《专业英语》考查课专业论文-高分子材料的研究进展.doc

河南工程学院专业英语考查课专业论文高分子材料的研究进展学生姓名： 学 院： 机械工程学院 专业班级： 材控1242 专业课程： 专业英语 任课教师： 2015年11月20日abstract : this paper contains an ester bond and an amide bond and an ester bond and an amide bond hybrid bond polymer biomaterials synthesis, modification and biocompatibility of research results. rich in hydrophilic groups degradable and degradation products can be absorbed by organisms or metabolic polymer material can meet the needs of tissue engineering , uncoupling protein -containing molecules, drug molecule active group polymer biomaterials will have a more large potential applications.key words : polymer biomaterials ; polyester ; polyamide1 introduction biological material known as biomedical materials, refers to an organism for treatment, diagnosis and replacement tissues and organs corrupted or promotional material of their functions. it is divided into metal materials, polymer materials, ceramics and composites four kinds 1. the late 1980s, people of biotechnology to the study of biological materials, combined with biological elements and functions to build the desired biologically active material, which made the concept of tissue engineering. tissue engineering marks the medicine will be out of the scope of the organization of organ transplantation, tissues and organs into the manufacturing era, thus tissue engineering in the 21st century high-tech industry has great potential. polymer science of the 20th century a strong impetus to the booming development of biological materials, bio-polymer material carrying drugs and release of biological scaffold material has broad application prospects. currently, the medical polymer materials around the world has more than 90 varieties, more than 1800 kinds of products, according to the western countries consumption growth rate of 10% to 20% annually. tissue engineering polymer desired biologically active materials not only have good biocompatibility, but also biodegradable, and easily absorbed or metabolic degradation products, and in favor of cell adhesion, growth, proliferation and gene expression and regulation, etc. an ester bond and an amide bond is readily hydrolyzable bond, and therefore the polymer is a polymer containing multiple biomaterials ester bond or an amide bond. polyglycolic acid and its copolymers hydroxy acids, such as polylactic acid (pla) and glycolic acid and lactic acid copolymer (plga) is typical of biological material containing ester bonds, poly amino acids are typical amide bond-containing biological material. their synthesis, modification and application in the biomedical aspects of a more extensive research.2 polyester-based biomaterials poly lactic acid and glycolic acid and lactic acid copolymer is generally used glycolide or lactide in the organic tin catalyst obtained by cationic polymerization mechanism, they can degrade in the physiological environment, the degradation the product can be metabolized and eliminated from the body. since 1970 polyglycolic acid has become commercially available surgical sutures 2,3, with glycolic acid and lactic acid monomer biodegradable polymer caused widespread concern, the researchers biodegradable degradation mechanisms depending on the desired mechanical properties and design the polymer 4. pla and polyglycolic acid (pga) polymers are highly crystalline, by hydrolysis in the physiological environment of the first occurrence in the amorphous regions, since there are side-methyl-pla, pga