Carboxymethyl Chitosan Research Articles

Loading and Release of Curcumin from Carboxymethyl Chitosan Conjugated with Coordinative Composite

Loading and Release of Curcumin from Carboxymethyl Chitosan Conjugated with Coordinative Composite

“Mending with silk” enhances aged silk with mechanical and antibacterial properties

The reinforcement and preservation of historical silk are crucial for its continued research, heritage, and display. Herein, silk fibroin (SF) and carboxymethyl chitosan (CMCS) were utilized as raw materials to reinforce aged silk via two reinforcement methods, with transglutaminase (TGase) serving as a catalytic cross-linking agent. The covalent and non-covalent bond network formed by TGase catalytic cross-linking significantly improved the mechanical properties of aging silk, and CMCS as an antibacterial material gave excellent antibacterial properties of the aged silk. Compared with aged silk, the breaking stress and elongation at break of the aged silk after reinforcement are increased by 257.9% and 293.7% respectively. The antibacterial rate of the reinforced aged silk against Escherichia coli (E. coli) and Streptococcus aureus (S. aureus) exceeded 90%. Under accelerated simulated aging conditions, the aging rate of the reinforced silk was significantly reduced, demonstrating notable aging resistance. Notably, the one-step enhanced aged silk outperformed the two-step enhanced aged silk in all performance evaluations, while the appearance of the aged silk was not affected. This work provides a green and efficient process for the reinforcement and protection of silk-based cultural relics and the application of silk cultural relics protection materials.

Investigation for the Preparation and Performance of an Electrical Response Flexible Actuator

ABSTRACT In this study, tannic acid (TA) and carboxymethyl chitosan (CMCS) are employed as the primary materials to fabricate driver membranes through the vacuum freezedrying technique. With sodium alginate (SA) and multi-walled carbon nanotubes (MWCNTs) as the raw materials, electrode membranes are created by vacuum drying technique. The two films are assembled into the electrical response flexible actuator (ERFA). To examine the driver performance, the cross-linking state of varying TA addition (0, 7, 14, 21, 28 mg) and CMCS is investigated. The results show that the peak output force, specific capacitance and tensile strain of the samples without adding tannic acid are 1.95 mN, 68.36 mF·g−1 and 102.22%, respectively. Moreover, the surface structure of the membrane is dense and non-porous, exhibiting a layer stacking state. At 14 mg of TA addition, the peak output force, specific capacitance and tensile strain of the samples are 6.12 mN, 99.82 mF·g−1, 151.23%. The driver membrane pore distribution becomes more uniform and ultimately displays a large pore structure with filamentary cross-linking. This generates an optimization of the driver and electrochemical performance. Meanwhile, the deflection mechanism is analyzed from the perspective of ion migration, which establish a new foundation for the study of the ERFA.

Carboxymethyl Chitosan as a Reversible Template of Calcium Phosphate for Multifunctional Conservation of Carbonate Stone.

The accelerated deterioration of carbonate stone artifacts under climate change has long been an urgent issue. Inspired by biomineralization, we developed carboxymethyl chitosan-diammonium hydrogen phosphate (CD) composite and investigated the conservation effectiveness of the CD composite compared to diammonium hydrogen phosphate (DAP) on limestone. The morphologies and microstructures were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The consolidating effectiveness was investigated through a compressive strength test. The protective ability was assessed by disintegration resistance test, acid attack resistance test, salt attack resistance test, and freeze-thaw aging cycle test. SEM observations revealed that carboxymethyl chitosan (CMCS) served as an effective template, inducing the in situ formation of a uniform and continuous calcium phosphate coating on both the surface and interior of the stone. The tests indicated that the CD composite further enhanced the consolidating effectiveness and improved resistance to disintegration and freeze-thaw cycles. Notably, as an amphiphilic polyelectrolyte, CMCS functioned as a pH buffer and a protective barrier against sodium sulfate salts, which improved the resistance to acid and salt attacks. Additionally, the CD composite did not cause significant variations in the esthetic appearance or water vapor permeability. We then applied the CD composite at an actual carbonate stone cultural heritage site, successfully demonstrating the feasibility of CD application and the reversibility of CMCS in a real-world setting. Based on the study's results, our approach provides a new perspective for developing multifunctional and sustainable conservation materials for carbonate stone artifacts.

