Chitosan Oligosaccharide Research Articles

Mechanistic insights into mitigating Cd stress in plants using typical organic waste fermentation solutions.

Finding practical solutions for utilizing agricultural organic wastes has always been a challenge. To address this, our study investigated the effects and mechanisms of different exogenous organic waste fermentation solutions on alleviating Cd stress in plants using hydroponic experiments. Out of the seven fermentation solutions examined, pea fermentation liquid (T3), chicken manure (T5), molasses (T6), and chitosan oligosaccharide broth (T9) exhibited positive effects. They increased shoot fresh weight by 1.17%, 26.83%, 7.94%, and 15.59%, and root fresh weight by 50.00%, 12.21%, 81.19%, and 19.47%, respectively. Conversely, amino acid mother liquid (T7) and potassium polyaspartate liquid (T8) reduced shoot fresh weight by 34.21% and 24.74%, and root fresh weight by 27.06% and 7.10%, respectively. All organic waste liquids reduced Cd concentration in shoots and roots. Corn fermentation liquid (T4) reduced Cd in shoots from 87.91 to 19.20 mg/kg, while molasses (T6) reduced Cd in roots from 980.94 to 260.47 mg/kg. SEM-EDX results revealed that molasses (T6) effectively repaired Cd damage on root surfaces. In addition, several waste liquids mitigated microelement absorption disturbances. All waste liquids reduced MDA, corn fermentation liquid (T4), chicken manure (T5), molasses (T6), potassium polyaspartate liquid (T8), and chitosan oligosaccharide liquid (T9) significantly decreased H2O2 by 21.6-38.3%. Structural equation model (SEM) and correlation analysis highlighted the importance of root Mg, Cu, and Zn content and CAT activity in relieving Cd stress and promoting plant growth. Overall, molasses (T6) and chicken manure (T5) demonstrated the most beneficial combined effects, while amino acid mother liquid (T7) and chitosan oligosaccharide liquid (T9) should be exercised with caution due to their weaker effects.

Effects of dietary chitosan oligosaccharide on the growth, intestinal microbiota and immunity of juvenile red claw crayfish (Cherax quadricarinatus)

This study aimed to evaluate the potential benefits of chitosan oligosaccharide (COS) on red claw crayfish (Cherax quadricarinatus) and explore its underlying mechanisms. The crayfish were randomly divided into six groups, and the diets were supplemented with COS at levels of 0 (C0), 0.2 (C1), 0.4 (C2), 0.6 (C3), 0.8 (C4), and 1 (C5) g kg−1. Treatment with COS significantly improved the growth performance of the crayfish with a higher weight gain rate (WGR) and specific growth rate (SGR) in the C2 group compared to the C0 group. Additionally, the content of crude protein in the crayfish muscles in the C1 group was significantly higher than that of the C0 group. Regarding non-specific immunity, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and alkaline phosphatase (AKP), and the levels of expression of the genes related to immunity (SOD; anti-lipopolysaccharide factor [ALF]; thioredoxin1 [Trx1]; C-type lysozyme, [C-LZM]; and GSH-Px) in the hepatopancreas and hemolymph increased significantly (P < 0.05) after supplementation with 0.4 g kg−1 of COS, while the content of malondialdehyde (MDA) decreased (P < 0.05). The survival rate of C. quadricarinatus increased (P < 0.05) in the C2, C3, C4, and C5 groups after the challenge with Aeromonas hydrophila. This study found that COS has the potential to modulate the composition of the intestinal microbiota and significantly reduce the abundance of species of the phylum Proteobacteria and the genera Aeromonas and Vibrio in the gut of C. quadricarinatus, while the abundance of bacteria in the phylum Firmicutes and the genus Candidatus_Hepatoplasma improved significantly. This study suggests that the inclusion of COS in the diet of C. quadricarinatus can enhance growth, boost immunity, and increase resistance to infection with A. hydrophila, especially when supplemented at 0.4–0.8 g kg−1.

