Chitosan Oligosaccharide Research Articles

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.

Vibrio cholerae virulence is blocked by chitosan oligosaccharide-mediated inhibition of ChsR activity.

Vibrio cholerae causes cholera, an important cause of death worldwide. A fuller understanding of how virulence is regulated offers the potential for developing virulence inhibitors, regarded as efficient therapeutic alternatives for cholera treatment. Here we show using competitive infections of wild-type and mutant bacteria that the regulator of chitosan utilization, ChsR, increases V. cholerae virulence in vivo. Mechanistically, RNA sequencing, chromatin immunoprecipitation with sequencing and molecular biology approaches revealed that ChsR directly upregulated the expression of the virulence regulator, TcpP, which promoted expression of the cholera toxin and the toxin co-regulated pilus, in response to low O2 levels in the small intestine. We also found that chitosan degradation products inhibit the ChsR-tcpP promoter interaction. Consistently, administration of chitosan oligosaccharide, particularly when delivered via sodium alginate microsphere carriers, reduced V. cholerae intestinal colonization and disease severity in mice by blocking the chsR-mediated pathway. These data reveal the potential of chitosan oligosaccharide as supplemental therapy for cholera treatment and prevention.

Water-in-water emulsions stabilized by nano-chitin

A water-in-water (W/W) emulsion consists of microdroplets was formed by the spontaneous liquid–liquid separation by mixing polyacrylic acid and chitosan oligosaccharide in water, and these microdropletes were stabilized by nano-chitin, formed water-in-water Pickering emulsions. By taking the advantage of interfacial adsorption of nano-chitin, the W/W emulsion droplets composed of polyacrylic acid/chitosan oligosaccharide (COS/PAA) polyelectrolyte coacervate were successfully stabilized. Research results indicated that composite microspheres were formed by the nano-chitin stabilized COS/PAA emulsion, and the size of these composite microspheres was related to the concentration and morphology of the nano-chitin. As the concentration of nano-chitin increases, the size of the composite microspheres first increases and then decreases, gradually becoming more uniform; whereas a decrease in the length of nano-chitin will lead to an increase in the size of the composite microspheres. The formation of composite microspheres may be due to the electrostatic interactions between nano-chitin and the emulsion droplets. In addition, the composite microspheres exhibit the best release effect for berberine hydrochloride at a pH value of 3.

Melt-Processed Polybutylene-Succinate Biocomposites with Chitosan: Development and Characterization of Rheological, Thermal, Mechanical and Antimicrobial Properties.

The current research is devoted to the development and characterization of green antimicrobial polymer biocomposites for food packaging applications. The biocomposites were developed by melt compounding on the basis of two different succinate polymer matrices with varying chain stiffness-polybutylene succinate (PBS) or its copolymer with 20 mol.% of polybutylene adipate (PBSA). Fungi chitosan oligosaccharide (C98) and crustacean chitosan (C95) were used as antimicrobial additives. The rheological properties of the developed biocomposites were determined to clear out the most suitable temperature for melt processing. In addition, mechanical, thermal, barrier and antimicrobial properties of the developed biocomposites were determined. The results of the investigation revealed that PBSA composites with 7 wt% and 10 wt% of the C98 additive were more suitable for the development of green packaging films because of their higher ultimate elongation values, better damping properties as well as their superior anti-microbial behavior. However, due to the lower thermal stability of the C98 additive as well as PBSA, the melt processing temperatures of the composites desirably should not exceed 120 °C. Additionally, by considering decreased moisture vapor barrier properties, it is recommended to perform further modifications of the PBSA-C98 composites through an addition of a nanoclay additive due to its excellent barrier properties and thermal stability.