exhibited stronger than the hydrophobic, and therefore of pla hydrolysis difficult than hydrolysis of the pga. the copolymerization of glycolic acid with lactic acid, by adjusting the ratio of the two monomers, is expected to give the desired rate of hydrolysis of biological material 5. pla, pga and plga has good biocompatibility and safety, and their carrying of biological scaffolds have been widely studied 6 on drugs. drug carrying particle micro-encapsulated nano particles, and, generally spray drying method, three methods of w / o / w double emulsion solvent evaporation method and aerosol extraction method 7. drug-loaded particles can enter the organism by the oral, subcutaneous and intramuscular way. akiko japanese scientists, who reported to the pla and plga microencapsulation of material for luteinizing hormone release in vitro studies, the results showed that, ph value of the medium, salt concentration and other factors will affect the release of the drug. hongkee et al 9 reported a mixture of pla and pga micro encapsulating material to control bovine serum albumin, transfer and pancreatic protein ferritin analog protein release, we found that the microencapsulation can achieve a continuous release of an antigen, can effectively replace the multiple injections of antigens, have potential applications in terms of vaccine inoculation. zambaux et al reported the preparation and characterization of load protein c (a plasma factor) of pla nanoparticles in 1999, and found that protein c is adsorbed on the hydrophobic interaction based on pla nanoparticles. prabba, who reported carrying different sizes of plga nanoparticles on dna in 2002, the result is the smaller the particle size, the higher the efficiency of dnas carrying. breitenbach et analysis of linear polyesters carrying proteins and other macromolecules hydrophilic macromolecules on the basis of unfavorable factors, by changing the polyester structure and increase the hydrophilic polymer, effectively regulate the degradation rate of the polymer and the release rate of the drug. they were synthesized with polyethylene oxide (peo) branched star structure polyester and dextrin or polyvinyl alcohol-based chain, polyester comb polymer branched, research shows that they can be used as intestinal ideal drug carrier material outside. vila, who designed and fabricated with polyethylene glycol (peg) for the coating of pla nanoparticles coated with chitosan and chitosan nanoparticles plga nanoparticles carrying on their research activity of the protein the results showed that the stability of hydrophilized engineered nanoparticles and proteins contained negative amount are greatly increased. sahli, who studied the pla and peo-pla nanoparticles in mice with the after effects of plasma factor found no hydrophilic structure of pla nanoparticles clumping factor is very sensitive, peo-pla nanoparticles containing hydrophilic structure of cohesion factors have a stronger role in the resistance, it can be a long time stability in the blood. biocompatibility studies with plga as a segment to the b segment of peo aba block copolymer zange and others with fibroblast cell culture model, found that increasing the content of peo, the degradation rate of the copolymer is increased, as fiber cell adhesion and growth thereon situation is more favorable.in pla or plga-based materials, through enhanced modified, it can be made to obtain the required scaffold for tissue engineering. wang