Quaternary Ammonium Chitosan Research Articles

Immobilization of multilayer sodium alginate/polysaccharide antibacterial material composite beads as glufosinate controlled release matrices

To find a new way to slow down the release of glufosinate (GA) pesticide and to solve the susceptibility to decomposition by soil microorganisms, a series of novel antibacterial polysaccharide-based sustained release beads (PSRB) were prepared. The PSRB was prepared by immobilization of GA loaded polysaccharide-based chitosan quaternary ammonium salt (PS-HACC) microcapsules in the core and layers of the multilayer sodium alginate beads. The PSRB was characterized by FI-IR spectroscopy, XRD, SEM, and BET to reveal their composition and surface morphology. The optimal conditions of the slow release beads were as follows, the concentration of Ca2+, pH, temperature and the coating layer number was 0.1 mol/L, 7, 25 °Cand 3, respectively. The kinetic study showed that the slow release of PSRB was in accordance with the Higuchi kinetic model, and the FI-IR and XRD analyses revealed that the PS-HACC and GA were successfully cross-linked to the PSRB. BET showed that PSRB were greater than PSRB3 at surface area, pore volume and pore size. Inhibition circles experiments demonstrated that WPSRB3 has good antibacterial activity. The weed control in soybean with PSRB3 application is perfect and the weed control cycle is long. Therefore, this technology can provide a potential way to control GA release, improve utilization efficiency, reduce pesticide use and environmental pollution, and at the same time, provide a potential way to achieve ecological agriculture.

Effect of the structure of chitosan quaternary ammonium salts with different spacer groups on antibacterial and antibiofilm activities

In this study, three types of dodecyl chitosan quaternary ammonium salts, each with different spacer groups were synthesized. These chitosan derivatives are N′,N′-dimethyl-N′-dodecyl-ammonium chloride-N-amino-acetyl chitosan (DMDAC), N′-dodecyl-N-isonicotinyl chitosan chloride (DINCC) and N′,N′-dimethyl-N′-dodecyl-ammonium chloride-N-benzoyl chitosan (DMDBC). The synthesized products were characterized using Fourier transform infrared spectrometers, nuclear magnetic resonance, thermogravimetric analysis, and elemental analysis. The antibacterial and antibiofilm activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated. The experimental results indicated that the introduction of hydrophobic groups of spacer groups could enhance the antibacterial and antibiofilm activities of the chitosan derivatives. The antibacterial rates of the chitosan derivatives were over 90 % for both E. coli and S. aureus at a concentration of 0.5 mg/mL. The chitosan derivatives removed >50 % of the mature biofilm of E. coli and over 90 % of the mature biofilm of S. aureus at a concentration of 2.5 mg/mL. Further, the synthesized chitosan derivatives were determined to be non-toxic to L929 cells. Among them, DMDBC exhibited the most promising overall performance and show potential for wide-ranging applications in food preservation, disinfectants, medical, and other fields.

Microstructure induction of quaternary ammonium chitosan microcapsules based on magnetic field and study of their aroma release

Traditional pressure-sensitive microcapsules used in textiles face challenges of insufficient environmental friendliness in the production process and uncontrollable fragrance release. To address this issue, this study utilized quaternary ammonium chitosan and silica as wall materials to develop a magnetic aromatic microcapsule. The microstructure of the microcapsules was controlled by magnetic field induction, and its evolution pattern was investigated. After magnetic field induction, the microcapsules exhibited a trend of evolving from spherical to asymmetrical shapes, accompanied by significant changes in mechanical properties. Asymmetrical microcapsules showed higher adhesion and lower stiffness. When applied to cotton textiles, the cotton textiles treated with asymmetrical microcapsules released 63.40 % of lavender essential oil after 200 friction cycles, representing an 11.3 % improvement in release efficiency compared to regular microcapsules, indicating better mechanical stimulus responsiveness. Additionally, in antibacterial tests, aromatic cotton exhibited a 96.52 % inhibition ratio against Escherichia coli. In summary, this study explores methods to adjust the mechanical properties of microcapsules and the relationship between mechanical properties and microstructure, providing a new approach for functional textiles.