Effect of chitosan oligosaccharides with different molecular weight in alleviating textural deterioration of chicken myofibrillar protein gel with high-temperature treatment

The molecular weight (MW) of oligosaccharides on gel properties of myofibrillar protein (MP) at high temperature remains unclear. In this study, it was found that chitosan oligosaccharides (CO) with different MW all significantly alleviated the textural deterioration of MP gel with high-temperature treatment. Moreover, MP-CO gel with the largest MW had the highest breaking force and the lowest cooking loss. Low-field NMR results further indicated that MP-CO gel with larger MW of CO had gradually increased relaxation rate, thus binding water more tightly. Rheological and microrheological tests suggested the addition of CO with larger MW resulted in much tighter gel network. These results indicated that CO with larger MW improved the quality of MP gel more effectively, which was because CO with larger MW inhibited aggregation of MP to a larger extent, resulting in smaller MP aggregates. Then MP-CO gel with much denser and more homogeneous structure was formed. Besides, MP-CO gel with larger MW of CO had higher content of β-sheet, resulting in MP gel with more ordered structure and better gel quality. Therefore, this study provided theoretical guidance for choosing the appropriate CO in improving texture of high temperature meat products.

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.

Study on preparation of “ping-pong” shaped chitosan oligosaccharide -based hollow mesoporous carbon as a carrier for efficient anthocyanin loading

Carriers for efficient loading and delivery of compounds are urgently needed. A multifunctional nanoplatform of ordered hollow mesoporous carbon (HMC) was developed to load anthocyanins (AN) efficiently. The morphology, specific surface area, binding mode, and biocompatibility of HMC were verified. HMCs were uniformly spherical with well-defined cavities and mesoporous shells, similar to a “ping-pong” ball shape, and this shape of HMC provided a more spatial location for the load of the AN. And the best loading result of AN was 33.39 % ± 3.00 %. Coarse-grained molecular dynamics (CGMD) simulations showed that HMC and AN may bind by electrostatic interaction and hydrogen bonding, the binding process indicated that HMC contributed to the loading of AN, and the cytotoxicity results showed no significant toxicity of the complex. The homogeneous morphology and good biocompatibility of HMC offer new probabilities for the high effectiveness of oral delivery of active substances.

Chitosan Oligosaccharide Modified Bovine Serum Albumin Nanoparticles for Improving Oral Bioavailability of Naringenin.

With the rapid development of nanotechnology, the research and development of nano-drugs have become one of the development directions of drug innovation. The encapsulation of the nanoparticles can change the biological distribution of the drug in vivo and improve the bioavailability of the drug in vivo. Naringenin is poorly soluble in water and has a low bioavailability, thus limiting its clinical application. The main purpose of this study was to develop a nano-sized preparation that could improve the oral bioavailability of naringenin. Chitosan oligosaccharide modified naringenin-loaded bovine serum albumin nanoparticles (BSA-COS@Nar NPs) were prepared by emulsification solvent evaporation and electrostatic interaction. The nanoparticles were characterized by HPLC, laser particle size analyzer, transmission electron microscope and X-ray diffraction analysis. The release in vitro was investigated, and the behavior of nanoparticles in rats was also studied. The caco-2 cell model was established in vitro to investigate the cytotoxicity and cellular uptake of nanoparticles. BSA-COS@Nar NPs were successfully prepared, and the first-order release model was confirmed in vitro release. In vivo pharmacokinetic results indicated that the area under the drug concentration- time curve (AUC) of BSA-COS@Nar NPs was 2.37 times more than free naringenin. Cytotoxicity and cellular uptake results showed that BSA-COS@Nar NPs had no significant cytotoxic effect on Caco- 2 cells and promoted cellular uptake of the drug. BSA-COS@Nar NPs could improve the in vivo bioavailability of naringenin.

Designing and the anticancer activity of chitosan and chitosan oligosaccharide lactate nanobeads loaded with Biginelli hybrid.

This study focuses on the designing and characterization, and anticancer evaluation of chitosan-based nanoparticles (NPs) loaded (enriched) with a Biginelli hybrid compound (BH). NPs based on chitosan (CH) or chitosan oligosaccharide lactate (CHOL), are carefully designed to encapsulate a tetrahydropyrimidine derivative (BH) with already proven anticancer properties. The formulations were evaluated for their physicochemical properties, including particle size distribution and morphology, using techniques such as infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The cytotoxicity profiles were assessed on different cancer cell lines, showing a higher selectivity towards HeLa and A549 cells related to BH. BH-CH showed better cytotoxic profile related to BH-CHOL NPs. A cell cycle analysis revealed an accumulation of cells in the G2/M phase after a treatment with these NPs, indicating the ability to induce mitotic arrest in cancer cells. In summary, the results underscore the promising application of CH-based natural nanocarriers for the targeted delivery of Biginelli hybrids, showcasing a significant potential for further in vivo testing.

