Advances in characterisation and biological activities of chitosan and chitosan oligosaccharides

Design, characterization, and biocompatibility of chitosan-nano-hydroxyapatite/tricalcium phosphate sponges

Chitosan-based sponges, incorporating tricalcium phosphate and hydroxyapatite, are extracellular components that represent a novel and impactful advancement in bone regeneration. Their bioactive composition, porous structure, and controlled release capacity are designed to stimulate osteogenesis effectively and could enhance the interrelations of cells in tissues and organs. The objective is to manufacture and characterize chitosan (CHT)-based sponges with different concentrations of nano-hydroxyapatite (nHAP) and tricalcium phosphate (TCP), as well as evaluate their biocompatibility. Composite sponges were manufactured in different concentrations: CHT (S1), 50:30:20 (S2), 60:20:20 (S3), and 70:20:10 (S4) and characterized by FTIR-ATR, TGA, and swelling. For biocompatibility, a cell proliferation assay, hemocompatibility, alizarin red, and its bactericidal effect were performed. Main groups of CHT are detected, and the presence of phosphate groups characteristic of TCP and nHAP was confirmed by FTIR. The nHAP/TCP content was validated using the Thermo Gravimetric Analysis (TGA), and the swelling tests were carried out with simulated body fluid (SBF), which proved stable for S2 and S3. About the biocompatibility tests of the cell proliferation assay, The TCP and nHAP present in the sponges caused a significant increase in cell proliferation (up 50-80 %). In contrast, in the control sample (S1), cell proliferation decreased without becoming cytotoxic (down 25 %). The hemolysis degree was less than 2 % at the times evaluated. Using alizarin red (ARS), it was shown that the different sponges were able to increase calcium deposits by approximately 10-45 % Through the antibiogram, it is assumed that the zone of inhibition occurs about the amount of CHT present in each sponge. Incorporating nHAP/TCP into CHT sponges favors the physical and thermal stability of the material. The sponges were demonstrated to have biocompatible and osteoinductive properties.

Harnessing the immunomodulatory potential of chitosan and its derivatives for advanced biomedical applications

The success of biomaterial applications in medicine, particularly in tissue engineering, relies on achieving a balance between promoting tissue regeneration and controlling the immune response. Due to its natural origin, high biocompatibility, and versatility, chitosan has emerged as a promising biomaterial especially for immunomodulation purposes. Immunomodulation, refers to the deliberate alteration of the immune system's activity to achieve a desired therapeutic effect either by enhancing or suppressing the function of specific immune cells, signaling pathways, or cytokine production. This modulation opens up the unlimited possibilities for the use of biomaterials, especially about the use of natural polymers such as chitosan. Although numerous chitosan-based immunoregulatory strategies have been demonstrated over the past two decades, the lack of in-depth exploration hinders the full potential of strategies that include chitosan and its derivatives in biomedical applications. Thus, in this review, the possible immunomodulatory effects of chitosan, chitosan derivatives and their potential combined with various agents and therapies are investigated in detail. Moreover, this report includes agents for localized immune response control, chitosan-based strategies with complementary immunomodulatory properties to create synergistic effects that will influence the success of cell therapies for enhanced tissue acceptance and regeneration. Finally, the challenges and outlook of chitosan-based therapies as a powerful tool for improving immunomodulatory applications are discussed for paving the way for further studies.

Chito-oligosaccharide impairs the proliferation, invasion and migration of pancreatic cancer cells

BACKGROUND

Chito-oligosaccharide (COS) is a low molecular weight polymer obtained by degrading chitosan through special enzymatic technology, with good water solubility and high biological activity. It is also the only positively charged cationic basic amino oligosaccharide in nature. Studies have confirmed that COS has antitumour effect, but research on its effect on pancreatic cancer (PC) remains limited and unclear. This study aimed to explore the effects of COS on PC cells (PANC-1 and MIAPaCa-2).

METHOD

We used different concentrations of COS to treat PC cells and conducted Cell Counting Kit-8, wound-healing, and transwell assays to evaluate the proliferation, invasion, and migration ability of PC cells, respectively. Western blot was conducted to assess the expression levels of epithelial-mesenchymal transition (EMT) related markers.

RESULT

The proliferation, invasion, and migration ability of PC cells (PANC-1 and MIAPaCa-2) gradually decreased in a manner dependent on COS concentration. COS at 10 mg/mL exerted the strongest inhibitory effect on the two PC cell lines. At 10 mg/mL, the proliferative activity was 60.61% ± 5.25% and 64.02% ± 4.96%, respectively; the invasive ability was (18.67 ± 4.416) and (31.33 ± 3.162), respectively; and the cell-migration ability was 26.83% ± 0.442% and 17.66% ± 0.647%, respectively. The expression levels of N-cadherin and vimentin were significantly downregulated in PANC-1 cells (0.198 ± 0.047 and 0.225 ± 0.038, respectively) and MIAPaCa-2 cells (0.214 ± 0.094 and 0.214 ± 0.094, respectively) at 10 mg/mL, respectively. Conversely, E-cadherin was upregulated (0.460 ± 0.037 and 0.491 ± 0.047, respectively). Compared with control group, the differences were statistically significant.

CONCLUSION

The upregulation of E-cadherin and the downregulation of vimentin and N-cadherin suggested that the specific mechanism of COS in PC may be related to EMT. This study provided a new direction for PC treatment.

Natural Feed Supplements From Crustacean Processing Side Streams for Improved Growth of Finfishes and Crustaceans: A Review

Natural feed additives of plant/animal/microbial origin are researched as supplements in aquaculture to improve the properties of feed, minimize the usage of chemical alternatives, reduce food safety risks and ensure sustainability to combat global food and nutritional security. Side streams generated during shellfish processing possess valuable ingredients: protein, lipids, carotenoids, minerals and chitins. Considering the current trend of organic farming and antibiotic-free fish and shellfish, crustacean processing side streams and their derivatives seem promising and emerging resources as natural additives/supplements for formulating high-quality feeds with superior benefits. Lower concentrations of chitin and chitosan in diets are reported to stimulate the growth of shellfish and finfish under controlled conditions. Oligomers of chitosan and nano-chitosan are also the other potential derivatives as natural supplements in feed for better growth performance of aquaculture varieties. This review focuses on the significance of crustacean processing side streams and their derivatives, especially shrimp head meal, chitin, chitosan and chitosan oligosaccharides as potential natural additives in aquafeeds for promoting the growth performance of cultured fin fishes and shell fishes. Utilization in aquafeeds and the development of natural value-added supplements from crustacean processing side streams, especially shrimp head and shell leftover, offer an answer to the negative environmental impact due to its dumping; reduce the dependency on food fish for fish meal production & fishmeal for aquafeeds; solution to maintain the economic viability of the fish farmers & industry as well as to ensure the supply of safer and healthy aquatic foods to meet the objectives of sustainable development goals.

