聚甲基丙烯酸丁酯／纳米二氧化硅涂层支架的生物相容性研究

目的评价不锈钢支架聚甲基丙烯酸丁酯,纳米二氧化硅涂层的生物相容性。方法聚甲基丙烯酸丁酯,纳米二氧化硅涂层支架与裸金属支架分别置入犬冠状动脉回旋支,每组9只,术后4周时行冠状动脉造影及组织病理学分析,涂层组支架置入前与置入后4周采集血清样本做肝肾功能检测。结果两组犬4周时冠状动脉造影显示支架段管腔狭窄,无血栓形成、栓塞及动脉瘤,光学纤维镜下未见内膜下出血和中层坏死,无附壁血栓,无明显炎症细胞浸润;扫描电子纤维镜显示所有支架段血管基本内皮化,管壁无血小板和纤维蛋白沉积。两组犬损伤积分差异无统计学意义（P〉0．05）,新生内膜厚度、管腔面积、管腔面积狭窄率及内膜平滑肌细胞百分率比较差异无统计学意义（P〉0．05）,涂层支架置入后与置入前比较对肝肾功能无明显影响（P〉0．05）。结论不锈钢支架聚甲基丙烯酸丁酯,纳米二氧化硅涂层具有良好的生物相容性,不引起严重的局部组织反应,可用于药物洗脱支架的制作。     

Paclitaxel releasing films consisting of poly(vinyl alcohol)-graft-poly(lactide-co-glycolide) and their potential as biodegradable stent coatings.

Although substantial progress in catheter and stent design has contributed to the success of percutaneous transluminal angioplasty (PTA) of atherosclerotic disease, the incidence of restenosis caused by in-stent neointimal hyperplasia remains a serious problem. Therefore, stents with a non-degradable polymer coating showing controlled release of active ingredients have become an attractive option for the site-specific delivery of anti-restenotic agents. Biodegradable coatings using polyesters, namely poly(lactic-co-glycolic acid) (PLGA) and different poly(vinyl alcohol)-graft-poly(lactic-co-glycolic acid) (PVA-g-PLGA) as paclitaxel-eluting stent coating materials were investigated here to evaluate their influence on the release kinetic. Whereas PLGA showed sigmoid release behavior, the paclitaxel release from PVA-g-PLGA films was continuous over 40 days without initial drug burst. Wide angle X-ray diffraction confirmed that paclitaxel is dissolved in the polymer matrix. Paclitaxel crystallization can be observed at a drug load of > or =10%. The effect of drug loading on polymer degradation was studied in films prepared from PVA300-g-PLGA30 with paclitaxel loadings of 5% and 15% over a time period of 6 weeks. The results suggest a surface-like erosion mechanism in films. A model stent (Jostent peripheral) coated with Parylene N, a poly(p-xylylene) (PPX) derivate, was covered with a second layer of PVA300-g-PLGA15, and PVA300-g-PLGA30 by using airbrush method. Morphology of coated stents, and film integrity after expansion from 3.12 to 5 mm was investigated by scanning electron microscopy (SEM). The devices resisted mechanical stress during stent expansion and merit further investigation under in vivo conditions.     

电纺纳米纤维可降解输尿管支架肌肉埋植的降解性能

背景:作者前期研究了电纺纳米纤维聚乳酸-羟基乙酸共聚物可降解输尿管支架材料的体外降解性能,发现80/20聚乳酸-羟基乙酸共聚物电纺纳米纤维材料在尿液中的降解时间可以满足临床需要。目的:观察80/20聚乳酸-羟基乙酸共聚物电纺纳米纤维输尿管支架的肌肉埋植降解性能。方法:采用静电纺丝法制备80/20聚乳酸-羟基乙酸共聚物纳米纤维输尿管支架,观察其在家兔脊柱旁肌肉中的降解情况。结果与结论:成功制备了电纺纳米纤维输尿管支架,扫描电镜见微观形貌良好。80/20的聚乳酸-羟基乙酸共聚物纳米纤维输尿管支架在体内降解至10周时,支架管降解至初始质量的60%左右,支架出现断裂和崩解,虽降解速度较体外降解稍慢,但其降解性能仍能够满足临床对可降解输尿管支架的需要。     

