Preparation, biocompatibility, and wound healing effects of O-carboxymethyl chitosan nonwoven fabrics in partial-thickness burn model.

This study was aimed at preparing O-carboxymethyl chitosan (CM-CTS) fabrics, and examining the wound healing effects on partial-thickness burn. The functional polysaccharides were produced from chitosan needle-punched nonwovens reacted with chloroacetic acid. Then the biocompatibility and biological functions were evaluated through fibroblast L-929 and SD rats. CM-CTS fabrics were obtained with elongation at break more than 42%, tensile strength reaching 0.65 N/mm2, and water vapor transmission rate about 2600 g/m2∙24 h. Moreover, CM-CTS fabrics could effectively promote the mouse L-929 migration in vitro. CM-CTS fabrics yielded satisfactory results in angiogenesis, collagen deposition, interleukin-6 content, transforming growth factor level and healing rate, which were superior to the positive control and model groups after rats suffering with partial-thickness burn. In conclusion, CM-CTS fabrics possessed proper mechanical properties, air permeability, favorable biocompatibility, acceleration on fibroblasts migration and healing capacity for partial-thickness burn injury, and owned good potential as high-quality wound dressing.

Novel chitosan-ulvan hydrogel reinforcement by cellulose nanocrystals with epidermal growth factor for enhanced wound healing: In vitro and in vivo analysis.

Several dressing materials can be used efficiently in recent times, both in their natural and synthetic combinations like; microfibers, film, nanofibers, hydrogels, and various drugs. The specific characteristics, such as biocompatibility and providing a favorable environment for wound healing, make many polysaccharides pivotal as wound dressings. Keeping in view the importance of these polysaccharides, we have developed novel chitosan-ulvan hydrogel incorporated by cellulose nanocrystals (CNCs) loading epidermal growth factor (EGF) drug (CS-U-CNC-EGF) by the freeze-dried process. The morphological features of novel hydrogel were perceived by FTIR, XRD, FESEM, and DSC analysis. The incorporation of the nanocrystals content modified the porous microstructure at pore size from 237 ± 59 µm to 53 ± 16 µm, improved mechanical stress curve from 0.57 MPa to 1.2 MPa, thermal and swelling behavior. The novel nanocomposites revealed non-toxic behavior and excellent cell proliferation. Whereas hydrogel showed sustained release of the epidermal growth factor (EGF), thereby enhancing EGF delivery at the wound site for 15 days from a 100% wound contraction treated group. Moreover, the controlled release of EGF from CS-U-CNC-EGF hydrogels showed significantly faster-wound healing efficiency concerning considerably faster granulations tissue formation and collagen deposition. The study's results point to possible future applications of this composite hydrogel in wound healing as a wound dressing material.

Wound Dressing Hydrogel of Enteromorpha prolifera Polysaccharide-Polyacrylamide Composite: A Facile Transformation of Marine Blooming into Biomedical Material.

Great endeavors have been dedicated to the development of wound dressing materials. However, there is still a demand for developing a wound dressing hydrogel that integrates natural macromolecules without requiring extra chemical modifications, so as to enable a facile transformation and practical application in wound healing. Herein, a composite hydrogel was prepared with water-soluble polysaccharides from Enteromorpha prolifera (PEP) cross-linked with boric acid and polyacrylamide cross-linked via polymerization (PAM) using a one-pot method. The dual-network of this hydrogel enabled it to have an ultratough mechanical strength. Moreover, interfacial characterizations reflected that the hydrogen bonds and dynamic hydroxyl-borate bonds contributed to the self-healing ability of the PEP-PAM hydrogel, and the surface groups on the hydrogel allowed for tissue adhesiveness and natural antioxidant properties. Additionally, human epidermal growth factor-loaded PEP-PAM hydrogel promoted cell proliferation and migration in vitro and significantly accelerated wound healing in vivo on model rats. These progresses suggested a prospect for the PEP-PAM hydrogel as an effective and easily available wound dressing material. Remarkably, this work showcases that a wound dressing hydrogel can be facially developed by using natural polysaccharides as a one component and offers a new route for the high-value utilization of disastrous marine blooming biomass by transforming it into a biomedical material.

Study on the transfection efficiency of chitosan-based gene vectors modified with poly-l-arginine peptides.