Environmental innovation: polyaniline-cuttlebone nanocomposite as a potent antimicrobial agent and a synergistic barrier against doxorubicin-induced toxicity

This work emphasizes the importance of utilizing cuttlebone waste as a sustainable solution for waste management and the development of antimicrobial materials by incorporating it as a supporting phase for polyaniline (PANI) to form a nanocomposite. The three prepared materials were fully characterized using various techniques, including FTIR, XRD, SEM, EDX for elemental analysis, Brunauer-Emmett-Teller (BET) surface area measurements, particle size distribution analysis, and zeta potential measurements. The study focuses on the development of novel molecules with potential antibacterial and antifungal activity against clinical pathogens responsible for infectious diseases. The antibacterial and antifungal activities of the polyaniline/cuttlebone (PANI/CB) composite were evaluated using methods such as minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and disk diffusion for bacterial samples, as well as MIC, minimum fungicidal concentration (MFC), antifungal percentage, and disk diffusion for fungal samples. Notably, the PANI/CB composite exhibited a distinct crystallite size and characteristic XRD pattern, along with a significant BET surface area, demonstrating strong antimicrobial properties. Cuttlebone not only serves as a bioactive agent but also acts as a sustainable support to enhance the properties of polyaniline, forming a nanocomposite with a low MIC range (8-66 μg mL-1) and effective action against Gram-positive bacteria such as S. aureus, although it showed less susceptibility against Gram-negative bacteria like E. coli. The MTT assay results demonstrated that while PANI and CB alone exhibited minimal cytotoxicity on Huh7 cells, the combination of doxorubicin (DOX) with PANI/CB significantly enhanced the cytotoxic effect, suggesting a synergistic interaction that could improve the therapeutic efficacy of DOX. Additionally, the effectiveness of the polyaniline/cuttlebone composite in protecting against DOX-induced hepatic and renal damage in rats was evaluated. Tissue damage was assessed using serum markers such as alanine transaminase (ALT), aspartate transaminase (AST), urea, and creatinine. The results demonstrated a decrease in oxidative damage and significant improvements in liver and kidney function markers in the polyaniline/cuttlebone-treated groups compared to those treated with individual components. Specifically, ALT levels decreased from 48 ± 2.8 IU L-1 to 21 ± 0.4 IU L-1, AST from 195 ± 0.7 IU L-1 to 13 ± 1.08 IU L-1, urea from 86 ± 1.4 mg dL-1 to 39 ± 0.7 mg dL-1, and creatinine from 1.05 ± 0.03 mg dL-1 to 0.53 ± 0.01 mg dL-1. These findings highlight the potential of utilizing cuttlebone waste as a sustainable material in antimicrobial applications, offering an eco-friendly solution for waste management while contributing to the development of potent antimicrobial nanocomposites.

A review on the biological activities and the nutraceutical potential of chitooligosaccharides

Chitooligosaccharides (CHOS) or chitosan oligosaccharides (COS) are oligomers mainly composed of d-glucosamine (GlcN) units and structured in a positively charged, basic, amino molecule obtained from the degradation of chitin/chitosan through physical, chemical, or enzymatic methods. CHOS display physicochemical properties attractive to applications from the food to the biomedical field, such as non-toxicity to humans, high water solubility, low viscosity, biocompatibility, and biodegradability. These properties also allow CHOS to exert important biological activities, for example, antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, antitumor, and hypocholesterolemic ones, besides to exhibit applications in food systems, technological, and nutraceutical potential. Therefore, this study summarized the synthesis and chemical structure, biological functions, and mechanisms of action of CHOS; with this, we aimed to contribute to the knowledge about the application of CHOS from the food to the biomedical industries.

Protective Effects of Chitosan Oligosaccharide Against Lipopolysaccharide-Induced Inflammatory Response and Oxidative Stress in Bovine Mammary Epithelial Cells

Chitosan oligosaccharide (COS) is receiving increasing attention as a feed additive in animal production. COS has a variety of biological functions, including anti-inflammatory and antioxidant activities. Mastitis is a major disease in dairy cows that has a significant impact on animal welfare and production. Hence, this research aimed to investigate the mechanism of COS on the lipopolysaccharide (LPS)-stimulated inflammatory response and oxidative stress in bovine mammary epithelial cells (BMECs). In this study, the results demonstrated that COS protected BMECs from the inflammatory response induced by LPS by restraining the excessive production of toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). COS treatment also suppressed excessive reactive oxygen species (ROS) production and restored antioxidant enzyme activity under LPS-induced oxidative stress conditions. Furthermore, the results also demonstrated that COS promote nuclear factor erythroid 2-related factor 2 (Nrf2) expression and inhibit TLR4 levels and p65 and IκBα phosphorylation in BMECs exposed to LPS. In summary, the results demonstrate that the protective mechanism of COS on the LPS-induced inflammatory response and oxidative stress depend on the TLR4/nuclear factor-κB (NF-κB) and Nrf2 signaling pathways, indicating that COS could serve as natural protective agents for alleviating BMECs in mastitis.

Preparation of vanillin nanoparticle/polyvinyl alcohol/chitosan film and its application in preservation of large yellow croaker

The novel polyvinyl alcohol/chitosan films incorporated with vanillin/zein/κ-carrageenan nanoparticles (VZCNPs) were developed. The polyvinyl alcohol/chitosan/vanillin nanoparticles (PVA/CS/NPs) films had exhibited enhanced tensile strength, hydrophobicity, antioxidant activities and antimicrobial efficacy, all of which varied with the different concentrations of VZCNPs. Notably, the PVA/CS/NPs-10 film exhibited exceptional performance, with a reduced Moisture Content of 15.68 ± 0.46 %, an increased water contact angle of 65.75°, and improved ABTS scavenging rate of 77.39 ± 0.54 %, demonstrating outstanding antioxidant activity and antimicrobial properties. The PVA/CS/NPs films were further applied to the packaging of large yellow croaker (Pseudosciaena crocea) to evaluate their preservation capability at 4 °C. The results indicated that the PVA/CS/NPs films effectively inhibited microbial growth and lipid oxidation, thereby delaying the spoilage of large yellow croaker. High-throughput sequencing study showed that the films effectively inhibited spoilage bacteria, including Comamonas, Pseudomonas, and, Burkholderia and affected the distribution of bacterial populations during storage. This study provides new insights into prolonging the shelf life of fresh-frozen large yellow croaker and developing advanced preservation methods for the future development of the aquatic product.

Chitosan oligosaccharides: A potential therapeutic agent for inhibiting foam cell formation in atherosclerosis

Foam cell formation is a key hallmark in atherosclerosis and associated cardiovascular diseases (CVDs). The potential anti-atherosclerotic potential of chitosan oligosaccharides (COS) was investigated using oxLDL-treated RAW264.7 murine cells. COS treatment led to a significant inhibition of lipid accumulation, as demonstrated by Oil Red O staining, and reduced levels of total cholesterol, free cholesterol, cholesterol esters, and triglycerides in.oxLDL-treated RAW264.7 cells. COS blocked cholesterol influx through down-regulating class A1 scavenger receptors (SR-A1) and cluster of differentiation 36 (CD36) expression and stimulated cholesterol efflux through up-regulating ABC transporters ABCA-1 and ABCG-1 expressions. Additionally, COS treatment stimulated nuclear signaling pathways involving peroxisome proliferator-activated receptor-γ (PPAR-γ) and liver X receptor α (LXR-α), and also led to the phosphorylation of AMP-activated protein kinase (AMPK). COS further demonstrated anti-inflammatory effects by inhibiting the production of pro-inflammatory cytokines and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in oxLDL-treated RAW264.7 cells, through suppression of NF-κB signaling. Furthermore, COS alleviated oxidative stress induced by oxLDL by activating Nrf2 signaling and enhancing the expression of antioxidant genes, including heme oxygenase-1 (HO-1), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase (CAT). In conclusion, COS can be beneficial in preventing atherosclerosis and related diseases.

Isolation of a novel Bacillus strain with industrial potential of producing alkaline chitosanase

A novel Bacillus strain, designated as HZ20-1, was discovered. This strain can produce naturally alkaline chitosanase without induction. Genomic analysis revealed that this chitosanase belongs to glycoside hydrolase family 8. When colloidal chitosan is used as a substrate, the maximum enzyme activity of 2.39 ± 0.03 U/mL is observed at a pH range of 8.5-9. This alkaline enzyme holds advantages over common acidic enzymes in various fields such as medicine, the environment, and daily chemical products, and thus has great market value. Moreover, as the chitosanase is a constitutive enzyme, there is no need for substrate induction. This can simplify fermentation equipment and reduce production cost. Additionally, in a preliminary study, we found that this strain can also degrade chitin and chitosan derivatives. After analysis, it was discovered that it has genes in glycoside hydrolase families 18 and 23. By controlling the enzymatic hydrolysis time, it is possible to produce products with different molecular weights, including N-acetylglucosamine, glucosamine, chito-oligosaccharides, and chitin oligosaccharides. Consequently, Bacillus sp. HZ20-1 is considered to have great potential for future industrial production of enzymes and oligosaccharides.