电纺纳米纤维可降解输尿管支架肌肉埋植的降解性能

背景：作者前期研究了电纺纳米纤维聚乳酸-羟基乙酸共聚物可降解输尿管支架材料的体外降解性能,发现80/20聚乳酸-羟基乙酸共聚物电纺纳米纤维材料在尿液中的降解时间可以满足临床需要。目的：观察80/20聚乳酸-羟基乙酸共聚物电纺纳米纤维输尿管支架的肌肉埋植降解性能。方法：采用静电纺丝法制备80/20聚乳酸-羟基乙酸共聚物纳米纤维输尿管支架,观察其在家兔脊柱旁肌肉中的降解情况。结果与结论：成功制备了电纺纳米纤维输尿管支架,扫描电镜见微观形貌良好。80/20的聚乳酸-羟基乙酸共聚物纳米纤维输尿管支架在体内降解至10周时,支架管降解至初始质量的60%左右,支架出现断裂和崩解,虽降解速度较体外降解稍慢,但其降解性能仍能够满足临床对可降解输尿管支架的需要。     

Poly(ethylene carbonate): a thermoelastic and biodegradable biomaterial for drug eluting stent coatings?

A first feasibility study exploring the utility of poly(ethylene carbonate) (PEC) as coating material for drug eluting stents under in vitro conditions is reported. PEC (Mw 242 kDa, Mw/Mn=1.90) was found to be an amorphous polymer with thermoelastic properties. Tensile testing revealed a stress to strain failure of more than 600%. These properties are thought to be advantageous for expanding coated stents. In vitro cytotoxicity tests showed excellent cytocompatibility of PEC. Based on these findings, a new stenting concept was suggested, pre-coating a bare-metal stent with PPX-N as non-biodegradable basis and applying a secondary PEC coating using an airbrush method. After manual expansion, no delamination or destruction of the coating could be observed using scanning electron microscopy. The surface degradation-controlled release mechanism of PEC may provide the basis for "on demand" drug eluting stent coatings, releasing an incorporated drug predominantly at an inflamed implantation site upon direct contact with superoxide-releasing macrophages. As a release model, metal plates of a defined size and area were coated under the same conditions as the stents with PEC containing radiolabelled paclitaxel. An alkaline KO(2-) solution served as a superoxide source. Within 12 h, 100% of the incorporated paclitaxel was released, while only 20% of the drug was released in non-superoxide releasing control buffer within 3 weeks.     

Development of biodegradable zein-based bilayer coatings for drug-eluting stents

Drug-eluting stents (DES) have been widely used for the treatment of cardiovascular diseases. Nevertheless, chronic inflammation and delayed re-endothelialization still represent challenges for their clinical use. In the present work, we developed novel bilayer coatings for stent applications that could overcome these limitations, exclusively using biodegradable plant-based drugs and polymers. In particular, stainless steel surfaces were coated with rutin-loaded zein (the active layer) and cross-linked alginate (the sacrificial layer) via facile dip and spray coating methods. Various mechanical tests and analysis tools, such as infrared spectroscopy, water contact angle measurements, and scanning electron microscopy were used to characterize the coated surfaces. Degradation and release studies of the films were extensively carried out and compared. The release rate of rutin from the bilayer coating reached 66.1 ± 3.2% within 24 hours of incubation (initial burst period), while the rest of the drug was released over 21 days in a sustained manner. Antioxidant assays confirmed that rutin retained its free radical scavenging ability after being eluted in phosphate buffer at 37 °C. In vitro results with human fibroblasts and endothelial cells suggested that the coating materials and their degradation products are highly biocompatible. In conclusion, our novel drug-eluting coatings, fabricated with natural biodegradable polymers, are promising materials for DES applications, allowing a sustained drug delivery and improving the biocompatibility of cardiovascular implanted devices.

Zein-based biodegradable bilayer coatings were successfully prepared and characterized. Release profiles, antioxidant potential, and biocompatibility were investigated, aiming for more sustainable coatings for drug-eluting stents.     

A novel drug-eluting stent spray-coated with multi-layers of collagen and sirolimus.

