Carboxymethyl Chitosan Research Articles

An injectable and retrievable bioartificial pancreas fabricated by time-sequentially assembling islets-laden microgels for minimally invasive treatment of type 1 diabetes

Islets transplantation is a promising method to treat type 1 diabetes. Unfortunately, current islet encapsulation and transplantation strategies are difficult to simultaneously achieve the minimally invasive transplantation, rapid mass transportation, accurate positioning, long-term stability and easy retrieval. Herein, we present a novel strategy for islet encapsulation and transplantation that integrates the advantages of microencapsulation and macroencapsulation. Specifically, islets are first encapsulated in methacrylated carboxymethyl chitosan (CMCSMA) microgels by droplet microfluidic technology, and then oxidized sodium alginate-succinimide ester (OSA-NHS) as the assembling agent is added to time-sequentially assemble the islets-laden microgels. The as-formed microgel assembly (MA-CHO/NHS), or namely bioartificial pancreas, is injectable before transplantation due to the quick formation of dynamic Schiff base bonds, and becomes quite stable after transplantation with the slow formation of stable amide bonds. In addition, the interconnected micropores inside the microgel assembly is beneficial for mass transportation, and the abundant aldehyde and succinimide ester groups on assembling agent ensures good tissue adhesion. This injectable, tissue-adhesive, microporous, positionable and retrievable bioartificial pancreas can reverse the blood glucose levels of diabetic mice from hyperglycemia to normoglycemia for at least 90 days, and thus shows a broad application prospect in the field of diabetes treatment.

ROS-responsive carboxymethyl chitosan nanoparticles loaded with astaxanthin for alleviating oxidative damage in intestinal cells

The controlled release of antioxidant substances at the intestinal oxidative damage site is crucial for alleviating intestine-related diseases. Herein, the novel ROS-responsive carrier was synthesized through simple amidation reaction between carboxymethyl chitosan (CMC) and methionine (Met), a natural organic compound containing ROS-responsive linkages (thioether). Initially, astaxanthin (AXT) nanoparticles (AXT2@CMT) with excellent stability and drug loading capacity (39.68 ± 0.23 μg/mL) were prepared by optimizing various reaction conditions. In the simulated high-concentration ROS environment of the intestine, CMT achieved a transition from hydrophobic groups (thioether) into hydrophilic groups (sulfone), which was conducive to the controlled release of AXT. In vitro cell experiments revealed that AXT2@CMT could effectively alleviate the oxidative damage in intestinal epithelioid cell line No. 6 (IEC-6 cell) caused by H2O2. This study achieved a straightforward preparation of ROS-responsive nanocarrier through food ingredients, offering a theoretical foundation for the controlled release of AXT at the intestinal oxidative damage site.

Molybdesum selenide-based platelet-rich plasma containing carboxymethyl chitosan/polyvinyl pyrrolidone composite antioxidant hydrogels dressing promotes the wound healing

Excess free radicals at the wound site can cause an inflammatory response, which is not conducive to wound healing. Hydrogels with antioxidant properties can prevent inflammatory storms by scavenging free radicals from the wound site and inhibiting the release of inflammatory factors. In this study, we prepared the carboxymethyl chitosan (CMCS)/polyvinyl pyrrolidone (PVP)/Molybdenum (IV) Selenide (MoSe2), and platelet-rich plasma (PRP) (CMCS/PVP/MoSe2/PRP) hydrogels for accelerating the repair of wounds. In the hydrogels, the MoSe2 can scavenge various free radicals to reduce oxidative stress at the site of inflammation, endowed the hydrogels with antioxidant properties. Interestingly, growth factors released by PRP assisted the tissue repair by promoting the formation of new capillaries. CMCS as a backbone not only showed good biocompatibility and biodegradability but also played a significant role in maintaining the sustained release of growth factors. In addition, incorporating PVP enhanced the tissue adhesion and mechanical properties. The multifunctional composite antioxidant hydrogels have good swelling properties and biodegradability, which is completely degraded within 28 days. Thus, the antioxidant CMCS/PVP/MoSe2/PRP hydrogels provide a new idea for designing ideal multifunctional wound dressings.

