical, filtration, and textile sectors, owing to its exceptional biodegradability, non-allergenicity, antimicrobial properties, and eco-friendly nature. However, the limitations of chitosan, such as low surface area, poor solubility at neutral to alkaline pH, and inadequate thermal-mechanical properties, have prompted researchers to explore innovative modification strategies, including graft copolymerization, quaternization, and cross-linking. This review delves into the remarkable potential of a specific chitosan derivative, N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan salts (N-HTCS), a quaternized form of chitosan. This review uniquely examines the properties and multifaceted applications of N-HTCS, spanning biomedical, textile, food packaging, and environmental domains. The outstanding features of N-HTCS, including antioxidant, anticancer, and antimicrobial bioactivity, as well as biocompatibility, biodegradability, hemostatic, piezoelectric, superparamagnetic, water solubility, and permeation-enhancing effects, offer novel solutions to the limitations of unmodified chitosan. Notably, while previous reviews have addressed the significance of chitosan, this work presents a groundbreaking focus on the N-HTCS derivative, providing a fresh perspective and paving the way for the design and engineering of cutting-edge N-HTCS-based devices and applications. The comprehensive coverage of this review aims to inspire researchers and industry professionals to explore the untapped potential of this remarkable chitosan derivative, unlocking new frontiers in material science and technology.

Recent Advances in the Preparation, Antibacterial Mechanisms, and Applications of Chitosan

Chitosan, a cationic polysaccharide derived from the deacetylation of chitin, is widely distributed in nature. Its antibacterial activity, biocompatibility, biodegradability, and non-toxicity have given it extensive uses in medicine, food, and cosmetics. However, the significant impact of variations in the physicochemical properties of chitosan extracted from different sources on its application efficacy, as well as the considerable differences in its antimicrobial mechanisms under varying conditions, limit the full realization of its biological functions. Therefore, this paper provides a comprehensive review of the structural characteristics of chitosan, its preparation methods from different sources, its antimicrobial mechanisms, and the factors influencing its antimicrobial efficacy. Furthermore, we highlight the latest applications of chitosan and its derivatives across various fields. We found that the use of microbial extraction shows promise as a new method for producing high-quality chitosan. By analyzing the different physicochemical properties of chitosan from various sources and the application of chitosan-based materials (such as nanoparticles, films, sponges, and hydrogels) prepared using different methods in biomedicine, food, agriculture, and cosmetics, we expect these findings to provide theoretical support for the broader utilization of chitosan.

Dual Antimicrobial Activity of HTCC and Its Nanoparticles: A Synergistic Approach for Antibacterial and Antiviral Applications Through Combined In Silico and In Vitro Studies

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC), a quaternized chitosan derivative, has been shown to exhibit a broad spectrum of antimicrobial activity, especially against bacteria and enveloped viruses. Despite this, molecular docking studies showing its atomic-level mechanisms against these microorganisms are scarce. Here, for the first time, we employed molecular docking analyses to investigate the potential antibacterial activity of HTCC against Staphylococcus aureus and its antiviral activity against human immunodeficiency virus 1 (HIV-1). According to the findings, HTCC exhibited promising antibacterial activity with high binding affinities; however, it had limited antiviral activity. To validate these theoretical outcomes, experimental studies were conducted. Different derivatives of HTCC were synthesized and characterized using NMR, XRD, FTIR, and DLS. The in vitro assays validated the potent antibacterial efficacy of HTCC against S. aureus, whereas the antiviral studies did not show good antiviral activity. However, our research also revealed a promising avenue for further exploration of the antimicrobial activity of HTCC nanoparticles (NPs), since, thus far, no studies have been conducted to show the antiviral activity of HTCC NPs against HIV-1. The nanosized HTCC exhibited superior antiviral performance compared to the parent polymers, with complete (100%) inhibition of HIV-1 viral activity at the highest tested concentration (0.33 mg/mL).

Preparation, characterization, antimicrobial evaluation, and grape preservation applications of polyvinyl alcohol/gelatin composite films containing zinc oxide@quaternized chitosan nanoparticles

This study employed a precipitation method to synthesize zinc oxide@quaternised chitosan nanoparticles (ZnO@QAC NPs) containing different concentrations of zinc oxide, namely ZnO@QAC-2, ZnO@QAC-4, and ZnO@QAC-6. Subsequently, these nanoparticles were incorporated into matrices consisting of gelatine (Gn) and polyvinyl alcohol (PVA) separately, which were prepared by casting to form a biodegradable film. We assessed the physicochemical properties of ZnO@QAC NPs and physicochemical characteristics, antioxidant properties, antimicrobial activity and grape preservation efficacy of the film. Compared to the control group, the films showed a reduction in water vapor permeability by >9.38 %, an increase in tensile strength by over 51.95 %, over 70 % scavenging of ABTS free radicals, and good biocompatibility. Additionally, the antimicrobial activity of the films containing ZnO@QAC-6 increased by 37.6 %. In the grape preservation experiment, the weight loss of grapes wrapped in ZnO@QAC-2 film was reduced by 40.13 % on day 15 compared to unwrapped grapes. These results demonstrate that ZnO@QAC/PVA/Gn films have considerable potential for food packaging applications.