In the study, a novel drug-eluting stent for treating the coronary arterial stenosis was developed. Using a spray-coating method, aqueous bovine type I collagen and sirolimus were coated layer-by-layer alternatively onto the surface of a metallic stent and a topcoat of collagen was used as a barrier to control drug release. To prevent dissolution of the collagen matrices, the spray-coated collagen was further crosslinked by genipin, a naturally occurring crosslinking agent. The results obtained in the atomic force microscopy (AFM) examination suggested that the spray-coated collagen was tightly adhered to the surface of the stent. Additionally, the collagen coating was demonstrated by the scanning electron microscopy (SEM) to be sufficiently flexible to allow balloon expansion of the stent without cracking or peeling from the wire. The resistance against enzymatic degradation and the hemocompatibility of the collagen matrices increased significantly as their degree of crosslinking increased. All the studied sirolimus-loaded stents exhibited a nearly linear sustained-release profile (except at the end stage of release) with no significant burst releases. It was found that a topcoat of collagen on the collagen/sirolimus coated stent did slow down the release of sirolimus to some extent. Additionally, the number of layers of collagen/sirolimus coated significantly affected the duration of sirolimus released. Furthermore, the sustained-release duration of sirolimus was proportional to the actual amount of drug loaded on the stent. The aforementioned results indicated that the drug-eluting stent developed had a tightly adhered collagen coating and can be used as a drug reservoir to sustain release of sirolimus.     

不同类型脑血管支架材料的特点及临床应用

背景：随着基础研究、临床应用,以及血管支架材料的不断发展,血管内支架置入治疗已被广泛应用于脑血管疾病治疗中。目的：综述这几种支架材料的特点及临床应用情况。方法：应用计算机检索CNKI数据库、万方数据库、PubMed数据库从建库到2014年3月的相关文献,中文检索关键词为“脑血管病,支架,生物相容性”,英文检索关键词为“cerebrovascular disease,stents, biocompatibility”。结果与结论：按释放方式可将脑血管支架分为球囊扩张式支架与自膨式支架。最初应用的支架材料主要为裸金属材料,由记忆合金、医用不锈钢、钽、钴、镍钛合金等制成。由于金属支架置入后会释放金属离子,易致血栓形成,再狭窄率高,后来对其表面进行改性,出现了涂层支架与覆膜支架。支架置入治疗的围手术期并发症主要有过度灌注综合征、急性血栓形成、血管破裂和远端血管栓塞、血管痉挛和穿刺相关并发症,远期并发症主要是支架置入后再狭窄问题。相信随着科技的进步,支架材料和制作工艺的不断改进,血管支架置入治疗将更加安全有效。     

64 MSCT对冠状动脉支架通畅性评价的准确性与支架材料的关系

目的：探讨64 MSCT对冠状动脉支架通畅性评价的准确性以及与支架材料的关系。方法：采用64排螺旋CT对42例冠状动脉支架植入术后的患者（共89个支架，其中不锈钢支架32个，镍钛合金支架57个）进行MSCT冠状动脉成像，观察支架的通畅性以及与支架材料的关系。并与传统冠状动脉造影（CAG）对照。结果：32个不锈钢支架中，CAG显示正常23个（包括支架内再狭窄<50%），支架内再狭窄（ISR）9个（ISR≥50%）；57个镍钛合金支架中，CAG显示正常47个（包括ISR<50%），狭窄10个（ISR≥50%）。与CAG对照，MSCT正确诊断不锈钢支架狭窄4个（ISR≥50%），正常（包括ISR<50%）18个，不能评价1个。镍钛合金支架狭窄9个（ISR≥50%），正常（包括ISR<50%）45个。MSCT对不锈钢支架和镍钛合金支架狭窄的敏感性、特异性、阳性预测值和阴性预测值分别为44%，81.8%，50%，78%和90%，95.7%，81.8%，97.8%。MSCT对不同材料支架通畅性评价有显著性差异（P＜0.05）。结论：64 MSCT冠脉成像是评价镍钛合金冠脉支架通畅性的一种安全可靠的方法，但对不锈钢支架评价有一定局限性。     

冠状动脉药物涂层支架与置入后的血管再狭窄

背景：近年来随着药物涂层支架研究的增多及临床应用不断扩大,使冠状动脉内支架置入后再狭窄率显著降低,且在预防再狭窄中较裸支架具有独特应用价值。目的：阐述药物涂层支架的临床应用进展,并探讨支架的涂层材料、类型与置入后再狭窄的关系及与宿主的相容性。方法：作者以＂冠脉支架,金属支架,药物涂层支架,再狭窄＂为检索词,在中国期刊全文数据库及Medline数据库中,采用电子检索的方式进行文献检索。排除Meta分析及重复性研究,共检索到27篇文献。结果与结论：药物涂层支架的确是介入心脏病学的一项重要突破,使介入心脏病学进入了一个新的时代,但其远期效果仍需进一步观察。各种药物涂层支架所含药物或含量不同,其作用机制不同,而且药物释放的速率也不同,所以药物涂层支架临床应用后的效用和安全性需要由严谨和大量的临床研究来证实。现今药物支架的载体材料经过长时间的人体腐蚀,材料本身会老化、脱落,在血管组织内形成小块,从而可能引起晚期的不良反应。如果采用生物可降解的材料作为药物载体材料,那么就有可能减少晚期不良反应的出现。因此,开发一种理想的支架系统,目前主要的研究方向是可降解的低致炎性聚合物材料以及高效的药物控释体系。     