Genipin crosslinked quaternary ammonium chitosan hydrogels for wound dressings

Bacterial infection can lead to various complications, such as inflammations on surrounding tissues, which can prolong wound healing and thus represent a significant clinical and public healthcare problem. Herein, a report on the fabrication of a novel genipin/quaternized chitosan (CS) hydrogel for wound dressing is presented. The hydrogel was prepared by mixing quaternized CS and genipin under 35 °C bath. The hydrogels showed porous structure (250–500 μm) and mechanical properties (3000–6000 Pa). In addition, the hydrogels displayed self-healing ability and adhesion performance on different substrates. Genipin crosslinked quaternized CS hydrogels showed antibacterial activities against E. coli and S. aureus. The CCK-8 and fluorescent images confirmed the cytocompatibility of hydrogels by seeding with NIH-3T3 cells. The present study showed that the prepared hydrogel has the potential to be used as wound dressing.

Hydroxypropyl methylcellulose reinforced bilayer hydrogel dressings containing L-arginine-modified polyoxometalate nanoclusters to promote healing of chronic diabetic wounds

Diabetes-related slow healing of wounds is primarily driven by bacterial infections and angiogenesis disorder and presents a substantial hurdle in clinical treatment. To solve the above problems, an advanced multifunctional hydrogel system based on natural polymer was created here to facilitate wound healing in patients with chronic diabetes. The prepared dressing was composed of an outer hydrogel containing polyvinyl alcohol and hydroxypropyl methyl cellulose in dimethyl sulfoxide and water as binary solvents, and an inner hydrogel containing chitosan quaternary ammonium salt, flaxseed gum, and polyvinyl alcohol. Thus, a polysaccharide based bilayer hydrogel (BH) with superior mechanical strength and biocompatibility was created. This bilayer hydrogel could easily bind to dynamic tissue surfaces, thereby generating a protective barrier. Meanwhile, L-arginine-modified polyoxometalate (POM@L-Arg) nanoclusters were loaded in the inner hydrogel. They released NO when stimulated by the peroxide microenvironment of diabetic wounds. NO as a signal molecule regulated vascular tension and promoted cell proliferation and migration. Additionally, because of the synergistic effect of NO and the chitosan quaternary ammonium salt, the hydrogel system exhibited excellent antibacterial performance. The NO released reduced the levels of proinflammatory factors IL-6 and TNF-α in the diabetic wounds, which thus accelerated wound healing. In short, BH + POM@L-Arg is expected to serve as an ideal wound dressing as it exerts a good promotion effect on diabetes-related wound healing.

The numerical simulation investigates the influence of agitator parameters on particle suspension characteristics

This study investigates the effect of different agitator parameters in a baffleless stirred reactor on solid particle suspension during quaternary ammonium chitosan synthesis. Computational Fluid Dynamics (CFD) simulations investigate different agitator configurations, including blade diameter, rotational speed, and bottom clearance, to optimize chitosan particle distribution. Reducing the bottom clearance reduces particle accumulation, but can create stagnant zones that may disrupt fluid flow. Increasing the rotational speed improves particle distribution until a saturation point is reached. Increasing paddle diameter improves axial fluid circulation. Optimal settings for the vane size of a 180 mm reactor vessel are identified as 0.45 times the diameter, with a speed of 350 rpm, and a bottom clearance of 0.25 times the diameter. These simulations provide critical insight into the suspension of solid particles in baffleless stirred reactors and provide valuable guidance for optimizing stirrer parameters.

Construction of quaternary ammonium chitosan-coated protein nanoparticles as novel delivery system for curcumin: Characterization, stability, antioxidant activity and bio-accessibility

This research aimed to develop a novel, effective, and stable delivery system based on zein (ZE), sodium caseinate (SC), and quaternary ammonium chitosan (HACC) for curcumin (CUR). The pH-driven self-assembly combined with electrostatic deposition methods were employed to construct CUR-loaded ZE-SC nanoparticles with HACC coating (ZE-SC@HACC). The optimized nanocomposite was prepared at ZE:SC:HACC:CUR mass ratios of 1:1:2:0.1, and it had encapsulation efficiency of 89.3%, average diameter of 218.2 nm, and ζ-potential of 40.7 mV. The assembly of composites and encapsulation of CUR were facilitated primarily by hydrophobic, hydrogen-bonding, and electrostatic interactions. Physicochemical stability analysis revealed that HACC coating dramatically enhanced ZE-SC nanoparticles' colloidal stability and CUR's resistance to chemical degradation. Additionally, antioxidant activity and simulated digestion results indicated that CUR-ZE-SC@HACC nanoparticles showed higher free radical scavenging capacity and bio-accessibility of CUR than CUR-ZE-SC nanoparticles and free CUR. Therefore, the ZE-SC@HACC nanocomposite is an effective and viable delivery system for CUR.