Synthesis, characterization and antifungal activity of imidazole chitosan derivatives

Five novel imidazole-functionalized chitosan derivatives 3a-3e were synthesized via addition reactions of chitosan with imidazole derivatives. The partial incorporation of imidazole moiety in chitosan were confirmed by FTIR, UV, 1H NMR, XRD, SEM and GPC. Meanwhile, the antifungal activity against three common plant pathogenic fungi: Phytophthora nicotianae (P. nicotianae), Fusarium graminearum (F. graminearum) and Rhizoctonia solani (R. solani), was assayed in vitro at 0.5 and 1.0 mg/mL by hyphal measurement, and the introduction of imidazole group can influence the antifungal activity. At 0.5 mg/mL, 3e inhibited P. nicotianae growth by 42 % and had an inhibitory index against R. solani of 50 %. Derivative 3e was more effective than unmodified chitosan whose antifungal index was 17 % against P. nicotianae and 22 % against R. solani. To our surprise, at 1.0 mg/mL, the inhibition rate of 3e against R. solani can reach 99 %, while the inhibition rate of chitosan is only 38 %. These results indicated that some imidazole chitosan derivatives with enhanced antifungal activities could serve as potential biomaterial for antifungal application.

Trinitroglycerin-loaded chitosan nanogels: Shedding light on cytotoxicity, antioxidativity, and antibacterial activities

AIM AND BACKGROUND

Trinitroglycerin (TNG) is a remarkable NO-releasing agent. Here, we synthesized TNG based on chitosan Nanogels (Ngs) for ameliorating complications associated with high-dose TNG administration.

METHOD

TNG-Ngs fabricated through ionic-gelation technique. Fourier-transformed infrared (FT-IR), zeta-potential, dynamic light scattering (DLS), and electron microscopy techniques evaluated the physicochemical properties of TNG-Ngs. MTT was used to assess the biocompatibility of TNG-Ngs, as the antioxidative properties were determined via lactate dehydrogenase (LDH), reactive oxygen species (ROS), and lipid peroxide (LPO) assays. The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE).

RESULTS

Physicochemical characterization reveals that TNG-Ngs with size diameter (96.2 ± 29 nm), polydispersity index (PDI, 0.732), and negative zeta potential (-1.1 mv) were fabricated. The encapsulation efficacy (EE) and loading capacity (LC) were obtained at 71.1 % and 2.3 %, respectively, with no considerable effect on particle size and morphology. The cytotoxicity assay demonstrated that HepG2 cells exposed to TNG-Ngs showed relative cell viability (RCV) of >80 % for 70 μg/ml compared to the TNG-free drug at the same concentration (P < 0.05). TNG-Ngs showed significant differences with the TNG-free drug for LDH, LPO, and ROS formation at the same concentration (P < 0.001). The antibacterial activity of the TNG-Ngs against S. aureus, E. coli, VRE, and MRSA was higher than the TNG-free drug and Ngs (P < 0.05).

CONCLUSION

TNG-Ngs with enhanced antibacterial and antioxidative activity and no obvious cytotoxicity might be afforded as novel nanoformulation for promoting NO-dependent diseases.

Chitosan and Its Derivatives: Preparation and Antibacterial Properties

This comprehensive review illuminates the various methods of chitosan extraction, its antibacterial properties, and its multifarious applications in diverse sectors. We delve into chemical, physical, biological, hybrid, and green extraction techniques, each of which presents unique advantages and disadvantages. The choice of method is dictated by multiple variables, including the desired properties of chitosan, resource availability, cost, and environmental footprint. We explore the intricate relationship between chitosan's antibacterial activity and its properties, such as cationic density, molecular weight, water solubility, and pH. Furthermore, we spotlight the burgeoning applications of chitosan-based materials like films, nanoparticles, nonwoven materials, and hydrogels across the food, biomedical, and agricultural sectors. The review concludes by highlighting the promising future of chitosan, underpinned by technological advancements and growing sustainability consciousness. However, the critical challenges of optimizing chitosan's production for sustainability and efficiency remain to be tackled.