Loading and release of insulin from chitosan oligosaccharide biopolymeric patch for oromucosal delivery

Loading and release of insulin from chitosan oligosaccharide biopolymeric patch for oromucosal delivery

Chitosan oligosaccharide improves intestinal function by promoting intestinal development, alleviating intestinal inflammatory response, and enhancing antioxidant capacity in broilers aged d 1 to 14

This study was conducted to investigate the effects of chitosan oligosaccharide (COS) supplementation on intestinal development and functions, inflammatory response, antioxidant capacity and the related signaling pathways in broilers aged d 1 to 14. A total of 240 one-day old male Arbor Acres broilers (40.47 ± 0.30 g) were randomly allotted to 4 groups, and each group consisted of 6 replicate pens with 10 broilers per replicate. Broilers fed a basal diet supplementation with COS at 0 (CON group), 200 (COS200 group), 400 (COS400 group), and 800 mg/kg (COS800 group) for 14 d, respectively. Broilers in the COS supplementation groups had no significant effects on growth performance. Compared to the CON group, dietary COS supplementation increased (P < 0.05) the relative weight of duodenum, jejunal lipase activity, duodenal and ileal villus surface area, and lower (P < 0.05) ileal amylase and alkaline phosphatase activity, and crypt depth. The expression level of duodenal glucose transporter 1 (GLUT1), Na+-glucose cotransporter 1 (SGLT1), peptide transporter 1 (PepT1), occludin, zonula occludens-1 (ZO-1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and interleukin-10 (IL-10), jejunal SGLT1, PepT1, occludin, tumor necrosis factor-α (TNF-α), and ileal SGLT1, PepT1, and fatty acid binding protein 1 (FABP1) was upregulated by COS. However, the expression level of duodenal FABP1 and TNF-α, jejunal GLUT1, ZO-1, TLR4, MyD88, nuclear factor kappa-B p65 (NF-κB p65), and IL-1β, and ileal GLUT1, NF-κB p65, and IL-1β was downregulated by COS. Furthermore, dietary COS supplementation increased duodenal catalase (CAT), glutathione peroxidase (GSH-Px), and total superoxide dismutase (T-SOD) activity, jejunal CAT and T-SOD activity, upregulated the expression level of duodenal nuclear factor-erythroid 2-related factor 2 (Nrf2), CAT, glutathione peroxidase 1 (GPX1), and copper and zinc superoxide dismutase (Cu/Zn SOD), jejunal CAT, and ileal Nrf2, CAT, and GPX1. These results suggested that COS could promote intestinal development and functions in broilers aged d 1 to 14, which might be mediated by alleviating intestinal inflammatory response and enhancing antioxidant capacity.

Genome-wide identification of CCO gene family in cucumber (Cucumis sativus) and its comparative analysis with A. thaliana

Carotenoid cleavage oxygenase (CCO) is an enzyme capable of converting carotenoids into volatile, aromatic compounds and it plays an important role in the production of two significant plant hormones, i.e., abscisic acid (ABA) and strigolactone (SL). The cucumber plant genome has not been mined for genomewide identification of the CCO gene family. In the present study, we conducted a comprehensive genome-wide analysis to identify and thoroughly examine the CCO gene family within the genomic sequence of Cucumis sativus L. A Total of 10 CCO genes were identified and mostly localized in the cytoplasm and chloroplast. The CCO gene is divided into seven subfamilies i.e. 3 NCED, 3 CCD, and 1 CCD-like (CCDL) subfamily according to phylogenetic analysis. Cis-regulatory elements (CREs) analysis revealed the elements associated with growth and development as well as reactions to phytohormonal, biotic, and abiotic stress conditions. CCOs were involved in a variety of physiological and metabolic processes, according to Gene Ontology annotation. Additionally, 10 CCO genes were regulated by 84 miRNA. The CsCCO genes had substantial purifying selection acting upon them, according to the synteny block. In addition, RNAseq analysis indicated that CsCCO genes were expressed in response to phloem transportation and treatment of chitosan oligosaccharides. CsCCD7 and CsNCED2 showed the highest gene expression in response to the exogenous application of chitosan oligosaccharides to improve cold stress in cucumbers. We also found that these genes CsCCD4a and CsCCDL-a showed the highest expression in different plant organs with respect to phloem content. The cucumber CCO gene family was the subject of the first genome-wide report in this study, which may help us better understand cucumber CCO proteins and lay the groundwork for the gene family's future cloning and functional investigations.

