PMMA人工晶状体的等离子体改性研究

【作者】 张丽华；

【导师】 陈亚芍；

【作者基本信息】 陕西师范大学 ， 物理化学， 2008， 硕士

【摘要】 聚甲基丙烯酸甲酯（PMMA）人工晶状体是临床应用最广泛的用于白内障手术时植入人体的材料,在人体水环境下,对其生物相容性要求很高,与此同时,透光率也是衡量人工晶状体的一个重要指标。但PMMA是一类极性极小的疏水性树脂,植入眼内,表面炎性细胞的黏附比亲水的水凝胶多,并且它和角膜上皮细胞的接触会导致角膜上皮细胞的永久损伤。本文报道了等离子体作用下,在PMMA人工晶状体表面化学键合不同物质,以提高其生物相容性,降低其在紫外光范围的透光率,并对其相应性质进行了表征。（1）CF₄及CF₄/O2等离子体改善PMMA性质研究进行了CF₄等离子体PMMA表面处理,讨论了等离子体辉光放电的时间、功率及压强对PMMA表面性能的影响。通过衰减全反射红外光谱（ATR-FTIR）、X射线光电子能谱（XPS）表征分析可知,通过CF₄等离子体处理,PMMA表面键合了含氟基团,并以C-F_x的形式存在:接触角测定（CA）得出材料表面的疏水性急剧增加,从而可减少各种亲水性细胞的黏附,进而防止血栓。进行了CF₄/O₂混合气体等离子体PMMA表面处理,讨论等离子体辉光放电的时间、功率及压强对PMMA表面各种性能的影响。通过ATR-FTIR、XPS表征分析可知,PMMA表面键合了含氟和含氧基团:通过CA测定得出,修饰材料表面的亲水性增加。进一步通过血小板黏附的扫描电镜观察（SEM）证明了CF₄及CF₄/O₂等离子体处理均可改善PMMA表面的生物相容性,由此得出,防止血小板在材料表面黏附主要是由于等离子体处理后PMMA表面键合了含氟基团;紫外可见近红外光谱（UV-Vis）表征分析可得出,CF₄及CF₄/O₂等离子体处理均可极大地降低PMMA材料在紫外范围内的透光率,而且CF₄/O₂修饰的紫外光隔离效率高于CF₄修饰的PMMA材料。（2）聚乙二醇（PEG）及肝素（Hp）对PMMA改性研究利用等离子体技术,在PMMA表面进一步接枝大分子物质。实验中,以PMMA为基体,将等离子体预处理后的PMMA分别放入PEG和Hp溶液中浸泡,真空干燥后分别进行Ar等离子体处理,引发物理吸附的PEG和Hp接枝于PMMA表面;进一步将接枝PEG的PMMA材料浸泡于Hp溶液中,再Ar等离子体引发Hp接枝于PEG-PMMA表面。通过ATR-FTIR、XPS表征分析可知,PEG和H_p键合在PMMA表面;CA测定可知,其表面结合的PEG和Hp增强了PMMA表面的亲水性,其亲水性强弱顺序为:PEG-PMMA>PEG-lip-PMMA>Hp-PMMA;血小板黏附的显微镜观察（OM）可知,等离子体预处理过的PMMA表面,尽管亲水性较好,但是与未处理的PMMA相比,其表面的生物相容性没有明显改善,而键合了PEG和Hp的PMMA表面的生物相容性得到了明显的改善,这可能是由于等离子体处理后的表面活性基团存在的时间较短的缘故;扫描电镜（SEM）观察可知,多步的等离子体处理方式并未对PMMA表面形貌产生影响;由UV-Vis可知,处理后的样品在可紫外范围内透光率明显降低。（3）壳聚糖（CS）及聚乙烯吡咯烷酮（PVP）对PMMA改性研究将PMMA浸泡在CS的HAc溶液中,真空干燥后Ar等离子体处理引发反应,将CS化学结合在PMMA表面;将PMMA浸泡在PVP溶液中,真空干燥后Ar等离子体处理引发反应,使PVP化学键合于PMMA表面。通过ATR-FHR、XPS表征分析可知,CS、PVP已键合在PMMA表面;CA测定得出,CS-PMMA、PVP-PMMA材料表面的亲水性明显提高,并且PVP-PMMA>CS-PMMA;血小板黏附的SEM表明,键合的CS、PVP改善了其PMMA表面的生物相容性。进一步推知,修饰后其表面生物相容性的改善是由于CS和PVP分子中的生物活性基团-NH₂,因此对其作用机理做了进一步探讨。更多还原