Protective effect of water-soluble nervonic acid micro-powder coated with chitosan oligosaccharide and silk fibroin on hippocampal neuronal HT22 cells

Nervonic acid (NA) is an extremely long chain monounsaturated fatty acid that plays a crucial biological role in brain development and repair. However, its low solubility reduced bioavailability and limited its applications. In this study, spherical water-soluble nervonic acid composite micro-powder (NA-WM) was constructed by layer-by-layer self-assembly technology under electrostatic interaction and hydrogen bond, in which electronegative NA was used as the core material, and electropositive COS (Chitosan oligosaccharide) with neuroprotective properties and electronegative SF (Silk fibroin) with biocompatibility and anti-inflammatory synergism were used as the wall material. In the preparation process, the electronegative NA was first combined with electropositive COS by antisolvent method, and then the electropositive COS-NA complex was encapsulated with electronegative SF to form NA-WM. The optimal preparation conditions were screened and optimized via single-factor and BBD method. Under the optimum conditions, the average particle size of NA-WM was 420 ± 35 nm. The results of TGA (Thermogravimetric), SEM (Scanning electron microscopy), and FTIR (Fourier transform infrared spectroscopy) confirmed that NA-WM had good thermal stability and spherical-defined layer-to-layer structure. Additionally, at pH 1.5, the NA release rate of NA-WM was as high as 89.54 % within 2.5 h. Through measuring the levels of MDA (Malondialdehyde), CAT (Catalase), SOD (Superoxide dismutase), GSH-Px (Glutathione peroxidase), and LDH (Lactate dehydrogenase), as well as flow cytometry and SEM analysis, it was confirmed that NA-WM could protect Aβ1-42-induced HT22 by inhibiting oxidative stress and reducing mitochondrial membrane potential. This study provided data support for the development and application of NA.

Does Fungal Chitosan Leave Noticeable Traces in Treated Wines?

Background (1): The use of fungal chitosan as an antiseptic in wine appears as a promising alternative to sulfur dioxide for the elimination of Brettanomyces bruxellensis sensitive strains. Nevertheless, its utilization raises the question, "how are the treated wines different from the untreated ones?" Methods (2): Chitosan treatment residues were sought in the oligosaccharide and polysaccharide fractions and among 224 low MW ions (<1800 g·mol-1) in several wines by using liquid chromatography (size exclusion HPLC or LC-MS) and GC-MS. Standard oenological parameters were also examined as well as possible sensory modifications by a panel of tasters composed of experts and non-experts. Results (3): None of these methods enabled the reproducible and reliable identification of a treated wine without comparing it to its untreated control. The fingerprints of treatment are not reliably detectable by the analytical methods used in this study. However, the treated wines seem permanently protected against the development of chitosan-sensitive strains of B. bruxellensis. Conclusions (4): If chitosan treatment modifies the wine, the associated changes were not identified by the liquid chromatography method mentioned above and they were not perceived by most people in our taster panel. However, the expected antimicrobial action of chitosan was observed on B. bruxellensis sensitive strains and persisted at least one year. Tolerant strains were less affected by these persistent effects.

Improved cellular immune response induced by intranasal boost immunization with chitosan coated DNA vaccine against H9N2 influenza virus challenge

The H9N2 avian influenza virus (AIV) is spreading worldwide. Presence of H9N2 virus tends to increase the chances of infection with other pathogens which can lead to more serious economic losses. In a previous study, a regulated delayed lysis Salmonella vector was used to deliver a DNA vaccine named pYL233 encoding M1 protein, mosaic HA protein and chicken GM-CSF adjuvant. To further increase its efficiency, chitosan as a natural adjuvant was applied in this study. The purified plasmid pYL233 was coated with chitosan to form a DNA containing nanoparticles (named CS233) by ionic gel method and immunized by intranasal boost immunization in birds primed by oral administration with Salmonella strain. The CS233 DNA nanoparticle has a particle size of about 150 nm, with an encapsulation efficiency of 93.2 ± 0.12 % which protected the DNA plasmid from DNase I digestion and could be stable for a period of time at 37°. After intranasal boost immunization, the CS233 immunized chickens elicited higher antibody response, elevated CD4+ T cells and CD8+ T cells activation and increased T-lymphocyte proliferation, as well as increased productions of IL-4 and IFN-γ. After challenge, chickens immunized with CS233 resulted in the lowest levels of pulmonary virus titer and viral shedding as compared to the other challenge groups. The results showed that the combination of intranasal immunization with chitosan-coated DNA vaccine and oral immunization with regulatory delayed lytic Salmonella strain could enhance the immune response and able to provide protection against H9N2 challenge.

Chitosan-Clay Mineral Nanocomposites with Antibacterial Activity for Biomedical Application: Advantages and Future Perspectives

Polymers of natural origin, such as representatives of various polysaccharides (e.g., cellulose, dextran, hyaluronic acid, gellan gum, etc.), and their derivatives, have a long tradition in biomedical applications. Among them, the use of chitosan as a safe, biocompatible, and environmentally friendly heteropolysaccharide has been particularly intensively researched over the last two decades. The potential of using chitosan for medical purposes is reflected in its unique cationic nature, viscosity-increasing and gel-forming ability, non-toxicity in living cells, antimicrobial activity, mucoadhesiveness, biodegradability, as well as the possibility of chemical modification. The intuitive use of clay minerals in the treatment of superficial wounds has been known in traditional medicine for thousands of years. To improve efficacy and overcome the ubiquitous bacterial resistance, the beneficial properties of chitosan have been utilized for the preparation of chitosan-clay mineral bionanocomposites. The focus of this review is on composites containing chitosan with montmorillonite and halloysite as representatives of clay minerals. This review highlights the antibacterial efficacy of chitosan-clay mineral bionanocomposites in drug delivery and in the treatment of topical skin infections and wound healing. Finally, an overview of the preparation, characterization, and possible future perspectives related to the use of these advancing composites for biomedical applications is presented.

Chitosan and its derivatives regulate lactic acid synthesis during milk fermentation

Introduction

The influence of chitosan's physicochemical characteristics on the functionality of lactic acid bacteria and the production of lactic acid remains very obscure and contradictory to date. While some studies have shown a stimulatory effect of oligochitosans on the growth of Lactobacillus spp, other studies declare a bactericidal effect of chitosan. The lack and contradiction of knowledge prompted us to study the effect of chitosan on the growth and productivity of L. bulgaricus in the presence of chitosan and its derivatives.

Methods

We used high molecular weight chitosan (350 kDa) and oligochitosans (25.4 and 45.3 kDa). The experiment was carried out with commercial strain of L. bulgaricus and the low fat skim cow milk powder reconstituted with sterile distilled water. After fermentation, dynamic viscosity, titratable acidity, pH, content of lactic acid, colony forming units, chitosan and oligochitosans radii were measured in the samples. Fermented dairy products were also examined using sodium dodecyl sulfate electrophoretic analysis, gas chromatography-mass spectrometry and light microscopy.

Results and discussion

The results of the study showed that when L. bulgaricus was cultured in the presence of 25.4 kDa oligochitosans at concentrations of 0.0025%, 0.005%, 0.0075% and 0.01%, the average rate of LA synthesis over 24 hours was 11.0 × 10-3 mol/L/h, 8.7 × 10-3 mol/L/h, 6.8 × 10-3 mol/L/h, 5.8 × 10-3 mol/L/h, respectively. The 45.3 kDa oligochitosans had a similar effect, while the average rate of lactic acid synthesis in the control sample was only 3.5 × 10-3 mol/L/h. Notably, 350 kDa chitosan did not affect the rate of lactic acid synthesis compared with the control sample. Interestingly, interaction of chitosan with L. bulgaricus led to a slowdown in the synthesis of propanol, an increase in the content of unsaturated and saturated fatty acids, and a change in the composition and content of other secondary metabolites. The quantity of L. bulgaricus in a sample with 0.01% chitosan exceeded their content in the control sample by more than 1,700 times. At the same chitosan concentration, the fermentation process was slowed down, increasing the shelf life of the fermented milk product from 5 to 17 days while maintaining a high content of L. bulgaricus (6.34 × 106 CFU/g).