et al. reported a hydroxyapatite ceramic particles to enhance pla, the material can be given biological activity, can induce the formation of bone tissue hydroxyapatite similar on the surface. campbell found that a mixture of the polycaprolactone, plga and hydroxyapatite have potential applications in bone tissue engineering. the porous component composition of a mixture of these may be degraded in water and serum-containing medium, and the degradation rate of materials increases with plga content quickly.although the pla, plga or pga have a good biocompatibility been widely studied and used as part of the clinical application of the drug carrying material and other material aspects of the implant, but as a long-term implanted device materials, their acidic degradation productsit is also of concern, because the acidic degradation products of cell adhesion and growth, unfavorable, and may lead to tissue inflammation. to overcome these problems, and others with diethanolamine lu zejian of pla modified by introducing hydrophilic amine has a weak alkaline, to neutralize the acidic degradation products, the surface of the material to improve cell adhesion, promotes cell increase. ambrosio et al. in polyphosphazene mixture and poly hydroxy acids are biological materials degrade system investigated by ph change, and found degradation products polyphosphazenes and poly hydroxy acids can neutralize acidic degradation products, reduce the degradation of the mixture acidic, increasing the biocompatibility of the material.therefore, pla, pga and plga-based biomaterials, if trying to introduce a hydrophilic portion, will be more conducive to carrying and releasing drugs. if introduced to neutralize acidic degradation products of components, will impart better biocompatible materials. ga and la ratio changes, you can adjust the degradation rate of plga.polyester with side carboxyl or amine groups have good solubility in water, and loading and sustained-release pharmaceutical. cammas, who first aspartic acid as the starting material synthesis of macromolecular drugs may carry a high molecular weight poly (- malic acid). kazuhiro others with 3 (s) - (benzyloxy carboxy) methyl -1,4-dioxane-2,5-dione ring-opening polymerization to obtain a carboxyl group-containing side polyglycolic acid. fietier et al. the serine amino protection, and then into the lactone ring, and then the lactone ring-opening polymerization and deprotection, synthesis of amine functional polyester with a side. but, so far about the band rarely seen side of carboxyl or amine polyester reports biomedical area.3 poly-amino acids are typical of biological material polylactic acid amide-containing polymers they are rich in the side functional groups, and the degradation products are simple - amino acids, biological materials to do with it, has obvious advantages. early polyglutamic acid synthesis, an amino acid is first reacted with an excess of phosgene n- carboxy anhydride (nca), and then the anionic ring-opening polymerization. phosgene synthesis nca, requires a large excess of highly toxic phosgene, is not conducive to the stoichiometry and master balance. 