Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginat...Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate （A- SA）. Carboxymethyl chitosan was modified with ethylenediamine （ED） in the presence of water-soluble N-（3-Dimethylaminopropyl）-N＇-ethylcarbodiimide hydrochloride （EDC） to introduce additional amino groups to get amino-carboxymethyl chitosan （A-CS）. Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff＇s base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff＇s base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.展开更多
SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction tem...SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction temperature,reaction time and the amount of catalyst used on the yield were investigated by using orthogonal designation method.The order of the effect of the above factors is:base>the amoun t of catalyst>reaction temperature>the molar ratio of base and and iodobenzene>react ion time>the molar ratio of butyl acrylate and iodobenzene.Under the optimal reaction conditions:2 mmol iodobenzene,1.5∶1 molar ratio of butyl acrylate and iodobenzene,1.8∶1 molar ratio of（n-Bu）3N and iodobenzene,0.07g catalyst,4mLODMF,140℃for 4 hours,99.9%yield of buty l cinnamate can be achieved,and the catalyst could be reused for 12 times without the loss of activity.It can also catalyze the coupling reaction of the other substrates in high yields.展开更多
基金Acknowledgements The authors sincerely appreciate the supports of the National Major Research Program of China （2016YFC1100202）, the National Natural Science Foundation of China （Grant No. 31470941）, the Yantai Double Hundred Talent Plan, and the ＂111 Project＂ Biomedical Textile Materials Science and Technology, China （Grant No. B07024）.
文摘Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate （A- SA）. Carboxymethyl chitosan was modified with ethylenediamine （ED） in the presence of water-soluble N-（3-Dimethylaminopropyl）-N＇-ethylcarbodiimide hydrochloride （EDC） to introduce additional amino groups to get amino-carboxymethyl chitosan （A-CS）. Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff＇s base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff＇s base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.
文摘SiO2 supported chitosan Schiff-base Palladiam catalyst was prepared and used in the Heck reaction.Effects of the molar ratio of butyl acrylate and iodobenzene,base,the molar ratio of base and ioidobenzene,reaction temperature,reaction time and the amount of catalyst used on the yield were investigated by using orthogonal designation method.The order of the effect of the above factors is:base>the amoun t of catalyst>reaction temperature>the molar ratio of base and and iodobenzene>react ion time>the molar ratio of butyl acrylate and iodobenzene.Under the optimal reaction conditions:2 mmol iodobenzene,1.5∶1 molar ratio of butyl acrylate and iodobenzene,1.8∶1 molar ratio of（n-Bu）3N and iodobenzene,0.07g catalyst,4mLODMF,140℃for 4 hours,99.9%yield of buty l cinnamate can be achieved,and the catalyst could be reused for 12 times without the loss of activity.It can also catalyze the coupling reaction of the other substrates in high yields.