Transcriptome Analysis of the Cultured Hybrid Grouper (♀Epinephelus fuscoguttatus×♂E. lanceolatus) Immunized with Vibrio harveyi formalin-killed cells vaccine (FKC) combined with chitosan oligosaccharide

Grouper has become an essential mariculture species in China, while vibriosis caused by Vibrio harveyi significantly impacts its culture. Our previous study confirmed the V. harveyi formalin-killed cells vaccine (FKC) combined with chitosan oligosaccharide (FKC+COS) effectively prevents vibriosis. As an adjuvant, COS could significantly enhance FKC effectiveness against V. harveyi in grouper. In the present study, we performed transcriptome analysis of grouper spleens tissue 14 days post-immunization of PBS and FKC+COS, respectively. After assembly and annotation, 2,503 differentially expressed genes (DEGs) were obtained, including the upregulated 1,894 DEGs and downregulated 609 DEGs between the PBS group and FKC+COS group. To explore the relevance of DEGs in immunity, enrichment analysis in the KEGG database revealed that the main pathways of DEGs distribution associated with immunity were antigen processing and presentation, lysosome, the intestinal immune network for IgA production and FcγR-mediated phagocytosis. In conclusion, transcriptome analysis of spleens was performed to explore the potential mechanism of COS as an adjuvant enhancing the protection effectiveness of FKC against vibriosis in grouper.

Chitosan Oligosaccharide Based Waterborne Polyurethane with UV Resistance and Oxidation Resistance for Functional Fabric

AbstractChitosan oligosaccharide (COS) is an abundant polysaccharide in nature, which has various functions such as antioxidant and antibacterial. The possibilities of using COS can be extended by applying it to polyurethane materials. Herein, Chitosan oligosaccharide‐based waterborne polyurethane (CWPU) with intramolecular crosslinking network is prepared by using COS as chain extender. The mechanical properties of CWPU are improved, with tensile strength and elongation at break reaching 14.83 MPa and 449.63%, respectively. The DPPH free radical scavenging rate of CWPU increases from 8.43% to 70.98%, indicating that CWPU has favorable antioxidant performance. The tensile strength of the CWPU‐treated fabrics obtained by the padding method improve from 542.77 to 605.33N and there is no significant change in the whiteness of the fabric. Furthermore, the CWPU‐treated fabrics, with the UV protection factor of 30.39 and the UVA transmittance below 3%, can be used as UV‐protective fabrics. This work introduces COS into the molecular structure of polyurethanes to obtain functional PUs, expanding the application of COS in polyurethanes.

Rapid Induction of Long-Lasting Systemic and Mucosal Immunity via Thermostable Microneedle-Mediated Chitosan Oligosaccharide-Encapsulated DNA Nanoparticles.

