Peptides surface modification to prevent stent blockage

肽表面修饰以防止支架堵塞

• 批准号: 6867449
• 负责人: Joseph W Leung
• 金额: $ 14.5万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6867449
• 关键词: Enterococcus; Escherichia coli; beta glucuronidase; bile ducts; biliary tract; bilirubin; biofilm; blood vessel prosthesis; calcium ion; combinatorial chemistry; confocal scanning microscopy; disease /disorder prevention /control; enzyme activity; fluorescence microscopy; high throughput technology; implant; infection; jaundice; medical implant science; peptide library; peptides; plastics; scanning electron microscopy; surface coating; technology /technique development

DESCRIPTION (provided by applicant): Biliary stent blockage is the major complication of endoscopic stenting for the palliation of malignant obstructive jaundice. Bacteria adhere to the stent surface with their pili and also through the production of glycocalyx to form a bacterial biofilm. Biliary stents become blocked as a result of bacterial biofilm formation and accumulation of sludge within the lumen of the stent. Biliary sludge formed as a result of deconjugation of bilirubin diglucuronide by bacterial Beta-glucuronidase, resulting in the precipitation of calcium bilirubinate. This is attributed to enzymatic activities of aerobic bacteria such as E. coli and anaerobic bacteria such as C. perfringens. Different methods have been tried to prevent bacterial attachment and stent blockage including use of different plastic materials, changing stent designs, biocide impregnation and systemic antibiotic prophylaxis. However, none of these methods have produced significant clinical benefits. Small molecular peptides may influence the bacterial expression of gene/enzyme activities and affect their adherence characteristics. In this project, we explore the potential benefits of peptide surface modification using the "one-bead one-compound" combinatorial library method. This novel high through put technique can screen large numbers of different peptides that may affect bacterial adherence. In the first part of the experiment, we study the interaction between single bacteria E. coli and a mixed culture of E. coli and Enterococcus with a number of pre-generated peptide surfaces to identify peptide(s) that resist bacterial attachment. The amino acids sequence of these selected peptides are identified using automatic microsequencing. Large quantity of the specific purified resistant peptides are then synthesized and used to coat and modify plastic stents. The effects of these resistant peptide coated stents in delaying or preventing bacterial attachment is then tested with a special flow chamber or Modified Robbins Device. If significant benefit is observed with the in-vitro studies, a randomized controlled clinical study will be proposed to determine the benefits of the resistant peptide coated stents. The results may shed new lights in the prevention of chronic implanted medical device related infections and specifically in prolonging plastic stent patency.

描述(申请人提供)：胆道支架阻塞是内窥镜支架姑息性治疗恶性梗阻性黄疸的主要并发症。细菌与其菌毛附着在支架表面，也通过产生糖萼形成细菌生物膜。由于细菌生物膜的形成和支架管腔内淤泥的积累，胆道支架被堵塞。胆汁淤泥是细菌β-葡萄糖醛酸苷酶使胆红素二葡糖醛酸解结合而形成的，导致胆红素钙沉淀。这归因于需氧细菌(如大肠杆菌)和厌氧细菌(如产气假单胞菌)的酶活性。 人们尝试了不同的方法来防止细菌附着和支架堵塞，包括使用不同的塑料材料，改变支架设计，生物杀菌剂浸渍和全身抗生素预防。然而，这些方法都没有产生显著的临床益处。 小分子多肽可能影响细菌基因/酶活性的表达，影响其黏附特性。在这个项目中，我们探索了使用“一珠一化合物”组合文库方法进行多肽表面修饰的潜在好处。这种新颖的高通量放置技术可以筛选出大量可能影响细菌黏附的不同多肽。 在实验的第一部分，我们研究了单个细菌与具有多个预生成肽表面的大肠杆菌和肠球菌混合培养物之间的相互作用，以鉴定抵抗细菌附着的多肽(S)。利用自动微测序鉴定这些选定的多肽的氨基酸序列。然后合成大量的特定纯化的抗性多肽，并将其用于包裹和修饰塑料支架。然后用特殊的流动室或改良的Robbins装置测试这些耐药多肽涂层支架在延缓或防止细菌附着方面的效果。如果在体外研究中观察到显著的益处，将建议进行一项随机对照临床研究，以确定耐药多肽涂层支架的益处。这一结果可能会为预防慢性植入医疗器械相关感染，特别是延长塑料支架通畅率带来新的曙光。