Magnesium was considered as a revolutionary biodegradable implant material for orthopedic application. Concerning the weakness of intrinsic strength and corrosion behavior, a novel strategy of Mg/metal hybrid system w...Magnesium was considered as a revolutionary biodegradable implant material for orthopedic application. Concerning the weakness of intrinsic strength and corrosion behavior, a novel strategy of Mg/metal hybrid system was proposed for extension of orthopedic application, especially at load-bearing site. In this work, an Mg and HA composite layered coating was constructed on titanium by means of chemical conversion and vapor deposition. The HA transition interlayer was introduced to enhance the bonding between Mg film and Ti substrate. Compared with the bare Mg coating, the Mg/HA coating presented good interface bonding, which avoided the occurrence of Mg film peeling off from the substrate. The Mg/HA coating showed a uniform degradation and kept integrity after immersion of 14 d. The Mg ions release by degradation played a crucial role in osteopromotion and antibacterial effect. Incubation of MC3T3-E1 osteoblasts with the Mg/HA coating showed significant promotion on osteogenic differentiation according to ALP activity and Alizarin Red staining assays. Meanwhile the degradation of Mg exhibited strong suppression of bacteria proliferation. It was believed that this novel Mg/HA composite layered coating could be potentially applied in further development of bio-functional hybrid orthopedic implants.展开更多
Mg and its alloys evince strong candidature for biodegradable bone implants,cardiovascular stents,and wound closing devices.However,their rapid degradation rate causes premature implant failure,constraining clinical a...Mg and its alloys evince strong candidature for biodegradable bone implants,cardiovascular stents,and wound closing devices.However,their rapid degradation rate causes premature implant failure,constraining clinical applications.Bio-functional surface coatings have emerged as the most competent strategy to fulfill the diverse clinical requirements,besides yielding effective corrosion resistance.This article reviews the progress of biodegradable and advanced surface coatings on Mg alloys investigated in recent years,aiming to build up a comprehensive knowledge framework of coating techniques,processing parameters,performance measures in terms of corrosion resistance,adhesion strength,and biocompatibility.Recently developed conversion and deposition type surface coatings are thoroughly discussed by reporting their essential therapeutic responses like osteogenesis,angiogenesis,cytocompatibility,hemocompatibility,anti-bacterial,and controlled drug release towards in-vitro and in-vivo study models.The challenges associated with metallic,ceramic and polymeric coatings along with merits and demerits of various coatings have been illustrated.The use of multilayered hybrid coating comprising a unique combination of organic and inorganic components has been emphasized with future perspectives to obtain diverse bio-functionalities in a facile single coating system for orthopedic implant applications.展开更多
Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its in...Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration.Herein,we modify the physical and chemical properties of a PEI-coated Mg implant.A plasma immersion ion implantation technique is combined with direct current(DC)magnetron sputtering to introduce biologically compatible tantalum(Ta)onto the surface of the PEI coating.The PEI-coating layer is not damaged during this process owing to the extremely short processing time(30 s),retaining its high corrosion protection property and adhesion stability.The Ta-implanted layer(roughly 10-nm-thick)on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere,proliferate,and differentiate.Furthermore,in a rabbit femur study,the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability.These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.展开更多
There is considerable research interest and vigorous debate about the DNA binding of polypyridyl complexes including the electron transfer involving DNA. In this review, based on the fluorescence quenching experiments...There is considerable research interest and vigorous debate about the DNA binding of polypyridyl complexes including the electron transfer involving DNA. In this review, based on the fluorescence quenching experiments, it was proposed that DNA might serve as a conductor. From the time-interval CD spectra, the different binding rates of Δ- and Λ-enantiomer to calf thymus DNA were observed. The factors influencing the DNA-binding of polypyridyl complexes, and the potential bio-functions of the complexes are also discussed.展开更多
Chicken manure(CM)is one of the most common animal wastes produced worldwide.The conventional application of CM is as a fertilizer;however,in the present study,we introduce an approach for the straightforward and affo...Chicken manure(CM)is one of the most common animal wastes produced worldwide.The conventional application of CM is as a fertilizer;however,in the present study,we introduce an approach for the straightforward and affordable use of CM for fuel cell applications.It reports the functionalization of carbon nanofibers(CNFs)using CM to confer multiple functionalities.The elements that make up the functionalized CNF are nitrogen(7.40%,atoms ratio,the same below),oxygen(6.22%),phosphorous(0.30%),and sulfur(0.02%),etc.,according to energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and Fourier transform infrared spectroscopy studies.It has been verified that following treatment with CM,the morphology of the CNFs remains the same.The CM-modified CNFs exhibit a higher electrocatalytic activity(onset potential:−0.0756 V);limiting current density:2.69 mA/cm^(20)for the oxygen reduction reaction(ORR)at the cathode of a fuel cell.The electron transfer number for this sample is 3.68,i.e.,the ORR favours a four-electron pathway like Pt/C.The direct method of functionalizing the CNF is more effective;however,treatment of CNFs with Triton X-100 prior to functionalization shields their otherwise exposed open edge sites and in turn affects their ORR activity.A large surface area(99.866 m^(20/g)),the presence of multiple functional elements(oxygen,nitrogen,phosphorous,sulfur,etc.),surface charge redistribution and induced donor–acceptor interactions at the surface of CM-modified CNFs contribute to their enhanced electrochemical activity.This preliminary study reports the suitability of a facile and economical approach for treating CM for the most advanced clean energy applications.Hopefully,this study will pave the way for cutting-edge methods for handling other biowaste materials as well.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31500777)the Research Start-up Funds of DGUT(Grant No.GC300501-082)the Characteristic Innovation Project of University in Guangdong(Grant No.2020KTSCX148)。
文摘Magnesium was considered as a revolutionary biodegradable implant material for orthopedic application. Concerning the weakness of intrinsic strength and corrosion behavior, a novel strategy of Mg/metal hybrid system was proposed for extension of orthopedic application, especially at load-bearing site. In this work, an Mg and HA composite layered coating was constructed on titanium by means of chemical conversion and vapor deposition. The HA transition interlayer was introduced to enhance the bonding between Mg film and Ti substrate. Compared with the bare Mg coating, the Mg/HA coating presented good interface bonding, which avoided the occurrence of Mg film peeling off from the substrate. The Mg/HA coating showed a uniform degradation and kept integrity after immersion of 14 d. The Mg ions release by degradation played a crucial role in osteopromotion and antibacterial effect. Incubation of MC3T3-E1 osteoblasts with the Mg/HA coating showed significant promotion on osteogenic differentiation according to ALP activity and Alizarin Red staining assays. Meanwhile the degradation of Mg exhibited strong suppression of bacteria proliferation. It was believed that this novel Mg/HA composite layered coating could be potentially applied in further development of bio-functional hybrid orthopedic implants.