Most existing vaccines, delivered by intramuscular injection (IM), are typically associated with stringent storage requirements under cold-chain distribution and professional administration by medical personnel and often result in the induction of weak mucosal immunity. In this context, we reported a microneedle (MN) patch to deliver chitosan oligosaccharide (COS)-encapsulated DNA vaccines (DNA@COS) encoding spike and nucleocapsid proteins of SARS-CoV-2 as a vaccination technology. Compared with IM immunization, intradermal administration via the MN-mediated DNA vaccine effectively induces a comparable level of neutralizing antibody against SARS-CoV-2 variants. Surprisingly, we found that MN-mediated intradermal immunization elicited superior systemic and mucosal T cell immunity with enhanced magnitude, polyfunctionality, and persistence. Importantly, the DNA@COS nanoparticle vaccine loaded in an MN patch can be stored at room temperature for at least 1 month without a significant decrease of its immunogenicity. Mechanically, our strategy enhanced dendritic cell maturation and antiviral immunity by activating the cGAS-STING-mediated IFN signaling pathway. In conclusion, this work provides valuable insights for the rapid development of an easy-to-administer and thermostable technology for mucosal vaccines.

New Insights into the Dissolution Kinetics of Alite Powder and the Effects of Organic Toughening Materials.

Alite dissolution plays a crucial role in cement hydration. However, quantitative investigations into alite powder dissolution are limited, especially regarding the influence of chemical admixtures. This study investigates the impact of particle size, temperature, saturation level, and mixing speed on alite powder dissolution rate, considering the real-time evolution of specific surface area during the alite powder dissolution process. Furthermore, the study delves into the influence of two organic toughening agents, chitosan oligosaccharide (COS) and anionic/non-ionic polyester-based polyurethane (PU), on the kinetics of alite powder dissolution. The results demonstrate a specific-surface-area change formula during alite powder dissolution: SS0=0.348e1-m/m0/0.085+0.651. Notably, the temperature and saturation level significantly affect dissolution rates, whereas the effect of particle size is more complicated. COS shows dosage-dependent effects on alite dissolution, acting through both its acidic nature and surface coverage. On the other hand, PU inhibits alite dissolution by blocking the active sites of alite through electrostatic adsorption, which is particularly evident at high temperatures.

Effect of chitosan and chitosan oligosaccharide on the interaction and in vitro gastric digestive behavior of whey protein isolate

Carbohydrate-protein interactions can improve the properties and texture of proteins. The objective of this study was to investigate the effects of pH and preheating to 90 °C on the interaction between chitosan (CS)/chitosan oligosaccharide (COS) and whey protein isolate (WPI). Additionally, by simulating in vitro gastric digestion to evaluate the digestive behavior of the CS/COS-WPI complexes when applied to protein-supplemented beverages. The results demonstrated that only CS exhibited greater efficacy in preventing the denaturation and aggregation of WPI caused by heat treatment at pH 4.0. As pH continued to expand to 6.0, changes in the strength of electrostatic interactions and the tertiary structure of proteins influenced the formation of the complex system structure. The in vitro digestion experiments revealed that CS and COS inhibition of WPI digestion in the gastric resulted in an opposite trend with an increasing ratio. We hope that this work will offer promising strategies for developing protein-enrich beverages.

Research progress of new multifunctional bone cement in bone tumor therapy

The research progress of new multifunctional bone cement in bone tumor therapy in recent years was reviewed, in order to provide help for the future research of anti-tumor bone cement. The related literature on the treatment of bone tumors with new multifunctional bone cement at home and abroad in recent years was extensively reviewed and summarized. The new multifunctional bone cements include those with the functions of photothermotherapy, magnetic thermotherapy, chemoradiotherapy, and antibacterial after operation, which are discussed from the aspects of anti-tumor, drug controlled release, and cytotoxicity. Controlled drug release has been achieved in multifunctional bone cements by adjusting heat and pH or incorporating particles such as chitosan oligosaccharides and γ-cyclodextrin. At present, multifunctional bone cement with hyperthermia, radiotherapy, and chemotherapy has effectively inhibited the local recurrence and distant metastasis of bone tumors. Broadening the application of bone cement for photothermal and magnetic thermal therapy to deeper bone tumors, investigating more precise controlled release of drug-loaded bone cement, and introducing nanoparticles with both thermal conversion and intrinsic enzymatic activities into bone cement for synergistic anti-tumor therapy are promising research directions. The new multifunctional bone cement inhibits bone tumor cells, promotes new bone formation in bone defects, and prevents incision infection after tumor resection. Certain progress has been made in anti-tumor, antibacterial, drug-controlled release, and reduction of cytotoxicity. Expanding the deeper application range of the new multifunctional bone cement, verifying the safety in clinical application, and focusing on the individualized treatment of the new multifunctional bone cement are the problems that need to be solved in the future.

