Oxymatrine （OM）/N-succinyl-chitosan （Suc-Chi, with a degree of substitution being 0. 32） was synthesized via the ring-opening reaction of succinic anhydride with chitosan in dimethyl sulfoxide. OM-loaded Suc-Chi n...Oxymatrine （OM）/N-succinyl-chitosan （Suc-Chi, with a degree of substitution being 0. 32） was synthesized via the ring-opening reaction of succinic anhydride with chitosan in dimethyl sulfoxide. OM-loaded Suc-Chi nanoparticles were prepared by an ionotropic gelation process and OM was quantified via the HPLC method： The influences of the initial OM concentration on the nanoparticle characteristics and OM release behavior were evaluated. The nanoparticles were found to have a mean diameter within a range of 267-392 nm, a positive surface charge, and a zeta potential in the range of 19-27 inV. The formulation with an initial OM concentration of 100μg/mL provided the highest loaded capacity（0. 77% ） and the highest extent of the released OM （68% at 24 h）, suggesting the possibility to achieve a therapeutic dose. According to the data obtained, this Suc-Chi-based nanotechnology will open up new and interesting prospects for the development of new anticancer drugs.展开更多
Superabsorbent hydrogels were prepared successfully from N-succinyl chitosan grafted poly（acrylic acid-co-acrylamide）. The potassium persulfate（KPS）, N, N＇-methylenebisacrylamide（MBA） were used as the initiator...Superabsorbent hydrogels were prepared successfully from N-succinyl chitosan grafted poly（acrylic acid-co-acrylamide）. The potassium persulfate（KPS）, N, N＇-methylenebisacrylamide（MBA） were used as the initiator and crosslinker, respectively. Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy（SEM） were used to confirm the porous network structure of superabsorbent hydrogel. The effects of reaction parameters on the swelling behaviors of the superabsorbent hydrogels were investigated. The results indicated that water absorbency increased first, and then decreased gradually with the increase in the contents of monomer（AA＋AM）, KPS, MBA or acrylamide. The product had excellent water absorbency of 1375 g/g in distilled water and 83 g/g in 0.9wt% NaCl solution. Simultaneously, the superabsorbent hydrogels were p H sensitive. The antibacterial activities of the hydrogels against Escherichia coli（E. coli） were improved effectively because of polyamidoamine（PAMAM） dendrimer absorbed in the hydrogels.展开更多
To enhance the liquor absorptivity of chitosan fibers （CS-Fs）, N-succinyl surface-modified chitosan fibers （NSCS-Fs） were developed and evaluated for wound healing, The NSCS-Fs exhibited cracks on the surface and ...To enhance the liquor absorptivity of chitosan fibers （CS-Fs）, N-succinyl surface-modified chitosan fibers （NSCS-Fs） were developed and evaluated for wound healing, The NSCS-Fs exhibited cracks on the surface and high liquor absorbing capacity with absorbing-dissolvable equilibrium state in phosphate buffer solution （PBS）. The bacteriostasis ratios of NSCS-Fs against E. coli, S. aureus and C. albicans were higher than 80%. No cytotoxicity has been found for mouse embryo fibroblasts （MEFs） treated with NSCS-Fs leach liquor, Acute oral toxicity and skin irritation experiment were taken to evaluate the safety of NSCS-Fs in vitro. Muscle implant study showed that NSCS-Fs were biodegradable and non-toxic in vivo. These results suggested that the surface modified NSCS-Fs had favorable biological properties and improved liquor absorptivity, indicating that they could be used as promising dressing materials for wound care.展开更多
Chitosan is a natural polymer that can be modified into chemically different types.In order to imply biomedical applications,the chitosan dissolved in aqueous medium.Therefore,in the present study,functionally substit...Chitosan is a natural polymer that can be modified into chemically different types.In order to imply biomedical applications,the chitosan dissolved in aqueous medium.Therefore,in the present study,functionally substituted chemical groups such as O-carboxymethyl chitosan(CMC),N-succinyl chitosan(NSC),quaternary ammonium chitosan(QAC)and tripoly phosphate chitosan(TPC)were synthesized.The peptide derived from Clarias batrachus was used as a drug that is successfully entrapped with NSC nanoparticles and were characterized by FTIR,AFM,SEM,Zeta sizer,fluorescent imaging and SDS-PAGE.In addition,antimicrobial activity was examined.The results of NSC obtained particle size(~64 nm)with highest solubility and 80%of antimicrobial activity against multidrug resistant pathogen Klebsiella pneumonia.Finally,the release profile indicates that the NSC nanoparticles deliver the peptide with 75%sustainable release and good availability up to 96 h.The current research was the first to report the characterization of peptide with NSC nanoparticles by SDS-PAGE,in which the antimicrobial activity was enhanced up to 80%,the particle sizes were obtained~64 nm from SEM and AFM,and NSC-peptide exhibited 75%of sustainable release and good availability up to 96 h.展开更多
Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succini...Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succinic anhydride. The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy(IR), by which —COCH_ 2CH_ 2COOH was proved to be introduced to the —NH_ 2 of the low molecular weight chitosan. The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated. The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution. When the degree of substitution is greater than 38%, the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.展开更多
文摘Oxymatrine （OM）/N-succinyl-chitosan （Suc-Chi, with a degree of substitution being 0. 32） was synthesized via the ring-opening reaction of succinic anhydride with chitosan in dimethyl sulfoxide. OM-loaded Suc-Chi nanoparticles were prepared by an ionotropic gelation process and OM was quantified via the HPLC method： The influences of the initial OM concentration on the nanoparticle characteristics and OM release behavior were evaluated. The nanoparticles were found to have a mean diameter within a range of 267-392 nm, a positive surface charge, and a zeta potential in the range of 19-27 inV. The formulation with an initial OM concentration of 100μg/mL provided the highest loaded capacity（0. 77% ） and the highest extent of the released OM （68% at 24 h）, suggesting the possibility to achieve a therapeutic dose. According to the data obtained, this Suc-Chi-based nanotechnology will open up new and interesting prospects for the development of new anticancer drugs.
