Hydrogels for delivery of muscle stem cells to diaphragm

项目摘要 Duchenne肌营养不良症(DMD)是一种X连锁遗传病，每3,500名男性新生儿中就有1名患病 以进行性肌肉萎缩和虚弱为特征。结果，患者遭受了门诊疾病的痛苦。 残疾、心力衰竭和呼吸衰竭，后者是导致过早死亡的主要原因。 目前的呼吸护理治疗仍然是姑息性的，因为DMD还没有治愈的方法。其主要原因是 DMD是缺乏功能性肌营养不良蛋白，它是一种在肌膜之间提供结构支持的蛋白质 和细胞外基质。修复营养不良蛋白的一种策略是将卫星细胞移植到靶肌肉上。 虽然这种策略不是治疗全身DMD的有效方法，但横隔肌 由于卫星细胞在呼吸功能中的重要作用，卫星细胞是一种可行和重要的靶点。 在成功地将卫星细胞植入横隔肌后，肌营养不良蛋白、肌肉兴奋性和 可以恢复呼吸功能，延长DMD患者的预期寿命，提高生活质量 通过潜在地绕过对机械通风的需要。卫星细胞向横隔肌的传递 由于移植细胞的植入、存活和功能不佳，以及 隔膜的薄尺寸和深层位置。该项目旨在通过以下方式克服这些障碍 设计一种基于合成水凝胶的生物活性细胞注射载体，将卫星细胞运送到营养不良患者 隔膜和促进移植细胞存活、扩增、分化和植入的改善 隔膜功能。这项提议的目标将以循序渐进的方式实现。首先，我们将设计 用粘附肽功能化的合成水凝胶维持和指导肌肉卫星细胞的功能 3D，包括黏附、存活、扩张和分化。第二，我们将评估 基因工程水凝胶可以将绿色荧光蛋白肌肉卫星细胞输送和植入肌隔膜 Mdx/mtr小鼠和横隔膜功能改善的程度。这项工作取得了圆满的成果 将具有广泛的意义和影响，通过展示这一战略作为治疗 DMD患者的呼吸衰竭。与依靠机械辅助呼吸不同，患者接受 这种治疗可以从延长和改善生活质量中受益。此外，这项工作将建立在 更广泛的目标是证明设计干细胞输送和植入的生物材料 肌肉骨骼组织是鼓励靶组织再生的可行策略。

PROJECT ABSTRACT Duchenne muscular dystrophy (DMD) is an X-linked genetic disease that affects ~1 in 3,500 newborn males and is characterized by progressive muscle wasting and weakness. As a result, patients suffer from ambulatory disability, cardiac failure, and respiratory failure, the latter of which is a major contributor to premature death. Current treatments for respiratory care remain palliative, as there is no cure for DMD. The primary cause for DMD is the absence of functional dystrophin, a protein that provides structural support between the sarcolemma and extracellular matrix. A strategy for restoring dystrophin is to transplant satellite cells to a target muscle. Although this strategy would not be an efficient method to treat DMD throughout the body, the diaphragm muscle presents a viable and important target for the delivery of satellite cells due to its vital role in respiratory function. Upon successful engraftment of satellite cells to the diaphragm muscle, dystrophin, muscle excitability, and respiratory function can be restored, extending a DMD patient’s life expectancy, and improving the quality of life by potentially bypassing the need for mechanical ventilation. Delivery of satellite cells to the diaphragm muscle poses a challenge due to sub-optimal engraftment, survival, and function of transplanted cells, as well as the diaphragm’s thin dimensions and deep-seated location. This project seeks to overcome these hurdles by engineering a synthetic hydrogel-based bioactive cell injectable vehicle to deliver satellite cells to the dystrophic diaphragm and promote survival, expansion, differentiation, and engraftment of transplanted cells to improve diaphragm function. The goals of this proposal will be accomplished in a stepwise fashion. First, we will engineer synthetic hydrogels functionalized with adhesive peptides to maintain and direct muscle satellite cell function in 3D, including adhesion, survival, expansion, and differentiation. Second, we will evaluate the extent to which engineered hydrogels allow for delivery and engraftment of GFP+ muscle satellite cells in the diaphragm of mdx/mTR mice and the extent to which the diaphragm’s function improves. Successful outcomes in this work will have broad significance and impact by demonstrating the potential of this strategy as a treatment for respiratory failure in DMD patients. Rather than relying on mechanically assisted ventilation, a patient receiving this treatment can benefit from an extended and improved quality of life. Additionally, this work will build on a broader goal to demonstrate that designing biomaterials for stem cell delivery and engraftment to musculoskeletal tissue is a feasible strategy for encouraging regeneration of the targeted tissue.