简介:Anewconceptfordevelopmentofmetallicbiomaterialsisproposedinthisarticle,i.e.,acertainbio-functioncanberealizedforametalimplantthroughcontinuousreleaseofadesignedbio-functionalmetalelementfromsurfaceofthemetalimplantinthebodyenvironment.ThiscreativeideahasbeenverifiedtobepossiblebyseveraldifferentinvitroandinvivoexperimentalevidencesontheCu-bearingstainlesssteelsandmagnesiumbasedmetals.ItwasindicatedthatatraceamountofCureleasefromtheCu-bearingsteelscouldhaveobviousbio-functionsofreductionofthein-stentrestenosis(ISR),anti-bacterialinfection,inhibitingtheinflammatorycellsandevenpromotingtheearlyosteogenesis.Furthermore,thedegradationofmagnesiumbasedmetalsinbonescouldpromotethenewboneformation,enhancethebonemineraldensityfortheosteoporosismodeledanimal,andevenhavestronganti-bacterialabilityandstrongcytotoxicitytobonetumorcellsduetotheenhancementofpH.Specialbio-functionwithsatisfiedload-bearingcapacityformetallicbiomaterialswillbringhigherapplicationvaluesfortheimplantmadeofthisnovelmaterial.Thisisanattractivedirectionforresearchanddevelopmentwithmanychallenges,butthefinalsuccesswillbemuchbeneficialtothemajorityofpatients.
简介:通过自由基共聚的方法制备了聚偏氟乙烯-g-聚(N-异丙基丙烯酰胺)(PVDF—g-PNIPAAm)共聚物,进而采用浸没沉淀相转化法制备了PVDF—g—PNIPAAm共聚膜。采用超声时域反射法研究了不同凝固浴温度下PVDF—g-PNIPAAm的成膜动力学。结合PVDF—g—PNIPAAm的成膜动力学,研究了凝固浴温度对膜结构与性能的影响。结果表明,在不同凝固浴温度下,PVDF—g—PNIPAAm的成膜过程均由液液分相来控制,凝固浴温度为30℃时成膜时间最长,40℃时成膜时间最短;不同凝固浴温度下制备的PVDF—g—PNIPAAm共聚膜保持了PVDF的结晶特性,随着凝固浴温度的升高,结晶度降低。同PVDF—g—PNIPAAm共聚物相比,PNIPAAm在PVDF—g—PNIPAAm膜表面的含量更高,其中,30℃时所成膜表面的PNIPAAm含量最高。不同凝固浴温度下所成的膜均呈指状孔结构,其中,30℃下所成的膜指状孔最大,孔隙率最高。25℃下制备的PVDF—g—PNIPAAm膜具有明显的温度响应性能,其水通量在30℃附近有显著增加。
简介:类金刚石(DLC)膜是一种含有大量sp^3键的亚稳态非晶碳薄膜。类金刚石膜在化学、电学、热学、光学、生物相容性等方面具有良好性能,是微电子机械、医学、航空、汽车、光学等领域的理想材料,因而引起了人们极大兴趣,具有广阔的应用前景。简单介绍了DLC膜的结构、沉积法及在各个领域的应用与存在的问题。