Study On Synthesis Of Plasma Polymerized Specific Functional Coatings And Its Biological Effect

Plasma polymerization is becoming a more effective method for synthesis of new functional materials which have many characteristics such as homogeneous coatings, combine well with substrates, less pollution and so on. It also can synthesize functional materials in large area under low temperature and can deposit on all kinds of substrates. Due to its advantages, it has received wide application in biomediccal material polymerizations and surface modifications.In this article, we use RF-PECVD and DBD-PECVD setup, three different monomers were applied as the precursors to deposit functional films with specific functional groups on various substrates.Through synthesis experiments and analysis of the film properties, the plasma polymerization mechanism of these functional films has been investigated. By in-vitro cell culture and rich blood platelet adsorption tests, the influence of film structures, chemical components as well as its biocompatibilities were studied. The biological effect of functional coatings were also discussed preliminarily.The main contents of this work are as follows:Ⅰ. Plasma polymerized amine-containing functional films(1) The hydrophilicity of RF-PECVD deposited amine-containing functional films has been improved. In plasma polymerization, the chemical composition, microstructure and the surface properties of amine-containing functional films can be controlled by a certain plasma parameters, such as discharge power, work pressure, discharge mode and the duty cycle in moduled pulsed (MD) plasma. The amine-containing functional films deposited at 10W input power and a duty cycle of Ton:Toff =3ms:80ms pulsed plasma can obtain the film with high contents of 62.39% C, 19.02 % N and 18.59% O, whereas the precursor demonstrates 75% of C and 25 % of N. (2)In the measurement of in vitro cell culture, the properties of cell adhesion and wetting performance on the surface of plasma polymerized amine-containing functional films has increased in evidence. After culture of 48h, the fibroblast cell showed a tendency of oriented growth.(3) Amine-containing functional films can effectively improve the absorption and growth of cell in a short time in the MTT metabolic rate and secretive function (the estrogen (E2) quality concentration) measurement. And the value of amine-containing functional films'MTT metabolic rate on ovary cell was twice of the untreated films.Ⅱ. Plasma polymerized carboxyl functional films(1) The carboxyl functional films were deposited by DBD plasmas under high work pressures. The chemical compositions, microstructures and the surface properties of the films were investigated by controlling the plasma parameters, such as the frequency of power source, work pressure, discharge power and duty cycle in pulsed plasma. In the condition of high work pressure (1000Pa～2000Pa), small duty cycle and low discharge frequency (40kHz～60kHz), carboxyl functional groups with good performace can be polymerized.(2) The water contact angle values of these films which deposited under the different pulse duty cycle by plasma polymerization, became smaller with the duty cycle decrease, and the FTIR characteristic absorption of C=O peak appeared at 1730cm-1, O-H appeared near 3400cm-1 and C=C appeared near 1645cm-1 were more apparent. And also the film polymerized under duty cycle of 10% can effectively promote the cell adhesion, extension and accumulation on its surface.(3) The hydrophilicity of DBD plasma deposited carboxyl functional films under different discharge frequency has been improved. The films deposited under discharge frequency range from 40kHz to 60kHz have the typical characteristic of FTIR absorption peak that can also promote the cell capability. Meanwhile, the experimental results can concluded that the carboxyl functional groups dominate the whole properties of the film of its biological performance. Ⅲ. Plasma polymerized PEO-like functional films(1)In RF-PECVD polymerization, the properties of PEO-like function films can be controlled by adjusting plasma parameters. The content of EO functional groups deposited in pulse plasma is higher than in continuous wave(CW) plasma, the condition of small power in CW or long pulse interval in MD plasma have advantageous to the EO groups formation; Under the condition of pulse discharge plasma, the EO structure integrity in PEO-like films from the monomer can be retained well.(2) The bio-compatibility of the PEO-like functional films were tested by the rich blood platelet absorption and in vitro cell adhesion experiments. The blood compatibility of the films deposited in the condition of pulse duty cycle at 3:13, has been improved obviously. Meanwhile the absorption of blood platelet on its surface has a low value and basically has not showed the phenomenon of blood platelet accumulation.(3)PEO-like biologic functional films can be deposited under high pressures by DBD plasma polymerization The film with good properties can be preparied under the condition of high work pressure at 800Pa and low frequency power source (40 kHz～70 kHz) .(4)PEO-like biologic functional films polymerized under the condition of 800Pa and frequency of 40kHz～70kHz showed good blood compatibility, it can greatly reduce the blood platelet absorption on its surface. The anti-cell adsorption of the films were examined by in vitro cell culture test. And the films which deposited under 60kHz discharge frequency can effectively resist cell adhesion.Above all, the experimental results showed that different functional groups can be polymerized on the surface by controlling the polymerization process and thus we can realize the oriental growth of cell in future.