Surface Modified Nanofibers for Nerve Regeneration

用于神经再生的表面改性纳米纤维

• 批准号: 7750845
• 负责人: JOSEPH M. COREY
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7750845
• 关键词: Action Potentials; Activities of Daily Living; Adhesions; American; Atrophic; Autologous; Autologous Transplantation; Axon; Binding; Biochemical; Biological Assay; Caliber; Cues; Disabled Persons; Effectiveness; Extracellular Matrix Proteins; Face; Fiber; Glycolic-Lactic Acid Polyester; Growth; Growth Factor; Implant; In Vitro; Inferior; Injury; Integrin Binding; Knowledge; Laminin; Lead; Left; Length; Limb structure; Measures; Membrane; Modeling; Morbidity - disease rate; Motor; Motor Neurons; Muscle; Natural regeneration; Nerve; Nerve Regeneration; Neurites; Neurons; Operative Surgical Procedures; Outcome; Patients; Peptides; Performance; Peripheral Nerves; Peripheral nerve injury; Polymers; Population; Production; Proteins; Rattus; Recovery; Soldier; Solutions; Speed; Spinal; Spinal Ganglia; Surface; Surgeon; Technology; Testing; Time; Transplanted tissue; Travel; Walking; Woman; combat; disability; implantation; improved; in vivo; injured; nanofiber; nerve autograft; nerve gap; nerve injury; neurite growth; poly(lactide); prevent; promoter; protein aminoacid sequence; public health relevance; reinnervation; repaired; research study; scaffold; sciatic nerve; standard of care; tissue culture; tool; tyrosyl-isoleucyl-glycyl-seryl-arginine

DESCRIPTION (provided by applicant): Two central problems exist in nerve repair after traumatic injury. The first is finding a nerve guide suitable for large gaps in large diameter nerves. The second is that regeneration from proximal injuries occurs too slowly, which allows target muscle to atrophy preventing reinnervation and functional motor recovery after regenerating neurites arrive. Nerve guides that accelerate regeneration could improve motor recovery after nerve repair. Most nerve guides produce inferior results, even when filled or coated with extracellular matrix proteins (ECM) or growth factors that promote neurite outgrowth, including laminin, regarded as the most potent substrate-bound promoter of neurite outgrowth. Recently, aligned nanofibers have been introduced into nerve guidance channels to provide topographical cues that direct regenerating neurites. These fibers have been found to orient, direct, and promote faster growth of regenerating neurites in vitro and in vivo. However, their performance still lags behind autografts. Since the primary problem in achieving functional regeneration slow speed, we hypothesize that taking peptide sequences from laminin that promote neurite outgrowth and covalently-binding them to aligned nanofibers could speed nerve regeneration and make it more effective. A proposal to fabricate and test such fibers is presented. Specific aim 1 begins with electrospun poly (lactide-co-glycolide) (PLGA) nanofibers that can be covalently bound to IKVAV, a peptide in laminin that promotes neurite growth. Fibers will be characterized for alignment, diameter, and rate of degradation. Dissociated motor neurons and dorsal root ganglia explants will be grown on these surfaces and their neurite outgrowth assayed to compare to controls without IKVAV and to laminin-coated controls. In specific aim 2, gradients of IKVAV and YIGSR, another laminin peptide, will be covalently bound to PLGA nanofibers to see if gradients cause faster neurite growth. These fibers will be tested similarly as fibers in aim 1. In specific Aim 3, longitudinally-oriented aligned nanofibers will be placed in semipermeable membranes as nerve guides and implanted in rat sciatic nerve gaps. In these experiments, PLGA with covalently bound fibers as developed in the first two aims will be compared against plain fibers and autologous nerve grafts. It is hoped that this project will further knowledge of both the production of functionalized nanofiber nerve guides and their potential to be harnessed as a tool for nerve regeneration. PUBLIC HEALTH RELEVANCE: Over 21,000 combat wounded American servicemen and women have sustained injuries to the peripheral nerves of the face and limbs since March 2003. This produces dramatic disability impacting activities of daily life. Nerve injury is also a common cause of disability in the civilian population. Unfortunately, the present technology of surgically implanted nerve guidance channels used to promote regeneration after injury produces poor outcomes, leaving patients disabled. We have developed aligned polymer nanofibers that direct the growth of regenerating axons in tissue culture. We also have preliminary evidence that implanting these nanofibers in surgically created nerve injuries in rats helps nerves to regenerate. Here we propose binding the surfaces of these nanofibers with segments of protein known to make nerve cells grow faster. The proposed experiments may lead to improved nerve guidance channels that produce better nerve regeneration for injured soldiers and civilians alike.

描述（由申请人提供）： 创伤后神经修复中存在两个核心问题。首先是找到适合大直径神经中大间隙的神经指南。第二是，近端损伤的再生发生得太慢，这使靶向肌肉萎缩，以防止再生神经突到来后恢复和功能性运动恢复。神经指南，加速再生可以改善神经修复后的运动恢复。 大多数神经指南也会产生较低的结果，即使填充或涂有细胞外基质蛋白（ECM）或促进神经突生长的生长因子，包括粘胺，被视为最有效的神经突结合构造启动子神经突生长的启动子。最近，对齐的纳米纤维已被引入神经引导通道中，以提供直接再生神经突的地形线索。这些纤维在体外和体内都可以定位，直接和促进再生神经突的生长。但是，它们的性能仍然落后于自动移植。由于在实现功能再生慢速方面的主要问题，我们假设从层层粘连蛋白中采取肽序列，从而促进神经突生长并共价结合它们以使它们对齐的纳米纤维可以加快神经再生并更有效。 提出了制造和测试此类纤维的建议。特定的目标1始于电纺聚（乳酸 - 糖 - 糖苷）（PLGA）纳米纤维，该纳米纤维可以与IKVAV共价结合，IKVAV是层粘连蛋白中的一种肽，可促进神经突的生长。纤维的对齐，直径和降解速率的特征。解离的运动神经元和背根神经节外植体将在这些表面上生长，其神经突产物的生长测定，以与没有IKVAV的控制和粘贴蛋白涂层的对照进行比较。在特定的目标2中，另一种层粘连蛋白肽的IKVAV和YIGSR的梯度将与PLGA纳米纤维共价结合，以查看梯度是否会导致更快的神经突生长。这些纤维的测试将类似地与AIM 1中的纤维相似。在特定的AIM 3中，将纵向排列的纳米纤维作为神经指南置于可半透明的膜中，并将其植入大鼠坐骨神经隙。在这些实验中，将在前两个目标中开发的具有共价纤维纤维的PLGA与普通纤维和自体神经移植物进行比较。 希望该项目能够进一步了解功能化纳米纤维神经指南的产生及其作为神经再生工具的潜力。 公共卫生相关性： 自2003年3月以来，超过21,000名战斗受伤的美国军人和妇女对面部和四肢的周围神经造成伤害。这会产生戏剧性的残疾影响日常生活的活动。神经损伤也是平民残疾的常见原因。不幸的是，目前的手术植入神经引导渠道用于促进受伤后的再生，导致较差的预后，使患者残疾。我们已经开发了对齐的聚合物纳米纤维，这些纳米纤维指导组织培养中再生轴突的生长。我们还有初步证据表明，将这些纳米纤维植入大鼠的神经损伤有助于神经再生。在这里，我们提出了这些纳米纤维的结合，并具有已知使神经细胞生长更快的蛋白质段的结合。拟议的实验可能会导致改善的神经引导渠道，从而为受伤的士兵和平民提供更好的神经再生。