Sulfated oligosaccharide activates endothelial Notch for inducing macrophage-associated arteriogenesis to treat ischemic diseases.

Ischemic diseases lead to considerable morbidity and mortality, yet conventional clinical treatment strategies for therapeutic angiogenesis fall short of being impactful. Despite the potential of biomaterials to deliver pro-angiogenic molecules at the infarct site to induce angiogenesis, their efficacy has been impeded by aberrant vascular activation and off-target circulation. Here, we present a semisynthetic low-molecular sulfated chitosan oligosaccharide (SCOS) that efficiently induces therapeutic arteriogenesis with a spontaneous generation of collateral circulation and blood reperfusion in rodent models of hind limb ischemia and myocardial infarction. SCOS elicits anti-inflammatory macrophages' (Mφs') differentiation into perivascular Mφs, which in turn directs artery formation via a cell-to-cell communication rather than secretory factor regulation. SCOS-mediated arteriogenesis requires a canonical Notch signaling pathway in Mφs via the glycosylation of protein O-glucosyltransferases 2, which results in promoting arterial differentiation and tissue repair in ischemia. Thus, this highly bioactive oligosaccharide can be harnessed to direct efficiently therapeutic arteriogenesis and perfusion for the treatment of ischemic diseases.

Shelf-life extension of soy sauce by using chitosan oligosaccharides combined with tea polyphenols

Chitosan oligosaccharides (COs) and tea polyphenols (TPs) have antioxidant and antibacterial activities. This study aims to explore the preservative effects of 0.1 % COs alone and combined with 0.08 % TPs on soy sauce during room-temperature storage. Soy sauce treated with 0.1 % COs alone and combined with 0.08 % TPs had lower total bacterial count, Escherichia coli count and pH, and higher amino acid nitrogen and overall likeness score than those of the control group during room-temperature storage. Treatment with 0.1 % COs combined with 0.08 % TPs extended the shelf life of soy sauce by at least 15 months compared with the control group. Results showed 0.1 % COs combined with 0.08 % TPs may be a feasible method to extend the shelf life of soy sauce during room-temperature storage.

Valorization of shrimp processing waste-derived chitosan into anti-inflammatory chitosan-oligosaccharides (CHOS)

Bioconversion of chitosan into soluble anti-inflammatory chitosan oligosaccharides (CHOS) using a Bacillus chitosanase, BsCsn46A, was investigated, including food-grade approaches. After 48 h of enzymatic reaction, most of the final products were dimers and trimers. None of the CHOS products showed toxicity to human fibroblasts. Analysis of CHOS bioactivity against LPS-induced inflammation of human macrophages indicated that CHOS generated from different bioconversion processes have anti-inflammatory activity, the magnitude of which depends on the type of substrate and production process. Both lactic acid and HCl can be used to dissolve chitosan; however, the product generated from lactic acid solution was highly hygroscopic after lyophilization, hence not suitable for long-term storage. Downstream processes, i.e., centrifugation and filtration, affect its anti-inflammatory activity. Analysis of standard CHOS with known structure showed that an acetyl group at the reducing end and the degree of polymerization (DP) are critical for biological activity. Importantly, when applied at levels above the optimal concentrations, certain standard CHOS and CHOS mixtures could induce inflammation. These results support the potential of CHOS as anti-inflammatory agents but reveal batch-to-batch variation and possible side effects, indicating that careful quality assurance of CHOS preparations is essential.

