Dynamically Responsive Bioreactors for Cartilage Regeneration

用于软骨再生的动态响应生物反应器

• 批准号: 8540905
• 负责人: Stephanie J Bryant
• 金额: $ 16.3万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-07 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8540905
• 关键词: Age; Biochemical; Biomechanics; Bioreactors; Cartilage; Cells; Chemistry; Clinical; Coupled; Cues; Development; Drug Formulations; End Point Assay; Engineering; Environment; Enzymes; Ethylene Glycols; Feedback; Foundations; Fuzzy Logic; Gel; Goals; Grant; Growth; Hydrogels; Immunohistochemistry; Individual; Lead; Lipase; Measurement; Mechanical Stress; Mechanics; Mediating; Microscope; Oligopeptides; Outcome; Output; Physiological; Polyethylene Glycols; Positioning Attribute; Property; Qualifying; Research; Research Personnel; Review Literature; Source; Stress; Structure; Testing; Time; Tissue Engineering; Tissues; Ultrasonic Transducer; Ultrasonography; United States National Institutes of Health; base; cartilage regeneration; crosslink; design; design and construction; ethylene glycol; experience; heuristics; improved; indexing; innovation; novel; polycaprolactone; response; scaffold; skills

DESCRIPTION (provided by applicant): Our long-term goal is to engineer functionally competent cartilage for replacing damaged or diseased cartilage. While it is known that engineering a functionally competent cartilage depends on the mechanical environment, choosing the appropriate loading environment has proven challenging. This observation is largely in part due to the fact that the biomechanical cues sensed by the cells will be dictated by the mechanical structure and chemistry of the scaffold and will be dynamic in time as the scaffold degrades and neotissue develops. To overcome these challenges, the global hypothesis for this research is that a dynamic culture environment that detects and responds to changes in a tissue-engineered scaffold improves the quality of the engineered cartilage. Central to our hypothesis is a novel dynamic compressive bioreactor recently designed, constructed and validated with collaborators at NIST, which is equipped with online, nondestructive measurement capabilities comprised of individual load cells for assessing mechanical properties and an ultrasonic transducer coupled with a video microscope for assessing development and quality of the engineered tissue. To test the global hypothesis, the specific aims of the project are to: 1. Design a dual enzyme degrading polyethylene glycol (PEG) hydrogel with cell-mediated local degradation and 'on demand' bulk degradation capabilities. This aim tests the hypothesis that a hydrogel with crosslinks containing oligopeptides that are degraded by cells, leading to local degradation (critical for local matrix elaboration without sacrificing mechanical integrity) and polycaprolactone that is degraded 'on demand' by exogenous delivery of lipase, leading to bulk degradation (critical for macroscopic tissue development) yields improved engineered cartilage. 2. Develop and validate a dynamically responsive 'smart' bioreactor using a heuristic control loop to modify the biochemical and mechanical environment in real time. This aim tests the hypothesis that real time changes to bulk degradation and mechanical loading in response to the developing tissue will lead to improved engineered cartilage. We will achieve this aim by incorporating a fuzzy controller with a set of heuristic control actions into our current bioreactor where the output variables, the quality index estimated from ultrasound and mechanical properties, will be related to input variables that include strain amplitude, duty cycle, and enzyme addition. At the completion of this exploratory research, we expect to have developed i) a new class of dual enzyme degrading hydrogels based on cross-linked polyethylene glycol where degradation is more closely matched spatially and temporally to tissue growth and elaboration and ii) a dynamically responsive 'smart' bioreactor that is capable of detecting and responding in accord with tissue growth. We also expect to have answered the fundamental question; does a dynamically responsive culture environment lead to improved tissue elaboration and functional properties over a constant culture environment? It is anticipated that such a bioreactor would enable facile adaption to engineering cartilage from multiple cell sources (donor, age, species), which inherently have different dynamics and timescales for tissue development, and can readily be adapted to other scaffold types. Findings from this grant will lay the foundation for seeking competitively a NIH R01 and to pursue their (pre)clinical utility.

描述（由申请人提供）：我们的长期目标是设计在功能上有能力的软骨，以更换受损或患病的软骨。众所周知，工程功能胜任的软骨取决于机械环境，但选择适当的加载环境已被证明具有挑战性。该观察结果很大程度上是由于细胞感应的生物力学提示将由 脚手架的机械结构和化学性质，随着脚手架的降解和新疾病的发展，将在时间上动态。为了克服这些挑战，这项研究的全球假设是，一种动态文化环境检测并响应了组织工程脚手架的变化，可改善工程软骨的质量。我们假设的核心是一种新型的动态压缩生物反应器，最近与NIST的合作者设计，构建和验证，该合作者配备了在线，无损的测量能力，该功能由单个负载电池组成，该功能由单个负载电池组成，用于评估机械性能和超声传感器，以评估视频显微镜，以评估视频显微镜工程组织的开发和质量。为了检验全球假设，该项目的具体目的是：1。设计一种双酶降解聚乙烯乙二醇（PEG）水凝胶，并具有细胞介导的局部降解和“按需”体积降解能力。这个目的检验了以下假设：含有由细胞降解的含有寡肽的交联的水凝胶，导致局部降解（对于局部矩阵阐述至关重要而不牺牲机械完整性）和多碳酸酯，这些二肽和多碳酸酯通过外生的递送而导致“按需降解”，导致lipase的递送。散装降解（对宏观组织发育至关重要）产生改善的工程软骨。 2。使用启发式控制回路，开发和验证动态响应的“智能”生物反应器，以实时修改生化和机械环境。该目标检验了以下假设：实时会随着发育中的组织的响应而变化，机械负荷会导致改善工程软骨。我们将通过将模糊控制器与一组启发式控制动作合并到我们当前的生物反应器中，以实现这一目标，在我们当前的生物反应器中，输出变量（根据超声和机械性能估算的质量指数）将与包括应变振幅，占空比，占空比，占空比，占空比，占空比，占空比，占和酶添加。这项探索性研究完成后，我们希望开发出i）基于交联的聚乙二醇基于交联的聚凝胶降解水凝胶的新类别，在空间和时间上更加与组织生长和陈述更加紧密地匹配，并具有动态响应式响应式响应式效应能够根据组织生长检测和反应的“智能”生物反应器。我们还希望回答这个基本问题；动态响应式培养环境是否会在恒定的培养环境中改善组织阐述和功能性能？可以预料，这种生物反应器将从多个细胞来源（供体，年龄，物种）中促进对软骨的便捷适应，它们本质上具有不同的动力学和时间尺度，以用于组织发育，并且可以很容易地适应其他脚手架类型。这笔赠款的发现将奠定基础，以寻求竞争性的NIH R01并追求其（前）临床实用程序。