Molecular docking analysis of subtilisin-like alkaline serine protease (SLASP) and laccase with natural biopolymers

Abstract Alkaline serine proteases (ASPs) and laccases (Lacs) have been reported to possess several industrial applications, particularly in the food, cosmetic, and leather industries. Thus, in the present study, eighteen natural biopolymers, including agar, agarose, alginate, kappa carrageenan, cellulose, chitosan pentamer, chitosan oligosaccharide, chondroitin sulfate, dextran, fucoidan, heparin, hyaluronan, lignin, mannan, pectin, phytic acid, pullulan and starch soluble, were studied for their docking behavior, such as subtilisin-like alkaline serine protease (SLASP) KP-43 and Bacillus subtilis laccase (Bs Lac), using the SwissDock method. Additionally, the toxicity toward honey bees and human liver was determined by utilizing the free Bee-Tox and pkCSM web servers, respectively. Bee-Tox analysis demonstrated that four ligands (namely, agar, cellulose, lignin, and pullulan) exhibited acute oral toxicity toward honey bees (Apis mellifera). The docking study revealed that chitosan pentamer and lignin exhibited maximum binding energies of −9.67 and −11.37 kcal/mol against the target proteins SLASP (KP-43) and Lac (Bs Lac), respectively. Interestingly, in the present study, agarose was shown to interact with the His68 and Ser255 amino acid residues of SLASP (KP-43) from KSM-KP43 Bacillus sp. Thus, the current investigation showed the potential of eighteen natural biopolymers as immobilizing agents to prepare ASP and Lac nanoparticles for biomedical applications.

Plant protein-based complex coacervation via protein deamidation

Protein-polysaccharide complex coacervates, as common electrostatic assembly, have been widely used in probiotic encapsulation, emulsifiers, and binders. However, due to their own compact structure, plant proteins usually complex with polysaccharides to form solid-like precipitates via liquid-solid phase separation (LSPS) instead of droplet-like coacervates via liquid-liquid phase separation (LLPS). In this study, we adopted an enzymatic deamidation approach to promote the transition of protein-polysaccharide complexes from precipitates to coacervates. β-conglycinin (β-CG), as a common plant protein, was modified by protein-glutaminase (PG) and complexed with chitosan oligosaccharide (COS) to obtain droplet-like coacervates. Native-PAGE and SDS-PAGE results demonstrated that depolymerization of β-CG occurred during deamidation, leading to the production of oligomers and changes in the surface charge patchiness of β-CG. Isothermal titration calorimetry (ITC) results showed that precipitates were mainly driven by exotherm, while coacervates were driven by entropy gain. This study offers a novel approach for the generation of plant protein-based coacervates.

On-site monitoring of L-adrenaline neurotransmitter in biological samples by chitosan oligosaccharide derived carbon dots

Carbon quantum dots (CDs) are fascinating fluorescent nanomaterial for spectrofluorimetry sensor applications, owing to the fact of its strong chemical stability, high quantum yield and high photostability. At this instance, we have developed the fluorescent sensing technique to detect the L-adrenaline (L-Adr) by nitrogen-doped carbon quantum dots as a sensing probe. The nitrogen-doped carbon dots was synthesized using chitosan oligosaccharide by hydrothermal method. The synthesized chitosan oligosaccharide derived CDs (COL-CDs) exhibits blue fluorescence under UV light and the size of the carbon quantum dots is 3.39 ± 0.08 nm calculated from HR-TEM image. The hormone called L-Adr found in the human body is crucial for controlling visceral processes. Utilizing the process of photo-induced electron transfer (PET), the previously mentioned COL-CDs have applied to sense the L-Adr. The sensing mechanism have explained clearly using Rehm-Weller equation by calculating ΔG. Tap water, blood serum, urine and adrenaline drug samples employed as real sample for the sensing L-Adr. A reagent free paper-based kit established for the purpose of on-site monitoring L-Adr. The smartphone’s colour picker software used to measure the RGB intensity from the paper-based kit.