3D hydrogel microfibers promote the differentiation of encapsulated neural stem cells and facilitate neuron protection and axon regrowth after complete transactional spinal cord injury

Spinal cord injury (SCI) can cause permanent impairment to motor or sensory functions. Pre-cultured neural stem cell (NSC) hydrogel scaffolds have emerged as a promising approach to treat SCI by promoting anti-inflammatory effects, axon regrowth, and motor function restoration. Here, in this study, we performed a coaxial extrusion process to fabricate a core-shell hydrogel microfiber with high NSC density in the core portion. Oxidized hyaluronic acid, carboxymethyl chitosan, and matrigel blend were used as a matrix for NSC growth and to facilitate the fabrication process. During the in vitro differentiation culture, it was found that NSC microfibers could differentiate into neurons and astrocytes with higher efficiency compared to NSC cultured in petri dishes. Furthermore, during in vivo transplantation, NSC microfibers were coated with polylactic acid nanosheets by electrospinning for reinforcement. The coated NSC nanofibers exhibited higher anti-inflammatory effect and lesion cavity filling rate compared with the control group. Meanwhile, more neuron- and oligodendrocyte-like cells were visualized at the lesion epicenter. Finally, axon regrowth across the whole lesion site was observed, demonstrating that the microfiber could guide renascent axon regrowth. Experiment results indicate that the NSC microfiber is a promising bioactive treatment for complete SCI treatment with superior outcomes.

Fabrication and Characterization of Silver Nanoparticle-Doped Chitosan/Carboxymethyl Cellulose Nanocomposites for Optoelectronic and Biological Applications.

The synthesis of nanoparticles using environmentally friendly methods for applications in fields such as food packaging and biomedicine has been gaining increasing attention. Organic-inorganic nanostructures offer opportunities to create innovative materials suitable for use in optoelectronics and biological applications. In this study, we focused on producing nanocomposite films by blending carboxymethyl cellulose (CMC) and chitosan (CS) polymers in equal proportions (50/50 wt %) and adding silver nanoparticles (Ag NPs) through a solution casting process. Our objective was to examine how the introduction of Ag NPs influenced the structural, optical, mechanical, electrical, and antibacterial properties of the virgin CMC/CS composites. XRD patterns of the prepared samples indicated the presence of crystalline Ag phases within the CMC/CS blend. FT-IR spectroscopy showed the primary vibrational peaks associated with CMC and CS, which exhibited reduced intensity after the addition of Ag NPs. The UV absorption of the nanocomposites exhibited a gradual increase and a shift toward longer wavelengths. The electrical properties are enhanced with higher concentrations of Ag NPs. An increase in the content of Ag NPs resulted in a corresponding enhancement of antibacterial activity against both Staphylococcus aureus and Escherichia coli. The CMC/CS-Ag-doped films demonstrated significant enhancements in Young's modulus (Y), tensile stress (σt), and elongation at break (εB). These findings suggest that these nanocomposite films hold promise for potential applications in optoelectronics and biological fields.

Nerve tissue regeneration based on magnetic and conductive bifunctional hydrogel scaffold

The growth of neurons is often influenced by magnetic and electrical physical factors, and there is more and more research focused on designing a magnetic and conductive engineering scaffolds for nerve injury repair. In this study, electrospun poly lactic-co-glycolic acid (PLGA) fibers containing Fe3O4 magnetic nanoparticles were cryo-cut into magnetic short fibers (MSFs) and subsequently incorporated into sodium alginate (SA)/carboxymethyl chitosan (CMCS) hydrogel along with the addition of multi-wall carbon nanotubes (MWCNTs). MSFs can also achieve alignment by external magnetic fields within the hydrogel to construct magnetic and conductive bifunctional MSF/MWCNT/SA/CMCS hydrogel with anisotropic structure. The magnetic-conductive bifunctional hydrogel exhibited good magnetic responsiveness, electrically activity and mechanical property, in which both conductivity and mechanical property increased with the enhancement of MWCNTs contents. Notably, appearing of aligned structure significantly promoted the mechanical property of MSF/SA/CMCS hydrogel. The MSF/SA/CMCS hydrogel with aligned structure also facilitated greater primary neuron cells proliferation than random ones. Compared with individual magnetic or conductive hydrogel, there was a significant increase in cell viability in the primary cultured cortical neurons on MSF/MWCNT/SA/CMCS hydrogel with aligned structure. Simultaneously, electrical stimulation (ES) combined with magnetic stimulation (MS) delivered via magnetic and conductive bifunctional MSF/MWCNT/SA/CMCS hydrogel with aligned structure produced a better effect on promoting neuronal growth compared with individual ES or MS. Besides, hot plate measurement indicated that MSF/MWCNT/SA/CMCS hydrogel with aligned structure and MS significantly decreased the mice licking latency after sciatic nerve injury. Animal behavior studies confirmed the protective role of synergistic MS with magnetic hydrogel. Such hydrogel scaffolds have long-term potential for nerve tissue regeneration.