Hybrid Double-Sided Tape with Asymmetrical Adhesion and Burst Pressure Tolerance for Abdominal Injury Treatment.

Patients with open abdominal (OA) wounds have a mortality risk of up to 30%, and the resulting disabilities would have profound effects on patients. Here, we present a novel double-sided adhesive tape developed for the management of OA wounds. The tape features an asymmetrical structure and employs an acellular dermal matrix (ADM) with asymmetric wettability as a scaffold. It is constructed by integrating a tissue-adhesive hydrogel composed of polydopamine (pDA), quaternary ammonium chitosan (QCS), and acrylic acid cross-linking onto the bottom side of the ADM. Following surface modification with pDA, the ADM would exhibit characteristics resistant to bacterial adhesion. Furthermore, the presence of a developed hydrogel ensures that the tape not only possesses tissue adhesiveness and noninvasive peelability but also effectively mitigates damage caused by oxidative stress. Besides, the ADM inherits the strength of the skin, imparting high burst pressure tolerance to the tape. Based on these remarkable attributes, we demonstrate that this double-sided (D-S) tape facilitates the repair of OA wounds, mitigates damage to exposed intestinal tubes, and reduces the risk of intestinal fistulae and complications. Additionally, the D-S tape is equally applicable to treating other abdominal injuries, such as gastric perforations. It effectively seals the perforation, promotes injury repair, and prevents the formation of postoperative adhesions. These notable features indicate that the presented double-sided tape holds significant potential value in the biomedical field.

Tannic acid and quaternized chitosan mediated puerarin-loaded octacalcium phosphate /sodium alginate scaffold for bone tissue engineering

Current limitations in mechanical performance and foreign body reactions (FBR) often lead to implant failure, restricting the application of bioceramic scaffolds. This study presents a novel 3D-printed scaffold that combines the release of anti-inflammatory drugs with osteogenic stimulation. Initially, the inorganic and organic phases were integrated to ensure the scaffold's mechanical integrity through catechol chemistry and the electrostatic interactions between tannic acid and quaternary ammonium chitosan. Subsequently, layers of polydopamine-encapsulated puerarin-loaded zeolitic imidazolate framework-8 (ZIF-8) were self-assembled onto the stent's surface, creating the drug-loaded scaffold that improved drug release without altering the scaffold's structure. Compared with unloaded scaffolds, the puerarin-loaded scaffold demonstrated excellent osteogenic differentiation properties along with superior anti-inflammatory and osteogenic effects in a range of in vitro and in vivo studies. RNA sequencing clarified the role of the TNF and NF/κB signaling pathways in these effects, further supporting the scaffold's osteogenic potential. This study introduces a novel approach for creating drug-loaded scaffolds, providing a unique method for treating cancellous bone defects.

Tannic acid-crosslinked gelatin composite microspheres adsorbed with CQAS or Ca2+ for rapid hemostasis

In the case of massive blood loss due to natural disasters and wars, timely and rapid hemostasis is of great significance to improve the survival rate of injured people. Nevertheless, uncontrolled, noncompressible, and irregular bleeding wounds remain a giant challenge for rapid hemostasis. In this study, the tannic acid-crosslinked gelatin was first obtained by Michael addition reaction, and then the tannic acid-crosslinked gelatin composite microspheres (TGMs) were prepared by the emulsion cross-linking method. TGMs could significantly improve the water absorption and hemostatic performance compared with single component gelatin microspheres (GMs). Increasing the water absorption ratio and introducing blood coagulation factors into composite materials are simple and effective strategies to enhance the hemostatic properties. Therefore, chitosan quaternary ammonium salt (CQAS) and Ca2+ were electrostatic adsorbed to obtain two kinds of functional TGMs, which were respectively CQAS-absorbed TGMs (T2GMs-CQAS) and calcium ion-absorbed TGMs (T2GMs-Ca2+). Notably, T2GMs-CQAS, and T2GMs-Ca2+ could absorb water rapidly within 3 seconds, in addition, especially the water absorption ratio of T2GMs-CQAS could reach 2.95 times compared with GMs. Benefited from rapid water absorption, coagulation pathway activation, and red blood cells aggregation of T2GMs-CQAS and T2GMs-Ca2+, resulting in rapid blood coagulation in vitro. In addition, CQAS and Ca2+ provided strong and intrinsic antibacterial activity due to positive charge. Moreover, in the tail amputation and liver hemostatic models, T2GMs-CQAS and T2GMs-Ca2+ demonstrated superior hemostatic effects compared to commercial Yunnan Baiyao®. In conclusion, T2GMs-CQAS and T2GMs-Ca2+ have potential applications as hemostatic dressings in uncontrolled, noncompressible, and irregular bleeding wounds.