A Novel Rhodamine B Fluorescent Probe Derived from Carboxymethyl Chitosan for the Selective Detection of Fe3.

In this study, we synthesized a fluorescent material by modifying the C-2 amino group of carboxymethyl chitosan with a rhodamine B derivative, which was proposed and demonstrated using 1H NMR and FT-IR measurements. A series of experiments including selectivity, sensitivity, reversibility, pH, and water content were conducted to investigate the fluorometric and colorimetric properties of the grafted polymer. Utilizing a Fe3+-induced ring-opening mechanism of the rhodamine B spirolactam, we found that the grafted polymer exhibited a highly selective fluorescence response to Fe3+, with enhanced fluorescence at 583 nm compared to other tested metal ions and anions, accompanied by the characteristic absorption peak of rhodamine B that appeared at 561 nm with a noticeable color change from colorless to pink, facilitating visual observation. Additionally, the modified probe, composed of carboxymethyl chitosan, was easily regenerated through treatment with EDTA.

Reinforced enzyme mineralized chitosan hydrogels with superior mechanical and osteogenic properties

As a natural cationic polymer material, the application of chitosan hydrogel for bone tissue engineering has been greatly limited due to its poor mechanical strength. Enzymatic mineralization has drawn increased attention to effectively improve the mechanical properties of hydrogels. In this study, carboxymethyl chitosan (CMCS) hydrogels cross-linked with different concentrations of genipin (2.5 %, 5 % and 10 %) were prepared and further mineralized through enzyme-induced biomimetic mineralization. The mechanical properties of the CMCS hydrogels were significantly increased as a result of mineralization, showing improvement of 1200–1500 % on storage moduli, and even exhibiting certain tensile behavior with the elongation rate of 30–35 %, likely due to the uniform formation and small size of mineralized products. Interestingly, the cationicity of chitosan also exerted an important modulation effect and the mineralization behavior and mechanical properties of mineralized hydrogels. In addition, the enzymatic mineralized hydrogels showed enhanced biocompatibility and osteogenic differentiation in-vitro, likely due to its superior mechanical properties and the introduction of calcium phosphate biominerals. In vivo experiments further suggest excellent bone-forming activity for the enzymatic mineralized hydrogels. Overall, tuning cationicity and enzymatic mineralization provide an effective approach for the preparation of chitosan hydrogels with superior mechanical and biological properties for bone tissue engineering application.

Multifunctional Polysaccharide Self-Healing Wound Dressing: NIR-Responsive Carboxymethyl Chitosan / Quercetin Hydrogel.

As the misuse of antibiotics increases bacterial resistance, the treatment of infected wounds caused by bacteria encounters significant challenges. Conventional antimicrobial dressings often fall short in their ability to inhibit bacterial infections while simultaneously promoting wound healing. To address this issue, a polysaccharide self-healing hydrogel (CPP@PDA/Que3) wound dressing is successfully developed by incorporating quercetin and polydopamine nanoparticles into a carboxymethyl chitosan matrix. The dressing can be easily injected locally to create a protective barrier over the wound, effectively stopping bleeding and rapidly inhibiting inflammation. Furthermore, the CPP@PDA/Que3 hydrogel exhibits remarkable antioxidant and antibacterial properties, stemming from the combination of quercetin and near-infrared (NIR) photothermal therapy. It demonstrates the ability to eliminate 99.52% of Staphylococcus aureus and 99.39% of Escherichia coli in in vitro antibacterial experiments. Additionally, the in vivo wound healing experiment shows a healing rate of ≈97%. The experimental results indicate that under NIR laser (808nm) irradiation, the polysaccharide-based hydrogel dressing significantly inhibits bacterial growth, reduces oxidative stress, expedites angiogenesis, and thereby accelerates the transition from inflammation to wound healing. In summary, the CPP@PDA/Que3 hydrogel exhibits significant potential as a wound dressing, providing a novel approach for clinically advancing the treatment of bacterial wounds.