Designing and synthesis of injectable hydrogel based on carboxymethyl cellulose/carboxymethyl chitosan containing QK peptide for femoral head osteonecrosis healing

Femoral head necrosis is a debilitating disorder that typically caused by impaired blood supply to the hip joint. In this study, a novel injectable hydrogel based on Oxidized Carboxymethyl Cellulose (OCMC)-Carboxymethyl Chitosan (CMCS) polymers containing an angiogenesis stimulator peptide (QK) with a non-toxic crosslinking interaction (Schiff based reaction) was synthesized to enhance angiogenesis following femoral head necrosis in an animal model. The physicochemical features of fabricated injectable hydrogel were analyzed by FTIR, swelling and degradation rate, rheometry, and peptide release. Also, the safety and efficacy were evaluated following an in vitro hydrogel injection study and an avascular necrosis (AVN) animal model. According to the results, the hydrogel exhibited an appropriate swelling ratio and water uptake (>90 %, 24 h) as well as a suitable degradation rate over 21 days accompanied by a continuous peptide release. Also, data showed that hydrogels containing QK peptide boosted the proliferation, differentiation, angiogenesis, and osteogenic potential of both Bone Marrow mesenchymal Stem Cells (BM-MSCs) and human umbilical vein endothelial cells (HUVECs) (****p < 0.0001 and ***p < 0.001, respectively). Furthermore, molecular and histological evaluations significantly demonstrated the overexpression of Runx2, Osteocalcin, Collagen I, VEGF and CD34 genes (**p < 0.01 and ***p < 0.001, respectively), and also femoral head necrosis was effectively prohibited, and more blood vessels were detected in defect area by OCMC-CMCS hydrogel containing QK peptide (bone trabeculae >9000, ***p < 0.001). In conclusion, the findings demonstrate that OCMC-CMCS-QK injectable hydrogel could be considered as an impressive therapeutic construct for femoral head AVN healing.

Interpenetrating network based on soybean protein isolate and carboxymethyl chitosan: Investigation of intermolecular reaction mechanism, physicochemical stability and in vitro release properties of the hydrogel

In this study, interpenetrating network (IPN) hydrogels were constructed from soybean protein isolate (SPI) and carboxymethyl chitosan (CMCS) using TGase and genipin (GP) as cross-linking agents. And the influence of IPN formation on the physicochemical properties of hydrogels was illuminated. Multispectral analyses showed that there was a strong interaction between SPI and CMCS, which also promoted the increase of disulfide bonds and hydrophobic interactions in the hydrogels. The IPN was the densest when the addtion of SPI and CMCS were 10% and 3%, respectively. Meanwhile, this structure endowed the hydrogels with good mechanical properties and allowed them to exhibit thixotropy in rheological tests. The LF-NMR results showed that the IPN had a strong binding ability with water molecules and could effectively maintain the water in the hydrogel after freeze-thaw. Moreover, SPI-CMCS IPN hydrogels were pH responsive. This enabled it to adjust its own structure when pH changed, and to achieve controlled release of bioactives during simulated in vitro digestion. Overall, the results of this study showed that the IPN network formed by SPI and CMCS can effectively improve the performance of hydrogel. These results demonstrated the potential of SPI and CMCS as hydrogel synthesizers and provided a theoretical basis for the application of SPI-CMCS IPN hydrogel.

Elderberry (Sambucus nigra) and hawthorn (Crataegus oxyacantha) extract additives in carboxymethyl chitosan scaffolds for osteochondral tissue engineering applications

Elderberry (<i>Sambucus nigra</i>) and hawthorn (<i>Crataegus oxyacantha</i>) extract additives in carboxymethyl chitosan scaffolds for osteochondral tissue engineering applications

Exploring self-crosslinked hydrogel: Carboxymethyl chitosan and oxidized alginate for wound healing applications