Chitosan oligosaccharides inhibit the fibrillation of insulin and disassemble its preformed fibrils

In the current study, we first established that chitosan oligosaccharides (COS) have significant anti-fibrillogenic and fibril-destabilising effects on bovine insulin in vitro that proportionally expand with concentration growth. The obtained data were supported by the Thioflavin T (ThT) assay, circular dichroism (CD), attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, and atomic force microscopy (AFM). Interestingly, coincubation of insulin with COS in the ratio of 1 to 10 over 48 h at 37 °C leads to full prevention of insulin aggregation, and in the case of preformed fibrils, results in their destabilisation and disaggregation. Moreover, both a cationic polymer of allylamine (PAH) and a sulphated oligosaccharide (CROS) prepared from carrageenan had no inhibitory effect on insulin amyloid formation. Thus, we proposed that COS modulates insulin amyloid formation due to the presence of linear sugar units, the degree of polymerization, and the free amino group providing a positive charge. These findings highlight the potential implications of COS as a promising substance for the treatment of insulin-dependent diabetes mellitus and localised insulin-derived amyloidosis and, moreover, provide a new insight into the mechanism of the anti-diabetic and antitoxic properties of chitosan and chitosan-based agents.

Low molecular weight chitosan oligosaccharides form stable complexes with human lactoferrin.

Proteins in tears, including human lactoferrin (HLF), can be deposited and denatured on contact lenses, increasing the risk of microbial cell attachment to the lens and ocular complications. The surfactants currently used in commercial contact lens care solutions have low clearance ability for tear proteins. Chitosan oligosaccharide (COS) binds to a variety of proteins and has potential for use in protein removal, especially in contact lens care solutions. Here, we analyzed the interaction mechanism of COSs hydrolyzed from chitosan from different resources with HLF. The molecular weights (MWs) and concentrations of COSs were key factors for the formation of COS-HLF complexes. Lower MWs of COSs could form more stable COS-HLF complexes. COS from Aspergillus ochraceus had a superior effect on HLF compared with COS from shrimp and crab shell with the same MWs. In conclusion, COSs could bind to and cause a conformational change in HLF. Therefore, COSs, especially those with low MWs, have potential as deproteinizing agents in contact lens care solution.

Remdesivir-Loaded Nanoliposomes Stabilized by Chitosan/Hyaluronic Acid Film with a Potential Application in the Treatment of Coronavirus Infection.

An object of the present study was the development of liposomes loaded with the medicine Veklury® (remdesivir) stabilized by electrostatic adsorption of polysaccharide film formed from chitosans with different physicochemical characteristics and hyaluronic acid. The functionalization of the structures was achieved through the inclusion of an aptamer (oligonucleotide sequence) with specific affinity to the spike protein of the human coronavirus HCoV-OC43. The hydrodynamic size, electrokinetic potential and stability of the structures were evaluated at each step in the procedure. The encapsulation efficiency and loaded amount of remdesivir (99% and 299 µg/mL) were estimated by UV-vis spectroscopy. Our investigations showed manifestation of promising tendencies for prolonged periods of the drug release and increased effectiveness of its antiviral action. Among all studied versions of the delivery system, the most distinguished and suitable in a model coronavirus therapy are the liposomes formed from chitosan oligosaccharides. The cytotoxicity of the liposomes was determined against the HCT-8 cell line. A cytopathic effect inhibition test was used for the assessment of the antiviral activity of the compounds. The virucidal activity and the effect on the viral adsorption of the samples were reported by the end-point dilution method, and the alteration in viral titer was determined as Δlgs compared to untreated controls. The redox-modulating properties of the nanoparticles were studied in vitro in certain/several/a few chemical model systems. Our investigations showed a manifestation of promising tendencies for a prolonged effect of the drug release and increased effectiveness of its antiviral action.

