CAREER: High-Density Non-Fouling Bioactive Coatings for Processing of Biological Fluids

职业生涯1553183-细菌性败血症是一种常见的危及生命的疾病，每年仅在美国就导致数十万美国人死亡，造成约200亿美元的损失。目前脓毒症是用抗生素治疗的，但这不能清除循环中的死亡细菌和它们的细胞膜碎片(内毒素)，这可能会引起严重的免疫反应。降低这种风险的一个有希望的方法是让患者的血液通过一个设备捕获循环中的内毒素，帮助稳定免疫系统，并有可能改善他们的预后。然而，对于这种应用，所有与血液接触的材料必须是生物相容的(即抵抗污垢或凝结，并且不会引起不良的生物反应)。对于脓毒症的治疗，表面还必须以受控的方向和高密度提供内毒素结合剂。这些生物活性和生物相容的涂层必须廉价且易于应用于各种材料，包括用于医疗器械、针头、软管和其他相关设备的塑料。生物相容性和生物活性涂层可能会对脓毒症治疗的安全性和有效性产生革命性影响，即使是轻微的改善也可以导致许多人的生命和大量资金的节省。在其他生物医学应用中，这项技术还可以赋予各种其他家用、消费和工业产品生物活性。该项目的综合教育活动预计将实现以下好处：(A)研究概念将被纳入俄勒冈州立大学(OSU)的生物工程课程，实践学习模块将适用于俄勒冈州立大学的STEM学院，供大学预科学生使用；(B)该项目将与俄勒冈州立大学商学院合作，为该组织的研究生和教师提供夏季“创业训练营”。该项目的研究将通过以表面活性剂为基础的固定化引发剂进行活性聚合，开发高密度、无污垢的生物活性涂层(HNB‘s)，在表面生产支化的亲水性聚合物刷子。这种涂层本质上是一种超薄的固定化水凝胶，将提供出色的抗蛋白质吸附和细胞相互作用(生物兼容性)。为了在水凝胶表面赋予生物活性，将使用近乎理想的生物正交连接(BOL)将酶、多肽、多糖或其他生物活性分子固定在刷子的外围。这种化学使活性分子的稀溶液能够定量结合，从而精确地控制表面官能化。未反应的基团在生物上是相容的，在化学上是惰性的。多肽或蛋白质的经济固定化是通过遗传密码扩展(GCE)提供的，在GCE中，工程微生物表达活性蛋白，其中Bol反应基团结合在基因控制的位置。由此产生的仅从粗细胞裂解液中特定固定化所需的蛋白质，省去了昂贵的纯化或预浓缩步骤，并保证蛋白质处于精确定义的方向以获得最大的生物活性。虽然这项工作的主要目标是展示用于从血液中捕获病原体的设备的生物相容性和生物活性涂层，但还有许多其他潜在用途，例如更安全的医疗设备、食品加工、制药生产、活性包装和自清洁织物。

CAREER 1553183 - SchilkeBacterial sepsis is a common and life-threatening condition which kills hundreds of thousands of Americans and costs ~$20 billion every year in the U.S. alone. Sepsis is currently treated with antibiotics, but this does not remove the circulating dead bacteria and fragments of their cell membranes (endotoxin), which could cause a serious immune response. One promising method to mitigate this risk involves passing a patient's blood through a device to capture circulating endotoxin, helping to stabilize the immune system and potentially to improve their prognosis. However for this application, all materials in contact with blood must be biocompatible (i.e. resist fouling or clotting, and not induce an adverse biological response). For treatment of sepsis, surfaces must also present endotoxin-binding agents in controlled orientations and at high density. These bioactive and biocompatible coatings must be inexpensive and easy to apply to a wide range of materials, including plastics used in medical devices, needles, flexible tubing, and other associated equipment. Biocompatible and bioactive coatings could have transformative impact on the safety and efficacy of treatment of sepsis, in which even a modest improvement could result in many lives and much money saved. In other biomedical applications, the technology could also impart biological activity to a variety of other household, consumer and industrial products. The integrated educational activities of this project are expected to achieve the following benefits: (a) research concepts will be incorporated into bioengineering coursework at Oregon State (OSU) and hands-on learning modules will be adapted for OSU's STEM Academy for pre-college students and (b) the PI will work with the OSU business school to provide a summer "Entrepreneurship Boot Camp" for the group's graduate students and faculty mentors.The project's research will result in the development of high-density, non-fouling bioactive coatings (HNB's) by living polymerization from surfactant-based immobilized initiators, producing branched, hydrophilic polymer brushes on the surface. This coating, essentially an ultrathin immobilized hydrogel, will provide excellent resistance against protein adsorption and cell interactions (biocompatibility). To impart bioactivity at the hydrogel surface, a nearly-ideal bioorthogonal ligation (BOL) will be used to immobilize enzymes, peptides, polysaccharides, or other biologically active molecules at the periphery of the brush. This chemistry enables quantitative conjugation from even dilute solutions of the active molecule, allowing precise control of surface functionalization. Unreacted groups are biologically compatible and chemically inert. Economical immobilization of peptides or proteins is provided by Genetic Code Expansion (GCE), in which engineered microbes express active proteins with BOL reactive groups incorporated at genetically-controlled positions. The resulting specific immobilization of only the desired proteins from a crude cell lysate eliminates costly purification or pre-concentration steps, and guarantees that the protein is in a precisely defined orientation for maximal biological activity. Although the main objective of this work is to demonstrate biocompatible and bioactive coatings for devices to capture pathogens from blood, myriad other potential uses include safer medical devices, food processing, pharmaceutical production, active packaging, and self-cleaning fabrics, as examples.