This study reports the development and evaluation of self-healing hydrogel composed of carboxymethyl chitosan (CmCh) and oxidized alginate, with a focus on wound healing applications. Oxidized alginate was synthesized via metaperiodate oxidation and characterised. The hydrogels were formulated using Schiff base reactions with two weight ratios of oxidized alginate and CmCh, and their cross-linking mechanism was proposed. The developed hydrogels were characterised for their gelation, pH, self-healing capability, conductivity, and injectability. The optimized hydrogel was further evaluated for antibacterial activity, cytotoxicity, haemocompatibility, and in vitro wound healing studies. Results revealed that hydrogels with the lowest ratio of oxidized alginate to CmCh exhibited superior gelation, tensile strength, and injectability without needle clogging. Additionally, rapid self-healing of hydrogels was confirmed via Scanning Electron Microscope (SEM) analysis. The optimized hydrogel displayed good antibacterial activity against Staphylococcus aureus and Escherichia coli, alongside haemocompatibility. Additionally, in vivo studies demonstrated comparable wound healing efficacy to marketed formulations and significant improvement over control groups. These findings indicates the potential of self-healing hydrogels made up of oxidized alginate and CmCh for tissue engineering applications.

A Phosphorylated Dendrimer-Supported Biomass-Derived Magnetic Nanoparticle Adsorbent for Efficient Uranium Removal.

A novel biomass-based magnetic nanoparticle (Fe3O4-P-CMC/PAMAM) was synthesized by crosslinking carboxymethyl chitosan (CMC) and poly(amidoamine) (PAMAM), followed by phosphorylation with the incorporation of magnetic ferric oxide nanoparticles. The characterization results verified the successful functionalization and structural integrity of the adsorbents with a surface area of ca. 43 m2/g. Batch adsorption experiments revealed that the adsorbent exhibited a maximum adsorption capacity of 1513.47 mg·g-1 for U(VI) at pH 5.5 and 298.15 K, with Fe3O4-P-CMC/G1.5-2 showing the highest affinity among the series. The adsorption kinetics adhered to a pseudo-second-order model (R2 = 0.99, qe,exp = 463.81 mg·g-1, k2 = 2.15×10-2 g·mg-1·min-1), indicating a chemically driven process. Thermodynamic analysis suggested that the adsorption was endothermic and spontaneous (ΔH° = 14.71 kJ·mol-1, ΔG° = -50.63 kJ·mol-1, 298. 15 K), with increasing adsorption capacity at higher temperatures. The adsorbent demonstrated significant selectivity for U(VI) in the presence of competing cations, with Fe3O4-P-CMC/G1.5-2 showing a high selectivity coefficient. The performed desorption and reusability tests indicated that the adsorbent could be effectively regenerated using 1M HCl, maintaining its adsorption capacity after five cycles. XPS analysis highlighted the role of phosphonate and amino groups in the complexation with uranyl ions, and validated the existence of bimodal U4f peaks at 380.1 eV and 390.1 eV belonging to U 4f7/2 and U 4f5/2. The results of this study underscore the promise of the developed adsorbent as an effective and selective material for the treatment of uranium-contaminated wastewater.

Oral Synergism of Egg-White-Derived Peptides (EWDP) and Curcumin for Colitis Mitigation via Polysaccharide/Cyclodextrin Metal-Organic Framework-Based Assemblies.

Recently, oral deliverable strategies of multiple nutraceuticals for ulcerative colitis (UC) mitigation have attracted increasing attention. This study aimed to fabricate facile oral assemblies loaded with egg-white-derived peptides (EWDP) and curcumin based on carboxymethyl chitosan (CMCS) and an γ-cyclodextrin metal-organic framework (MOF). Herein, outer CMCS could coassemble with EWDP (both nutraceuticals and building blocks) into cobweb-like fibrils to promote bridging with inner MOF via coordinative noncovalent interactions (hydrogen bonding, hydrophobic interaction, and electrostatic interaction). Compared with conventional γ-cyclodextrin/MOF-based composites, the above coassembly could also endow the biocompatible assemblies with superior nanoscale colloidal properties, processing applicability (curcumin storage stability, bioaccessibility, and aqueous solubility), and bioactivity. Moreover, the oral synergism of EWDP and curcumin (initially nonsynergistic) for UC mitigation was achieved by alleviating inflammatory damage and gut microbiota imbalance. Overall, the novel assemblies could be a promising amplifier and platform to facilitate oral formulations of various nutraceuticals for food processing and UC relief.