文摘Mg and its alloys evince strong candidature for biodegradable bone implants,cardiovascular stents,and wound closing devices.However,their rapid degradation rate causes premature implant failure,constraining clinical applications.Bio-functional surface coatings have emerged as the most competent strategy to fulfill the diverse clinical requirements,besides yielding effective corrosion resistance.This article reviews the progress of biodegradable and advanced surface coatings on Mg alloys investigated in recent years,aiming to build up a comprehensive knowledge framework of coating techniques,processing parameters,performance measures in terms of corrosion resistance,adhesion strength,and biocompatibility.Recently developed conversion and deposition type surface coatings are thoroughly discussed by reporting their essential therapeutic responses like osteogenesis,angiogenesis,cytocompatibility,hemocompatibility,anti-bacterial,and controlled drug release towards in-vitro and in-vivo study models.The challenges associated with metallic,ceramic and polymeric coatings along with merits and demerits of various coatings have been illustrated.The use of multilayered hybrid coating comprising a unique combination of organic and inorganic components has been emphasized with future perspectives to obtain diverse bio-functionalities in a facile single coating system for orthopedic implant applications.
基金a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)the Ministry of Health&Welfare,Republic of Korea(grant number:HI18C0493).
文摘Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration.Herein,we modify the physical and chemical properties of a PEI-coated Mg implant.A plasma immersion ion implantation technique is combined with direct current(DC)magnetron sputtering to introduce biologically compatible tantalum(Ta)onto the surface of the PEI coating.The PEI-coating layer is not damaged during this process owing to the extremely short processing time(30 s),retaining its high corrosion protection property and adhesion stability.The Ta-implanted layer(roughly 10-nm-thick)on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere,proliferate,and differentiate.Furthermore,in a rabbit femur study,the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability.These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.
基金Acknowledgements We are grateful to the State Key Laboratory of Coordination Chemistry in Nanjing University, the State Key Laboratory of Bio-organic and Natural Products Chemistry in Shanghai Institute of Organic Chemistry for their financial support. T
文摘There is considerable research interest and vigorous debate about the DNA binding of polypyridyl complexes including the electron transfer involving DNA. In this review, based on the fluorescence quenching experiments, it was proposed that DNA might serve as a conductor. From the time-interval CD spectra, the different binding rates of Δ- and Λ-enantiomer to calf thymus DNA were observed. The factors influencing the DNA-binding of polypyridyl complexes, and the potential bio-functions of the complexes are also discussed.
基金Department of Science&Technology(New Delhi,India)for the award of the WOS-A project(No.DST/WOS-A/ET-33/2021)contributions of the SAP(University Grants Commission,New Delhi,India)+1 种基金PURSE(DST,New Delhi,India)TEQIP-Ⅱ/TEQIP-Ⅲ grants.
文摘Chicken manure(CM)is one of the most common animal wastes produced worldwide.The conventional application of CM is as a fertilizer;however,in the present study,we introduce an approach for the straightforward and affordable use of CM for fuel cell applications.It reports the functionalization of carbon nanofibers(CNFs)using CM to confer multiple functionalities.The elements that make up the functionalized CNF are nitrogen(7.40%,atoms ratio,the same below),oxygen(6.22%),phosphorous(0.30%),and sulfur(0.02%),etc.,according to energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and Fourier transform infrared spectroscopy studies.It has been verified that following treatment with CM,the morphology of the CNFs remains the same.The CM-modified CNFs exhibit a higher electrocatalytic activity(onset potential:−0.0756 V);limiting current density:2.69 mA/cm^(20)for the oxygen reduction reaction(ORR)at the cathode of a fuel cell.The electron transfer number for this sample is 3.68,i.e.,the ORR favours a four-electron pathway like Pt/C.The direct method of functionalizing the CNF is more effective;however,treatment of CNFs with Triton X-100 prior to functionalization shields their otherwise exposed open edge sites and in turn affects their ORR activity.A large surface area(99.866 m^(20/g)),the presence of multiple functional elements(oxygen,nitrogen,phosphorous,sulfur,etc.),surface charge redistribution and induced donor–acceptor interactions at the surface of CM-modified CNFs contribute to their enhanced electrochemical activity.This preliminary study reports the suitability of a facile and economical approach for treating CM for the most advanced clean energy applications.Hopefully,this study will pave the way for cutting-edge methods for handling other biowaste materials as well.
