角膜修复材料表面等离子体改性与表面性能研究

发布时间：2018-03-16 04:26

本文选题：壳聚糖膜　切入点：RGP接触镜　出处：《华南理工大学》2012年博士论文　论文类型：学位论文

【摘要】：壳聚糖和氟硅丙烯酸脂广泛应用于角膜修复材料的研究，角膜修复材料的发展对材料表面特性提出了更高的要求，但壳聚糖膜表面亲水性较差，表面自由能尤其是其极性分量较低，缺乏细胞识别位点，不利于细胞在材料表面的黏附与增殖。氟硅丙烯酸树脂（FSA）是新一代高透氧性硬性角膜接触镜材料，但材料表面憎水，不利于泪液在镜片表面的铺展与润湿；且表面非极性基团与蛋白质分子间的非极性相互作用容易导致蛋白与脂质等在镜片表面的黏附，影响镜片佩戴舒适性和佩戴时间。为改善两种角膜修复材料的表面特性，本论文在对材料表面性能进行综合表征的基础上，采用低温等离子体进行表面处理和表面接枝改性，改善其表面物化特性和生物学性能。采用角分辨XPS对壳聚糖膜表面化学基团的空间分布进行分析表征。结果表明，壳聚糖膜随着在空气中放置时间延长，其表面极性基团-OH等逐渐转移到膜的内部；壳聚糖膜表面N元素主要以-NH_2形式存在，其分子链上的-CONH_2主要伸向壳聚糖膜内部。表面极性基团的这种空间取向是造成壳聚糖膜表面亲水性较差，表面自由能较低的主要原因。实验分别采用非反应性O2和N_2低温等离子体对壳聚糖膜进行表面处理。壳聚糖膜在O_2等离子体处理下，表面引入-OH、-COO、H_2N-C=O等极性基团，表面亲水性得到改善；采用O_2等离子体进行改性的最佳工艺条件为100W下处理60s，如功率过大或处理时间过长，则容易引起壳聚糖膜表面刻蚀；O2等离子体对壳聚糖膜进行表面处理未造成明显的表面形貌变化，但表面粗糙度有一定增加。采用N_2等离子体处理，也能改善壳聚糖膜表面亲水性，但效果不如O_2明显，采用100W等离子体功率和60s处理时间，其表面接触角下降为65°；N_2等离子体处理可在表面引入一定量的N元素，引入的N元素主要是以O=C-NH_2的形式存在；等离子体处理后暴露于大气中，膜表面活性自由基与空气中的氧气、水汽等进行反应，在表面引入含氧极性基团是等离子体处理样品表面极化的主要过程。等离子体处理在壳聚糖膜表面引入的极性基团会随着时间的推移而逐渐转移到膜的内部，这种极性基团的翻转内迁，导致了等离子体处理效果的时效性，其亲水性逐渐下降，接触角增大，表面自由能尤其是其极性分量逐渐下降，壳聚糖膜表面等离子体处理的时效性大约为10天。实验采用Ar等离子体诱导接枝在壳聚糖膜表面引入聚乙二醇（PEG）分子链；表面接枝层厚度约10nm；PEGMA单体浓度10%、Ar等离子体功率100W、时间60s时表面接枝量最大；采用PEGMA单体比采用具有相同分子量的PEGDA单体接枝率高；将PEGMA单体接枝到壳聚糖膜表面后，其表面水接触角下降，亲水性改善，表面自由能和粗糙度增加。表面接枝壳聚糖膜具有较好的牛血清蛋白吸附特性；细胞试验结果表明等离子体处理和表面接枝壳聚糖膜表面的细胞黏附率高于未经处理的壳聚糖膜，表面改性壳聚糖膜具有较好的表面细胞相容性。采用O_2、N_2和Ar等离子体对硬性透气性（RGP）FSA角膜接触镜片进行表面处理均能极大地改善镜片表面的亲水性。等离子体处理在表面引入了含O基团，其中表面Si-CH3发生分子键的断裂，形成Si-O，硅烷转变为亲水性的无机硅氧基团（Si-O），是表面亲水性改善的主要原因。在等离子体处理下，表面分子中C-O发生部分断键，生成O-C=O。N2等离子体处理能够在RGP表面引入含N基团，N元素主要是以O=C-NH_2的形式存在。等离子体处理后表面活性自由基与空气中的氧气反应形成含氧基团是表面活化的主要过程，其中表面引入的O主要是与Si结合形成Si-O。等离子体处理对RGP表面形貌的影响主要取决于等离子体功率的大小，Ar等离子体相比O2和N2等离子体对表面的刻蚀更为明显，，等离子体处理工艺以100W和120s为宜。三种气氛等离子体相比较，N2相比Ar和O_2等离子体较为温和，而Ar等离子体在功率较大时，容易导致表面刻蚀，表面粗糙度增加，表面亲水性反而下降，这与等离子体中的粒子能量大小有关。采用Ar等离子体辅助接枝能有效地将PEGMA单体分子接枝聚合到RGP表面，所得PEGMA接枝层的厚度大约10纳米；结果表明：表面接枝量大小与单体浓度有关，采用去离子水作为溶剂，PEGMA单体浓度10%时具有最大的表面接枝量，RGP表面接枝PEG后，表面亲水性改善，RGP镜片表面溶菌酶蛋白质的吸附量减少，表面改性RGP镜片具有较好的表面细胞相容性。采用低温等离子体技术对壳聚糖膜和角膜接触镜材料进行表面改性，能有效改善材料表面的亲水性和生物学性能，在角膜修复材料领域具有广泛的应用前景。
[Abstract]:The study of chitosan and fluorosilicone acrylate is widely used in corneal repair materials, the development of corneal repair materials put forward higher requirements on the material properties of the surface, but the surface hydrophilic chitosan film is poor, especially the surface free energy of the polar component is low, the lack of cell recognition sites, is not conducive to cell adhesion and the proliferation of material surface. Fluorosilicone acrylic resin (FSA) is a new generation of rigid gas permeable contact lens material, but the material surface hydrophobicity, is not conducive to tear in spreading and wetting the surface of the lens; and the surface of non polar groups and protein molecular interactions can lead to protein and lipid the adhesion of the surface of the lens, lens wearing comfort and wear time. For improving the surface characteristics of two kinds of corneal repair materials, this paper is based on the comprehensive characterization of surface properties of materials, with low temperature etc. Plasma modification on the surface treatment and surface grafting, improve chemical properties and biological properties of the surface.
The angular resolution of XPS on chitosan membrane surface chemical groups to analyze the spatial distribution of characterization. The results showed that the chitosan membrane with the prolonging of time in air, the surface polar groups such as -OH gradually transferred to the internal membrane; chitosan membrane surface element N mainly exists in the form of -NH_2 within the molecular chains of the -CONH_2 is mainly to the chitosan membrane. The spatial orientation of polar groups on the surface is caused by the surface hydrophilic chitosan membrane is poor, mainly due to the lower surface free energy.
