红粘土/聚氨酯复合材料的制备及生物相容性、生物稳定性的研究
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摘要
聚氨酯(PU)由于具有良好的力学性能和生物相容性而在生物医学领域得到广泛应用,聚氨酯的医用制品包括人工心脏、人工血管、医用薄膜、弹性绷带、医用导管等的需求量正逐年增加。但是,作为长期植入体内的材料,聚氨酯的力学性能、生物相容性和生物稳定性仍无法满足要求,长期植入体内存在降解现象,限制了这类材料在长期植入领域中的应用。因此,提高聚氨酯的力学性能、生物相容性及生物稳定性对其在生物医用领域的应用具有重要意义。
     本研究中,采用华南地区广泛存在的矿物粘土-红粘土,将其提纯分散后获得超浓缩微纳米级的红粘土,采用溶剂法制备红粘土/PU复合材料。利用激光散射仪和透射电镜研究红粘土的粒度及微结构,利用扫描电镜及原子力显微镜研究复合材料的表面性能,并测定了复合材料的力学性能。分别采用四唑盐比色法(即MTT法)、直接接触细胞培养法、溶血率试验和凝血时间试验评价复合材料的细胞毒性及血液相容性。采用H_2O_2/CoCl_2体系,结合木瓜蛋白酶降解体系模拟聚氨酯在体内生理环境中的降解。使用扫描电镜、红外光谱仪和电子拉力机研究复合材料降解前后的表面形貌、分子结构及力学性能的变化,探讨复合材料的生物稳定性。取得了以下结论:
     1.红粘土原土平均粒度为1609nm,呈现叠聚式-辐射式粒团结构。经过提纯分散后,红粘土的平均粒度为227.8nm,以数量分析,提纯红粘土中以48nm组分的土粒数量最多,透射电镜下可观察到十几纳米的粘土粒子。对复合材料的微观结构研究显示,红粘土粒子均匀分散于PU基体中,与聚氨酯之间界面作用良好。红粘土含量5wt%PU复合材料的表面粗糙度与纯的PU膜比较,由14.23nm降低为9.626nm,有望减小材料表面对血液成分中的小分子物质的吸附。
     2.对复合材料的力学性能研究显示:红粘土含量小于10wt%时,红粘土/PU复合材料的拉伸强度和断裂伸长率随着红粘土的含量增加而呈现增长趋势。纯PU膜拉伸强度和断裂伸长率分别为37.67MPa和610.6%,红粘土含量5wt%的复合材料拉伸强度和断裂伸长率均达最大值,为42.62MPa和673.10%,与纯PU相比分别提高了13%和10%。当红粘土含量大于10wt%时,红粘土/PU复合材料的拉伸强度及断裂伸长率均下降。
     3.首次对红粘土类矿物填充PU制备的复合材料进行细胞毒性的研究,结果表明:纯PU的细胞毒性级别为1级,而红粘土/PU复合材料各个浓度组的细胞毒性级别均为0级,无细胞毒性,细胞与材料共培养后生长状态良好。红粘土/PU复合材料溶血率均低于空白PU膜的溶血率,低于国际标准规定值,符合作为植入材料应用于人体中。特别的,红粘土含量2wt%的复合材料的溶血率最低达0.31%,血液相容性最佳。
     4.首次对红粘土类矿物填充PU制备的复合材料的生物稳定性的研究,结果表明,红粘土/PU复合材料在加速氧化降解及酶降解后,表面出现裂纹和小洞,而纯PU表面几乎降解脱层。红外光谱分析表明,氧化自由基使得纯PU膜的聚醚软段氧化为酸和醇。而加入红粘土的复合材料的聚醚吸收峰强度不变,聚酯的C=O及C-O吸收峰未发现峰位移动现象,表明复合材料未氧化或氧化程度较小。加速氧化降解后,复合材料的拉伸强度并未降低,反之有少许上升,而酶降解后则有少许下降,降幅均比纯PU小。
     综上所述,红粘土在改善聚氨酯的力学性能、提高聚氨酯的生物相容性和生物稳定性有着明显的作用,能弥补PU在应用上的不足。由红粘土填充聚氨酯制备红粘土/PU复合材料综合性能优越,有望成为一种新型的生物材料应用于生物医学工程领域。
Polyurethane (PU) has been widely used in the biomedical field owing to good mechanical properties and biocompatibility. The demand of PU medical products including artificial heart, artificial blood vessels, medical films, elastic bandages, medical catheters, and so on is increasing year by year. However, as a long-term implantation materials, the mechanical properties, biocompatibility and biological stability of PU are still unable to meet the requirements yet. The degradation of PU productions in vivo limits its applications. Therefore, to improve the mechanical properties, biocompatibility and bio-stability of PU, was meaningful and significant.