Iron-based theranostic nanoenzyme for combined tumor magneto-photo thermotherapy and starvation therapy

To address the issue of high-dose treatment agents in magnetic hyperthermia-mediated multi-model tumor therapy, a unique iron-based theranostic nanoenzyme with excellent magnetothermal and catalytic properties was constructed. By using a high-temperature arc method, the iron carbon nanoparticles (MF1-3) with a particle size between 13.7 and 27.6 nm and shell thickness between 1 and 5 nm were prepared. After screening, we selected MF3 as the magnetic core due to its high Ms. value and excellent thermal properties. Under the magneto-photo dual thermal conditions, MF3 exhibited a remarkable specific absorption rate (SAR) of 4917 W/g, which was 20 times more than that of iron oxide. Notably, MF3 also exhibited best peroxidase (POD)-like catalytic in pH 5.0 and maintained stable catalytic performance at 45 °C. Considering the “starvation” strategy of cutting off the energy supply to tumor cells and killing them, the glucose oxidase (GOX) and chitosan oligosaccharide (COS) was further grafted onto MF3, forming the MF3/GOX/COS. This multifunctional therapeutic nanoenzyme not only exhibited significant peroxidase-like activity, but also had glucose decomposition and glutathione (GSH) consumption capabilities. The thermal effect significantly promoted the uptake of MF3/GOX/COS by 4T1 cells, and the IC50 value of MF3/GOX/COS reached low to 3.75 μg/mL. In vivo anti-tumor experiment, compared with single treatment methods, the combined therapy of MF3/GOX/COS mediated magneto-photo thermotherapy (M-PTT) and starvation therapy (ST) exhibited higher tumor inhibition rate of 82.1 % by increased cell apoptosis through the mitochondrial pathway. Overall, MF3/GOX/COS therapeutic nanoenzyme combined the advantages of nano-catalysis, M-PTT and ST, providing a solution for achieving sustained, stable, and effective tumor inhibition rates at lower dose levels.

Redox-Responsive Nanopesticides Based on Natural Polymers for Environmentally Safe Delivery of Pesticides with Enhanced Foliar Dispersion and Washout Resistance.

Based on the modified cross-linking of the degradable natural polymers chitosan oligosaccharides (COS) and gelatin (GEL) via introduction of a functional bridge 3,3'-dithiodipropionic acid, this study constructed an environmentally responsive dinotefuran (DNF) delivery system (DNF@COS-SS-GEL). The introduction of the disulfide bond (-S-S-) endowed DNF@COS-SS-GEL with redox-responsive properties, allowing for the rapid release of pesticides when stimulated by glutathione (GSH) in the simulated insect. Compared with commercial DNF suspension concentrate (DNF-SC), DNF@COS-SS-GEL showed superior wet spreading and retention performance on cabbage leaves with a reduced contact angle (57°) at 180 s and 4-fold increased retention capacity after rainfall washout. Nanoencapsulation effectively improved the UV-photostability with only a 31.4% decomposition rate of DNF@COS-SS-GEL at 96 h. The small scale and large specific surface area resulted in excellent uptake and transportation properties in plants as well as higher bioactivity against Plutella xylostella larvae. This study will help promote sustainable agricultural development by reducing environmental pollution through improved pesticide utilization.

Effect of feeding chitosan and blend of essential organic acids on growth performance, haematological parameters and innate immunity in early aged male layer chicks.