The effects of ad - libitum consumption of chitosan oligosaccharide with drinking water on laying quails

The aim of this study was to determine the effects of chitosan oligosaccharide on feed conversion ratio, some egg quality parameters, and some blood parameters in Japanise quails. Chitosan oligosaccharide (ChitO) was added to the drinking water of quails. A total of 192 (7 – 8 weeks old) Japanese quails (Coturnix coturnix Japonica) were divided into one control and 3 treatment groups, each consisting of 48 quails. Each group was divided into 6 replicates. While no additive was added to the control group, ChitO was added to the drinking water of the first, second, and third groups at the levels of 0.015, 0.030 and 0.045 g / L, respectively. They were given water and feed ad libitum. At the end of the study, no significant differences were observed between the control and treatment groups, except in their feed consumption and egg shell weight. In the first treatment group (given 0.015 g / L ChitO), it was observed that feed consumption decreased significantly compared to the control group; however, the difference between the other treatment groups was insignificant. The egg shell weight of the second treatment group (0.030 g / L ChitO) was found to be significantly higher (p &lt; 0.05) than that of the control group. In general, consumption of chitosan oligosaccharide with drinking water tended to decrease feed consumption, without adversely affecting feed efficiency, and tended to increase eggshell weight.

N-terminal truncation contributed to increasing the activity of a novel GH46 family chitosanase

Chitosanase could degrade chitosan efficiently under mild conditions to prepare chitosan oligosaccharides (COSs). COS possesses versatile physiological activities and has wide application prospects in food, pharmaceutical and cosmetic fields. Herein, a new glycoside hydrolase (GH) family 46 chitosanase (CscC) was cloned from Kitasatospora setae ATCC 33774 and heterologously expressed in Escherichia coli BL21(DE3). CscC has two structural domains, one is the F5_F8_type_C discoidal domain located at the N-terminal, and the other is the catalytic structural domain located at the C-terminal. The truncation of F5_F8_type_C discoidal domain (carbohydrate-binding module, CBM) was found to improve the enzymatic properties. Two mutants CscC-CT1 (retaining the linkage) and CscC-CT2 (without the linkage) were obtained. The specific activity of CscC-CT1 was 2.04-fold higher than that of CscC, and CscC-CT2 was almost completely inactivated. The optimum temperature and pH of CscC-CT1 were similar to those of CscC (55 °C and pH 5.0). In addition, the thermal stability and metal ion stability of CscC-CT1 were better than those of CscC. CscC and its truncation were both determined to be endo-type chitosanases with a polymerization degree of the final product mainly in the range of 1-3. This new chitosanase provides an efficient enzyme tool for clean production of COSs.

Active Targeted Janus Theranostic Nanoplatforms Enable Chemo-Photothermal Therapy to Inhibit the Growth of Breast Cancer.

Nanoscale structures have been developed to serve various functions in cancer therapy, encompassing areas such as diagnosis, biomedical visualization, tissue regeneration, and drug delivery. Based on biocompatible chitosan oligosaccharides (COS) and gold nanorods (GNRs), we designed the drug delivery systems (GNR@polyacrylic acid-Mn@COS Janus nanoparticles (JNPs)), which achieved paclitaxel (PTX) loaded on the side of GNRs, and the PAA-Mn domain served as magnetic resonance imaging contrast agents. This system was found to be effectively delivered to tumor sites through the enhanced permeability and retention (EPR) effect and the active target of the COS. The uniform JNPs selectively targeted cancer cells instead of normal cells through interacting with the COS on the surface of tumor cells, and the pH/NIR-responsive drug release behavior further enhanced their therapeutic effects. The in vivo effects of JNPs against tumors were evaluated using subcutaneous and orthotopic lung metastasis models, yielding promising outcomes for both tumor diagnosis and cancer treatment. In conclusion, the obtained JNPs hold great promise as a theranostic nanoplatform with synergistic chemotherapeutic and photothermal effects.