【Abstract】 Poly methyl methacrylate （PMMA） intraocular lens （IOL） is widely used in cataract surgery. Inwater environment of our body, the standard of biocompatibility is really high. At the same time,transmittance is another important guide line to estimate IOL. But PMMA is hydrophobic colophonywith low polarity. When PMMA IOL was implanted in eyes, adhesion of imflammation cells is morethan hydrogel. And the contact with cornea epithelia will lead to permanent damnification of corneaepithelia. In this article, different chamical materials were linked with PMMA by plasma treatment.The biocompatibility increased and ultraviolet transmittance decreased remarkablely for themodified PMMA.（1） CF₄ and CF4/O₂ plasma modification on PMMA surfaceThe PMMA surface were treated by CF₄ plasma, investigated the effect of time, power andpressure in plasma treatment. The results of ATR-FTIR and XPS analysis indicate thatfluorin-contained groups with C-F_X existed on the modified CF4-PMMA surface. Hydrophobility ofthe CF₄-PMMA surface increased by CA measurement. The amount of blood platelet adhesived onthe CF₄-PMMA surface decreased. The ultraviolet transmittance of the CF_4-PMMA reducedremarkably.The PMMA surface were treated by CF₄/O₂ plasma, investigated the effect of time, power andpressure in plasma treatment. The results of ATR-FTIR and XPS analysis indicate thatfluorin-contained groups and oxygen-contained groups existed on the modified CF₄/O₂-PMMAsurface. Hydrophobility of the CF₄/O₂-PMMA surface increased by CA measurement and thehydropilicity of CF-4/O₂-PMMA is more than that of CF₄-PMMA. The amount of blood plateletadhesived on the CF₄/O₂-PMMA surface decreased. The ultraviolet transmittance of theCF₄/O₂-PMMA reduced remarkably.（2） Plasma-induced polymerization of poly（ethylene glycol） （PEG） and heparin（Hp） on PMMAsurfacePlasma pretreated PMMA were put into PEG and Hp solution, respectively. Then by Ar plasmaphysical absorbed PEG and Hp were polymerized on the PMMA surface. Furthermore, Hp waspolymerized on the PEG-PMMA surface by plasma-induced polymerization. The results ofATR-FTIR and XPS analysis indicate that PEG and Hp were combined on the PMMA surface;Hydrophilicity of PEG-PMMA, Hp-PMMA and PEG-Hp-PMMA increase compared with thePMMA, and the order of hydrophilicity is PEG-PMMA > PEG-Hp-PMMA > Hp-PMMA. The results of blood platelet adhesion experiment prove that biocompatibility of the modification PMMAsurfaces was improved remarkabley. The transmittance of treated samples reduced in ultravioletregion.（3） Plasma-induced polymerization of chitosan（CS） and polyvinylpyrrolidone（PVP） on PMMAsurfacePlasma pretreated PMMA were put into CS and PVP solution, respectively. Then by Ar plasmaphysical absorbed CS and PVP were polymerized on the PMMA surface. It is been showed that CSand PVP were combined chemically with the PMMA substrate by ATR-FTIR and XPS. The CAmeasurement result indicated hydrophilicity increase of CS-PMMA and PVP-PMMA andPVP-PMMA > CS-PMMA. The results of blood platelet adhesion experiment proved thatbiocompatibility of CS-PMMA and PVP-PMMA increased. Furthermore, the mechanism ofCS-PMMA formation was discussed.更多还原