Design of tunable hyaluronic acid and O′-carboxymethyl chitosan formulations for the minimally invasive delivery of multifunctional therapies targeting rheumatoid arthritis

The development of injectable, dual-component formulations based on natural-based polysaccharides is a promising strategy for the localized treatment of rheumatoid arthritis (RA). In the present study, biomimetic formulations consisting of aldehyde-functionalized hyaluronic acid (AHA) and O-carboxymethyl chitosan (OCC) were developed, presenting rapid in situ gelation rates and finely tunable physicochemical properties. These two properties allowed for the controlled delivery of anti-inflammatory, antioxidant, and pro-regenerative agents (i.e., strontium-methotrexate (SrMTX) and europium-tannic acid nanocomplexes (EuTA NCs), making them suitable for application in in vivo RA-models. Biological analyses demonstrated the system's cytocompatibility and its ability to modulate the activity of human articular chondrocytes at the secretome level and scavenge nitric oxide (NO). Moreover, the loaded cargoes not only extended the anti-inflammatory properties of the formulation but also the radiolabeling of EuTA NCs with 68Ga allowed the visualization of the gel by positron emission tomography (PET). Overall, this work presents the design and in vitro evaluation of an easily modulable polymeric system that allows the in situ release of a multifunctional therapy with promising perspectives for RA treatment.

A processable and recyclable gelatin/carboxymethyl chitosan hydrogel electrolyte for high performance flexible zinc-ion batteries

Hydrogels are currently under extensive research as flexible quasi-solid electrolytes for zinc-ion batteries. However, the non-degradability and non-recyclability of hydrogel electrolytes pose significant issues, leading to resource wastage and plastic pollution. Moreover, the increasing needs of hydrogel electrolyte with various shapes to meet individual requirements of next-generation flexible battery raise significant challenges. In this study, we introduce the Hofmeister effect and multiple non-covalent interactions to fabricate an eco-friendly and recyclable multifunctional hydrogel electrolyte using biomass natural polymers. This is achieved by simply soaking primary hydrogel networks of carboxymethyl chitosan (CMCS) and gelatin in zinc sulfate (ZnSO4) aqueous solutions, abbreviated as GCZ-x. The GCZ-x hydrogels exhibit both stiffness and toughness due to the formation of crystalline domains and ionic crosslinks. The dynamic physical interactions and temperature and pH responsiveness of the GCZ-x hydrogels enable them excellent processability and recyclability. The zinc-ion battery with GCZ-x hydrogel as electrolyte exhibits high specific capacity and superior cyclic performance (2200 h at 0.1 A g−1) without the formation of zinc dendrites. The GCZ-x electrolyte is sustainable with high recycling rate (above 80 %). It is envisaged that the GCZ-x hydrogel electrolyte will initiate new prosperity of green zinc-ion batteries in energy-efficient and environmentally sustainable ways.

Transformation of water hyacinth into biodegradable film added with carboxymethyl cellulose and chitosan and its characterization