     In this paper, the mineral clay - red clay which widely exists in the South China region was introduced to improve the properties of PU. Due to its chemical and physical characteristics, it is supposed to be an efficacy modification. After being purified and dispersed, a super-concentrated system of micro-nano-red clay was got. And then, this micro-nano-red clay was added into the PU solution by a certain percentage of solvent to make different red clay/PU composites.
     Laser diffractometer and transmission electron microscopy (TEM) were introduced to investigate particle size and micro-structure of red clay. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the surface properties of different red clay/PU composites. Electronic universal testing machine was applied to measure the mechanical properties of this composite. The hemolytic rate, clotting time test, cytotoxicity test and direct contact method was introduced to evaluate the biocompatibility of them. The H_2O_2/CoCl_2 system together with papain degradation solution was published to simulate the degradation of PU in vivo. To find out the difference of surface morphology, molecular structure and mechanical properties before and after degradation, SEM, infrared spectrometer (FTIR) and the electronic universal testing machine were introduced. The results as below:
     1. The original red clay presented a structure of stacked-radiation type. The average particle size of original red clay was 1609nm. After purification and dispersion, the average particle size of red clay was reduced to 227.8nm. The largest number of purificatory red clay was in 48nm components, 17nm size of particles could be observed under TEM. Red clay particles uniformly dispersed in the matrix, and possess good interface interaction between the PU. Compared with pure PU, the surface roughness of 5wt% red clay content of PU composite was reduced, which is from 14.23nm to 9.626nm. The results indicate that red clay is conducive in reducing the surface adsorption of small molecules in blood components and improving the blood compatibility of PU.
     2. When the red clay content lower than 10wt%, the tensile strength and elongation at break of red clay/PU composite increasing with the increase of content of red clay. Tensile strength and elongation at break of pure PU were 37.67MPa and 610.6%. Especially, 5wt% red clay content of PU composite reached the peak which is 673.10% and 42.62MPa. There are 13% and 10% growth comparing with pure PU. Over the peak that the red clay content is 10wt%, the tensile strength and elongation at break of red clay / PU composite start to fall.
     3. Level of cytotoxicity of pure PU was 1. Various contents of the red clay/PU composite were 0, which indicates the cell toxicity is on low level or none. Hemolytic rates of red clay/PU composite were lower than pure PU, less than 5% of international standards. Especially, hemolytic rate of 3wt% red clay content of PU composite was the lowest which was 0.31%. Base on these results, the red clay/PU composite is supposed to be an efficacy modification in improving the biocompatibility of PU.
     4. After accelerate oxidative degradation and enzymatic degradation, cracks and holes could be observed on the surface of red clay/PU composite, however, the surface of pure PU almost delaminating. FTIR showed that free radical oxidation makes the ether bond of soft segments of pure PU depredates to carboxylic acid and alcohol. In the red clay/PU composite, any displacement of C=O and the C-O absorption peak of ester bond couldn't be found, which indicated the red clay/PU composite didn't depredate or depredate slightly. After accelerate oxidative degradation, the tensile strength of the composite didn't reduce, on the contrary, there was a little rise; After the enzyme degradation, the tensile strength was slightly declined but the decreasing amplitude was smaller than pure PU. All mentioned above indicate that composites with better bio-stability would be acquired by adding red clay into PU.
     In a word, red clay/PU composite not only improve the mechanical properties but also get better biocompatibility and biological stability than matrix, which has shown strengths and great potential in preparation of new modified PU medical products.