生物可降解高分子材料载内皮前体细胞CD34抗体涂层支架防治犬冠脉再狭窄的研究

目的评估携带内皮前体细胞CD34抗体冠脉内支架对冠状动脉支架置入术后血管内膜增生的影响。方法以多聚物为载体应用N-琥珀酰亚胺基-3-（2-吡啶二硫）-丙酸酯（SPDP）方法制成内皮前体细胞CD34抗体洗脱支架。以球囊扩张法建立犬冠状动脉狭窄模型，随机分为三组，每组5只，将紫杉醇支架、CD34抗体支架、裸支架分别植入到每组犬的冠状动脉狭窄段，4周后处死取出支架段血管行病理学观察及计算机图像分析血管总面积（TA）、内膜增生面积（IA）以及内膜增生面积百分比。结果CD34抗体支架组内膜增生面积及内膜增生百分比较裸支架组减低（P〈0．05），紫杉醇支架组内膜增生面积及内膜增生百分比较裸支架组也减低（P〈0．05），但较CD34抗体支架组无明显差别（P〉0．05）。结论生物可降解担载内皮前体细胞CD34抗体支架较裸支架，可明显加速内皮修复，明显隆低再德窄的枯毕．县一极具前景的研究方向。     

PEG-PLA-PGL／RGD 涂层支架对冠脉支架置入术后再狭窄的影响

目的 探 PEG-PLA-PGL/RGD 涂层支架置入后对猪冠状动脉内皮化及内膜增生的影响。方法 以 PEG-PLA-PLG 聚脂肪酸为载体,通过载体接枝精氨酸-甘-天冬氨酸三肽聚合物（RGD）,制成生物可降解高分子载 RGD冠脉支架。实验分为裸支架组、紫杉醇涂层支架组、PEG-PLA-PGL/RGD 涂层支架组,每组实验小型猪6只,将相应支架分别置入到每组猪的冠状动脉损伤段,分别4周及12周后处死,取出支架段血管行病理学观察及计算机图像分析测定管腔面积（lumen area,LA）、内弹力膜面积（internal elastic membrane area,IEMA）,并根据 LA 及 IEMA 计算出新生内膜面积（neointima area,NA）及面积狭窄百分数（percentage of area stenosis,％AS）。结果 PEG-PLA-PGL/RGD 涂层支架组内膜增生面积较裸支架组明显减低（P ＜0．05）,PEG-PLA-PGL/RGD 涂层支架组内膜增生面积与紫杉醇涂层支组无明显差别（P ＞0．05）。结论 PEG-PLA-PGL/RGD 涂层支架较裸支架,可明显加速内皮修复,明显降低再狭窄的发生,是一极具前景研究方向。     

多层螺旋CT评价靶血管通畅性图像的质量:冠状动脉支架材料及其结构有影响吗?

背景:由于金属材料对多层螺旋CT图像有伪影干扰作用,支架结构中金属管壁厚度和管腔内径也可明显影响多层螺旋CT靶血管支架内纵轴成像质量,但目前仅有少量报道涉及到这方面的问题.目的:观察不同材料的冠状动脉支架及其结构对多层螺旋CT评价靶血管通畅性图像质量的影响,希望实验数据能为改进和完善支架技术提供参考.设计、时间及地点:对比观察,于2006-01/2008-12在沈阳医学院沈洲医院及中国医科大学附属盛京医院完成.对象:纳入接受支架置入的冠状动脉粥样硬化性心脏病患者139例,共置入支架227枚,按置入支架材料和结构分组.不锈钢支架92枚,镍钛合金支架135枚:薄金属壁支架(<140 μm)85枚,厚金属壁支架(≥140 μm)142枚;小直径支架(<3 mm)71枚,大直径支架(≥3 mm)156枚.方法:随访期间采用64层螺旋CT机进行冠状动脉扫描,并做常规冠状动脉造影检查,比较不同组别靶血管通畅性图像质量的差异.主要观察指标:采取4分制进行多层螺旋CT图像质量评分,评价多层螺旋CT的敏感度、异度、准确度、阳性预期值与阴性预期值.结果:139例患者共置入支架227枚,按支架材料分组后,不锈钢支架组CT图像质量较差处明显多于镍钛合金组,前者的平均CT图像质量评分、敏感性、特异性、阳性和阴性预测值均明显低于镍钛合金组(P均<0,05).按支架厚度分组后,厚会属壁支架组CT图像质量较差处明显多于薄金属壁支架组,前者的平均CT图像质量评分、敏感性、特异性、阳性和阴性预测值均明显低于薄金属壁支架组(P均<0.05).按支架直径分组后,小直径支架组CT图像质量较差处明显多于大直径支架组,前者的平均CT图像质量评分敏感性、特异性、阳性和阴性预测值均明显低于大直径支架组(P均<0.05).结论:冠状动脉支架金属材料、金属壁厚度和管腔直径均可能影响多层螺旋CT靶血管成像质量.     