Glucose-Responsive Self-Healing Bilayer Drug Microneedles Promote Diabetic Wound Healing Via a Trojan-Horse Strategy.

Chronic nonhealing wounds are serious complications of diabetes with a high morbidity, and they can lead to disability or death. Conventional drug therapy is ineffective for diabetic wound healing because of the complex environment of diabetic wounds and the depth of drug penetration. Here, we developed a self-healing, dual-layer, drug-carrying microneedle (SDDMN) for diabetic wound healing. This SDDMN can realize transdermal drug delivery and broad-spectrum sterilization without drug resistance and meets the multiple needs of the diabetic wound healing process. Quaternary ammonium chitosan cografted with dihydrocaffeic acid (Da) and l-arginine and oxidized hyaluronic acid-dopamine are the main parts of the self-healing hydrogel patch. Methacrylated poly(vinyl alcohol) (methacrylated PVA) and phenylboronic acid (PBA) were used as the main part of the MN, and gallium porphyrin modified with 3-amino-1,2 propanediol (POGa) and insulin were encapsulated at its tip. Under hyperglycaemic conditions, the PBA moiety in the MN reversibly formed a glucose-boronic acid complex that promoted the rapid release of POGa and insulin. POGa is disguised as hemoglobin through a Trojan-horse strategy, which is then taken up by bacteria, allowing it to target bacteria and infected lesions. Based on the synergistic properties of these components, SDDMN-POGa patches exhibited an excellent biocompatibility, slow drug release, and antimicrobial properties. Thus, these patches provide a potential therapeutic approach for the treatment of diabetic wounds.

Mg-gallate metal-organic framework-based sprayable hydrogel for continuously regulating oxidative stress microenvironment and promoting neurovascular network reconstruction in diabetic wounds

Chronic diabetic wounds are the most common complication for diabetic patients. Due to high oxidative stress levels affecting the entire healing process, treating diabetic wounds remains a challenge. Here, we present a strategy for continuously regulating oxidative stress microenvironment by the catalyst-like magnesium-gallate metal-organic framework (Mg-GA MOF) and developing sprayable hydrogel dressing with sodium alginate/chitosan quaternary ammonium salts to treat diabetic wounds. Chitosan quaternary ammonium salts with antibacterial properties can prevent bacterial infection. The continuous release of gallic acid (GA) effectively eliminates reactive oxygen species (ROS), reduces oxidative stress, and accelerates the polarization of M1-type macrophages to M2-type, shortening the transition between inflammation and proliferative phase and maintaining redox balance. Besides, magnesium ions adjuvant therapy promotes vascular regeneration and neuronal formation by activating the expression of vascular-associated genes. Sprayable hydrogel dressings with antibacterial, antioxidant, and inflammatory regulation rapidly repair diabetic wounds by promoting neurovascular network reconstruction and accelerating re-epithelialization and collagen deposition. This study confirms the feasibility of catalyst-like MOF-contained sprayable hydrogel to regulate the microenvironment continuously and provides guidance for developing the next generation of non-drug diabetes dressings.

Dual redox reaction of V3+/V4+ and V4+/V5+ with in-situ carbonization of chitosan quaternary ammonium promoting sodium storage property and safety of Na3V2(PO4)3

