人工肺的膜材料:研究与应用

背景:人工肺是一项生命支持技术,可以在自身肺功能出现衰竭不能维持人体器官充分的氧供时使用,或者从长远发展来看,可永久性地植入人体,部分或完全替代人体肺功能。当前,通过改进膜材料、优化设计以及对各种性能的实验评估和临床评价,人工肺的研究着力于提高气体交换能力和生物相容性,为抢救患者的生命提供更可靠的手段。目的:利用Scopus数据库及CKNI数据库文献检索和深度分析功能,对人工肺膜材料的文献资料进行多层次探讨分析,根据检索文献结果分析人工肺膜材料的发展状况及趋势。方法:通过计算机检索Scopus数据库及CKNI数据库中2002/2011有关人工肺膜材料的文献,检索词为"人工肺(artificial lung),膜材料(membrane materials),生物相容性(biocompatibility),膜式氧合器(membrane oxygenator),膜式人工肺(membrane-type artificial lung),中空纤维(hollow fiber),高分子材料(polymer materials)"。结果与结论:目前人工肺膜的结构形式已从最初的卷筒式、平板折叠式发展到今天广为采用的微孔中空纤维膜式。用于制造中空纤维的材料主要为一些成纤性能良好的高分子材料,如聚丙烯、聚醚砜等。膜式人工肺可以提高气体交换能力和生物相容性。随着高新材料的开发、基础研究的深入和临床经验的积累,人工肺必将开创治疗重症呼吸系统疾患的新局面。Scopus数据库2002-01/2011-12收录人工肺膜材料的相关文献共172篇,该领域的文献产出量发展较平稳,总体无显著增加,《人工器官》杂志发表文献量最多。     

呼吸机膜材料的选择及其生物相容性

背景：随着医学和组织工程技术发展,各种生物材料相继出现,如何选择合适的膜材料成为人工肺技术发展的关键。目的：评价各种呼吸机膜生物材料的应用性能,寻找合适的呼吸机膜材料。方法：采用电子检索的方式,在万方数据库（http：//www.wanfangdata.com.cn/）中检索1991-01/2011-12有关生物材料应用于呼吸机膜的研究文章,关键词为＂膜式,人工肺,生物材料＂。排除内容重复、普通综述及Meta分析类文章。共纳入20篇文献进行评价,中文文献11篇,英文文献9篇。结果与结论：目前人工肺膜的结构形式已从最初的卷筒式、平板折叠式发展到今天广为采用的微孔中空纤维膜式。用于制造中空纤维的材料主要为一些成纤性能良好的高分子材料,如聚丙烯、聚醚砜等。膜式人工肺可以提高气体交换能力和生物相容性。随着高新材料的开发、基础研究的深入和临床经验的积累,人工肺必将开创治疗重症呼吸系统疾患的新局面。     

人工肺的应用与肺膜材料性能评价

人工肺是在膜两侧进行气体、血液之间交换的场所，一般中空纤维是人工肺的主要部件。膜式人工肺是一种接近人体生理状态，较为理想的人工肺。它以人工合成的高分子材料制备的微孔膜作血液和气体的交换场所，完成人体的生理氧和过程，因而可暂时代替人体肺进行气体交换，用以支持生命以争取心、肺病变治愈及功能恢复的机会。膜式人工肺因选用的高分子材料、微孔膜的形式、血液和气体的流动方式的不同可有多种类型。但是至今还存在着未能解决的问题是与血液相接触的膜材料血液相容性仍不理想。本文从肺的功能出发，分析膜式人工肺的特点，探讨改善膜式人工肺血液相容性的方法及其发展方向     

人工肺膜材料的生物相容性评价

膜式人工肺已广泛应用于心血管手术的体外循环和呼吸衰竭的抢救治疗,即体外生命支持或体外膜氧合,血管内氧合器也已初步应用于临床.尤其对病重、心功能差、估计手术时间长的患者,膜式氧合器的使用更为必要.当前,通过改进膜材料、优化设计以及对各种件能的实验评估和临床评价,人工肺的研究着力于提高气体交换能力和提高生物相容性,为抢救患者的生命提供更可靠的手段.     

