Biomedical magnesium is an ideal material for hard tissue repair and replacement.However,its rapid degradation and infection after implantation significantly hindersclinical applications.To overcome these two critical...Biomedical magnesium is an ideal material for hard tissue repair and replacement.However,its rapid degradation and infection after implantation significantly hindersclinical applications.To overcome these two critical drawbacks,we describe an integrated strategybased on the changes in pH and Mg^(2+)triggered by magnesiumdegradation.This system can simultaneously offer anticorrosion and antibacterial activity.First,nanoengineered peptide-grafted hyperbranched polymers(NPGHPs)with excellent antibacterial activity were introduced to sodium alginate(SA)to construct a sensitive NPGHPs/SA hydrogel.The swelling degree,responsiveness,and antibacterial activity were then investigated,indicating that the system can perform dual stimulation of pH and Mg^(2+)with controllable antimicrobial properties.Furthermore,an intelligent platform was constructed by coating hydrogels on magnesium with polydopamine as the transition layer.The alkaline environment generated by the corrosion of magnesium reduces the swelling degree of the coatingso that the liquid is unfavorable for contacting the substrate,thus exhibiting superior corrosion resistance.Antibacterial testing shows that the material can effectively fight against bacteria,while hemolytic and cytotoxicity testing suggest that it is highly biocompatible.Thus,this work realizes the smart integration of anticorrosion and antibacterial properties of biomedical magnesium,thereby providing broader prospects for the use of magnesium.展开更多
In this work, the biodegradable and histocompatibility properties of pure Mg and ZK60 alloy wereinvestigated as new temporary implants for urinary applications. The corrosion mechanism in artificialurine was proposed ...In this work, the biodegradable and histocompatibility properties of pure Mg and ZK60 alloy wereinvestigated as new temporary implants for urinary applications. The corrosion mechanism in artificialurine was proposed using electrochemical impedance spectroscopy and potentiodynamic polarizationtests. The corrosion potential of pure magnesium and ZK60 alloy were -1820 and -1561 mV, respectively,and the corrosion current densities were 59.66 ± 6.41 and 41.94 ± 0.53 μA cm^-2, respectively. Thein vitro degradation rates for pure Mg and ZK60 alloy in artificial urine were 0.382 and 1.023 mm/y,respectively, determined from immersion tests. The ZK60 alloy degraded faster than the pure Mg in bothartificial urine and in rat bladders (the implants of both samples are ø 3 mm × 5 mm). Histocompatibilityevaluations showed good histocompatibility for the pure Mg and ZK60 alloy during the 3 weeks postimplantationin rat bladders, and no harm was observed in the bladder, liver and kidney tissues. Theresults provide key information on the degradation properties and corrosion mechanism of pure Mg andZK60 alloy in the urinary system.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(no.51671179,51971014)the Excellent teacher ability improvement project(E1E40308).
文摘Biomedical magnesium is an ideal material for hard tissue repair and replacement.However,its rapid degradation and infection after implantation significantly hindersclinical applications.To overcome these two critical drawbacks,we describe an integrated strategybased on the changes in pH and Mg^(2+)triggered by magnesiumdegradation.This system can simultaneously offer anticorrosion and antibacterial activity.First,nanoengineered peptide-grafted hyperbranched polymers(NPGHPs)with excellent antibacterial activity were introduced to sodium alginate(SA)to construct a sensitive NPGHPs/SA hydrogel.The swelling degree,responsiveness,and antibacterial activity were then investigated,indicating that the system can perform dual stimulation of pH and Mg^(2+)with controllable antimicrobial properties.Furthermore,an intelligent platform was constructed by coating hydrogels on magnesium with polydopamine as the transition layer.The alkaline environment generated by the corrosion of magnesium reduces the swelling degree of the coatingso that the liquid is unfavorable for contacting the substrate,thus exhibiting superior corrosion resistance.Antibacterial testing shows that the material can effectively fight against bacteria,while hemolytic and cytotoxicity testing suggest that it is highly biocompatible.Thus,this work realizes the smart integration of anticorrosion and antibacterial properties of biomedical magnesium,thereby providing broader prospects for the use of magnesium.
基金This work is supported by the National Natural Science Foundation of China(NSFC,No.51431002&No.51601222)China Postdoctoral Science Foundation funded project(2016M591040)the Air Force General Hospital Grant(kz2015054).
文摘In this work, the biodegradable and histocompatibility properties of pure Mg and ZK60 alloy wereinvestigated as new temporary implants for urinary applications. The corrosion mechanism in artificialurine was proposed using electrochemical impedance spectroscopy and potentiodynamic polarizationtests. The corrosion potential of pure magnesium and ZK60 alloy were -1820 and -1561 mV, respectively,and the corrosion current densities were 59.66 ± 6.41 and 41.94 ± 0.53 μA cm^-2, respectively. Thein vitro degradation rates for pure Mg and ZK60 alloy in artificial urine were 0.382 and 1.023 mm/y,respectively, determined from immersion tests. The ZK60 alloy degraded faster than the pure Mg in bothartificial urine and in rat bladders (the implants of both samples are ø 3 mm × 5 mm). Histocompatibilityevaluations showed good histocompatibility for the pure Mg and ZK60 alloy during the 3 weeks postimplantationin rat bladders, and no harm was observed in the bladder, liver and kidney tissues. Theresults provide key information on the degradation properties and corrosion mechanism of pure Mg andZK60 alloy in the urinary system.