Synthesis of carboxymethyl chitosan–guar gum–poly(vinylpyrrolidone) ternary blended hydrogels with antibacterial/anticancer efficacy and drug delivery applications

Biopolymers have the utmost significance in biomedical applications and blending synthetic polymers has shown favorable characteristics versus individual counterparts. The utilization of the blends can be restricted through the use of toxic chemical agents such as initiators or crosslinkers. In this regard, a chemical agent-free ionizing irradiation is a beneficial alternative for preparing the hydrogels for biomedical applications. In this study, carboxymethyl chitosan (CM-CS), guar gum (GG), and poly(vinylpyrrolidone) (PVP) based ternary blends (TB) were crosslinked using various doses of ionizing irradiation to fabricate hydrogels. The prepared hydrogels were characterized for physicochemical properties, swelling analysis, biological assays, and drug delivery applications. Swelling analysis in distilled water revealed that the hydrogels exhibit excellent swelling characteristics. An in vitro cytocompatibility assay showed that the hydrogels have greater than 90% cell viability for the human epithelial cell line and a decreasing cell viability trend for the human alveolar adenocarcinoma cell line. In addition, the prepared hydrogels possessed excellent antibacterial characteristics against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). Finally, the release studies of anti-inflammatory Quercus acutissima (QA) loaded hydrogels exhibited more than 80% release in phosphate-buffered saline (pH = 7.4). These findings suggest that TB hydrogels can be used as suitable carrier media for different release systems and biomedical applications.

Fabrication, characterization and in vitro controlled-releasing of naringin nano-particles encapsulated by chitosan-carboxymethyl konjac glucomannan

Naringin (NR) is a prominent citrus bioflavonoid, but the application is greatly limited by its low bioavailability. To solve this problem, NR was encapsulated in carboxymethyl konjac glucomannan (CKGM) and chitosan (CS) to form core-shell nanoparticles (CS/CKGM-NR NPs). The physicochemical properties of CS/CKGM-NR NPs with ideal encapsulation efficiency of 82.70 ± 0.30% were characterized by fourier transform infrared spectroscopy and differential scanning calorimetry. The morphology and core-shell structure of CS/CKGM-NR NPs were observed to be successful formation (diameter 700 nm, +35 mV). Moreover, the releasing behavior of NR was evaluated in In Vitro digestion mode. The underlying mechanism indicated that carboxyl groups of CKGM were cross-linked with ammonium ion of CS by electrostatic interaction. Moreover, the releasing efficiency of NR in simulated gastric fluid (SGF, 20.62 ± 0.59%), simulated intestinal fluid (SIF, 17.08 ± 0.01%) and simulated colon fluid (SCF, 18.82 ± 0.61%) were greatly lowered compared with that of naked NR (52.70 ± 0.01% in SGF, 46.42 ± 3.30% in SIF, 69.35 ± 12.63% in SCF). The findings implied that CS/CKGM-NR NPs were created in core-shell structure with controlled-releasing effect. This study provided new insight into the fabrication of CS/CKGM-NR NPs that could be developed as a potential nano-delivery with controlled-releasing effect.

Molecular Properties of Carboxymethyl Chitosan and Its Complexes with Curcumin and Nicotinamide in Drug Delivery Applications: Molecular Docking and Molecular Dynamic Study

Carboxymethyl chitosan (CMCs) is a chitosan-derived compound usually used as a carrier matrix in drug delivery systems. There are three types of CMCs based on the location of carboxyl group substitution: N-CMCs, O-CMCs, and N,O-CMCs. The ability of CMCs as a carrier is related to the ability of CMCs to interact with drug molecules. In this work, curcumin and nicotinamide were used as drug models. The ability of CMCs to interact with drug models can be observed by the amount of interaction energy generated when CMCs interact with curcumin and nicotinamide. The purpose of this study is to determine the interaction energy generated when CMCs interact with curcumin and nicotinamide using molecular docking and molecular dynamic methods. The results showed the interaction energy between O-CMCs, N-CMCs, and N,O-CMCs (2 and 3 monomers) with curcumin and nicotinamide, respectively, ranged from -17.08 to -13.37 and -12.05 to -11.00 Kj/mol. Conformational changes in molecular dynamic simulations affect bond-free energy, RMSD, and potential energy complex values.

Assessment of the ability of Pseudomonas aeruginosa and Staphylococcus aureus to create biofilms during wound healing in a rat model treated with carboxymethyl cellulose/carboxymethyl chitosan hydrogel containing EDTA.

