The studies of plasma modified poly(lactic-co-glycolic acid) copolymer and poly(methyl methacrylate)

• Main Authors: I-chieh Wang, 王怡絜
• Other Authors: Meng-jiy Wang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/07561928983992599568

碩士 === 國立臺灣科技大學 === 化學工程系 === 98 === The goal of this work is to investigate the effects of plasma modification on surface properties of polymers and on the interactions between modified surfaces with L929 fibroblast cells. The two polymers used in this study are poly(DL-lactic-co-glycolic acid) (PLGA) and poly(methyl methacrylate) (PMMA). Polymer thin films were fabricated by solvent evaporation technique and treated by 6 different plasma gases (O2, CO2, N2, N2/H2, CF4 and SF6 gas). For the L929 fibroblast cells adhesion, two plasma gases, N2/H2 and CF4, were used to incorporate different functionalities and surface hydrophilicity on the surfaces of PLGA and PMMA. N2/H2 plasma altered the surface to more hydrophilic and caused more positive surface charge. On the other hand, CF4 plasma modified the surface of polymer to become hydrophobic and incorporated negative charged functional groups. For the surface treatment by using N2/H2 plasma, the effects of operational parameters such as treatment time, applied power on the physical-chemical properties of polymer thin films were evaluated by measuring wettability and zeta potential. The amount of adhered cells on the pristine and plasma modified samples was quantified by LDH assay and the results showed that the effect of applied power was more significant than the treatment time. The feed ratio of N2/H2 gases was also varied to study to examine the importance of the density of amine functionalities on the modulation of surface charge and biocompatibility. Moreover, by directly cultivating the cells on the same polymer with different surface morphology or with varied chemical compositions, it was found that the effect of chemical compositions of surface was more important than the surface topography on the proliferation of L-929 cells. For the polymers treated with CF4 plasma treatment, the AFM results showed that plasma etching phenomenon occurred and confirmed that the CF4 plasma incorporated hydrophobicity on the surfaces. Interestingly, CF4 plasma also effectively promoted cell adhesion and proliferation which suggested that the cell adhesion and proliferation were independent of the surface wettability and surface charge, while the effect of chemical functional groups incorporated on the surface of material played a more important role. The XPS results of plasma treated PLGA and PMMA revealed that C-N amount and F/C ratio increased significantly by applying N2/H2 and CF4 plasma, respectively. The trend of the increase of nitrogen or fluorine contents related closely to the cell behaviors and demonstrated that the modified PMMA showed better biocompatibility than the modified PLGA. In summary, we demonstrated an effective method to perform plasma surface modification on PLGA and PMMA. Moreover, the surface chemical functional groups are essential on biocompatibility of materials.