The development of biodegradable films using natural materials, such as water hyacinth, addresses the environmental impact of plastic waste. The production of plastics, especially single-use plastics, has caused significant pollution and poses a threat to environmental sustainability. Biodegradable films offer a promising solution to mitigate this problem, but selecting the right environmentally friendly materials remains a challenge. This study investigated the development and characterization of biodegradable films derived from water hyacinth. Biofilms with the addition of 6 % CMC and varying chitosan concentration significantly affected the films’ thickness, moisture content, solubility, swelling index, biodegradability, and color. The results showed that increasing the chitosan concentration produced thicker films and increased the swelling index and biodegradability. Films with 5 % chitosan exhibited better water resistance compared to other compositions, while achieving the highest degradation rate of 21.05 % within 10 days. Fourier-Transform Infrared Spectroscopy (FTIR) confirmed the presence of hydrophilic groups and indicated potential interactions in the film structure. Scanning Electron Microscopy (SEM) revealed improved cohesiveness and homogeneity of the film surface with increasing chitosan concentration, enhancing the film's strength and resistance to liquid penetration. Meanwhile, the addition of chitosan also improved the lightness and color homogeneity of the film, making it more visually appealing. These findings emphasize the potential of water hyacinth-derived biodegradable films as an environmentally friendly alternative, though further composition optimization is essential to achieve the desired properties for sustainable packaging applications.

Biomimetic fabricated tubular graft in situ immobilized with peptides to restore the vascular structure and regulate the inflammation homeostasis through gastrodin coating

Since inferior biomimetic fabrication and anti-thrombosis process always lead to the implantation failure of artificial vascular grafts, the development of bioactive platform which can promote endothelialization is fundamental in the research for blood vessel substitutes to overcome the low-efficiency or hyperplasia. To solve the limitation of insufficient autologous sources of small blood vessels, this study prepared a tri-layer small diameter vascular based on citrate, followed by covalently immobilizing of specific peptides to achieve in situ cells enrichment. The natural carbohydrate of carboxymethyl chitosan is creatively used as the inner layer of tubular graft, thus exerting the anti-thrombosis effect. Moreover, the gastrodin coating was employed to alleviate the inflammation response and increase the safety of this surgically implanted vascular scaffold. The synthesis process was characterized, its biocompatibility, hierarchically cell induction capacity, anticoagulant effect and the ability to promote neovascularization were evaluated. In such way, we hope to prepare a biodegradable small-diameter artificial vascular for the clinical application.

Antibacterial bioadaptive scaffold promotes vascularized bone regeneration by synergistical action of intrinsic stimulation and immunomodulatory activity

The coupling of angiogenesis and osteogenesis is the fundamental necessity in bone fracture healing, thus simulative action of tissue-engineered bone provides powerful and beneficial effects in the treatment of bone defect. Herein, an immunoregulatory biocomposite scaffold with intrinsic activities of coupling angiogenesis and osteogenesis was constructed based on polyelectrolytes-modified 3D-printed scaffold for enhanced bone regeneration. The doping of Sr-doped hydroxyapatite (SrHA) within 3D-printed polycaprolactone (PCL) scaffold and subsequent slit guidance ligand 3 (SLIT3) protein adsorption through surface coating of carboxymethyl chitosan (CCS)/hyperbranched polylysine (HBPL) achieved on-demand delivery of SLIT3 and Sr ions. The antibacterial property of polyelectrolytes-modified scaffold was characterized and was directly proportional to the layer number of polyelectrolytes coating. The dual-factor delivery scaffold had good biocompatibility to support cell proliferation and migration, and was capable of stimulating angiogenesis and osteogenesis by intrinsic stimulation from released SLIT3 protein and Sr ions. Importantly, the multifunctional scaffold had immunomodulatory effects of promoting M2-type polarization of macrophages and thereby increasing anti-inflammatory factors level, as well as indirectly promoting angiogenesis and osteogenesis. The in vivo experiments revealed that the anti-inflammatory effect was significantly reinforced for providing a better regenerative microenvironment and bone regeneration capacity was dramatically enhanced accompanied with type H vessels formation when implanted with multifunctional scaffold. Therefore, the bioadaptive scaffold possessed amplified bone regeneration performance through intrinsic stimulation and immunomodulatory effects, suggesting a promising therapeutic candidate for bone defect repair.