Characterization and Antioxidant Activity of the Polysaccharide Hydrolysate from Lactobacillus plantarum LPC-1 and Their Effect on Spinach (Spinach oleracea L.) Growth

This study presents a comparison between two hydrolysis systems (MnO2/H2O2 and ascorbic acid (VC)/H2O2) for the depolymerization of exopolysaccharide (EPS) from Lactobacillus plantarum LPC-1. Response surface methodology (RSM) was used to optimize these two degradation systems, resulting in two H2O2-free degradation products, MEPS (MnO2/H2O2-treated EPS) and VEPS (VC/H2O2-treated EPS), where H2O2 residues in the final products and their antioxidant activity were considered vital points. The relationship between the structural variations of two degraded polysaccharides and their antioxidant activity was characterized. Physicochemical tests showed that H2O2 had a notable impact on determining the total and reducing sugars in the polysaccharides, and both degradation systems efficiently eliminated this effect. After optimization, the average molecular weight of EPS was reduced from 265.75 kDa to 135.41 kDa (MEPS) and 113.11 kDa (VEPS), improving its antioxidant properties. Characterization results showed that the two hydrolysis products had similar major functional groups and monosaccharide composition as EPS. The crystal structure, main chain length, and branched chain number were crucial factors affecting the biological activity of polysaccharides. In pot testing, two degraded polysaccharides improved spinach quality more than EPS due to their lower molecular weights, suggesting the advantages of low-molecular-weight polysaccharides. In summary, these two degradation techniques offer valuable insights for further expanding the utilization of microbial resources.

Methotrexate-Loaded Chitosan Oligosaccharide-ES2 for Targeted Cancer Therapy

Cancer presents a significant health threat, necessitating the development of more precise, efficient, and less damaging treatment approaches. To address this challenge, we employed the 1-ethyl-(3-dimethyl aminopropyl) carbodiimide/N-hydroxy succinimide (EDC/NHS) catalytic system and utilized quaternized chitosan oligosaccharide (HTCOSC) as a drug carrier to construct a nanoparticle delivery system termed HTCOSC-cRGD-ES2-MTX (CREM). This system specifically targets integrin αvβ3 on tumor cell surfaces and enables simultaneous loading of the antiangiogenic agent ES2 (IVRRADRAAVP) and the chemotherapy drug methotrexate (MTX). Due to its amphiphilic properties, CREM self-assembles into nanoparticles in aqueous solution, exhibiting an average diameter of 179.47 nm. Comparative studies demonstrated that CREM, in contrast to free ES2 and MTX-free nanoparticles (CRE), significantly suppressed the proliferation of EAhy926 endothelial cells and B16 melanoma cells in vitro, resulting in inhibition rates of 71.18 and 82.25%, respectively. Furthermore, CREM exhibited a hemolysis rate below 2%, indicating excellent in vitro antiangiogenic and antitumor activity as well as favorable blood compatibility. Additionally, both CRE and CREM demonstrated favorable tumor targeting capabilities through the specific binding action of cyclic RGD (cRGD) to integrin αvβ3. Further in vivo investigations revealed that CREM induced apoptosis in tumor cells via the mitochondrial apoptotic pathway and reduced the expression of angiogenic factors such as vascular endothelial growth factor (VEGF), thereby inhibiting tumor angiogenesis. This potent antitumor effect was evident through a tumor suppression rate of 80.19%. Importantly, histopathological staining (HE staining) demonstrated the absence of significant toxic side effects of CREM on various organs compared to MTX. In conclusion, the CREM nano drug delivery system synergistically enhances the therapeutic efficacy of antiangiogenic drugs and chemotherapeutic agents, thus offering a novel targeted approach for cancer treatment.

Chitosanase-immobilized magnetite-agar gel particles as a highly stable and reusable biocatalyst for enhanced production of physiologically active chitosan oligosaccharides

A novel immobilized chitosanase was developed and utilized to produce chitosan oligosaccharides (COSs) via chitosan hydrolysis. Magnetite-agar gel particles (average particle diameter: 338 μm) were prepared by emulsifying an aqueous agar solution dispersing 200-nm magnetite particles with isooctane containing an emulsifier at 80 °C, followed by cooling the emulsified mixture. The chitosanase from Bacillus pumilus was immobilized on the magnetite-agar gel particles chemically activated by introducing glyoxyl groups with high immobilization yields (>80%), and the observed specific activity of the immobilized chitosanase was 16% of that of the free enzyme. This immobilized chitosanase could be rapidly recovered from aqueous solutions by applying magnetic force. The thermal stability of the immobilized chitosanase improved remarkably compared with that of free chitosanase: the deactivation rate constants at 35 °C of the free and immobilized enzymes were 8.1 × 10-5 and 3.9 × 10-8 s-1, respectively. This immobilized chitosanase could be reused for chitosan hydrolysis at 75 °C and pH 5.6, and 80% of its initial activity was maintained even after 10 cycles of use. COSs with a degree of polymerization (DP) of 2-7 were obtained using this immobilized chitosanase, and the product content of physiologically active COSs (DP ≥ 5) reached approximately 50%.

Progress in the Sustainable Development of Biobased (Nano)materials for Application in Water Treatment Technologies

Water pollution remains a widespread problem, affecting the health and wellbeing of people around the globe. While current advancements in wastewater treatment and desalination show promise, there are still challenges that need to be overcome to make these technologies commercially viable. Nanotechnology plays a pivotal role in water purification and desalination processes today. However, the release of nanoparticles (NPs) into the environment without proper safeguards can lead to both physical and chemical toxicity. Moreover, many methods of NP synthesis are expensive and not environmentally sustainable. The utilization of biomass as a source for the production of NPs has the potential to mitigate issues pertaining to cost, sustainability, and pollution. The utilization of biobased nanomaterials (bio-NMs) sourced from biomass has garnered attention in the field of water purification due to their cost-effectiveness, biocompatibility, and biodegradability. Several research studies have been conducted to efficiently produce NPs (both inorganic and organic) from biomass for applications in wastewater treatment. Biosynthesized materials such as zinc oxide NPs, phytogenic magnetic NPs, biopolymer-coated metal NPs, cellulose nanocrystals, and silver NPs, among others, have demonstrated efficacy in enhancing the process of water purification. The utilization of environmentally friendly NPs presents a viable option for enhancing the efficiency and sustainability of water pollution eradication. The present review delves into the topic of biomass, its origins, and the methods by which it can be transformed into NPs utilizing an environmentally sustainable approach. The present study will examine the utilization of greener NPs in contemporary wastewater and desalination technologies.

Multifunctional bilayer nanofibrous membrane enhances periodontal regeneration via mesenchymal stem cell recruitment and macrophage polarization

The continuous stimulation of periodontitis leads to a decrease in the number of stem cells within the lesion area and significantly impairing their regenerative capacity. Therefore, it is crucial to promote stem cell homing and regulate the local immune microenvironment to suppress inflammation for the regeneration of periodontitis-related tissue defects. Here, we fabricated a novel multifunctional bilayer nanofibrous membrane using electrospinning technology. The dense poly(caprolactone) (PCL) nanofibers served as the barrier layer to resist epithelial invasion, while the polyvinyl alcohol/chitooligosaccharides (PVA/COS) composite nanofiber membrane loaded with calcium beta-hydroxy-beta-methylbutyrate (HMB-Ca) acted as the functional layer. Material characterization tests revealed that the bilayer nanofibrous membrane presented desirable mechanical strength, stability, and excellent cytocompatibility. In vitro, PCL@PVA/COS/HMB-Ca (P@PCH) can not only directly promote rBMSCs migration and differentiation, but also induce macrophage toward pro-healing (M2) phenotype-polarization with increasing the secretion of anti-inflammatory and pro-healing cytokines, thus providing a favorable osteoimmune environment for stem cells recruitment and osteogenic differentiation. In vivo, the P@PCH membrane effectively recruited host MSCs to the defect area, alleviated inflammatory infiltration, and accelerated bone defects repair. Collectively, our data indicated that the P@PCH nanocomposite membrane might be a promising biomaterial candidate for guided tissue regeneration in periodontal applications.