Na3V2(PO4)3 (NVP) has been limited by the poor ionic and electronic conductivity. Besides, the sole redox pair of V3+/V4+ releases a relatively low capacity. Currently, a simultaneous modification strategy of Fe2+ substitution and chitosan quaternary ammonium (CHACC) in-situ carbonization is proposed to optimize NVP for the first time. Fe2+ substitution can generate a classic P-type doping effect to supply abundant hole carries, effectively enhancing the electronic conductivity. Noteworthily, a new redox reaction of V4+/V5+ is activated after Fe-doping, which releases extra reversible capacities at a high voltage platform of 3.9 V, obviously increasing the active capacity and energy density. Moreover, the reaction mechanism of reversible V4+/V5+ has been deeply explored by ex-situ XPS. Furthermore, Cl− in the CHACC infiltrates into the NVP phase to replace part of (PO4)3−, which can provide a wider migration path and more dedicated space for Na(2) type Na+, improving the ionic conductivity. Moreover, the N element in the CHACC results in vast of active sites and defects in the carbon substrate, which induces the graphitization of hydrogel carbon materials due to the distortion of lattice caused by defects. Comprehensively, the modified NVP/C-CHACC-Fe0.07 shows superior electrochemical and kinetic properties. It reveals a capacity of 121.1 mAh g−1 at 0.1 C. At 30 C and 120 C, it shows capacities of 81.2 mAh g−1 and 70.5 mAh g−1 with retention rates of 72.4 % and 71.2 % after 4000 and 7000 cycles, respectively. Innovatively, temperature monitoring system analyzes the temperature change and safety of the NVP/C-CHACC-Fe0.07 cell, demonstrating that the variate is only 0.8 °C during each cycle. And the temperature remains stable in the long-term operation, suggesting its excellent stability and safety.

Study on Adsorption Properties of New Sodium Alginate and Chitosan Quaternary Ammonium Salt for Heavy Metal Ions

Study on Adsorption Properties of New Sodium Alginate and Chitosan Quaternary Ammonium Salt for Heavy Metal Ions

Fast-polymerized lubricant and antibacterial hydrogel coatings for medical catheters

Medical catheters are highly susceptible to friction and infection when intervening or implanting in the body, and to thrombosis when in contact with blood. Coating medical catheters with lubricant and antibacterial hydrogel is an effective strategy but struggle to achieve. Here, hydrogel coating on the catheter surface with lubrication and antibacterial properties was constructed by the rapid polymerization of acrylamide (AAM) and sulfobetaine methacrylate (SBMA) in the presence of quaternary ammonium chitosan (QCS) based on the redox-based cross-linking method. First, the medical catheter surface was decorated with a polyethyleneimine (PEI) adhesive layer. The pre-gel solution was then applied to the catheter surface, followed by immersion in an aqueous FeSO4·7H2O solution, where a large amount of SO4-• was generated by a redox reaction between ammonium persulfate (APS) and Fe2+, which rapidly triggered the monomer to cross-link to form the coating. Polyelectrolyte PEI as the adhesive layer could bind the coating to the substrate through hydrogen bonding interactions and confer antimicrobial properties to the coating with the assistance of QCS (antibacterial rate of 95.88 % against E. coli and 97.11 % against B. subtilis). The hydrogel coatings exhibited outstanding lubricity with a low coefficient of friction (COF ≈ 0.053) and excellent antifouling properties (resists non-specific protein adsorption, inhibits platelet adhesion and prevents thrombosis (The clotting time was extended from 25.6 s to 74.7 s)) based on the integration of SBMA. This work shed new light on the design of hydrogel coatings to achieve modification of the substrate surface.

The application of chitosan quaternary ammonium salt to replace polymeric aluminum ferric chloride for sewage sludge dewatering

Inorganic coagulants such as poly aluminum ferric chloride (Al/Fe) are applied conventionally to sewage sludge dewatering and can be retained in the sludge cake, causing its conductivity to increase and generate secondary pollution. To reduce these disadvantages, there is a need to develop alternative, more sustainable chemicals as substitutes for conventional inorganic coagulants. In the present investigation, the application of a polymeric chitosan quaternary ammonium salt (CQAS) is explored as a complete, or partial, replacement for Al/Fe in the context of sludge dewatering processes. Laboratory experiments using digested sewage sludge showed that CQAS could effectively substitute for over 80 % of the Al/Fe inorganic coagulant in the sludge dewatering process. This substitution resulted in a reduction of sludge cake conductivity by more than 50 %. Simulation of sludge dewatering curves and imaging of the sludge surface indicated that the addition of CQAS led to an increase in nanosized pores, and a decrease in the specific resistance of the sludge filter cake as the dosage of Al/Fe decreased to around 30 %. The variations of fluorescence emission, quantum yield and carboxylic and amino groups, suggested that the chelating of Al/Fe decreased due to the bridging effects of CQAS. The CQAS had different flocculation bridging effects on various EPS fractions, which varied the amount of protein chelated with Al/Fe in each fraction. This study provides new information about the benefits of replacing conventional inorganic coagulants with natural organic polymers for sewage sludge dewatering, in terms of reduced sludge cake conductivity and greater dry solids content.