引文
[1]Chandran K B,Kim S H,Han G..Stress distribution on the cusps of a polyurethane trileaflet heart valve prosthesis in the closed position[J].Biomaterials,1991,24(6):385-395
    [2]Min B G,Kim H C,Lee SH,et al.A moving-actuator type electromechanical total artificial heart(1):Linear type and mock circulation experiments in Transactions on Biomedical Engineering[J].Biomaterials,1990,37(12):1186-1194
    [3]Szycher M,Poirier V,Dempsey D.Synthesis and fabrication of polyurethane elastomers for cardiac assist devices[C].Boston:American Society of Mechanical Engineers,Applied Mechanics Division,1979,743-747
    [4]Kaibara M,Kawamoto Y,Yanagida S,et al.In vitro evaluation of antithrombogenicity of hybrid-type vascular vessel models based on analysis of the mechanism of blood coagulation[J].Biomaterials,1995,16(16):1229-1234
    [5]Jones D S,Bonne M C,Gomran S P,et al.Sequential polyurethane poly(methylmethacrylate)interpenetrating polymer networks as urethral biomaterials:Mechanical properties and comparative resistance to urinary encrustation[J].Materi Sci Mater in Medi,1997,8(11):713-717
    [6]Murayama T.,McMillin C R.Dynamic mechanical properties of elastomers for use in circulatory assist devices[J].Appl Polym Sci,1983,28(6):1871-1877
    [7]章俊,胡兴斌,李雄.生物医用高分子材料在医疗中的应用[J].中国医院建筑与装备,2008.01:30-35
    [8]李洁华,谢兴益,何成生等.医用聚氨酯生物相容性研究新进展[J].生物医学工程杂志,2002,19(2):315-319
    [9]杜民慧,李建树,魏阳等.生物医用脂肪族聚氨酯的合成、表征及血液相容性研究[J].生物医学工程杂志,2003,20(2):273-276
    [10]Fujiwara T,Wynne KJ.Contrasting nanoscale surface morphologies of polyurethanes containing polyoxetane soft blocks with random and block segmer sequences[J].Macromolecules,2004,37:8491-8494
    [11]孙东豪,吴徵宇,李明忠等.等离子体引发丝素在聚氨酯膜表面接枝的研究[J].纺织学报,2005,26(3):4-7
    [12]王雪力,侯理,谭竞等.生物相容性聚氨酯支架材料的研究[J].高分子材料科学与程,2008,24(2):144-151
    [13]黄汉升.医用聚氨酯研究开发动向[J].化工新型材料,1995,(4):38-49
    [14]Iwasaki Y,Aiba Y,Morimoto N,et al.Semi-interpene trating polymer net works composed of biocompatible phospholipid polymer and segmented polyurethane[J].Journal of Biomedical Material Research,2000,52:701-708
    [15]孔桦,许海燕,蔺嫦燕等.纳米碳改性聚氨酯复合材料的表面抗凝血性能[J].基础医学与临床,2002,22(2):113-116
    [16]刘金成,易定华,徐学增等.聚氨酯硬段改性材料心室辅助装置血液相容性及毒性学研究[J].北京生物医学工程,2005,24(2):82-83
    [17]陈维涛,李树材.肝素化水性聚氨酯改性医用聚氯乙烯表面的研究[J].化工新型材,2005,33(1):46-48
    [18]许海燕,孔桦,杨子彬等.利用等离子体表面接枝技术提高医用聚氨酯血液相容性的研究[J].中国生物医学工程学报,2003,22(6):533-536
    [19]Corvita Corporation,Miami Fla.Crack resistant polycarbonate urethane polymer prostheses:US,5133742[P].1992 - 07 - 28
    [20]谢兴益,刘昉,钟银屏等.生物稳定聚氨酯的合成及性质初步研究[J].生物医学工程学杂志,1999,16(增刊):121-122
    [21]Young H K,Dong K H,Soo H K,et al.Enhanced blood compatibility of polymers grafted by sulfonated PEO via a negative cilia concept[J].Biomaterials,2003,24(13):2213-2223
    [22]李洁华,谭鸿,谢兴益.聚碳酸酯型聚氨酯的体外降解研究[J].中国生物医学工程学报,2004,23(4):300-304
    [23]李晓霞.基于聚碳酸酯和IPDI的生物材料的研究[D].天津:天津大学化工学院,2006
    [24]谭红梅,汪建新,张俊良.医用聚氨酯的改性及应用[J].化学推进剂与高分子材料,2009,7(2):23-26
    [25]Labow R S,Tang Y,et al.The effect of oxidation on the enzyme-catalyzed hydrolytic biodegradation of poly(ure-thane)s[J].Biomater Sci(Polymer Edition),2002,13(6):651