Fabrication and characterization of physically crosslinked alginate/chitosan-based hydrogel loaded with neomycin for the treatment of skin infections caused by Staphylococcus aureus

Staphylococcus aureus is a pathogen widely involved in wound infection due to its ability to release several virulence factors that impair the skin healing process, as well as its mechanism of drug resistance. Herein, sodium alginate and chitosan were combined to produce a hydrogel for topical delivery of neomycin to combat S. aureus associated with skin complications. The hydrogel was formulated by combining sodium alginate (50 mg/mL) and chitosan (50 mg/mL) solutions in a ratio of 9:1 (HBase). Neomycin was added to HBase to achieve a concentration of 0.4 mg/mL (HNeo). The incorporation of neomycin into the product was confirmed by scanning electron microscopy, FTIR and TGA analysis. The hydrogels produced are homogeneous, have a high swelling capacity, and show biocompatibility using erythrocytes and fibroblasts as models. The formulations showed physicochemical and pharmacological stability for 60 days at 4 ± 2 °C. HNeo totally inhibited the growth of S. aureus after 4 h. The antimicrobial effects were confirmed using ex vivo (porcine skin) and in vivo (murine) wound infection models. Furthermore, the HNeo-treated mice showed lower severity scores than those treated with HBase. Taken together, the obtained results present a new low-cost bioproduct with promising applications in treating infected wounds.

Chitosan and Chitooligosaccharides: Antifungal Potential and Structural Insights

Chitosan is a cationic polysaccharide derived from chitin deacetylation. This polysaccharide and its oligosaccharides have many biological activities and can be used in several fields due to their favorable characteristics, such as biodegradability, biocompatibility, and nontoxicity. This review aims to explore the antifungal potential of chitosan and chitooligosaccharides along with the conditions used for the activity and mechanisms of action they use to kill fungal cells. The sources, chemical properties, and applications of chitosan and chitooligosaccharides are discussed in this review. It also addresses the threat fungi pose to human health and crop production and how these saccharides have proven to be effective against these microorganisms. The cellular processes triggered by chitosan and chitooligosaccharides in fungal cells, and prospects for their use as potential antifungal agents are also examined.

Physiological and Proteome Analysis of the Effects of Chitosan Oligosaccharides on Salt Tolerance of Rice Seedlings

Rice (Oryza sativa L.) is an important social-economic crop, and rice seedlings are easily affected by salt stress. Chitosan oligosaccharide (COS) plays a positive role in promoting plant growth and development. To gain a better understanding of the salt tolerance mechanism of rice under the action of COS, Nipponbare rice seedlings were selected as the experimental materials, and the physiological and biochemical indexes of rice seedlings in three stages (normal growth, salt stress and recovery) were measured. Unlabelled quantitative proteomics technology was used to study differential protein and signaling pathways of rice seedlings under salt stress, and the mechanism of COS to improve rice tolerance to salt stress was elucidated. Results showed that after treatment with COS, the chlorophyll content of rice seedlings was 1.26 times higher than that of the blank group (CK). The root activity during the recovery stage was 1.46 times that of the CK group. The soluble sugar in root, stem and leaf increased by 53.42%, 77.10% and 9.37%, respectively. The total amino acid content increased by 77% during the stem recovery stage. Furthermore, the malondialdehyde content in root, stem and leaf increased by 21.28%, 26.67% and 32.69%, respectively. The activity of oxide dismutase (SOD), peroxidase (POD) and oxygenase (CAT) were increased. There were more differentially expressed proteins in the three parts of the experimental group than in the CK group. Gene Ontology (GO) annotation of these differentially expressed proteins revealed that the experimental group was enriched for more entries. Then, through the Kyoto Encyclopedia of Genes and Genomes (KEGG), the top ten pathways enriched with differentially expressed proteins in the two groups (COS and CK groups) were utilized, and a detailed interpretation of the glycolysis and photosynthesis pathways was provided. Five key proteins, including phosphofructokinase, fructose bisphosphate aldolases, glycer-aldehyde-3-phosphate dehydrogenase, enolase and pyruvate kinase, were identified in the glycolysis pathway. In the photosynthesis pathway, oxygen evolution enhancement proteins, iron redox proteins and ferredoxin-NADPH reductase were the key proteins. The addition of COS led to an increase in the abundance of proteins, a response of rice seedlings to salt stress. COS helped rice seedlings resist salt stress. Furthermore, using COS as biopesticides and biofertilizers can effectively increase the utilization of saline-affected farmland, thereby contributing to the alleviating of the global food crisis.

Analysis of molecular structure and topological properties of chitosan isolated from crab shell and mushroom

This investigation aimed to scrutinize the chemical and structural analogies between chitosan extracted from crab exoskeleton (High Molecular Weight Chitosan, HMWC) and chitosan obtained from mushrooms (Mushroom-derived Chitosan, MRC), and to assess their biological functionalities. The resulting hydrolysates from the hydrolysis of HMWC by chitosanase were categorized as chitosan oligosaccharides (csCOS), while those from MRC were denoted as mrCOS. The molecular weights (MW) of csCOS and mrCOS were determined using Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) mass spectrometry. Furthermore, structural resemblances of csCOS and mrCOS were assessed utilizing X-ray powder diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Intriguingly, no apparent structural disparity between csCOS and mrCOS was noted in terms of the glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) composition ratios. Consequently, the enzymatic activities of chitosanase for HMWC and MRC exhibited remarkable similarity. A topological examination was performed between the enzyme and the substrate to deduce the alteration in MW of COSs following enzymatic hydrolysis. Moreover, the evaluation of antioxidant activity for each COS revealed insignificance in the structural disparity between HMWC and MRC. In summary, grounded on the chemical structural similarity of HMWC and MRC, we propose the potential substitution of HMWC with MRC, incorporating diverse biological functionalities.

Eco-friendly management strategies of insect pests: long-term performance of rosemary essential oil encapsulated into chitosan and gum Arabic

This study focused on encapsulation of Rosmarinus officinalis essential oil (EO) on chitosan and gum Arabic matrix in various ratios and with varying essential oil concentrations. Additionally, UV/VIS spectroscopy was used to determine cumulative-release profiles. The insecticidal activity was tested against Tribolium castaneum and Oryzaephilus surinamensis, both pests of stored products. In terms of encapsulation efficiency (EE%) and loading capacity (LC%), capsules had EE at 45.8% and LC at 2.31%. Furthermore, many minor compounds were lost after encapsulation, until identifying only 1,8-cineole, α-terpineol, and camphor after 60 d of storage. The fumigant tests demonstrated that encapsulated EO exhibited an effective control against insect pest during storage periods, namely, 30, 45, and 60 d with 99, 66, and 46% mortality for T. castaneum and 100, 84, 82% mortality for O. surinamensis.

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Dielectric Barrier Discharge Plasma-Assisted Preparation of Chitosan-Based Hydrogels

Chitosan is widely used in the production of various hydrogels due to its non-biological toxicity, good biocompatibility, and strong biodegradability. However, chitosan-based hydrogels have not been widely used in tissue engineering due to their poor mechanical strength, poor stability and high biotoxicity of cross-linking agents. As a green technology, low temperature plasma is rich in active groups that can be involved in various chemical reactions, such as replacing the components on the chitosan chain, contributing to the cross-linking of chitosan. In this study, a plasma-assisted preparation method of chitosan-based hydrogels was developed and the properties, including mechanics, water absorption, and degradation (or stability), were characterized and analyzed. It is proved that plasma treatment plays a significant role in improving the mechanical strength and stability of hydrogels.