Nitric oxide-releasing self-healing hydrogel for antibacterial and antibiofilm efficacy against polymicrobial infection.

Aim: Bacterial infections and the formation of biofilms are currently key factors in the delay of wound healing. S-Nitroso glutathione (GSNO) is recognized as a nitric oxide (NO) donor that exhibits potent antibacterial and antibiofilm activities. However, some of the stability limitations of NO require it to be prepared pharmaceutically.Materials & methods: Here, we developed a self-healing hydrogel dressing consisting of GSNO, polyvinyl alcohol/borax (PVA/B)and carboxymethyl chitosan (cmCHI). This research aimed to determine the antibacterial and antibiofilm activities of a self-healing hydrogel (PVA-B-cmCHI/GSNO) against multiple bacteria and polymicrobial biofilms.Results: Forty mg/ml PVA-B-cmCHI/GSNO significantly increased the antibacterial activity against Pseudomonas aeruginosa, S. aureus, Methicillin resistant Staphylococcus aureus (MRSA), as indicated by a >5log reduction in bacterial viability (∼99.999% killing). PVA-B-cmCHI/GSNO showed antibiofilm activity three-times greater than that of the blank self-healing hydrogel (PVA-B-cmCHI) by inhibiting 80% of the biofilm formation.Conclusion: The results suggest that the NO-releasing self-healing hydrogels exhibit notable antibacterial and antibiofilm properties and thus could be a promising approach for the treatment of bacterial or biofilm-infected wounds.

An immunoregulatory and metabolism-improving injectable hydrogel for cardiac repair after myocardial infarction.

The hypoxia microenvironment post-myocardial infarction (MI) critically disturbs cellular metabolism and inflammation response, leading to scarce bioenergy supplying, prolonged inflammatory phase and high risk of cardiac fibrosis during cardiac restoration. Herein, an injectable hydrogel is prepared by Schiff base reaction between fructose-1,6-bisphosphate (FBP)-grafted carboxymethyl chitosan (CF) and oxidized dextran (OD), followed by loading fucoidan-coated baicalin (BA)-encapsulated zein nanoparticles (BFZ NPs), in which immunoregulatory and metabolism improving functions are integrally included. The grafted FBP serves to enhance glycolysis and provide more bioenergy for cardiomyocytes survival under hypoxia microenvironment, and elevating cellular antioxidant capacity via pentose phosphate pathway. OD with intrinsic anti-inflammatory effect can induce M2 polarization of macrophages to accelerate inflammatory elimination. While facing the possibility of endothelial-to-mesenchymal transition (EndoMT) caused by excessive expressed TGF-β1 secreted from M2 macrophages, BFZ NPs can target endothelia cells and intracellularly release BA to regulate the level of fatty acid oxidation, resulting in retained endothelial features and decreased risk of cardiac fibrosis. After being injecting the hydrogel into rats' infarcted cardiac, the 28-day-post surgical outcomes demonstrate its benign effects on restoring cardiac functions and attenuating adverse left ventricular remodeling. This study shows a promising measure for MI treatment with immunoregulating and metabolism regulation comprehensively.

Carboxymethyl chitosan and sodium alginate oxide pH-sensitive dual-release hydrogel for diabetes wound healing: The combination of astilbin liposomes and diclofenac sodium

Difficulty in diabetic wound healing presents a significant challenge in clinical practice. This study developed a hydrogel utilizing oxidized sodium alginate (OSA) and carboxymethyl chitosan (CMCS) as the matrix. Astilbin (ASB), known for its antioxidant properties, was incorporated into Astilbin liposome (AL) using a thin film dispersion method. Diclofenac sodium (DS) and AL, both possessing anti-inflammatory properties, were then encapsulated in the hydrogel to create a pH-responsive dual-release system for topical application to expedite diabetic wound healing. Results from the research demonstrate that the composite hydrogel exhibits favorable biodegradability, stable rheology, and swelling capacity, facilitating the controlled release of AL and DS. In vivo and in vitro data demonstrated that the hydrogel was biocompatible and anti-inflammatory, antibacterial and homeostatic, and significantly promoted the process of inflammation suppression, angiogenesis and fibrotic repair of wounds. In conclusion, this novel hydrogel provides a simple and effective method for the repair of chronic diabetic wounds.