The use of antibiotics as conventional feed additives in poultry operations have proven useful, however resulted serious health concerns to consumer due to their bio-accumulation, besides rising problem of antimicrobial resistance in microbes, thus, an alternative to antibiotic growth promoter have called for. One of the aim of the experiment was to assess the lone and combined effects of feeding of chitosan oligosaccharide (COS) and blend of organic acids and short chain fatty acids in essential oils on growth performance, haematological parameters, relative lymphoid organ weight and innate immunity in early aged layer chick(male birds). A total of ninety, day-old chicks were randomly allotted into five groups: CO, Control group fed only poultry feed ; AGP, antibiotic growth promoter fed Avilomycin at the dose of 200mg/kg of poultry feed; CH, chitosan oligosaccharide fed at the rate of 100mg/kg feed; OE, blend of organic acids and short chain fatty acids in essential oils contained 1000 to 2000mg/kg feed in a graded dose per week and CH + OE, chitosan oligosaccharide plus blend of organic acids and short chain fatty acids in essential oils at consistent rate and manner as followed for each of given feed additives when fed individually. Data on growth performance, samples for haematological parameters and innate immunity were measured and assayed on 7th, 21st and 42nd day post feeding (dpf) respectively. The results showed that compared with the control group; there is a marginal gain in body weight at 7th and 21st dpf in CH group and the corresponding CH + OE group. Feed conversion ratio in CH group was remarkably good at 7th and 21st dpf. No significant difference was observed in relative organ weights of thymus, spleen and Bursa of Fabricius in treatment groups as compared to control birds; however a significant rise in splenic weight index in OE fed birds at 42nd dpf noted. Haematological changes were inconsequential in treatment groups with an exception to enhancement of heterophil to lymphocyte ratio (H:L ratio) in CH group at 42nd dpf. Serum lysozyme activity proportionately elevated in CH + OE group on 21st and 42nd dpf when measured against control group; on the other hand no detectable augmentation of gut lysozyme activity observed. Both serum bactericidal and gut bactericidal activity boosted in combinatorial group at 42nd dpf. These results indicated that early age feeding of chitosan individually or combination with organic acids and short chain fatty acids in layer chick is beneficial, as it has the potential to enhance body weight gain to some extent and improves systemic and localized innate immunity to offer protection against infectious assaults thus may avoid early chick mortality in farms.

Conjugation of chitosan oligosaccharide to papain for controllable anti-felting finishing of wool textiles

The application of protease as a biocatalyst for the anti-felting finishing of wool has been widely explored. However, commercial proteases tend to hydrolyze the non-keratinized proteins in the cell membrane complex (CMC) layer while removing wool scales, resulting in excessive hydrolysis and unacceptable fiber damage. Herein, chitosan oligosaccharide (COS) was covalently grafted to papain using carbodiimide/N-hydroxysuccinimide (EDC/NHS) to prepare a less-destructive modified protease of Pap-COS. Subsequently, one-bath anti-felting finishing of wool was carried out using reducing agent and Pap-COS, aiming at achieving low shrinkage and reduced strength loss. The results reveal that Pap-COS achieved a larger particle size than native papain, accompanied by a prolongation of its half-life and a decrease in the thermal inactivation rate, demonstrating improved stability. Under the same incubation conditions, the felting shrinkage of wool fabrics treated with papain and Pap-COS was similar (approximately 5 %). In contrast, native papain caused a 20.82 % decrease in fabric strength, while Pap-COS resulted in a substantially lower decrease (8.10 %), meeting the requirements of commercial woolen products. Furthermore, the dyeing performance and wearability of the Pap-COS-treated wool fabrics were also dramatically improved. The present work provides an alternative for eco-friendly shrink-resistant finishing of woolen textiles in wool industry.

Cationic Curcumin Nanocrystals Liposomes for Improved Oral Bioavailability: Formulation Development, Optimization, In Vitro and In Vivo Evaluation.

Curcumin, a naturally occurring poorly water-soluble polyphenol with a broad spectrum, is a typical BCS IV drug. The objective of this study was to develop curcumin nanocrystals liposomes with the aim of improving bioavailability. In this study, we prepared cationic curcumin nanocrystals with a particle size of only 29.42 nm; such a phenomenal range of particle sizes is very rare. Moreover, we summarized and evaluated the parameters of the nanocrystal preparation process, including methods, formulations, etc., and the rules we concluded can be generalized to other nanocrystal preparation processes. To counteract the instability of the nanocrystals in the digestive tract, cationic curcumin nanocrystals were loaded into negatively charged liposomes through gravitational force between different charges. Unexpectedly, chitosan oligosaccharide was found to promote the self-assembly process of curcumin nanocrystal liposomes. In vitro and in vivo experiments demonstrated that chitosan-modified curcumin nanocrystal liposomes exhibited enhanced resistance to enzyme barriers, mucus barriers, and cellular barriers, resulting in a 5.4-fold increase in bioavailability compared to crude powder formulations. It can be concluded that cationic nanocrystals liposomes represent an appropriate novel strategy for improving the dissolution rate and bioavailability of poorly soluble natural products such as curcumin.