1988 daly reported the synthesis of nca with triphosgene work, as triphosgene is a crystalline solid, store safe and easy to use, stoichiometry, soluble in organic solvents such as thf and hexane, which greatly facilitates the synthesis of the nca. however, in addition to poly-glutamic acid, other poly amino acid is difficult to dissolve, and poor physical properties and processing properties. recently, however, klok through continuous open loop - deprotection step polymerization of highly branched dendritic water-soluble poly-lysine, such polymers is expected to have wide use in biological medicine. therefore, it has not yet developed a poly-amino acid products have value.over the past decade, in order to improve the solubility of poly-amino acids and workability, studied copolymerization very active. cammas and others with one end of the primary amino groups of peo initiated - benzyl ester -n- -l- aspartic acid anhydride-containing hydrophilic segments peo and di-block copolymer poly amino acid ester segments, the copolymer in water to form stable micelles, and freeze-dried to obtain a powder having a diameter of 35nm micelles. kataoka reported the use of a primary amine group at one end of polyethylene glycol (peg) initiator substituted lysine nca, obtained diblock polymers, and of partially substituted for lysine structural adhesive bundle of influence. yuan et al., with both ends of polyoxyethylene primary amine initiators l- phenylalanine nca, to obtain a better hydrophilic triblock polymers. kang et al., both ends of a primary amine of polypropylene oxide (ppo) triggered nca - benzyl glutamate to give the middle ppo triblock polymer, the polymer and blood compatibility gas permeation studies have shown that the introduction of amorphous poly amino acids ppo, help to improve the permeability and gas anticoagulant effect of block copolymers.since poly (- -l- glutamic acid methyl ester) with a natural look and feel like leather, but its resilience and good adhesion to cells. uchida et al. reported separately with a primary amine, tertiary amine and hydrazine as initiator, synthetic polymer containing polyurethane segment and poly (- benzyl glutamate) segments, studies have shown that the polymer modified resilience and adhesion of cells have been improved significantly.4-hydroxy acids and amino acid copolymers type of biological material hydroxy acids and amino acid copolymers formed, will combine excellent performance of two types of polymers are biodegradable, absorption and metabolism of the very potential of tissue engineering materials. since glycolide or lactide open-loop via a cationic mechanism, nca via anionic ring opening mechanism, and therefore can not be put together lactide and copolymerizing nca. barrera, who first synthesized cyclic dimer containing lysine units and amino acid structural unit to be protected, then the cyclic dimer lactide co together via cationic ring-opening polymerization, go protection , you get containing 2.6% of lactic acid lysine unit and lysine copolymer. amine groups of the copolymer can be conjugated peptides, giving it a better biological activity. jin, who synthesized serine-containing 2% lactic acid and serine, copolymers of the free hydroxyl groups at both ends of the peo isocyanato reaction, increasing the amorphous content of the polymer, improved polymer biofacies capacitive. so far, the amino acid modification is introduced into the main structure and hydrophilic adjust its crystallinity, thereby improving the polymers biodegradation behavior and histocompatibility. although researchers have realized a total of polymerization of amino acids and hydroxy acids, but amino acid content of the copolymer of structural units is very low. related amino acid copolymers reported in terms of biological material is very rare.reference:1 俞耀庭(yuyao-ting),陈兴栋(chenxin-dong).