Carboxymethylchitosan nanofibers containing silver nanoparticles: Preparation, Characterization and Antibacterial activity.

Herein we prepare antibacterial composite from carboxymethylchitosan (CMCS) nanofibers and silver nanoparticles (AgNPs) by using poly (vinyl alcohol) (PVA) as reducing, capping and fiber aiding material and investigated to be used in biomedical applications. The AgNPs has spherical shapes and its diameter ranged from 15 to 25 nm and distributed within the prepared nanofibers. The electrospinning parameters from the effect of the CMCS and PVA mass ratio, extrusion rate and field were studied. The optimum condition for electrospinning were 7% for CMCS and 8% from PVA. UV-vis, TEM and XRD used to characterize AgNPs whereas FTIR and SEM used to characterize nanofibers. Results showed that ultra-fine fibers were generated after addition of PVA to CMCS in different mass ratios to from 8 wt. % concentration solutions. Electrospun PVA (AgNPs)/CMCS nanofibers showed good antibacterial effects towards Gram-positive and Gram-negative bacteria. Antibacterial activities of electrospun nanofibers increased by increasing both CMCS and AgNPs content in the electrospun nanofibers.

Preparation, characterization and evaluation of a novel tumor targeting superparamagnetic iron oxide nanoparticles / 中国药学杂志

OBJECTIVE: To improve superparamagnetic iron oxide nanoparticles (SPIO-NP) stability, biocompatibility and tumor-targeting and evaluate their tumor targeting in vitro. METHODS: The folic acid-carboxymethylchitosan-superparamagnetic iron oxide nanoparticles (FA-OCMCS-SPIO-NPs) were synthesized by "three-steps": at first, superparamagnetic oxide iron nanoparticles were synthesized by coprecipitation, then, O-carboxymethyl chitosan and folic acid were successfully immobilized on the surface of SPIO-NPs in turn. The fourier transform infrared spectroscopy, X-Ray diffraction were used to confirm their synthesis, meanwhile, transmission electron microscope (TEM), dynamic light scattering (DLS), Zeta-potential measurement and vibrating sample magnetometry (VSM) were applied to characterize their physicochemical properies. Ferrozine assay and Prussian blue staining were used to evaluate their tumor targeting in vitro. RESULTS: X-Ray diffraction showed the crystalline powder of FA-CMCS-SPIO-NPs agree with the standard Fe3O4, Fourier transform infrared results showed O-carboxymethylchitosan and folic acid were covalently modified on the surface of SPIO-NPs successfully, TEM showed all synthesized SPIO-NPs were almost spherical or ellipsoidal. Their sizes were less then 20 nm, dynamic light scattering (DLS), Zeta-potential results demonstrate the intensity particle size distributions of FA-OCMCS-SPIO-NPs were (41.4±0.132)nm, Zeta potential were (-21.36±15)mV. The surface modification may lead to decrese of magnetisms Ferrozine assay and Prussian blue staining results showed FA-OCMCS-SPIO-NPs had good tumor targeting and the tumor targeting had good relations with the amount of FR on surface of tumor cells. CONCLUSION: FA-OCMCS-SPIO-NPs with strong superparamagnetic property, excellent stability, and good folate receptor targeting is successfully synthesized, which demonstrated the potential for tumor MRI diagnose and therapy.

Carboxymethylchitosan, alginate and tulle gauze wound dressings: a comparative study in the treatment of partial-thickness wounds.

Background: Carboxymethylchitosan is a chitosan-derivative obtained from the carboxymethylation of chitin with chloroacetic acid in alkaline solution. It has shown its potential in animal model studies as an accelerator of wound healing. Materials and methods: Prospective, comparative clinical trials of traditional tulle gauze, alginate membrane, and carboxymethylchitosan sponge were carried out in the treatment of partial- thickness skin graft donor sites. Between June 2005 and March 2006, 70 donor sites from 44 patients were randomly treated by these three different wound dressing materials. Each wound was treated until it was completely healed, and a visual analogue scale was used for the pain evaluation. Results: The results showed that the donor sites dressed with carboxymethylchitosan or alginate healed more rapidly than those treated with tulle gauze. There was no significant difference in the healing rate between carboxymethylchitosan and alginate. The pain scores evaluated among these three dressing groups did not significantly differ. Conclusion: Carboxymethylchitosan is as efficacious as traditional tulle gauze or alginate membrain in the treatment of partial thickness skin graft donor sites.