人工肺膜材料的生物相容性评价

人工肺又名氧合器,集氧合、变温、储血、过滤、回收血等功能于一体,将含氧量低的静脉血经过氧合后成为含氧量高的动脉血,是一种接近人体生理状态,较为理想的人工脏器.膜式人工肺已广泛应用于心血管手术的体外循环,也广泛应用于呼吸衰竭的抢救治疗,即体外生命支持或体外膜氧合,血管内氧合器也已初步应用于临床.尤其对病重、心功能差、估计手术时间长的患者,膜式氧合器的使用更为必要.当前,通过改进膜材料、优化设计以及对各种性能的实验评估和临床评价,人工肺的研究着力于提高气体交换能力和生物相容性,为抢救患者的生命提供更可靠的手段.     

国产希健Ⅰ型膜式氧合器的临床应用

国产希健Ⅰ型膜式氧合器集氧合、变温、储血为一体，是西京医疗用品有限公司研制的中空纤维外走血型膜式氧合器，已在全国各大医院广泛应用。     

膜式氧合器和鼓泡式氧合器对瓣膜置换病人呼吸功能的不同影响

目的　通过比较鼓泡式氧合器和膜式氧合器对瓣膜置换病人呼吸功能的不同影响阐明膜式氧合器良好的肺保护作用。方法　 80例风湿性心脏病瓣膜置换病人随机分为观察组和对照组各 40例 ,观察组术中使用膜式氧合器 ,对照组术中使用鼓泡式氧合器。分别测定两组病人术后血游离血红蛋白含量、动脉血氧分压和氧饱和度、辅助呼吸时间和主要肺部并发症发生率。结果　术后血游离血红蛋白含量、辅助呼吸时间、肺部并发症发生率观察组均低于对照组 (P均 <0 .0 5 )。术后动脉血氧分压和血氧饱和度两组差异不显著 (P >0 .0 5 )。结论　与鼓泡式氧合器相比 ,膜式氧合器具有良好的肺保护作用 ,瓣膜置换手术中可首选膜式氧合器。     

有关生物人工肝膜材料的一些问题

1 人工肝膜材料的基本要求? 出于安全考虑,大多数生物反应器采用膜材料将肝细胞与血液相隔离.无论是平板型还是中空纤维型膜材料血液透析器,都已被证实具有运送氧气和血液中溶质成分的能力,并且具有良好的血液、血浆生物相容性.     

生物人工肝系统的生物反应器

目的:介绍生物反应器的基本作用、功能、条件和要求,并对主要生物反应器的研究进展予以探讨.方法:由第一作者应用计算机检索PubMed数据库(http://www.ncbi.nlm.nih.gov/PubMed,英文)及CNKI数据库(www.cnki.net/index.htm,中文).检索时限1994-01/2009-08.中文检索关键词:生物人工肝,生物反应器,膜材料.英文检索关键词:bioartificial liver,bioreactor,membrane material.文献筛选、纳入标准:①选取针对性强,相关度高的文献.②对同一领域的文献选择近期发表或权威杂志的文献.③排除较陈旧的理论观点以及一些重复性研究.结果:计算机初检到150篇文献,阅读标题和摘要进行初筛,排除研究目的与本文无关的文献88篇,内容重复性研究32篇,共30篇文献符合标准.结果显示生物人工肝系统正在成为肝衰竭患者体外有效的肝支持治疗手段,生物反应器为肝细胞提供良好的生长代谢环境、物质交换及免疫隔离的平台,是人工肝最重要的组成部分.以纤维素半透膜为基础的生物反应器主要有平板式反应器、中空纤维型反应器,半透膜材料主要有混合纤维素酯膜、醋酸纤维素膜、铜仿膜、聚偏二氟乙烯膜、聚丙烯膜等.结论:生物反应器作为一个动态体系,伴随着生物反应器本身控制系统的优化,能够更好地控制反应器内部的传质,建立仿生物理化学梯度,实现肝细胞最小结构单元的模拟构建,膜材料的选择是构建人工肝支持系统生物反应器的首要和基础环节之一.     

体外膜肺氧合致活化凝血时间延长超极限的原因分析及护理

<正>体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)具有人工心和人工肺功能,是指将部分静脉血从体内引流到体外,再经膜式氧合器在体外完成氧合及二氧化碳清除后,由驱动泵将血液回输体内。ECMO通过对循环呼吸功能较长时间的有效辅助使心肺得到充分地休息,支持期间保证全身氧供,维持机体内环境和血流动力学的相对稳定,为心肺功能的恢复赢得时间[1]。     

Anionic nanoparticle-lipid membrane interactions: the protonation of anionic ligands at the membrane surface reduces membrane disruption

Monolayer-protected gold nanoparticles (Au NPs) are promising biomedical tools with applications in diagnosis and therapy, thanks to their biocompatibility and versatility. Here we show how the NP surface functionalization can drive the mechanism of interaction with lipid membranes. In particular, we show that the spontaneous protonation of anionic carboxylic groups on the NP surface can make the NP-membrane interaction faster and less disruptive.

