Plasma Modification Of Pmma Intraocular Lens

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.