生 物医用材料(biomaterials).天津大学出版社(tianjinuniversitypress),第1版(edition1),2000:12.2 gilgingdk,reedam.polymer,1979,20:1459.3 reedam,gildingdk.polymer,1981,22:494.4 lisab.internationaljournalofpharmaceutics,1995, 116(1):1. 5kisse,vargha-butlerei.colloidsandsurfaceb: biointerfaces,1999,15(34):181. 6 akikok,shgeruk,akiras,etal.j.controlled rel.,1996,40(3):269. 7 claudiaw,ericd.j.controlledrel.,1998,51(2 3):327. 8 rocioh,miguelrf.advanceddrugdelevery reviews,2001,52(1):5. 9 hongkees,robintont,chieny.j.controlledrel., 1995,35(23):137.中文原文:摘要:综述了含酯键和酰胺键以及酯键和酰胺键混合键的高分子生物材料的合成、改性以及生物相容性等方面的研究成果。富含亲水基团的可降解以及降解产物可被生物体吸收或代谢的高分子材料可满足组织工程的需要,含可偶联蛋白分子、药物分子活性基团的高分子生物材料将有更大的应用潜力。关键词:高分子生物材料;聚酯;聚酰胺1 引言 生物材料又称生物医用材料,是指对生物体进行治疗、诊断和置换坏损的组织器官或增进其功能的材料。它分为金属材料、高分子材料、陶瓷材料及复合材料四种1 。20世纪80年代后期,人们将生物技术应用于生物材料的研究,结合生物要素和功能去构建希望的有生物活性的材料,从而提出了组织工程的概念。组织工程标志着医学将走出组织器官移植的范畴,进入制造组织和器官的时代,因而组织工程是21世纪具有巨大潜力的高科技产业。20世纪的高分子科学的蓬勃发展有力地推动了生物材料的发展,生物高分子材料在药物载送释放和生物支架材料等方面有广泛的应用前景。目前,全世界的医用高分子材料已有90余个品种,1800多种产品,西方国家的消耗按每年10%20%的速度增长。组织工程期望的高分子生物活性材料不仅有良好的生物相容性,而且可生物降解和降解产物容易吸收或代谢,并且有利于细胞的粘附、生长、增殖以及基因表达和调控等。 酯键和酰胺键是容易水解的化学键,因此高分子生物材料多是以含酯键或酰胺键的聚合物。聚羟基酸及其羟基酸的共聚物,如聚乳酸(pla)和羟基乙酸和乳酸的共聚物(plga)是典型的含酯键的生物材料,聚氨基酸是典型的含酰胺键的生物材料。对它们的合成、改性以及在生物医用方面的应用有较广泛的研究。2 聚酯类生物材料 聚乳酸和羟基乙酸与乳酸的共聚物一般是用乙交酯或丙交酯在有机锡催化剂作用下按阳离子机理聚合得到的,它们可以在生理环境中降解,其降解产物可被代谢而排除体外。自1970年聚羟基乙酸成为商用外科缝合线以来2,3,以羟基乙酸和乳酸为单体的生物降解聚合物引起广泛关注,研究者根据所期望的降解机制及力学性能设计可生物降解的聚合物4。pla和聚羟基乙酸(pga)都是高结晶的聚合物,它们在生理环境中的水解首先发生在非晶区,由于pla有侧甲基,表现出比pga更强的憎水性,因此pla的水解比pga的水解困难。将羟基乙酸与乳酸共聚合,通过调节两单体的配比,可望得到预期水解速率的生物材料5 。pla、pga及plga有良好的生物相容性和生物安全性,它们在药物载送和生物支架材料方面已得到广泛研究 6 药物载送的微包囊、微粒及纳米粒子的制备,一般有喷射干燥法、w/o/w双乳液溶剂蒸发法和气溶胶提取法等三种方法7。负载药物的粒子可以通过口服、皮下注射和肌肉注射等方式进入生物体。日本科学家akiko等人报道了以pla和plga为材料的微包囊对促黄体激素的体外释放研究,结果表明,介质的ph值、盐浓度等因素都会影响药物的释放。hongkee等人9 报道了pla和pga混合物为材料的微包囊对牛血清蛋白、转移铁蛋白及胰蛋白等模拟蛋白的控制释放,发现这种微包囊可以实现对抗原的连续释放,可以有效代替抗原的多次注射,在疫苗的接种方面有潜在的应用。zambaux等人于1999年报道了负载蛋白c(一种血浆因子)的pla纳米粒子的制备及表征,并发现蛋白c基于疏水作用吸附在pla纳米粒子上。prabba等人在2002年报道了 不同粒径的plga纳米粒子对dna的载送,结果是粒径愈小对dna的载送效率越高。breitenbach等在分析线形聚酯对蛋白类大分子及其它亲水大分子的载送的不利因素的基础上,通过改变聚酯结构和增加聚合物的亲水性,有效调节聚合物的降解速率和药物的释放速率。他们合成了以聚氧化乙烯(peo)为支链的星形结构聚酯和以糊精或聚乙烯醇为主链、聚酯为支链的梳形结构聚合物,研究表明,它们可作为肠外药物的理想载送材料。vila等人设计并制备了以聚乙二醇(peg)为涂层的pla纳米粒子、以壳聚糖为涂层的plga纳米粒子和壳聚糖纳米粒子,研究了它们对活性蛋白的载送,结果表明,经亲水化改造的纳米粒子的稳定性和对蛋白的载负量都大大增加。sahli等人 研究了pla和peo-pla纳米粒子在小鼠体内与血浆因子的作用后发现,无亲水结构的pla纳米粒子对凝聚因子很敏感,含亲水结构的peo-pla纳米粒子对凝聚因子有较强的抵抗作用,能在血液中较长时间稳定。zange等人用成纤细胞培养模式研究了以plga为a段,以peo为b段的aba型嵌段共聚物的体外生物相容性,发现增加peo的含量,共聚物的降解速率增加,成纤细胞在其上面的粘附和增长情况更加良好。 以pla或plga为基础材料,通过增强改性,可以制得组织工程所需的支架材料。wang等人报道了以羟基磷灰石生物陶瓷粒子增强pla,可赋予材料的生物活性,能在其表面上诱导形成类似骨组织的羟基磷灰石。campbell等人发现由聚己内酯、plga及羟基磷灰石组成的混合物在骨组织工程中有潜在应用价值。由这些成分组成的多孔混合物可以在水和含血清的介质中降解,并且材料的降解速率随plga含量的增加而加快。 虽然pla、plga或pga等有良好的生物相容性,在用做药物载送材料和其它植入材料方面得到广泛研究和部分临床应用,但作为长期植入的器件材料,它们降解产物的酸性也备受关注,因为偏酸性的降解产物对细胞的粘附和增长不利,并且可能导致组织发炎。为克服这些问题,卢泽俭等人用二乙醇胺对pla改性,通过引入有弱碱性的亲水胺基,来中和降解的酸性产物,改进细胞在该材料表面的粘附性,促进细胞的增长。ambrosio等人以聚磷腈和聚羟基酸的混合物为生物材料,通过考察降解体系的ph变化,发现聚磷腈的降解产物可以中和聚羟基酸的酸性降解产物,降低混合物降解的酸性,增加材料的生物适应性。 因此,以pla、pga和plga为基础的生物材料,若设法引入亲水部分,将更有利于药物的载送和释放。若引入可中和酸性降解产物的组分,将更好地赋予材料的生物适应性。改变ga和la的配比,可以调节plga的降解速率。带侧羧基或胺基的聚酯有良好的水溶性,并可负载和持续释放药物。cammas等人第一次以天冬氨酸为起始原料合成出可载送大分子药物的高分子量的聚(-苹果酸)。kazuhiro等人用3(s)-(苄氧基羧基)甲基-1,4-二氧六环-2,5-二酮开环聚合,得到含侧羧基的聚羟基酸。fietier等通过对丝氨酸胺基的保护,然后环化成内酯,再对内酯开环聚合及去保护,合成出有侧胺基的功能聚酯。不过,至今很少见到有关带侧羧基或胺基的聚酯在生物医用方面的报道。3 聚氨基酸类生物材料 聚氨基酸是典型的含酰胺键的聚合物,它们富含侧功能基,且降解产物是简单的-氨基酸,用它做生物材料,具有明显的优越性。聚谷氨酸的早期合成方法,都是先用氨基酸与过量光气反应生成n-羧酸酐(nca),然后再阴离子开环聚合。用光气合成nca,需要大大过量的剧毒光气,不利于