The interaction between anionic Au nanoparticles and model lipid membranes is facilitated by the spontaneous protonation of the NP ligand carboxylate groups, COO⁻˙ → COOH, in the lipid headgroup region.     

Placental membrane transport

Brush border (microvillous) plasma membranes (BBM) and the basal surfaces (BCM) from the syncytiotrophoblast of human term placenta were prepared by a method of sonication, dialysis and differential centrifugation in specific buffer systems. Such plasma membranes formed closed, osmotically active, right-side-out vesicles in which amino acid transport could be studied unidirectionally by a carefully designed membrane filtration assay under reduced pressure. In such vesicles,l-leucine (1 mM) was found to be transported in a time-dependent manner, peak accumulation being attained at 45 s in both BBM and BCM. The accumulation of leucine in the vesicles was dependent on an inward NaCl gradient, as replacing the Na⁺with K⁺, Li⁺and choline, or replacing the Cl^? with SO ₄ ^2? failed to influence the amino acid movement. Leucine transport in the vesicles also appeared to be dependent on the substrate concentration, indicating saturation at a higher concentration. The transport process showed a k_t (affinity constant) of 3.85 and 6.67 mM, while the values recorded for the J_max (maximum apparent initial velocity) were 270.27 and 384.62 nmol/mg protein^?1 per min in the BBM and BCM respectively. Leucine transport was inhibited by a number of amino acids, among which amino isobutyric acid (AIB) produced the maximum inhibition. The k_i (inhibition constant) for different amino acids has also been listed. Lysine showed the least k_i value, thus showing it to be the most inhibitory compound. These findings are discussed in relation to the mechanism and regulation of transplacental amino acid transfer.     

Extracorporeal membrane oxygenation

PURPOSE OF REVIEW: Extracorporeal membrane oxygenation (ECMO) has become a more or less accepted standard in the algorithm of advanced acute respiratory distress syndrome therapy in adult patients when all other treatment options have failed. This article reviews the current status of ECMO therapy with particular focus on new technical developments and their potential implications for performance and indications for ECMO therapy. RECENT FINDINGS: A recently published review on a single-center experience in 255 adult ECMO patients identified using multivariate logistic regression analysis age, sex, initial pH 7.10 or lower and PaO2/FiO2 ratio, and days of mechanical ventilation before ECMO as a significant predictors of survival. Additionally, a careful cost-effectiveness study for neonatal ECMO relating a 4-year base to the UK neonatal ECMO trial has clearly demonstrated cost-effectiveness. SUMMARY: Over the years, the technique for ECMO therapy underwent substantial changes in indications and the materials used. Impressive technical progress has been made in pumps, oxygenators, and coating of artificial surfaces, leading to a higher biocompatibility and to a lower rate of procedure-related complications. The potential of new inline pumps in combination with a decreasing rate of procedure-related complications might lead to a re-evaluation of the role of extracorporeal lung support in acute respiratory distress syndrome therapy. A very recent development is the use of spontaneous arteriovenous devices for carbon dioxide removal, allowing significant reduction of ventilator settings at decreased carbon dioxide partial pressures and at increased pH values. Ongoing studies are looking at the potential of this approach to reduce side effects of mechanical ventilation further.     

Association between the glycation of erythrocyte membrane proteins and membrane fluidity

Erythrocyte membrane ghosts prepared from normal individuals were incubated in vitro at different glucose concentrations for 72 h. Incubation with increasing concentrations of glucose resulted in increased glycation (nonenzymatic glycosylation) of membrane proteins and a decrease of erythrocyte membrane fluidity measured by the use of the fluorescent label pyrene. It would therefore seem likely that the changes in erythrocyte membrane fluidity previously reported in diabetic subjects (1-3) are related to in vivo glycation of membrane proteins as well as to changes in lipid composition, as was previously suggested (2).     

红细胞膜蛋白异常与膜骨架相关溶血性贫血的发生

红细胞膜为双层磷脂结构,其间镶嵌着多种膜蛋白。这些膜蛋白包括包埋在脂质双分子层中的整合蛋白及存在于膜内侧的细胞膜骨架蛋白,而后者与红细胞膜缺陷所致的