Complexation and interaction between silver and amino group were applied to induce an efficient immobilization of papain on silica spheres.Tbe silver nanoparticles were deposited on the silica spheres before p apainwa...Complexation and interaction between silver and amino group were applied to induce an efficient immobilization of papain on silica spheres.Tbe silver nanoparticles were deposited on the silica spheres before p apainwas coupled to the silica spheres. The silica spheres with silver nanoparticles were characterized by high resolution transmission electron microscopy （HR-TEM）, Fournier transform infrared spectroscopy （FT-IR）, and UV-Vis scanning spectrometer. FT-IR spectrum was also used to characterize the immobilized and free papain. Effect of some factors on the activities of the immobilized papain was investigated. It was observed that the coupled yield and relative activity of the papain on Ag/SiO2 were 1.17 and 1.86 times of those on the bare SiO2, respectively. At an optimum concentration of silver, theobserved activity of the immobilized papain was 2.1 timesof that on the bare.silica.In addition, the maximum specific activity of papain immobilized on Ag/SiO2 was 819.9 U·mg·^-1, which is slightly lower than that of the free papain, 906.2 U·mg^-1 . Stability of the immobilized papain was also examined. The resuits indicate that the silver nanoparticles successfully induce a fine immobilization of papain.展开更多
Aseptic loosening of implant is one of the main causes of Ti-based implant failure.In our previous work,a novel stable collagen/hyaluronic acid(Col/HA)multilayer modified titanium coatings(TCs)was developed by layer-b...Aseptic loosening of implant is one of the main causes of Ti-based implant failure.In our previous work,a novel stable collagen/hyaluronic acid(Col/HA)multilayer modified titanium coatings(TCs)was developed by layer-by-layer(LBL)covalent immobilization technique,which showed enhanced biological properties compared with TCs that were physically absorbed with Col/HA multilayer in vitro.In this study,a rabbit model with femur condyle defect was employed to compare the osteointegration performance of them.Results indicated that Col/HA multilayer with favourable stability could better facilitate osteogenesis around implants and bone-implant contact.The Col/HA multilayer covalentimmobilized TC may reduce aseptic loosening of implant.展开更多
Amino-modified silica hydrogel(N-MSHG)was prepared by a simple sol-gel processing via the cocondensation of commercial silica sol with 3-aminopropyltrieoxysilane.Penicillin G acylase(PGA),a model enzyme,was covalently...Amino-modified silica hydrogel(N-MSHG)was prepared by a simple sol-gel processing via the cocondensation of commercial silica sol with 3-aminopropyltrieoxysilane.Penicillin G acylase(PGA),a model enzyme,was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin.The samples were characterized by Nitrogen sorption analysis,FT-IR and thermal gravimetric analysis(TGA).The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17 nm.The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency.The yield of the synthesis of amoxicillin in aqueous media was 38%for 2.5 h.This sol-gel preparation is simple and shows prominent potential value in industrial processing.展开更多
基金Supported by the National High Technology Research and Development Program of China （2006AA02Z211）, the National Natural Science Foundation of China （20376034）, the Natural Science Foundation of Jiangsu Province （BK2006181）, and the Foundation of Jiangsu Province for College Postgraduate Students in Innovation Engineering （2007）.
文摘Complexation and interaction between silver and amino group were applied to induce an efficient immobilization of papain on silica spheres.Tbe silver nanoparticles were deposited on the silica spheres before p apainwas coupled to the silica spheres. The silica spheres with silver nanoparticles were characterized by high resolution transmission electron microscopy （HR-TEM）, Fournier transform infrared spectroscopy （FT-IR）, and UV-Vis scanning spectrometer. FT-IR spectrum was also used to characterize the immobilized and free papain. Effect of some factors on the activities of the immobilized papain was investigated. It was observed that the coupled yield and relative activity of the papain on Ag/SiO2 were 1.17 and 1.86 times of those on the bare SiO2, respectively. At an optimum concentration of silver, theobserved activity of the immobilized papain was 2.1 timesof that on the bare.silica.In addition, the maximum specific activity of papain immobilized on Ag/SiO2 was 819.9 U·mg·^-1, which is slightly lower than that of the free papain, 906.2 U·mg^-1 . Stability of the immobilized papain was also examined. The resuits indicate that the silver nanoparticles successfully induce a fine immobilization of papain.
基金This work is supported by the National Natural Science Foundation of China(Grant No.81501856).
文摘Aseptic loosening of implant is one of the main causes of Ti-based implant failure.In our previous work,a novel stable collagen/hyaluronic acid(Col/HA)multilayer modified titanium coatings(TCs)was developed by layer-by-layer(LBL)covalent immobilization technique,which showed enhanced biological properties compared with TCs that were physically absorbed with Col/HA multilayer in vitro.In this study,a rabbit model with femur condyle defect was employed to compare the osteointegration performance of them.Results indicated that Col/HA multilayer with favourable stability could better facilitate osteogenesis around implants and bone-implant contact.The Col/HA multilayer covalentimmobilized TC may reduce aseptic loosening of implant.
文摘Amino-modified silica hydrogel(N-MSHG)was prepared by a simple sol-gel processing via the cocondensation of commercial silica sol with 3-aminopropyltrieoxysilane.Penicillin G acylase(PGA),a model enzyme,was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin.The samples were characterized by Nitrogen sorption analysis,FT-IR and thermal gravimetric analysis(TGA).The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17 nm.The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency.The yield of the synthesis of amoxicillin in aqueous media was 38%for 2.5 h.This sol-gel preparation is simple and shows prominent potential value in industrial processing.