Although in a series of studies, arginine peptides had shown the ability to promote the targeting delivery efficacy, the relationship between the transfection efficiency and the length of the poly-l-arginine chain had seldom been reported. This study was aimed to explore whether the chain length of poly-l-arginine grafted on chitosan had a great significance on the transfection efficiency of entering the cells. Herein, arginine and arginine peptide modified chitosan were synthesized as gene vectors (CS-Arg and CS-5Arg) and then the chemical structures were characterized by using 1 H NMR. The CS-Arg and CS-5Arg were combined with plasmids by electrostatic interactions to form stable particles. The morphology features, Zeta potentials, and buffering capacity of the complex particles were analyzed. Afterward, the combination ability with DNA and the protection ability to DNase I were studied, and the gene transfection efficiency and cellular uptake were investigated in vitro. The results showed that the gene transfection efficiency of the chitosan was significantly enhanced by arginine-graft modification. However, there were no significant differences between the CS-Arg and the CS-5Arg. The molecular simulation results indicated that the guanidine groups of grafted arginine were shielded by chitosan molecule and the guanidine groups contributed little to the gene transfection efficiency. The results demonstrated that the increased chain length of grafted arginine had no significantly enhanced effect on the transfection efficiency, which could provide convincing evidence for the construction and application of arginine and chitosan derivatives as gene vectors, and could promote the development of gene delivery system.

[The effect of carboxymethyl chitosan zinc and peptide on IL-1,TNF-α and PGE-2 in gingival crevicular fluid of miniature pigs].

PURPOSE: This experiment was aimed at exploring whether carboxymethyl chitosan zinc and peptide （CMC-Zn(+)-P） can reduce the occurrence and development of periodontal tissue inflammation effectively by observing the change of IL-1,TNF-α and PGE-2 level in gingival crevicular fluid （GCF） before and after brushing, so as to find a new effective material in preventing and treating periodontal diseases. METHODS: Miniature pigs were selected as experimental subjects and divided into 4 groups randomly: the control group; CMC-Zn(+)-P group (material group);brushing group; brushing + CMC-Zn(+)-P group (composite group). Gingival crevicular fluid before and one month after the experiment was collected. The levels of IL-1, TNF-α and PGE-2 were examined by enzyme-linked immune-sorbent assay, while the clinical periodontal index was recorded. SPSS 18.0 software package was used for statistical analysis. RESULTS: There was no significant difference in levels of IL-1, TNF-α and PGE-2 and clinical periodontal index between the 4 groups before experiment. After one month, the levels of IL-1, TNF-α, PGE-2 in GCF had significant difference between 4 groups. The levels of IL-1, TNF-α, PGE-2 in composite group were significant lower than that of the other three groups (P<0.008).The levels of IL-1, TNF-α and PGE-2 in the material group and brushing group were significantly lower than that of the control group (P<0.008). Compared with materials group, the brushing group had significantly lower level of IL-1,significantly higher level of PGE-2 ,but no difference in the level of TNF-α.In addition, the teeth calculus index of composite group was significantly lower than that of other groups (P<0.05). CONCLUSIONS: CMC-Zn(+)-P can effectively reduce periodontal tissue inflammation and cut down the speed of deposition of dental calculus. If used cooperatively with brushing, the effect will be better.

[Antibacterial effect of the carboxymethyl chitosan zinc peptide on several periodontal pathogens in vitro].

OBJECTIVE: To determine the antimicrobial effects of carboxymethyl chitosan zinc (CMC-Zn(+)) and CMC-Zn(+)-peptide (CMC-Zn(+)-P) on four kinds of periodontal pathogens. METHODS: Dilution method was used to determine the minimum inhibitory concentration (MIC) of CMC-Zn(+) for Porphyromonas gingivalis (Pg), Actinobacillusactinomycetemcomitans (Aa), Prevotella intermedia (Pi) and Actinomyces viscosus (Av). The antimicrobial characters of CMC-Zn(+) and CMC-Zn(+)-P on these four kinds of pathogens were evaluated by disk diffusion method. RESULTS: The MIC of CMC-Zn(+) for Pg, Aa, Pi and Av was 0.312 5%, 0.156 25%, 0.156 25% and 0.078 125% respectively. Significant antimicrobial effects were improved along with the increased concentration of CMC-Zn(+) and CMC-Zn(+)-P (P < 0.01), while the best antimicrobial concentrations of both CMC-Zn(+) and CMC-Zn(+)-P were 5%. The antimicrobial effect of CMC-Zn(+)-P was better than that of CMC-Zn(+) on the same kind of periodontal pathogen (P < 0.01). CMC-Zn(+)-P showed different antimicrobial effects on the four periodontal pathogens (Av > Aa > Pi or Av > Aa > Pg, P < 0.01). CONCLUSIONS: CMC-Zn(+) and CMC-Zn(+)-P have inhibition effect on Pg, Aa, Pi and Av, and the best antibacterial concentration was 5%. The CMC-Zn(+)-P has better antibacterial effect than CMC-Zn(+) on Pg, Aa, Pi and Av.