基金Funded by the National Natural Science Foundation of China(Nos.51303145,51273156,and 51373130)
文摘Superabsorbent hydrogels were prepared successfully from N-succinyl chitosan grafted poly（acrylic acid-co-acrylamide）. The potassium persulfate（KPS）, N, N＇-methylenebisacrylamide（MBA） were used as the initiator and crosslinker, respectively. Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy（SEM） were used to confirm the porous network structure of superabsorbent hydrogel. The effects of reaction parameters on the swelling behaviors of the superabsorbent hydrogels were investigated. The results indicated that water absorbency increased first, and then decreased gradually with the increase in the contents of monomer（AA＋AM）, KPS, MBA or acrylamide. The product had excellent water absorbency of 1375 g/g in distilled water and 83 g/g in 0.9wt% NaCl solution. Simultaneously, the superabsorbent hydrogels were p H sensitive. The antibacterial activities of the hydrogels against Escherichia coli（E. coli） were improved effectively because of polyamidoamine（PAMAM） dendrimer absorbed in the hydrogels.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 81271727 and 31300786）, the International Science Technology Cooperation Program of China （Grant No. 2012DFB50140）, Ph.D. Programs Foundation of Ministry of Education of China （Grant No. 20120132110012）, the National Science Foundation for Post-doctor （Grant No. 2013 M541961 ）, and Applied Basic Research Plan of Qingdao （Grant No. 14-2-4-98-jch）.
文摘To enhance the liquor absorptivity of chitosan fibers （CS-Fs）, N-succinyl surface-modified chitosan fibers （NSCS-Fs） were developed and evaluated for wound healing, The NSCS-Fs exhibited cracks on the surface and high liquor absorbing capacity with absorbing-dissolvable equilibrium state in phosphate buffer solution （PBS）. The bacteriostasis ratios of NSCS-Fs against E. coli, S. aureus and C. albicans were higher than 80%. No cytotoxicity has been found for mouse embryo fibroblasts （MEFs） treated with NSCS-Fs leach liquor, Acute oral toxicity and skin irritation experiment were taken to evaluate the safety of NSCS-Fs in vitro. Muscle implant study showed that NSCS-Fs were biodegradable and non-toxic in vivo. These results suggested that the surface modified NSCS-Fs had favorable biological properties and improved liquor absorptivity, indicating that they could be used as promising dressing materials for wound care.
文摘Chitosan is a natural polymer that can be modified into chemically different types.In order to imply biomedical applications,the chitosan dissolved in aqueous medium.Therefore,in the present study,functionally substituted chemical groups such as O-carboxymethyl chitosan(CMC),N-succinyl chitosan(NSC),quaternary ammonium chitosan(QAC)and tripoly phosphate chitosan(TPC)were synthesized.The peptide derived from Clarias batrachus was used as a drug that is successfully entrapped with NSC nanoparticles and were characterized by FTIR,AFM,SEM,Zeta sizer,fluorescent imaging and SDS-PAGE.In addition,antimicrobial activity was examined.The results of NSC obtained particle size(~64 nm)with highest solubility and 80%of antimicrobial activity against multidrug resistant pathogen Klebsiella pneumonia.Finally,the release profile indicates that the NSC nanoparticles deliver the peptide with 75%sustainable release and good availability up to 96 h.The current research was the first to report the characterization of peptide with NSC nanoparticles by SDS-PAGE,in which the antimicrobial activity was enhanced up to 80%,the particle sizes were obtained~64 nm from SEM and AFM,and NSC-peptide exhibited 75%of sustainable release and good availability up to 96 h.
文摘Low molecular weight N-succinyl-chitosans with different degrees of substitution were synthesized by controlling reaction temperature, reaction time, and the molar ratio of the low molecular weight chitosan to succinic anhydride. The structure of the low molecular weight N-succinyl-chitosan was characterized by infrared spectroscopy(IR), by which —COCH_ 2CH_ 2COOH was proved to be introduced to the —NH_ 2 of the low molecular weight chitosan. The moisture adsorption and moisture retention capacities of the low molecular weight chitosan derivatives with different degrees of substitution were investigated. The results indicate that the moisture adsorption and moisture retention capacities of the low molecular weight N-succinyl-chitosan increase with the increase of the degree of substitution. When the degree of substitution is greater than 38%, the derivatives have better moisture adsorption and moisture retention capacities than hyaluronic acid.