Antibacterial conductive polyacrylamide/quaternary ammonium chitosan hydrogel for electromagnetic interference shielding and strain sensing

The utilization of biomass-based conductive polymer hydrogels in wearable electronics holds great promise for advancing performance and sustainability. An interpenetrating network of polyacrylamide/2-hydroxypropyltrimethyl ammonium chloride chitosan (PAM/HACC) was firstly obtained through thermal-initiation polymerization of AM monomers in the presence of HACC. The positively charged groups on HACC provide strong electrostatic interactions and hydrogen bonding with the PAM polymer chains, leading to improved mechanical strength and stability of the hydrogel network. Subsequently, the PAM/HACC networks served as the skeletons for the in-situ polymerization of polypyrrole (PPy), and then the resulting conductive hydrogel demonstrated stable electromagnetic shielding performance (40 dB), high sensitivity for strain sensing (gauge factor = 2.56). Moreover, the incorporation of quaternary ammonium chitosan into PAM hydrogels enhances their antimicrobial activity, making them more suitable for applications in bacterial contamination or low-temperature environments. This conductive hydrogel, with its versatility and excellent mechanical properties, shows great potential in applications such as electronic skin and flexible/wearable electronics.

Promoting the healing of diabetic wounds with an antimicrobial gel containing AgNPs with anti-infective and anti-inflammatory properties

Diabetic wounds are prone to develop chronic wounds due to bacterial infection and persistent inflammatory response. However, traditional dressings are monofunctional, lack bioactive substances, have limited bacterial inhibition as well as difficulties in adhesion and retention. These limit the therapeutic efficacy of traditional dressings on diabetic wounds. Therefore, finding and developing efficient and safe wound dressings is currently an urgent clinical need. In this study, an antimicrobial gel loaded with silver nanoparticles (AgNPs) (referred to as AgNPs@QAC-CBM) was prepared by crosslinking quaternary ammonium chitosan (QAC) with carbomer (CBM) as a gel matrix. AgNPs@QAC-CBM exhibited a reticulated structure, strong adhesion, good stability, and remarkable bactericidal properties, killing 99.9% of Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa within 1 min. Furthermore, AgNPs@QAC-CBM improved the wound microenvironment and accelerated wound healing in diabetic mice by promoting tissue production and collagen deposition, inducing M2 macrophages, reducing pro-inflammatory factor secretion and increasing anti-inflammatory factor levels. Moreover, AgNPs@QAC-CBM was proven to be safe for use through skin irritation and cytotoxicity tests, as they did not cause any irritation or toxicity. To summarize, AgNPs@QAC-CBM showed promising potential in enhancing the diabetic wound healing process.

Construction Strategy and Mechanism of a Novel Wood Preservative with Excellent Antifungal Effects.

Wood is a naturally porous material prone to microbial erosion and degradation in outdoor environments. Therefore, the development of an environmentally friendly wood preservative with excellent antibacterial effects and low toxicity is urgently needed. In this study, nitrogen-doped carbon quantum dots (N-CQDs) with excellent antifungal performance and fluorescent properties were synthesized using a one-step hydrothermal method with chitosan quaternary ammonium salt (HACC) as the raw material. The fluorescence characteristics of N-CQD preservatives can help track their position and distribution in wood. The minimum inhibitory concentration (MIC) of N-CQDs is 1.8 mg/mL, which was nearly 22 times lower than that of HACC (40.0 mg/mL) in the PDA medium. The decay resistance test demonstrated that wood treated with N-CQDs showed a considerably reduced decay degree and its mass loss rate decreased from 46 ± 0.5% to 3.8 ± 0.5%. Biological transmission electron microscopy revealed that N-CQDs effectively destroyed fungal cell structures, thereby hindering the growth of Coriolus versicolor. N-CQDs synthesized using the one-step hydrothermal method can be used as an efficient wood preservative that can effectively improve the utilization and service life of wood.

Quaternized chitosan-based organic-inorganic nanohybrid nanoparticles loaded with prothioconazole for efficient management of fungal diseases with minimal environmental impact

Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.