Chitosan Versus Dapagliflozin in a Diabetic Cardiomyopathy Mouse Model

Diabetes mellitus is a metabolic disorder with global economic implications that can lead to complications such as diabetic cardiomyopathy. The aim of this study was to compare the effects of chitosan versus dapagliflozin in mouse diabetic cardiomyopathy. We used 32 C57Bl/6 male mice aged between 8 and 10 weeks, which were randomly divided into Control-without diabetes mellitus (DM), type 1 DM (T1DM), T1DM + Chitosan, and T1DM + Dapapgliflozin groups. We induced diabetes with streptozotocin and treated the animals for 12 weeks. The analysis showed a reduction in intramyocardial fibrosis in the T1DM + Dapapgliflozin compared to T1DM animals. In T1DM + CHIT, a reduction in intramyocardial fibrosis was observed although, accordingly, there was also no significant decrease in blood glucose. The level of oxidative stress was reduced in the groups of treated animals compared to T1DM. All these observed changes in the structure and function of hearts were highlighted in the echocardiographic examination. In the treated groups, there was delayed appearance of left ventricular (LV) hypertrophy, a slight decrease in the ejection fraction of the LV, and an improved diastolic profile. The results demonstrate that chitosan has promising effects on diabetic cardiomyopathy that are comparable to the beneficial effects of dapagliflozin.

An overview of the potential application of chitosan in meat and meat products

Chitosan is considered the second most ubiquitous polysaccharide next to cellulose. It has gained prominence in various industries including biomedicine, textile, pharmaceutical, cosmetic, and notably, the food industry over the last few decades. The polymer's continual attention within the food industry can be attributed to the increasing popularity of greener means of packaging and demand for foods incorporated with natural alternatives instead of synthetic additives. Its antioxidant, antimicrobial, and film-forming abilities reinforced by the polymer's biocompatible, biodegradable, and nontoxic nature have fostered its usage in food packaging and preservation. Microbial activity and lipid oxidation significantly influence the shelf-life of meat, resulting in unfavorable changes in nutritional and sensory properties during storage. In this review, the scientific studies published in recent years regarding potential applications of chitosan in meat products; and their effects on shelf-life extension and sensory properties are discussed. The utilization of chitosan in the form of films, coatings, and additives in meat products has supported the extension of shelf-life while inducing a positive impact on their organoleptic properties. The nature of chitosan and its compatibility with various materials make it an ideal biopolymer to be used in novel arenas of food technology.

Therapeutic applications of sustainable new chitosan derivatives and its nanocomposites: Fabrication and characterization

Chitosan (CS) is a biologically active biopolymer used in different medical applications due to its biodegradability, biocompatibility, and nontoxicity. Nanotechnology is an exciting and quick developing field in medical applications. Nanoparticles have shown great potential in the treatment of cancer and inflammation. In the present work modification of chitosan and its (Ag, Au, or ZnO) nanocomposites by N-aminophthalimide (NAP) occurred through the reaction with epichlorohydrin (ECH) as a crosslinker in the presence or absence of glutaraldehyde (GA) under different reaction conditions using microwave irradiation to give modified chitosan derivatives CS-2, CS-6, and their nanocomposites. Modified chitosan derivatives were characterized using different tools. CS-2 and CS-6 derivatives displayed enhancement of thermal stability and crystallinity compared to chitosan. Additionally, CS-2, CS-6, and their nanocomposites exhibited improvements in antitumor activity against HeLa cancer cells and enzymatic inhibitory against trypsin and α-chymotrypsin enzymes compared to chitosan. However, CS-2 revealed the highest cell growth inhibition% toward HeLa cells (89.02 ± 1.46 %) and the enzymatic inhibitory toward α-chymotrypsin enzyme (17.13 ± 1.59 %). Furthermore, CS-Au-2 showed the highest enzymatic inhibitory against trypsin enzyme (28.14 ± 1.76 %). These results suggested that the new chitosan derivatives CS-2, CS-6, and their nanocomposites could be a platform for medical applications against HeLa cells, trypsin, and α-chymotrypsin enzymes.

Chitin and Its Derivative Chitosan: Distribution in Nature, Applications, and Technology Research (A Review)

The present review highlights the chitin/chitosan as biopolymers that are promising for biomedical research development. Our goal was to assess the potential for practical use of these biopolymers and to summarize information on traditional and innovative technologies for their production and purification. The widespread occurrence of chitin and chitosan in nature as well as the unique chemical and biological properties of chitosan are reasons of growing interest in the use of the latter in several pharmaceutical fields. The main stages of chitin extraction and its further modification into chitosan are deproteinization, demineralization, deacetylation, and the main methods of chitosan purification are filtration, dialysis and reprecipitation. The profitability of the production of chitin/chitosan from crustaceans and edible mushrooms is approximately at the same level. The cost of mushroom products can be reduced by using agricultural or forestry waste as nutrient substrates. This makes the use of fungi as sources of chitin/chitosan in forested regions a rather promising issue.

Nuciferine-loaded chitosan hydrogel-integrated 3D-printed polylactic acid scaffolds for bone tissue engineering: A combinatorial approach

Critical-sized bone defects resulting from severe trauma and open fractures cannot spontaneously heal and require surgical intervention. Limitations of traditional bone grafting include immune rejection and demand-over-supply issues leading to the development of novel tissue-engineered scaffolds. Nuciferine (NF), a plant-derived alkaloid, has excellent therapeutic properties, but its osteogenic potential is yet to be reported. Furthermore, the bioavailability of NF is obstructed due to its hydrophobicity, requiring an efficient drug delivery system, such as chitosan (CS) hydrogel. We designed and fabricated polylactic acid (PLA) scaffolds via 3D printing and integrated them with NF-containing CS hydrogel to obtain the porous biocomposite scaffolds (PLA/CS-NF). The fabricated scaffolds were subjected to in vitro physicochemical characterization, cytotoxicity assays, and osteogenic evaluation studies. Scanning electron microscopic studies revealed uniform pore size distribution on PLA/CS-NF scaffolds. An in vitro drug release study showed a sustained and prolonged release of NF. The cyto-friendly nature of NF in PLA/CS-NF scaffolds towards mouse mesenchymal stem cells (mMSCs) was observed. Also, cellular and molecular level studies signified the osteogenic potential of NF in PLA/CS-NF scaffolds on mMSCs. These results indicate that the PLA/CS-NF scaffolds could promote new bone formation and have potential applications in bone tissue engineering.

Eco-benign synthesis of nano‑gold chitosan-bacterial cellulose in spent ground coffee kombucha consortium: Characterization, microbiome community, and biological performance

Biomaterials that are mediocre for cell adhesion have been a concern for medical purposes. In this study, we fabricated nano‑gold chitosan-bacterial cellulose (CBC-Au) via a facile in-situ method using spent ground coffee (SGC) in a kombucha consortium. The eco-benign synthesis of monodispersed gold nanoparticles (Au NPs) in modified bacterial cellulose (BC) was successfully achieved in the presence of chitosan (CHI) and a symbiotic culture of bacteria and yeast (SCOBY). The dominant microbiome community in SGC kombucha were Lactobacillaceae and Saccharomycetes. Chitosan-bacterial cellulose (CBC) and CBC-Au affected the microfibril networks in the nano cellulose structures and decreased the porosity. The modified BC maintained its crystallinity up to 80 % after incorporating CHI and Au NPs. Depth profiling using X-ray photoelectron spectroscopy (XPS) indicated that the Au NPs were distributed in the deeper layers of the scaffolds and a limited amount on the surface of the scaffold. Aspergillus niger fungal strains validated the biodegradability of each scaffold as a decomposer. Bacteriostatically CBC-Au showed better antimicrobial activity than BC, in line with the adhesion of NIH-3T3 fibroblast cells and red blood cells (RBCs), which displayed good biocompatibility performance, indicating its potential use as a medical scaffold.