颅内动脉狭窄支架置入与植入材料的生物相容性

背景：颅内动脉狭窄支架按照结构和材质可将血管内支架分为金属支架、聚合物支架、涂层支架等类型。那么哪一种支架更具临床应用价值呢？目的：对颅内动脉狭窄支架置入治疗的理论、应用、并发症及疗效进行评定,并分析植入材料的生物相容性。方法：应用计算机应用计算机检索PubMed数据库及西文生物医学期刊文献数据库（EMCC）2000-01/2010-10期间的相关文章,检索词为＂Intracranial arterial stenosis,stent Implantation＂,并限定文章语言种类为English。同时计算机检索中国期刊全文数据库（CNKI）等2000-01/2010-10期间的相关文章,检索词为＂颅内动脉狭窄,支架置入＂,并限定文章语言种类为中文。此外还手工查阅相关专著数部。纳入不同材料支架置入治疗颅内动脉狭窄的研究,包括基础研究、临床应用、并发症及材料的生物相容性评定。初检得到151篇文献,根据纳入标准选择33篇文章进行分析。结果与结论：颅内动脉狭窄的支架置入治疗较单纯药物治疗有明显的优势。近年来,随着冠脉支架及Wingspan支架的运用,支架治疗颅内动脉狭窄已成为一种安全有效的方法。虽然支架置入治疗后会发生不同并发症如再狭窄、脑出血高灌注综合征、缺血性脑卒中等,但支架治疗颅内动脉狭窄在短期及中期有很好的疗效,同时远期疗效还有待进一步研究。提示,支架置入治疗颅内动脉狭窄是一种安全的方法,短、中期内有效,但远期疗效有待进一步研究。药物涂层支架和Wingspan支架与人体的生物相容性并没有显著差异,尚待进一步论证。     

脑血管置入材料的生物相容性及并发症

背景：虽然支架置入技术的发展为脑血管疾病提供了较为有效的治疗手段,但其安全性和有效性还有待进一步验证。目的：阐述脑血管支架与宿主间的生物相容性,分析支架置入并发症的原因,并探讨管理方法。方法：以＂脑血管病,支架,生物相容性,并发症＂和＂Cerebrovascular disease,stents,biocompatibility,complication＂为检索词,计算机检索中国期刊全文数据库、PubMed数据库（1993-01/2010-11）与脑血管支架生物相容性、支架置入治疗并发症相关的文章,按纳入和排除标准对文献进行筛选,重点对18篇文章进行分析讨论。结果与结论：脑血管支架临床应用较多的是颅内支架,由于血管的管径限制支架的直径,不同病变对支架直径的要求不同。支架置入并发症主要有腹膜后血肿,颈动脉窦反应,高灌注综合征,脑血管痉挛和血栓形成。在各种脑血管支架中,金属支架生物相容性较差,聚合物支架、涂层支架和药物支架生物相容性均好于金属支架,能有效的预防支架置入后的再狭窄。治疗过程中进行充足的置入前准备,选择合适的支架类型,严格遵循适应证,支架置入中仔细观察病情变化,置入后良好的监测和管理可预防并发症的发生。     