The primary objective of this study was to develop a carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCS) hydrogel containing ethylene diamine tetra acetic acid (EDTA) as the materials for wound healing. CMC and CMCS solutions were prepared with a concentration of 4% (w/v). These solutions were made using normal saline serum with a concentration of 0.5% (v/v). Additionally, EDTA with the concentrations of 0.01%, 0.05%, 0.1%, 0.5%, 1%, and 2% (w/v) was included in the prepared polymer solution. The analysis of the hydrogels revealed that they possess porous structures with interconnected pores, with average in size 88.71 ± 5.93 μm. The hydrogels exhibited a swelling capacity of up to 60% of their initial weight within 24 h, as indicated by the weight loss and swelling measurements. The antibacterial experiments showed that the formulated CMC/CMCS/EDTA 0.5% hydrogel inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, the produced hydrogels were haemocompatible and biocompatible. At the last stage, the evaluation of wound healing in the animal model demonstrated that the use of the produced hydrogels significantly improved the process of wound healing. Finally, the findings substantiated the effectiveness of the formulated hydrogels as the materials for promoting wound healing and antibacterial agents.

Synthesis of carboxymethyl cellulose from coconut fibers and its application as solid polymer electrolyte membranes

AbstractCarboxymethyl cellulose (CMC) is one of the important cellulose derivatives, and it can be developed as a host polymer for solid polymer electrolyte (SPE) membrane. This study aimed to synthesis of CMC from coconut fiber cellulose and it was applied to prepare the SPE membranes. Cellulose isolation was conducted through the delignification and bleaching process, while the CMC synthesis was conducted through alkalization and carboxymethylation treatments. SPE membranes were prepared by blending CMC with carboxymethyl chitosan (CMCh) (80/20) and mixed with various weight percentages of LiOAc at room temperature. SPE membranes characterizations were conducted using FTIR, EIS, XRD, SEM, and tensile testing. Cellulose and CMC yields were 23.1% and 65.44%, respectively. Incorporating 20 wt% LiOAc into the CMC/CMCh (80/20) SPE membrane yielded the highest ionic conductivity of 1.37 × 10−3 S/cm. Based on the results, CMC obtained from coconut fibers has the potential to produce solid polymer electrolyte membranes with some modification.

Nanofiber-reinforced self-healing polysaccharide-based hydrogel dressings for pH discoloration monitoring and treatment of infected wounds

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.

Carboxymethyl chitosan and dialdehyde cellulose nanocrystal based injectable self-healing emulsion gel

The study aims to demonstrate a general method for producing emulsion gels with self-healing properties. Specifically, the self-healing emulsion gels were fabricated by crosslinking carboxymethyl chitosan (CMC) stabilized emulsion with dialdehyde cellulose nanocrystal (DACNC). The reversible imine bonds between primary amino groups from CMC and aldehyde groups from DACNC endow the emulsion gel with self-healing properties. The compressive strength of the emulsion gels was greatly increased from 37.43 kPa 83.7 kPa by encapsulating emulsion droplets (φ = 0 %–40 %.) in the gel matrix. Moreover, the emulsion gels exhibited much better self-healing and injectability ability compared to hydrogel because the emulsion droplets interacted with the 3D gel matrix, which were observed by cryo-SEM and CLSM. The emulsion droplets distributed in the gel matrix improved the mobility and interfacial contact area of CMC and DACNC. Water contact measurement confirmed that the CMC/DACNC self-healing emulsion gels showed a hydrophilic surface. The CMC/DACNC emulsion gels could maintain a good structural stability as the oil loss was <1 % after centrifugation. This research provides a method to keep the structural stability of emulsion gels by inducing self-healing ability and modified cellulose nanocrystals, which could extend the shelf life and application area of emulsion gels.

Mn(II) Coordination Complex Loaded Hydrogel: Synthesis, Characterization, Fluorescence Properties, and Application in Treating Knee Arthritis.

Using a mixed-ligand approach, we successfully obtained two Mn(II)-based coordination compounds, namely [Mn2(L1)(TBIP)·H2O]n (1) and [Mn2(L2)(NPTA)·H2O]n (2) (where L1 and L2 are 1,4-bis(thiabenzimidazol-1-ylmethyl)benzene and 1,2-bis(thiabenzimidazol-1-ylmethyl)benzene, H2NPTA is 2-nitroterephthalic acid, and H2TBIP is 5-tert-butylisophthalic acid). Fluorescence performance testing of complexes 1 and 2 showed excellent green and blue fluorescence properties. Based on this, we further prepared HA/CMCS hydrogels using natural polysaccharides hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials and studied their internal structural characteristics using scanning electron microscopy. Using "Duhuo Jisheng Decoction" as a drug model, two metal gel scaffolds loaded with "Duhuo Jisheng Decoction" were prepared, and their potential for treating knee osteoarthritis was evaluated.