    [26]J ahangir R,McCloskey C B,et al.The influence of protein adsorption and surface modifying macromolecules on the hy-drolytic degradation of a poly(ether-urethane) by cholesterol esterase[J].Biomaterials,2003,24(1):121
    [27]黄健,陈庆民,徐学海.聚碳酸酯弹性体的模拟生物老化性能的研究[J].功能高分子学报,1996,9(1):39-46
    [28]马继盛,漆宗能等.聚氨酯弹性体/蒙脱土纳米复合材料的合成、结构与性能[J].高分子学报,2001,3:325-328
    [29]Jain Xu,Xinhua Dai,et al.Study on Structure and Orientation Action of Polyurethane Nanocomposites[J].Macromolecules,2004,37:5615-5623
    [30]Maged A.Osman,Vikas Mittal,et al.Polyurethane Adhesive Nanocomposites as Gas Permeation Barrier[J].Macromolecules,2003,36:9851-9858
    [31]Mariarosaria Tortoraa,Giuliana Gorrasi,et al.Structure characterization of polyurethanes containing poly-dimethylsiloxane[J].Polymer,2002,43:6147-6157
    [32]Lei Songa,Yuan Hu,et al.Study on the properties of flame retardant polyurethane Porganoclay nanocomposite[J].Polymer Degradation and Stability,2004,87:111-116
    [33]马晓燕,梁国正,鹿海军等.累托石粘土/热塑性聚氨酯弹性体纳米复合材料的热性能研究[J].高分子学报,2003,(5):655-660
    [34]王心葵,亢茂青,张永成等.一种纳米膨润土水基聚氨酯复合材料的制备方法:CN,03143317.O[P].2003-09-25
    [35]陈小金,陈宪宏.聚氨酯/纳米复合材料的研究进展[J].材料科学与工程学报,2005,23(6):929-932
    [36]廖义玲,余培厚.红粘土的微结构及其概化模型[J].工程地质学报,1994,2(1):27-37
    [37]谭罗荣,孔令伟.某类红粘土的基本特性与微观结构模型[J].岩土工程学报,2001,23(4):458-462
    [38]程昌炳,康哲良,徐昌伟.针铁矿与高岭土“胶结”本质的微观研究初探[J].岩土力学,1992,13(2):53-56
    [39]程昌炳,陈琼,周良忠.由~(27)AL的核磁共振谱看高岭土与针铁矿的胶结本质[J].波谱学报,1995,12(6):593-598
    [40]孔令伟,罗鸿禧,袁建新.红粘土有效胶结特征的初步研究[J].岩土工程学报,1995,17(5):42-47
    [41]敖宁建,陈美,周慧玲等.红粘土/天然橡胶纳米复合材料的结构与性能研究[J].电子显微学报,2002,21(2):233-206
    [42]杜辉,赵雨花,殷宁等.无机有机材料对聚氨酯弹性体的改性研究.化工新型材料, 2008,36(2):53-57
    [43]贾金兰,蒋迎忠,刘敏.聚氨酯无机纳米复合材料的研究进展[J].山西化工,2007,27(6):18-21
    [44]周长忍.生物材料学[M].北京:中国医药科技出版社,2004,131
    [45]顾汉卿,徐国风.生物医学材料学[M].天津:天津科技翻译出版社,2004,145-160
    [46]Timothy A.Petrie,Jenny E.Raynor,Catherine D.Reyes,et al.The effect of integrant-specific bioactive coatings on tissue healing and implant Osseo integration[J].Biomaterials,2008,29(9):2849-2857
    [47]李晓霞.基于聚碳酸酯和IPDI的生物稳定性聚氨酯材料的研究[D].天津:天津大学化工学院,2006,34-35
    [48]Shinji Sugiura,Jun-ichi Edahiro,Kimio Sumaru,Toshiyuki Kanamori.Surface modification of polydimethylsiloxane with photo-grafted polyethylene glycol for micropatterned protein adsorption and cell adhesion[J].Colloids and Surfaces B:Biointerfaces,2008,63(2):301-305
    [49]Narita,T.,Hirai,A.,Xu,J.,et al.Substrate Effects of Gel Surfaces on Cell Adhesion and Disruption[J].Biomacromolecules(Article),2000,1(2):162-167
    [50]Chris A.Bashur,Linda A.Dahlgren,Aaron S.Goldstein.Effect of fiber diameter and orientation on fibroblast morphology and proliferation on electrospun poly(lactic-co-glycolic acid)meshes[J].Biomaterials,2006,27(33):5681-5688
    [51]Ryuji Kato,Chiaki Kaga,Mitoshi Kunimatsu,et al.Peptide array-based interaction assay of solid-bound peptides and anchorage-dependant cells and its effectiveness in cell-adhesive peptide design[J].Journal of Bioscience and Bioengineering,2006,101(6):485-495
