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Enzyme-mediated fabrication of an oxidized chitosan hydrogel as a tissue sealant
Phuong, Nguyen Thi,Anh Ho, Viet,Hai Nguyen, Dai,Khoa, Nguyen Cuu,Quyen, Tran Ngoc,Lee, Yunki,Park, Ki Dong Technomic Pub. Co 2015 Journal of bioactive and compatible polymers Vol.30 No.4
<P>Oxidized polysaccharide-based hydrogels have recently attracted much attention for tissue regeneration because of their biocompatibility and tissue-adhesive property. In this study, we introduce a new type of chitosan-based hydrogel as a tissue sealant, which was prepared by enzymatic mediation from periodate-oxidized chitosan–polyethylene glycol–tyramine. The oxidized chitosan backbone was expected to enhance the interconnection between the hydrogel layer and collagen in the tissues via the Schiff-base reaction. Proton nuclear magnetic resonance spectra indicated that tyramine-functionalized polyethylene glycol-nitrophenyl carbonate ester was conjugated to the oxidized chitosan. The degree of oxidation of the chitosan backbone was around 14% of the glucosamine units by proton nuclear magnetic resonance. The hydrogel was rapidly formed in situ (within a few seconds) in the presence of horseradish peroxidase and hydrogen peroxide. In vitro experiments with live/dead cell assays showed that the oxidized chitosan-based hydrogel was cytobiocompatible. The hydrogel exhibited high tissue adhesion strength on porcine skin models as well as good tissue-adhesive ability and wound healing properties on rabbit skin. These positive results could be promising for the application of oxidized chitosan-based hydrogels as a wound sealant.</P>
Cao, Van Du,Nguyen, Phuong Phong,Khuong, Vo Quoc,Nguyen, Cuu Khoa,Nguyen, Xuan Chuong,Dang, Cap Ha,Tran, Ngoc Quyen Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.9
In this paper ultrafine copper nanoparticles (CuNPs) were prepared from copper salt via chemical reduction method with sodium citrate dispersant and polyvinylalcol (PVA) capping polymer. The colloidal CuNPs were characterized by using UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD) techniques. Our obtained results indicated that the CuNPs were produced ranging from 2 to 4 nm in diameter. The colloidal solution at 7 ppm of CuNPs exhibited a powerful antifungal activity against Corticium salmonicolor (C. Salmonicolor). Fungal killing assays showed colloid solutions containing 10 ppm of CuNPs killed entirely the cultured fungus. A highly killing activity against the fungus was also performed when the CuNPs were sprayed on pink disease-infected rubber trees. These positive results may offer a great potential to produce CuNPs-based eco-fungicide for pink disease.
Van Du Cao,Phuong phong Nguyen,Vo Quoc Khuong,Cuu Khoa Nguyen,Xuan Chuong Nguyen,Cap Ha Dang,Ngoc Quyen Tran 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.9
In this paper ultrafine copper nanoparticles (CuNPs) were prepared from copper salt via chemical reduction method with sodium citrate dispersant and polyvinylalcol (PVA) capping polymer. The colloidal CuNPs were characterized by using UV–Visible spectroscopy, Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD) techniques. Our obtained results indicated that the CuNPs were produced ranging from 2 to 4 nm in diameter. The colloidal solution at 7 ppm of CuNPs exhibited a powerful antifungal activity against Corticium salmonicolor (C. Salmonicolor). Fungal killing assays showed colloid solutions containing 10 ppm of CuNPs killed entirely the cultured fungus. A highly killing activity against the fungus was also performed when the CuNPs were sprayed on pink disease-infected rubber trees. These positive results may offer a great potential to produce CuNPs-based eco-fungicide for pink disease.
Thanh Son Cu,Ngoc Quyen Tran,Van Du Cao,Cuu Khoa Nguyen 한국고분자학회 2014 Macromolecular Research Vol.22 No.4
In this paper, we report the preparation and stabilization of colloidal silver nanoparticle solution, with theassistance of chitosan dihydroxyphenyl acetamide (CDHPA), or oligochitosan dihydroxyphenyl acetamide (OCDHPA). The structure of the chitosan derivatives were characterized by nuclear magnetic resonance (1H NMR) spectroscopy. The morphology of the synthesized silver core-chitosan shell nanoparticles were observed by transmission electronmicroscopy (TEM) and X-ray diffraction (XRD) techniques, and showed a well-defined core-shell structure of polymer-coated silver nanoparticles (AgNPs). The core-shell NPs exhibited a strong antibacterial activity against E. coliand S. aureus, at a very low concentration of AgNPs (2.5 ppm). Our studies offer a new method for the preparationand protection of silver nanoparticles for antibacterial applications.