Chitosan-glucose derivative as effective wall material for probiotic yeasts microencapsulation

A chitosan-glucose derivative (ChG) with lower antimicrobial activity against whey native probiotic yeast K. marxianus VM004 was synthesized by the Maillard reaction. The ChG derivative was characterized by FT-IR, 1H NMR, and SLS to determine the structure, deacetylation degree (DD), and molecular weight (Mw). In addition, we evaluated the antioxidant, cytotoxic, and antimicrobial activities of ChG. ChG was then used for microencapsulation of K. marxianus VM004 by spray drying. The microcapsules were characterized by evaluating their encapsulation yield, encapsulation efficiency, morphology, tolerance to the gastrointestinal tract, and viability during storage. The results indicated that a non-cytotoxic product with lower MW and DD and higher antioxidant activity than native chitosan was obtained by the Maillard reaction. The yeast ChG microcapsules exhibited an encapsulation efficiency >57 %, improved resistance to gastrointestinal conditions, and enhanced stability during storage. These results demonstrate that ChG may be a promising wall material for the microencapsulation of probiotic yeasts.

Chitotriose Enhanced Antitumor Activity of Doxorubicin through Egr1 Upregulation in MDA-MB-231 Cells

Dietary supplementation is proposed as a strategy to reduce the side effects of conventional chemotherapy for triple-negative breast cancer (TNBC). Chitosan oligosaccharides (COS), a functional carbohydrate, have been identified to potentially inhibit cancer cell proliferation. However, a detailed investigation is required to fully understand its exact influence, particularly in terms of COS composition. The antitumor activities of COS oligomers and its monomer of glucosamine, when combined with doxorubicin separately, were evaluated in MDA-MB-231 cells. Chitotriose was identified to have the most significant synergistic effect. Preincubation with chitotriose was observed to promote the entry of doxorubicin into the cell nuclei and induce morphological changes in the cells. Mechanism analysis at the transcriptional level revealed that the early growth response 1 (Egr1) gene was a key regulator in enhancing the suppressive effect. This gene was found to modulate the activity of its downstream gene, growth arrest, and DNA damage-inducible alpha (Gadd45a). The role of Egr1 was confirmed through a small interfering RNA test and function assay. These findings provide insight into the effect and underlying mechanism of chitotriose supplementation for TNBC therapy.

Chitosan as a Control Tool for Insect Pest Management: A Review

Chitosan, a polysaccharide derived from the deacetylation of chitin, is a versatile and eco-friendly biopolymer with several applications. Chitosan is recognized for its biodegradability, biocompatibility, and non-toxicity, beyond its antimicrobial, antioxidant, and antitumoral activities. Thanks to its properties, chitosan is used in many fields including medicine, pharmacy, cosmetics, textile, nutrition, and agriculture. This review focuses on chitosan's role as a tool in insect pest control, particularly for agriculture, foodstuff, and public health pests. Different formulations, including plain chitosan, chitosan coating, chitosan with nematodes, chitosan's modifications, and chitosan nanoparticles, are explored. Biological assays using these formulations highlighted the use of chitosan-essential oil nanoparticles as an effective tool for pest control, due to their enhanced mobility and essential oils' prolonged release over time. Chitosan's derivatives with alkyl, benzyl, and acyl groups showed good activity against insect pests due to improved solubility and enhanced activity compared to plain chitosan. Thus, the purpose of this review is to provide the reader with updated information concerning the use and potential applications of chitosan formulations as pest control tools.

Preparation of chitosan/citral forward osmosis membrane via Schiff base reaction with enhanced anti-bacterial properties

In this study, hydrogels generated by the Schiff base reaction between citral and chitosan (CS) were used for the first time to improve the anti-bacterial property of forward osmosis (FO) membranes. The composite membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Water contact angle (WCA), Zeta potential and confocal laser scanning microscopic (CLSM). In the FO filtration experiment, the membrane performance of TFC-1 with 1 M sodium chloride solution as the draw solution and deionized water as the feed solution was the best, with the water flux of 25.54 ± 0.7 L m-2 h-1 and the reverse salt flux of 4.7 ± 0.4 g m-2 h-1. Although the hydrogel coating produced a certain hydraulic resistance, the flux of the modified membrane was only reduced by about 8%, compared with the unmodified membrane. However, the anti-bacterial property (Pseudomonas aeruginosa) and anti-fouling properties (bovine serum protein and lysozyme protein) of the modified membranes were improved, showing good antibacterial properties (99%) and flux recovery rate (over 90%). The modified method has the advantages of easy access to raw materials, simple operation and no risk of secondary pollution, which can effectively reduce the cost of chemical cleaning and extend the service life of the membrane. The modification of membrane by chitosan-based hydrogel is a promising option in the field of membrane anti-bacteria.

The source, activity influencing factors and biological activities for future development of chitin deacetylase

Chitin deacetylase (CDA), a prominent member of the carbohydrate esterase enzyme family 4 (CE4), is found ubiquitously in bacteria, fungi, insects, and crustaceans. This metalloenzyme plays a pivotal role in recognizing and selectively removing acetyl groups from chitin, thus offering an environmentally friendly and biologically-driven preparation method for chitosan with immense industrial potential. Due to its diverse origins, CDAs sourced from different organisms exhibit unique functions, optimal pH ranges, and temperature preferences. Furthermore, certain organic reagents can induce structural changes in CDAs, influencing their catalytic activity. Leveraging CDA's capabilities extends beyond chitosan biocatalysis, as it demonstrates promising application value in agricultural pest control. In this paper, the source, reaction mechanism, influencing factors, the fermentation methods and applications of CDA are reviewed, which provides theoretical help for the research and application of CDA.

Sustainable functionalized chitosan based nano-composites for wound dressings applications: A review

Functionalized chitosan nanocomposites have been studied for wound dressing applications due to their excellent antibacterial and anti-fungal properties. Polysaccharides show excellent antibacterial and drug-release properties and can be utilized for wound healing. In this article, we comprise distinct approaches for chitosan functionalization, such as photosensitizers, dendrimers, graft copolymerization, quaternization, acylation, carboxyalkylation, phosphorylation, sulfation, and thiolation. The current review article has also discussed brief insights on chitosan nanoparticle processing for biomedical applications, including wound dressings. The chitosan nanoparticle preparation technologies have been discussed, focusing on wound dressings owing to their targeted and controlled drug release behavior. The future directions of chitosan research include; a) finding an effective solution for chronic wounds, which are unable to heal completely; b) providing effective wound healing solutions for diabetic wounds and venous leg ulcers; c) to better understanding the wound healing mechanism with such materials which can help provide the optimum solution for wound dressing; d) to provide an improved treatment option for wound healing.

Research progress on chitin/chitosan-based emulsion delivery systems and their application in lipid digestion regulation

Excessive lipid intake is linked to an elevated risk of health problems. However, reducing lipid contents may influence food structure and flavor. Some alternatives are needed to control the lipid absorption. Emulsions are common carriers for lipids, which can control the hydrolysis and absorption of lipids. Chitin (Ch) and chitosan (CS) are natural polysaccharides with good biodegradability, biocompatibility, and unique cationic properties. They have been reported to be able to delay lipolysis, which can be regarded as one of the most promising agents that regulates lipid digestion (LiD). The application of Ch/CS and their derivatives in emulsions are summarized in this review with a focus on their performances and mechanisms for LiD regulation, aiming to provide theoretical guidance for the development of novel Ch/CS emulsions, and the regulation of LiD. A reasonable design of emulsion interface can provide its resistance to the external environment and then control LiD. The properties of emulsion interface are the key factors affecting LiD. Therefore, systematic study on the relationship between Ch/CS-based emulsion structure and LiD can not only instruct the reasonable design of emulsion interface to accurately regulate LiD, but also provide scientific guidelines for applying Ch/CS in functional food, medicine and other fields.