    [52]Ai Ping Zhu,Ning Fang,Mary B.Chan-Park,Vincent Chan.Adhesion contact dynamics of 3T3 fibroblasts on poly(lactide-co-glycolide acid) surface modified by photochemical immobilization ofbiomacromolecules[J].Biomaterials,2006,27(12):2566-2576
    [53]Watanabe,J.,Eriguchi,T.,Ishihara,K..Cell Adhesion and Morphology in Porous Scaffold Based on Enantiomeric Poly(lactic acid) Graft-type Phospholipid Polymers[J].Biomacromolecules,2002,3(6):1375-1383
    [54]张伶俐,朱蔚精,谭言坛等.生物材料溶血性标准化评价方法比较:溶血率法和氰化铁血红蛋白法[J].生物医学工程学杂志,2000,421(1):111-114
    [55]Mosher D F.Adhesive proteins and their cellular receptors[J].Cardiovascular Pathology, 1993,2(3):149-155
    [56]杨珠英,房红莹,顾冠彬,万海燕.医疗产品体外细胞毒性的试验研究[J].Chin J Hemorh,2004,14:402-403
    [57]汤顺清,毛萱.无机生物材料学[M].广州:华南理工大学出版社,2008
    [58]何斌,万玉青,贝建中等.L-丙交酯-p苹果酸-共聚物的体外降解及细胞亲和性研究[J].高分子学报,2004,5:693-699
    [59]孟舒献,温晓娜,冯亚青等.肝素化聚氨酯表面修饰材料的研究[J].生物医学工程杂志,2004,21,579-601
    [60]罗兰,窦宏仪.抗凝血生物医用聚氨酯材料研究进展[J].热固性脂,2005,20:42-44
    [61]郝和平主编.医疗器械生物学评价标准实施指南[M].北京:中国标准出版社,2000
    [62]王翔,闰蕾,贾光等.纳米材料潜在健康影响的研究进展[J].毒理学杂志,2005,19(1):15-17
    [63]Gerhard Rossberg,D.Megighian,H.Decher.The dependence of osteoblastic response on variations in the chemical composition and physical properties of hydroxyapatite[J].Journal of Materials Science:Materials in Medicine,1997,8:222-228
    [64]Anderson,J.M.,Hiltner,A.,Zhao,Q.H.,et al.Cell/polymer Interactions in the Biodegradation of Polyurethanes in:Biodegradable Polymers and Plastics,M.Vert,J.Feijen,A.Albertsson,et al.,Editors,Royal Society of Chemistry,Cambridge,England,1992,122-136
    [65]Schubert,M.A.,Wiggins,M.J.,Anderson,J.M.,et al.,Role of Oxygen in Biodegradation of Poly(etherurethane urea) Elastomers[J].Journal of Biomedical Materials Research,1997,34:519-530
    [66]Zhao,Q.,Donovan,M.,Schroeder,P.,et al.Invitro Modulation of MacroPhage Phenotype and Inhibition of Polymer Degradation by Dexamethasoneina Human MacroPhage/Fe/Stress System[J].biomedical material Research,1999,46:475-484
    [67]K.Stokes,P.Urbanski,J.Upton.The in vivo Auto-oxidation of Polyether Polyurethane by Metal Ions[J].Journal of Biomaterials Science:Polymer Edition,1990,1(3):207-230
    [68]傅皓,李赛,李洁华等.生物降解型聚氨酯在医学中的应用[J].生物医学工程学杂志,2003,20,348-351
    [69]李保强,胡巧玲,方征平等.组织工程用聚氨酯的研究进展[J].高分子通报,2003,2:1-7
    [70]Stokes.KB,Urbanski.P.W.The Biodegradation of Nonbiodegradable Polymers,in:Degradation Phenomenaon Polymeric Biomaterials[J].Springer-Verlag Berlin Heidelberg,1992,37-57
    [71]Zhao,Q.,Casas-Bejar,J.,Urbansky,P.,Stokes,K..Glass Wool-H2O2/CoCl2:Test System for in vitroEvaluation of Biodegradative Stress Cracking in Polyurethanes Elastomer System[J].Biomedcal material Research,1995,29:467-475
    [72]李洁华,谭鸿,谢兴益.聚碳酸酯型聚氨酯的体外降解研究[J].中国生物医学工程学报,2004,23(4):300-304
    [73]Santerre JP,Labow RS,Adams GA,et al.Biodegradation evaluation of polyether and polyester-urethanes with oxidative and hydrolytie enzyme[J].Biomed.Mater.Res,1994,28(31):1187-1199

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