ScCO2-processed thermoplastic starch/chitosan oligosaccharide blown films and their oxygen barrier or antibacterial applications

Abstract Antibacterial and oxygen barrier films were inventively prepared by blending very small loadings (<2 wt%) of chitosan oligosaccharide (COS) or chitosan (CS) in thermoplastic starch (TPS) and/or processing with supercritical carbon dioxide (scCO2). Oxygen transmission rates (OTR) and free-volume-hole (FVH) characteristics of scCO2-processed TPS/COS and TPS/CS blown films diminish to a minimum, as their COS or CS approach a specific compatibility limit content. The minimum OTR and FVH characteristics of scCO2-processed TPS/COS films are somewhat smaller than those of corresponding TPS/COS films without scCO2-assistance, and decrease further with decreasing COS molecular weights. The minimum OTR values of scCO2-processed TPS/COS blown films with COS’s molecular weight of 200 and 500 are only 4.1 and 4.5 cm3/m2 × day × atm, respectively, and their antibacterial rates of Staphylococcus aureus are ≥97 %, which make them as promising antibacterial and oxygen barrier films having OTR ≦ 5 cm3/m2 × day × atm. Among other things, longitudinal or transversal tensile strengths acquired for the properly scCO2-processed TPS/COS or TPS/CS films are ∼30 to ∼50 % higher than those of the TPS films. Dynamic mechanical relaxation results of these scCO2-processed reveal that chitosan oligosaccharide or chitosan are compatible with TPS, as COS or CS contents are ≤ the compatibility limit value.

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.

Synbiotic effects of Lactobacillus rhamnosus fermented with different prebiotics on the digestive enzyme activities, SCFAs and intestinal flora of Macrobrachium rosenbergii in vitro

Synbiotics are combinations of probiotics and prebiotics. It has been shown to be beneficial to aquatic animals. In this study, Lactobacillus rhamnosus was cultured with different prebiotics as the sole carbon source, including inulin, acanthopanax senticosus polysaccharide (ASPS), chitosan oligosaccharide (COS), saposhnikovia divaricata polysaccharide (SDP), polysaccharide of atractylodes macrocephala koidz (PAMK), astragalus polysaccharides (APS), Yu-Ping-Feng polysaccharide (YPFP), xylooligosaccharides (XOS) and mannose (MAN). Screening and gradient experiments revealed that the suitable prebiotics and concentrations were: 2 % MAN, 3 % APS, 3 % YPFP, 4 % PAMK, 3 % SDP. L. rhamnosus (108 CFU/mL) and suitable prebiotics were inoculated into the media supplemented with the intestinal chyme of Macrobrachium rosenbergii. Based on the preliminary screening experiment with the gradients. The in vitro fermentation experiment comprised seven groups: a control group (CT); L. rhamnosus group (LGG); L. rhamnosus + 2 % MAN group (LGG+MAN); L. rhamnosus + 3 % APS group (LGG+APS); L. rhamnosus + 3 % YPFP group (LGG+YPFP); L. rhamnosus + 4 % PAMK group (LGG+PAMK); L. rhamnosus + 3 % SDP group (LGG+SDP). The in vitro fermentation results revealed that the amylase activity was significantly increased in LGG+PAMK, LGG+SDP and LGG+APS groups than in the CT group (P<0.05). The LGG+MAN group showed the highest protease activity (P<0.05), while the activity of lipase was significantly greater in the LGG and LGG+YPFP groups than in the CT group (P<0.05). Moreover, the acetic acid and valeric acid contents were significantly increased in the LGG+PAMK, LGG+YPFP and LGG+SDP groups than in the CT and LGG groups (P<0.05). Additionally, the LGG+APS, LGG+PAMK, LGG+YPFP and LGG+SDP treatments significantly decreased the abundance of Aeromonas (P<0.05). Lactobacillus was more abundant in the LGG+YPFP group than in the other groups (P<0.05). In general, based on in vitro fermentation of M. rosenbergii intestine, the combination of L. rhamnosus with 3 % YPFP is the optimal synbiotic for the prawn.