Antibacterial carboxymethyl chitosan hydrogel loaded with antioxidant cascade enzymatic system for immunoregulating the diabetic wound microenvironment

Diabetic wound healing faces several complex challenges, such as hypoxia, oxidative stress, and bacterial infections, which severely inhibit the wound-healing process. Herein, a quaternary ammonium salt-crosslinked carboxymethyl chitosan hydrogel (TPC) with excellent antioxidant and antibacterial properties was developed to immunoregulate the diabetic wound microenvironment. The TPC hydrogel was prepared by first mixing carboxymethyl chitosan (CMCS) and protocatechualdehyde (PA), followed by the addition of a quaternary ammonium cross-linker (TSPBA) and a superoxide dismutase (SOD)–catalase (CAT) cascade system. The immobilized SOD and CAT retained their activity, continuously converting endogenous ·O2− and H2O2 to O2 and H2O. PA also provided the TPC hydrogel excellent oxygen and nitrogen radical scavenging capacity. The quaternary ammonium groups in TSPBA significantly enhanced the inherent antibacterial ability of CMCS-based hydrogels. In diabetic wound-healing experiments, this porous and adhesive TPC hydrogel effectively closed wounds and regenerated skin tissue, resulting in shorter wound edges, thicker granulation, and higher collagen deposition levels compared with other groups. The TPC hydrogel also promoted macrophage polarization toward the M2 phenotype, accelerating wound healing by upregulating IL-10 expression, downregulating IL-6 expression, and enhancing angiogenesis. These results demonstrate the great potential of TPC hydrogel as a promising therapeutic dressing for treating diabetic wounds.

Mechanoresponsive self‐powered piezoelectric energy‐generating composite hydrogels based on carbon nanotube‐reinforced fungal‐carboxymethyl chitosan‐bacterial cellulose nanofibers for wearable electronics

AbstractDeveloping conductive hydrogels with both enhanced mechanical properties and superior sensing capabilities for wearable, flexible electronics remains challenging. Here, we developed mechanoresponsive self‐powered piezoelectric energy‐generating composite hydrogels. These hydrogels were prepared by blending fungal‐derived carboxymethyl chitosan (FC), carboxylate‐bacterial cellulose nanofibers (CBC‐NFs), and carbon nanotubes (CNTs) within a covalently crosslinked polyacrylamide (PAM) network (CNT‐FBCNF). The resulting hydrogels showed remarkable mechanical properties due to the molecular interactions between polymer chains. The hydrogels showed a self‐recoverable property and high stability under compressive mechanical force at 40% of strain (2000 cycles). The maximum compressive load (N) of 27.8 N was obtained for the optimized hydrogel, CNT‐FBCNF (1% CNT content). This hydrogel exhibited a good conductivity of 1.3 S/m, which was attributed to the homogeneous dispersion of CNTs within the hydrogel matrix and sufficient biocompatibility with skin fibroblasts. The hydrogel also exhibited impressive performance as a strain sensor, boasting a wide strain range (10–40%), excellent stability, and repeatability. Furthermore, strategic cutting and assembly of the hydrogel generated a flexible strain sensor capable of accurately monitoring finger and thumb pressure in real‐time. This study will significantly accelerate the development of hydrogel‐based sensors within the rapidly advancing field of wearable soft electronics.Highlights CNT‐reinforced composite hydrogel was developed The optimized hydrogel showed good electrical conductivity (1.3 S/m) The optimized hydrogel showed good self‐recovery properties The optimized hydrogel exhibited impressive strain‐sensing capability between 10% and 40% strain

