BACKGROUND: Carboxymethyl chitosan is a water-soluble derivate modified from chitosan, with various biological activities. It is a good ligand of metal ion and can integrate Ca~(2+) to prepare a novel biological material. OBJECTIVE: To explore a method for preparing carboxymethyl chitosan calcium (CCC) and analyze its properties and structure. METHODS: CCC was produced by carboxymethyl ohitosan reacting with solution of calcium chloride. The solubility, carboxymethylation degree, rotational viscosity, and calcium content of CCC were determined, and infrared and ultraviolet spectral analyses were performed.RESULTS AND CONCLUSION: The calcium content of CCC was approximately 15%. Compared with carboxymethyl chitosan, infrared spectrum and ultraviolet spectrum of CCC were changed. The prepared CCC is a new calcium compound through property and structural analysis.

Objective To observe the effect of carboxymethyl chitosan calcium(CCC) on the concentration of lead,calcium,and liver antioxidative capacity in lead poisoned mice.Methods mice were randomly divided into 6 groups.Three test groups were treated with CCC at three doses.The lead poisoned mice model was established by giving water containing lead acetate,and then CCC was administered to mice once a day.After 30 days,the mice were killed and the content of lead in blood,liver,brain and femur were determined by atomic absorption spectrophotometer,and antioxidative capacity in liver was measured using assay kit.Results CCC could reduce the contents of lead in blood,brain,liver and femur significantly,decrease the level of maleicdialdehyde(MDA),increase activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and total antioxidative capacity(T-AOC) in liver markedly. Conclusion CCC can promote the excretion of lead,increase the content of calcium in femur and antioxidative capacity in lead poisened mice.

Objective A strain with high alginase activity was screened and isolated by decomposing sodium alginate from the decaying parts of brown alga Laminaria japonica and Undaria pinnatifida,in order to produce alginase.Methods The strain s4 with high alginase activity was chosen by filtration.The alginase producing media was optimized and the alginase was produced and its characterization was investigated.Results The optimum fermentation conditions for alginate lyase producing as follows: media AlgNa 1.2%,NH4Cl 0.9%,NaCl 1.5%,pH=7.5,and temperature 25℃.Conclusion The alginase produced by strain s4 showed high alginase activity and good stability.

Effects of carboxymethyl-chitosan (CM-Chitosan) with different molecular weight on the proliferation of skin fibroblasts and keratinocytes were examined in vitro; bFGF and EGF, as controls, were seperately used for comparison. Chitosan with different molecular weight was prepared by acid degradation and oxidation degradation; CM-Chitosan with different molecular weight was synthesized from corresponding Chitosan. Microscopy and MTT method were applied to evaluate the different effects. The results demonstrated that CM-Chitosan with different molecular weight promoted the proliferation of skin fibroblasts and keratinocytes at 1-1000 ppm, and the concentration at 100 ppm had the strongest effects. The effects of low molecular weight CM-Chitosan were greater than those of high molecular weight CM-Chitosan. CM-Chitosan (Mn= 3KD) had the strongest promotive effects on skin fibroblasts and keratinocytes; it had equivalent effects when compared with bFGF and EGF.
Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Chitosan ; analogs & derivatives ; chemical synthesis ; pharmacology ; Fibroblasts ; cytology ; drug effects ; Humans ; Keratinocytes ; cytology ; drug effects ; Mice ; Molecular Weight ; Skin ; cytology

The sacrum is a common site of stress injury. The occurrence of pressure ulcers not only leads to the aggravation of the patient′s condition, the prolongation of hospital stay, the increase of medical costs, the decline of life quality, but also aggravates the burden of society, family and medical staff. Early reasonable and effective application of sacral dressing can prevent the occurrence of pressure injury. In this study, the characteristics and effectiveness of different types of sacral dressings were reviewed by reviewing relevant literatures at home and abroad and summarizing the existing relevant studies, so as to provide guidance for clinical application.

Objective:To investigate whether the antibacterial copper sulfide (CuS)/graphene oxide (GO) nanosheets composite film can promote angiogenesis and osteogenesis in vitro. Methods:GO and CuS/GO nanosheets were synthesized and mixed into polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC) hydrogel films. The study was conducted in 4 groups: PVA/CMC/GO, PVA/CMC/CuS/GO, PVA/CMC (only PVA/CMC-based film) and blank control (no material). The PVA/CMC, PVA/CMC/GO and PVA/CMC/CuS/GO films were characterized by electron scanning microscopy and energy dispersive spectrometer. The biocompatibility of different films (PVA/CMC/CuS/GO films with concentrations of CuS/GO nanotablets of 0, 50, 100, 200, 400, and 800 μ g/mL) was evaluated by CCK-8, live/dead cell staining, and hemolysis test. The angiogenesis was evaluated by cell migration and tube forming test in vitro. Alkaline phosphatase and alizarin red staining were used to evaluate osteogenesis in vitro, and the expression of osteogenic genes was measured by immunofluorescence staining and RT-qPCR. In addition, the bacterial plate counting method and bacteriostatic circle method were used to evaluate the antibacterial activity of films. Results:In the PVA/CMC/GO and PVA/CMC/CuS/GO groups, the surface of the PVA/CMC-based film was smooth and flat whereas the nanosheets composite films were irregularly flaky and convex. The biosafety experiments showed that the PVA/CMC-based film composited with GO or CuS/GO nanosheets at the concentration of 100 μg/mL had good biocompatibility. The results of angiogenesis in vitro showed that the migration ratio of HUVEC cells in the PVA/CMC/CuS/GO group was significantly better than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). In the experiment of tube forming area and length, the PVA/CMC/CuS/GO group was significantly better than the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). The osteogenic differentiation in vitro displayed that the alkaline phosphatase and alizarin red staining of MC3T3-E1 cells in the PVA/CMC/CuS/GO group were significantly better than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). In addition, the fluorescence intensity of immunofluorescence staining in alkaline phosphatase and type Ⅰcollagen on MC3T3-E1 cells, and the mRNA expression levels of osteogenic related genes including alkaline phosphatase, bone morphogenetic protein 2, osteocalcin and osteopontin in the PVA/CMC/CuS/GO group were significantly higher than those in the PVA/CMC/GO, PVA/CMC and control groups ( P<0.001). The antibacterial assay showed that the PVA/CMC/CuS/GO group had a significantly greater antibacterial activity and a significantly larger inhibition zone against Gram-positive bacteria and Gram-negative bacteria than the PVA/CMC/GO, PVA/CMC and control groups ( P< 0.001). Conclusions:PVA/CMC films composited with GO or CuS/GO nanosheets demonstrate ideal biocompatibility and antibacterial properties which promote angiogenesis and osteogenic differentiation in vitro. In particular, antibacterial PVA/CMC/CuS/GO composite films with the coupling function of angiogenesis and osteogenesis are expected to provide a new strategy for infectious bone defects.