种植骨髓间充质干细胞脑血管支架的性能评价

背景：一般认为对支架表面进行修饰,尤其是种植细胞,可能会加速或导致其内皮化,避免支架内血栓形成而引起再狭窄的发生。目的：寻找骨髓间充质干细胞种植血管支架的最佳条件。方法：将1×10^6,1×10^7,1×10^8,1×10^9 L-1的第3代大鼠骨髓间充质干细胞分别接种至不锈钢血管支架制备细胞-支架复合物,接种48 h后电镜观察细胞形态变化。取SD大鼠160只,20只为正常对照组,其余140只制作缺血性脑卒中模型,造模8周后随机分为7组,分别植入不锈钢支架、高分子材料支架及不同浓度细胞-支架复合物,以不植入任何材料的为模型对照。植入后8周,蛋白免疫印迹技术检测植入支架上细胞的血管内皮生长因子表达,流式细胞仪检测各组大鼠血小板活化。结果与结论：种植的干细胞均能在不锈钢支架上贴壁生长,当细胞浓度为1×10^7 L-1时,上皮样细胞完整覆盖支架,细胞及细胞器形态正常。缺血性脑卒中模型实验中,1×10^7 L-1细胞-支架组细胞生长良好,在血管内环境诱导下具有良好的内皮化趋势,并且可显著抑制血小板活化。表明当细胞种植浓度为1×10^7 L-1时制备的血管支架通畅,具有良好的生物学效应。     

Is stent thrombosis the new Achilles heel of interventional cardiology? State of the Art clinical trials, causes and approaches for prevention

Coronary stents are the mainstay of percutaneous coronary intervention. Stent thrombosis is a potentially catastrophic and often life-threatening complication. If it occurs it presents in up to 80% as myocardial infarction, about half of the affected patients die from this complication. The dual antiplatelet therapy has markedly reduced its occurrence. Today, stent thrombosis occurs in <1%, usually as a delayed event; but compared to bare metal stents the overall incidence has not increased in meta-analyses of randomized trials. The advent of drug-eluting stents (DES) has raised concerns regarding the occurrence of delayed stent thrombosis. Delayed arterial wall healing as well as prothrombotic characteristics of the drug eluting stent itself may contribute to stent thrombosis. In order to prevent stent thrombosis a standardized fixed dose antiplatelet therapy with ASA and clopidogrel is recommended. But, their efficacy depends on patient's individual characteristics such drug metabolism. Therefore, individual determination of platelet function in each patient undergoing stent implantation may help to avoid prothrombotic as well as bleeding complications.     

Current and future drug-eluting coronary stent technology

Despite the impressive benefits obtained following the introduction of the drug-eluting stent, safety concerns have been raised over their long-term safety with particular regard to stent thrombosis. Various mechanisms such as delayed endothelialization, local hypersensitivity and endothelial dysfunction owing to the durable polymer coating and/or the drug itself have been suggested as possible causes of this phenomenon. Therefore, to address these concerns, a newer-generation of drug-eluting stents has been developed and they are currently undergoing preclinical and clinical evaluation in order to increase both the safety and biocompatibility by optimizing the three major components of drug-eluting stents: the stent platform, the polymer and the drug. This article critically reviews the key clinical trials and the current status of these new coronary devices as well as preventing future perspectives for their continued development.     

冠状动脉药物涂层支架与置入后的血管再狭窄

背景:近年来随着药物涂层支架研究的增多及临床应用不断扩大,使冠状动脉内支架置入后再狭窄率显著降低,且在预防再狭窄中较裸支架具有独特应用价值.目的:阐述药物涂层支架的临床应用进展,并探讨支架的涂层材料、类型与置入后再狭窄的关系及与宿主的相容性.方法:作者以"冠脉支架,金属支架,药物涂层支架,再狭窄"为检索词,在中国期刊全文数据库及Medline 数据库中,采用电子检索的方式进行文献检索.排除Meta分析及重复性研究,共检索到27篇文献.结果与结论:药物涂层支架的确是介入心脏病学的一项重要突破,使介入心脏病学进入了一个新的时代,但其远期效果仍需进一步观察.各种药物涂层支架所含药物或含量不同,其作用机制不同,而且药物释放的速率也不同,所以药物涂层支架临床应用后的效用和安全性需要由严谨和大量的临床研究来证实.现今药物支架的载体材料经过长时间的人体腐蚀,材料本身会老化、脱落,在血管组织内形成小块,从而可能引起晚期的不良反应.如果采用生物可降解的材料作为药物载体材料,那么就有可能减少晚期不良反应的出现.因此,开发一种理想的支架系统,目前主要的研究方向是可降解的低致炎性聚合物材料以及高效的药物控释体系.