β-cyclodextrin-modified carboxymethyl chitosan/hyaluronic acid-based crosslinked composite nanogels as a dual responsive carrier for targeting anti-tumor therapy

Advanced nanosized drug delivery systems can significantly improve efficacy and safety of first-line chemotherapeutics by enhancing tumor targeting. Herein, one-pot covalent crosslinking approach was developed to generate biodegradable tumor-targeted composite Nanogels from carboxymethyl chitosan, hyaluronic acid, cystamine and 6-ethylene-diamine-6-deoxy-β-cyclodextrin loaded with doxorubicin (DOX) for controlled intracellular DOX release. The optimized synthetic procedures generated Nanogels of about 190 nm in size and 28.3 % drug loading capability. DOX-loaded Nanogels was effectively internalized into tumor cells mainly by CD44 receptor-mediated endocytosis and rapidly released DOX in response to the high level of GSH in cytoplasm and acidic intracellular environments. DOX-loaded Nanogels significantly inhibited the tumor growth especially without appreciable side toxicities in 4 T1 tumor-bearing mice model owing to CD44 receptor-mediated active targeting and the passive targeting of Nanogels by enhanced permeation and retention effect. Overall, our newly developed composite Nanogels might be employed as a potentially effective therapeutic strategy for tumor therapy.

Smart Mesoporous Silica Nanoparticles Loading Curcumin Inhibit Liver Cancer.

Curcumin (CUR) as one of the natural edible pigments is approved by the World Health Organization due to its nontoxic and anticancer effect. However, the utility of CUR is restricted due to its low oral bioavailability. Nanoparticle drug delivery systems like mesoporous silica nanoparticles (MSNs) have been extensively used due to their high specific surface area, high loading rate, and ease of modification. This study developed lactobionic acid (LA)-modified carboxymethyl chitosan (CMCS)-coated MSNs to deliver CUR specifically targeting hepatocellular carcinoma. Among these nanoparticles, LA targets liver cancer cells. CMCS utilizes pH-responsive release of CUR. The LA-CMCS-MSN@CUR (MSN@CUR) were evaluated using several methods, including Fourier transform infrared spectroscopy, transmission electron microscopy, and zeta potential measurements. Liver cellular uptake of MSN@CUR depends on a specific LA receptor-mediated endocytosis mechanism. Additionally, MSN@CUR performed with a better antitumor effect than Cur in H22 orthotopic transplantation of liver cancer and H22 solid tumor mouse models. Treatment with MSN@CUR significantly reduced the protein of VEGF, p-PI3K, and AKT, increased the protein of caspases 3 and 8, ultimately inhibited tumor migration, and promoted apoptosis. This study provides a new path for delivery of natural active ingredients with excellent bioavailability in the antitumor field.

Novel Hybrid Catalysts of Cysteine Proteases Enhanced by Chitosan and Carboxymethyl Chitosan Micro- and Nanoparticles.

Micro- and nanoparticles of chitosan and carboxymethyl chitosan were synthesized, both with and without ascorbic acid. Methods were developed to form complexes between these micro- and nanoparticles and plant proteases-ficin, papain, and bromelain. It was demonstrated that the activity of cysteine protease complexes with carboxymethyl chitosan micro- and nanoparticles was higher compared to those with chitosan micro- and nanoparticles. Additionally, the complexes of ficin, papain, and bromelain with chitosan and carboxymethyl chitosan micro- and nanoparticles synthesized in the presence of ascorbic acid exhibited greater proteolytic activity than those formed with particles prepared without ascorbic acid. Molecular docking studies revealed that the amino acid residues of ficin, papain, and bromelain primarily interact with chitosan and carboxymethyl chitosan through hydrogen bonding and hydrophobic interactions. The amino acid residues in the active sites of these enzymes participate in a complex formation, which likely contributes to the increased activity and stability of cysteine proteases in complexes with chitosan and carboxymethyl chitosan micro- and nanoparticles.