Effect of carboxymethyl-chitosan on proliferation and collagen synthesis in keloid fibroblasts in vitro / 中华医学美学美容杂志

Objective To investigate the effects of carboxymethyl-chitosan (CM-CH) on keloid fibroblasts (KFB) proliferation and collagen synthesis. Methods Keloid fibroblasts were isolated from fresh keloid tissue and cultured. The effect of CM-CH on proliferation was examined by MTT assay. The synthesis of collagen was evaluated by hydroxy proline (HP) colorimetric analysis. Results The fibroblasts were treated with CM-CH at concentration of 10 ?g/ml, 50 ?g/ml, and 100 ?g/ml 48h and 72h after treatment, and all of the three concentrations showed inhibitory effects significantly (P0.05) at 200 ?g/ml concentration after 24h, 48h, and 72h. CM-CH at concentration of 10 ?g/ml, 50 ?g/ml, and 100 ?g/ml after treatment for 48h on KFB could markedly decrease the synthesis of collagen (P

Effect of carboxymethylchitosan on autocrine growth factor and morphology of fibroblasts cultured in vitro / 第二军医大学学报

Objective:To investigate the effect of carboxymethylchitosan on autocrine growth factor and morphology of fibroblasts cultured in vitro,so as to discuss the possible mechanism by which carboxymethylchitosan alleviates overhealing and prevents adhesion in wound healing.Methods: Fibroblasts were cultured in vitro.Fibroblasts of passage 4-6 were treated with different concentrations of carboxymethylchitosan(0.01,0.1,1.0 and 10 mg/ml) for 4 days or with 0.1 mg/ml carboxymethylchitosan for 1,2,3, 4,5,and 6 days.The levels of autocrine transforming growth factor-?_(1 )(TGF-?_(1)) and epidermal growth factor(EGF) of fibroblasts were determined by ELISA and radioimmunoassay.The fibroblastic morphology was detected by transmission electron microscopy(TEM) and microscope after fibroblasts were treated with different strategies.Results: Carboxymethylchitosan(≥0.1 mg/ml)inhibited autocrine TGF-?_(1) of fibroblast in a time-and concentration dependent manner(P0.05).Carboxymethylchitosan ((≥0.1 mg/ml))also inhibited the proliferation of fibroblasts and caused their ultrastructural changes.Conclusion: Carboxymethylchitosan (≥0.1 mg/ml)can inhibit fibroblasts proliferation and reduce tissue adhesion, possibly through altering fibroblast ultrastructure and selectively inhibiting secretion of TGF-?_(1).

Preliminary study on the biological characters of Ornidazole Slow-Release Membrane / 中国海洋药物

Objective To evaluate the biocompatibility and antibacterial activities of the Ornidazole Slow-Release Membrane.Methods 1.The lower lips of 12 rats were sewed into 12 pockets and the pockets were immited with extracting solution of the ornidazole membrane, formaldehyde and normal saline respectively once per day.The specimens were examined histologically 7 days later.2.The dorsal muscles of 16 rats were implanted with the membranes or silk threads,and examined histologically 1 week and 2,4,6 weeks later respectively.3. The antibacterial activity against Streptococcus mutans and Fusobacterium nucleatum was observed on solid culture medium in vitro.Results The animal experiments showed the membranes were not irritative to the oral mucosa.It was found that the tissue reaction of the membranes was similar to that of the silk threads after implanted into dorsal muscles and the membranes had been degraded in the second week.And the membranes had effective antibacterial action against Streptococcus mutans and Fusobacterium nucleatum.Conclusion The Ornidazole Slow-Release Membrane possesses favorable biocompatibility and antibacterial activities.

Synthesis of lactosaminated carboxymethylchitosan and its action of plasmid DNA delivery / 中国海洋药物

Objective To study the synthesis of lactosaminated carboxymethylchitosan (Lac-CMCS) and its action of delivering plasmid DNA into cells. Methods The lactosaminated carboxymethylchitosan was synthesized by reductive amination and was conjugated with plasmid contained antisense x gene. This complex was delivered into cells and these cells were cultured in 37℃,5%CO_(2). Testing the inhibition on HBV by determining HBsAg and HBeAg produced by HepG2.2.15 cells with ELISA technique. Results The molar ratio between lactose and CMCS was 15∶1 in this covalence conjugate. The best mass ratio of DNA to Lac-CMCS was 1∶10 in DNA/Lac-CMCS which was able to deliver gene into cells, and the ma-ximal inhibition rate was 83.6%. Conclusion In vitro, the lactosaminated carboxymethylchitosan can effectively deliver DNA into cells.