The experiment used non reactive O2 and N_2 low temperature plasma on chitosan membrane surface treatment. The chitosan membrane in the O_2 plasma treatment, the surface of the introduction of -OH, -COO, H_2N-C=O and other polar groups, the surface hydrophilicity was improved; the optimum conditions were modified by O_2 plasma 100W treatment by 60s, such as power too big or too long, it is easy to cause the etching on the surface of chitosan membrane; O2 plasma surface treatment on chitosan membrane surface morphology caused no obvious change, but the surface roughness is increased by N_2 plasma treatment, can also improve the surface hydrophilicity of chitosan membrane, but the effect is not obvious as O_2, the 100W plasma power and treatment time of 60s, the surface contact angle decreased to 65 degrees; N_2 plasma treatment N element by introducing a certain amount in the surface of the N element is introduced mainly based on O= C-NH_2 The form is present. After the plasma is exposed to the atmosphere, the active free radicals on the membrane react with oxygen and water vapor in the air. The introduction of oxygen containing polar groups on the surface is the main process of the polarization of the plasma surface.
Plasma treatment groups were introduced into the chitosan membrane with the passage of time will gradually shift into the internal membrane, the migration of polar groups led to flip, ageing of plasma treatment, the hydrophilicity decreased gradually, the contact angle increases, especially the surface free energy of polar component gradually decreased, timeliness of chitosan membrane surface plasma treatment is about 10 days.
The experiment using Ar plasma induced grafting onto chitosan membrane surface with polyethylene glycol (PEG) molecular chain; surface graft thickness is about 10nm; the PEGMA monomer concentration was 10% Ar, the plasma power is 100W, the maximum amount of time of 60s surface grafting; using PEGDA monomer grafted PEGMA monomer has the same molecular weight than the rate will be high; the PEGMA monomer was grafted onto chitosan membrane surface, the surface water contact angle decreased, improve the hydrophilicity, surface free energy and surface roughness increase. Grafted chitosan has good adsorption characteristics of bovine serum protein; cell test results show that the plasma treatment and grafting of chitosan film on the surface of cell adhesion rate is higher than that without chitosan membrane treatment, surface modification of chitosan membrane surface has good compatibility with cells.
Using O_2, N_2 and Ar in plasma of rigid gas permeable contact lens (RGP) FSA surface treatment can improve the hydrophilicity of the surface of the lens greatly. The plasma processing on the surface is introduced with O group, the fracture surface of Si-CH3 molecular bond formation of Si-O silane into inorganic hydrophilic silica group the (Si-O), is the main reason for surface hydrophilicity improvement. In plasma processing, part of the bond breaking of C-O surface molecules, generated O-C=O.N2 plasma treatment can be introduced containing N group on the surface of RGP, N elements are mainly in the form of O= C-NH_2. After treatment of plasma free radical reaction of surface activity and in the air the formation of oxygen oxygen containing groups is the main process of surface activation, which is mainly introduced to the surface of the O and Si combine to form the Si-O. effect of plasma treatment on the surface morphology of RGP mainly depends on the plasma power The rate of the size of plasma etching on the surface of Ar compared to O2 and N2 plasma is more obvious, plasma processing technology in 100W and 120s as appropriate. Three kinds of atmosphere plasma compared to N2 compared to Ar and O_2 plasma and Ar plasma in moderate, power is large, easily lead to surface etching, the surface roughness increases, surface hydrophilicity decreased, which is related to the size of particle energy in the plasma.
Using Ar plasma assisted grafting can effectively PEGMA monomers grafted onto the RGP surface, the PEGMA graft layer thickness of about 10 nm; the results show that the surface graft size and monomer concentration, using deionized water as the solvent, with the largest amount of PEGMA surface grafting monomer concentration of 10%, RGP grafted after PEG, the hydrophilicity of the surface to improve the adsorption capacity of RGP, the lens surface of lysozyme protein decreased, the surface modification of RGP lens surface has good compatibility with cells.
Surface modification of chitosan membrane and contact lens material with low temperature plasma technology can effectively improve the hydrophilic and biological properties of the material surface, and has wide application prospects in the field of corneal repair materials.

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R318.08

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