Synthesis of acylated derivatives of chitosan oligosaccharide and evaluation of their potential antifungal agents on Fusarium oxysporum

Chitosan oligosaccharide (COS) is an important carbohydrate-based biomaterial for synthesizing candidate drugs and biological agents. This study synthesized COS derivatives by grafting acyl chlorides of different alkyl chain lengths (C8, C10, and C12) onto COS molecules and further investigated their physicochemical properties and antimicrobial activity. The COS acylated derivatives were characterized using Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy, X-ray diffraction, and thermogravimetric analysis. COS acylated derivatives were successfully synthesized and possessed high solubility and thermal stability. As for the evaluation of antibacterial activity, COS acylated derivatives did not significantly inhibit Escherichia coli and Staphylococcus aureus, but they significantly inhibited Fusarium oxysporum, which was superior to that of COS. Transcriptomic analysis revealed that COS acylated derivatives exerted antifungal activity mainly by downregulating the expression of efflux pumps, disrupting cell wall integrity, and impeding normal cell metabolism. Our findings provided a fundamental theory for the development of environmentally friendly antifungal agents.

Biological Macromolecule-Based Scaffolds for Urethra Reconstruction

Urethral reconstruction strategies are limited with many associated drawbacks. In this context, the main challenge is the unavailability of a suitable tissue that can endure urine exposure. However, most of the used tissues in clinical practices are non-specialized grafts that finally fail to prevent urine leakage. Tissue engineering has offered novel solutions to address this dilemma. In this technology, scaffolding biomaterials characteristics are of prime importance. Biological macromolecules are naturally derived polymers that have been extensively studied for various tissue engineering applications. This review discusses the recent advances, applications, and challenges of biological macromolecule-based scaffolds in urethral reconstruction.

Growth, Biochemical Characteristics, Flesh Quality, and Gut Microbiota of the Pacific White Shrimp (Penaeus vannamei) Fed a Defatted Superworm (Zophobas atratus) Larvae Meal

This study evaluated the effects of defatted superworm (Zophobas atratus) larvae meal (DBWLM) as an alternative protein ingredient for juvenile Pacific white shrimp (Penaeus vannamei). Six isonitrogenous and isolipidic experimental diets were characterized by replacing 0%, 15%, 30%, 45%, 60%, and 75% fish meal (DBWLM0, DBWLM15, DBWLM30, DBWLM45, DBWLM60, and DBWLM75, respectively) with DBWLM on a w/w basis and feeding them to juvenile shrimp (0.34 ± 0.04 g) for 56 days. The results showed that the replacement of up to 75% fish meal by DBWLM had no negative effect on the growth performance of P. vannamei. The survival of shrimp in the DBWLM30 group was the highest, and the weight gain, specific growth rate, feed conversion ratio, condition factor, and apparent digestibility coefficients of dry matter in the DBWLM15 group were the highest. The substitution of DBWLM for fish meal significantly increased the elasticity of flesh, improved the total content of umami amino acids in flesh (aspartic acid, glutamic acid, glycine, and alanine), promoted lipid metabolism in shrimp, and reduced serum lipid levels. With the increase in DBWLM level, serum acid phosphatase, alkaline phosphatase activity, and intestinal inflammatory gene expression (IGF-1 and IL-6) were inhibited, malondialdehyde content decreased, and total antioxidant capacity level and superoxide dismutase activity increased significantly. Histological sections of the hepatopancreas showed that when 60% or more fish meal was replaced, the hepatopancreas atrophied and had irregular lumen distortion, but the cell membrane was not damaged. Microbiome analysis showed that the abundance of Bacteroidetes and Firmicutes increased and the abundance of Proteobacteria decreased in the DBWLM replacement group, and it was rich in "metabolism"-related functional pathways. It is worth mentioning that the expression of amino-acid-related enzymes was upregulated in the DBWLM15 and DBWLM30 groups, and the DBWLM75 group inhibited the biosynthesis of steroids and hormones. To conclude, the replacement of 15%-45% fish meal with DBWLM can result in better growth and immune status, improved meat elasticity, and reduced inflammation in P. vannamei. However, it is recommended that the replacement level should not exceed 60%, otherwise it will cause atrophy of hepatopancreas cells.

Repurposing chitin-rich seafood waste for warm-water fish farming

The pisciculture industry has grown multi-fold over the past few decades. However, a surge in development and nutrient demand has led to the establishment of numerous challenges. Being a potential solution, chitosan has gained attention as a bio nanocomposite for its well-acclaimed properties including biodegradability, non-toxicity, immunomodulatory effects, antimicrobial activity, and biocompatibility. This biopolymer and its derivatives can be transformed into various structures, like micro and nanoparticles, for various purposes. Consequently, with regards to these properties chitin and its derivatives extend their application into drug delivery, food supplementation, vaccination, and preservation. This review focuses on the clinical advancements made in fish biotechnology via chitosan and its derivatives and highlights its prospective expansion into the pisciculture industry-in particular, warm-water species.

Chitosan oligomers (COS) trigger a coordinated biochemical response of lemongrass (Cymbopogon flexuosus) plants to palliate salinity-induced oxidative stress

Plant susceptibility to salt depends on several factors from its genetic makeup to modifiable physiological and biochemical status. We used lemongrass (Cymbopogon flexuosus) plants as a relevant medicinal and aromatic cash crop to assess the potential benefits of chitosan oligomers (COS) on plant growth and essential oil productivity during salinity stress (160 and 240 mM NaCl). Five foliar sprays of 120 mg L^-1 of COS were applied weekly. Several aspects of photosynthesis, gas exchange, cellular defence, and essential oil productivity of lemongrass were traced. The obtained data indicated that 120 mg L^-1 COS alleviated photosynthetic constraints and raised the enzymatic antioxidant defence including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities that minimised salt-induced oxidative damage. Further, stomatal conductance (g_s) and photosynthetic CO₂ assimilation (A) were improved to support overall plant development. The same treatment increased geraniol dehydrogenase (GeDH) activity and lemongrass essential oil production. COS-induced salt resilience suggests that COS could become a useful biotechnological tool in reclaiming saline soil for improved crop productivity, especially when such soil is unfit for leading food crops. Considering its additional economic value in the essential oil industry, we propose COS-treated lemongrass as an excellent alternative crop for saline lands.

Hybrid Cryogels with Superabsorbent Properties as Promising Materials for Penicillin G Retention

This present study describes the investigation of new promising hybrid cryogels able to retain high amounts of antibiotics, specifically penicillin G, using chitosan or chitosan-biocellulose blends along with a naturally occurring clay, i.e., kaolin. In order to evaluate and optimize the stability of cryogels, three types of chitosan were used in this study, as follows: (i) commercial chitosan; (ii) chitosan prepared in the laboratory from commercial chitin; and (iii) chitosan prepared in the laboratory from shrimp shells. Biocellulose and kaolin, previously functionalized with an organosilane, were also investigated in terms of their potential to improve the stability of cryogels during prolonged submergence under water. The organophilization and incorporation of the clay into the polymer matrix were confirmed by different characterization techniques (such as FTIR, TGA, SEM), while their stability in time underwater was investigated by swelling measurements. As final proof of their superabsorbent behavior, the cryogels were tested for antibiotic adsorption in batch experiments, in which case cryogels based on chitosan extracted from shrimp shells seem to exhibit excellent adsorption properties for penicillin G.

Chitooligosaccharide boosts the immunity of immunosuppressed blunt snout bream against bacterial infections

The immunosuppression hazard of fish brought by intensive aquaculture needs to be addressed urgently, while chitooligosaccharide (COS) shows the potential application in the prevention the immunosuppression of fish due to its superior biological properties. In this study, COS reversed the cortisol-induced immunosuppression of macrophages and improved the immune activity of macrophages in vitro, promoting the expression of inflammatory genes (TNF-α, IL-1β, iNOS) and NO production, and increasing the phagocytic activity of macrophages. In vivo, the oral COS was absorbed directly through the intestine, significantly ameliorating the innate immunity of cortisol-induced immunosuppression of blunt snout bream (Megalobrama amblycephala). Such as facilitated the gene expression of inflammatory cytokines (TNF-α, IL-1β, IL-6) and pattern recognition receptors (TLR4, MR) and potentiated bacterial clearance, resulting in an effective improvement in survival and tissue damage. Altogether, this study demonstrates that COS offers potential strategies in the application of immunosuppression prevention and control in fish.