Antitumor and antimetastasis effects of macerating solutions from an injectable chitosan-based hydrogel on hepatocarcinoma.

In our previous studies, injectable chitosan-based hydrogel (CH) was prepared and its application in surgery removal of tumor was studied. In this study, the antitumor and antimetastasis effects of the macerating solutions from CH were investigated. Our in vitro results showed that macerating solutions from CH significantly increased the proliferation of human normal liver L02 cells. In contrast, macerating solutions from CH showed significant inhibitory effects on the growth of human hepatoma Bel-7402 cells. In a mouse H22 tumor model, intraperitoneal injection of macerating solutions from CH decreased tumor growth and prevented tumor diffusion. Tumor weight was decreased dramatically in mice treated with macerating solutions from CH. The thymus index and spleen index were significantly increased by treatment with macerating solutions from CH. Administration of macerating solutions from CH also remarkably increased serum levels of TNF-α, IL-2, IFN-γ, and decreased serum VEGF content as compared with the control group treated with saline. The antimetastasis studies showed that the number of pulmonary nodules, pulmonary metastases index, and lymph nodes index were significantly decreased in experimental groups treated with macerating solutions from CH. This study provided more supporting data for the potential clinical application of CH after surgical removal of tumor.

An in situ formed biodegradable hydrogel for reconstruction of the corneal endothelium.

Biodegradable hydrogels are important biomaterials for tissue engineering and drug delivery. For the purpose of corneal regenerative medicine, we describe an in situ formed hydrogel based on a water-soluble derivative of chitosan, hydroxypropyl chitosan (HPCTS), and sodium alginate dialdehyde (SAD). Periodate oxidized alginate rapidly cross-links HPCTS due to Schiff's base formation between the available aldehyde and amino groups. Hydrogel cytotoxicity, degradability and histocompatibility in vivo were examined. The potential of the composite hydrogel for corneal endothelium reconstruction was demonstrated by encapsulating corneal endothelial cells (CECs) to grow on Descemet's membranes. The results demonstrate that the composite hydrogel was both non-toxic and biodegradable and that CECs transplanted by the composite hydrogel could survive and retain normal morphology. These results provide an opportunity for corneal endothelium reconstruction based on tissue engineering by the in situ formed composite hydrogel.

Pharmacokinetics and biodegradation mechanisms of a versatile carboxymethyl derivative of chitosan in rats: in vivo and in vitro evaluation.

Carboxymethyl chitosan (CM-chitosan), which is a water-soluble derivative of chitosan, has attracted much attention as a new biomedical material. The safety study of this material was persuasive for its potential application. The present study was conducted to assess the tissue distribution, pharmacokinetics, biodegradation mechanism, and excretion of CM-chitosan in rats. After the rats were intraperitoneally injected at the dose of 50 mg/kg, the fluorescein isothiocyanate (FITC)-labeled CM-chitosan was absorbed rapidly and distributed to different organs, including liver, spleen, and kidney. The highest level of CM-chitosan was found in liver. It was at the level of 1.6 +/- 0.6 mg/liver and made up approximately 10-22% of the total injected FTC-CM-chitosan. Urinary excretion was the predominant way of excretion of FITC-labeled CM-chitosan, and 85% of the dose was excreted in urine over the period of 11 days. The molecular weights of body distributed FTC-CM-chitosan and urinary excreted FTC-CM-chitosan were analyzed by gel chromatography. The results indicated that the FTC-CM-chitosan was degraded in abdominal dropsy. The absorbed CM-chitosan forms were found with a relatively high molecular weight (approximately 300 kDa), whereas the molecular weight of the urinary excreted FTC-CM-chitosan was less than 45 kDa. In vitro research revealed that the CM-Chi was also degradable in plasma and homogenate of liver. The CM-chitosan with a molecular weight of approximately 800k was thoroughly degraded to a small molecule after it was incubated in homogenate of liver at 37 degrees C for 24 h. The results suggested that the liver plays a central role in biodegradation of CM-chitosan. The excellent biodegradability of CM-chitosan could potentially contribute to the clinical applications. The results also provide important clues for further modification of CM-chitosan as the postsurgical and other biomedical materials.