Synergistic Enhancement of Peripheral Nerve Defect Repair using Peptide Functionalized Aligned Nanofiber Conduits

使用肽功能化对齐纳米纤维导管协同增强周围神经缺损修复

• 批准号: 10626956
• 负责人: Matthew L Becker
• 金额: $ 40.97万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10626956
• 关键词: Acceleration; Axon; Binding; Biocompatible Materials; Cells; Clinic; Clinical; Cues; Data; Defect; Diameter; Elements; Extracellular Matrix; Fiber; Goals; Growth; Growth Factor; In Vitro; Infiltration; Injury; Integrin Binding; Knowledge; Laboratories; Laminin; Limb structure; Macrophage; Modeling; Molecular; Molecular Analysis; Motivation; Nanofiber Scaffold; Natural regeneration; Nerve Block; Nerve Fibers; Nerve Regeneration; Neurites; Neurofibrillary Tangles; Neurons; Operative Surgical Procedures; Outcome; Pathway Analysis; Pathway interactions; Peptide Fragments; Peptides; Peripheral Nerves; Peripheral nerve injury; Play; Process; Protein Fragment; Proteins; Rattus; Recovery; Recovery of Function; Regenerative capacity; Reporting; Research; Role; Schwann Cells; Sensory; Site; Speed; Touch sensation; Transforming Growth Factor beta; Translation Process; Translations; Trauma; United States; Work; axon regeneration; biodegradable polymer; cell motility; cell type; experience; extracellular; fabrication; healing; improved; improved outcome; in vivo; injury and repair; innovation; interest; long term recovery; migration; motor function recovery; nanofiber; nanopolymer; nerve injury; nerve repair; novel; peptidomimetics; peripheral nerve damage; peripheral nerve regeneration; peripheral nerve repair; reconstruction; recruit; regenerative; repaired; response; sciatic nerve; tyrosyl-isoleucyl-glycyl-seryl-arginine

Peripheral nerve regeneration has moved through a variety of stages. Over the past few decades, new details regarding the process of peripheral nerve regeneration have been elucidated. While the axonal regrowth process has long been studied, it was noted recently that the regrowth and repair proceeds in tandem with Schwann cell (SC) infiltration into the injured peripheral nerve defect. SC recruitment and directed migration has been a topic of interest in our laboratories, with a focus on biased SC migration using topographical and ECM-mimicking peptides. Our in vitro preliminary data shows a clear induction of directional SC migration using tethered concentration gradients of both TGF-β peptide and YIGSR-peptide. Our in vivo preliminary data further demonstrates that synthetic nanofibers support SC infiltration and maturation. Together, these data have provided us with substantial motivation to further investigate mechanisms that mimic the neuroregenerative process through the recruitment of SC. To pursue these goals, we have developed functional, degradable polymers and versatile touch-spinning fabrication strategies to generate spatially-defined, bioactive, aligned nanofiber conduits and we propose to use this platform to improve the regenerative capacity of injured peripheral nerves. We believe that cell-free material solutions that enhance the endogenous repair process are translationally-relevant and will provide the best options for translation of these functional conduits to the clinic in the near term. We hypothesize that tethered, peptide-based bioactive factors in distinct concentration profiles, in combination with topographical cues, will increase SC infiltration, and therefore, neuroregeneration, across critical-sized gaps. We will pursue this hypothesis with three independent aims. Specific Aim 1: Tethered laminin peptide gradients to enhance neural cell migration and SC infiltration. We will investigate how concentration gradients of tethered laminin peptide enhance neurite and SC response, singly and in an explant (multicellular) model. The outcome of this Aim will yield an optimal nanofiber (diameter, laminin-peptide gradient) to advance to our proposed in vivo studies in Aim 3. Specific Aim 2: Tethered TGF-β peptide gradients to enhance neural cell migration and SC infiltration. We will investigate how concentration gradients of tethered TGF-β peptide-based growth factor in combination with RGD enhance neurite and SC response, singly and in an explant (multicellular) model. The outcome of this Aim will yield an optimal nanofiber (diameter, TGF-β peptide gradient) to advance to our proposed in vivo studies in Specific Aim 3. Specific Aim 3: In vivo neural regeneration outcomes improve with combinations of laminin peptide gradients and TGF-β gradients. We will use the best nanofiber scaffolds independently identified in Aims 1 and 2 to investigate whether combinations of laminin peptide and TGF-β peptide concentration gradients will synergistically enhance the initial process of neural regeneration and long- term functional recovery in vivo in a well-established rat sciatic nerve defect model. With a focus on the early steps in endogenous repair, along with a long-term recovery metric, this work will provide foundational evidence in the role that SC play in the nerve regeneration processes. This knowledge will shift our focus in nerve repair from the axon to cells that are known to support the regeneration process to enhance recovery.

在过去的几十年里，周围神经再生经历了多个阶段，出现了新的细节。 关于周围神经再生过程的研究已得到阐明，而轴突再生过程则已得到阐明。 长期以来一直被研究，最近注意到再生和修复与雪旺细胞同步进行 (SC) 浸润到受伤的周围神经缺损中 SC 募集和定向迁移一直是一个话题。 我们的实验室感兴趣，重点是使用地形和 ECM 模拟进行有偏差的 SC 迁移 我们的体外初步数据显示，使用系留可明显诱导 SC 定向迁移。 我们的体内初步数据进一步 这些数据表明合成纳米纤维支持 SC 渗透和成熟。 为我们进一步研究模拟神经再生的机制提供了巨大的动力 为了实现这些目标，我们开发了功能性、可降解的 SC。 聚合物和多功能接触纺丝制造策略，以产生空间定义的、生物活性的、对齐的 纳米纤维导管，我们建议使用该平台来提高受伤外周的再生能力 我们相信，无细胞材料解决方案可以增强内源性修复过程。 翻译相关，将为将这些功能性导管转化为临床提供最佳选择 在短期内，我们勇敢地面对不同浓度的基于肽的生物活性因子， 与地形提示相结合，将增加 SC 浸润，从而增加神经再生 临界尺寸的间隙。 我们将通过三个独立的目标来追求这一假设：束缚层粘连蛋白肽梯度。 为了增强神经细胞迁移和 SC 浸润，我们将研究束缚的浓度梯度。 层粘连蛋白肽单独和在外植体（多细胞）模型中增强神经突和 SC 反应。 这一目标将产生最佳的纳米纤维（直径、层粘连蛋白-肽梯度），以推进我们提出的体内 目标 3 中的研究。具体目标 2：拴系 TGF-β 肽梯度以增强神经细胞迁移和 SC 我们将研究基于 TGF-β 肽的生长因子的浓度梯度如何影响渗透。 与 RGD 结合可增强神经突和 SC 反应，无论是单独还是在外植体（多细胞）模型中。 这一目标的结果将产生最佳的纳米纤维（直径，TGF-β肽梯度），以推进我们的研究 具体目标 3 中提出的体内研究。具体目标 3：体内神经再生结果改善 层粘连蛋白肽梯度和TGF-β梯度的组合我们将使用最好的纳米纤维支架。 在目标 1 和 2 中独立鉴定，以研究层粘连蛋白肽和 TGF-β 的组合是否 肽梯度将协同增强神经再生和长时间集中的初始过程 在成熟的大鼠坐骨神经缺损模型中进行体内长期功能恢复，重点是早期功能恢复。 内源性修复的步骤以及长期恢复指标，这项工作将提供基础证据 SC 在神经再生过程中所扮演的角色将转移我们对神经修复的关注。 从轴突到已知支持再生过程以增强恢复的细胞。