Hydrogels for delivery of muscle stem cells to diaphragm

项目摘要 杜氏肌营养不良症（DMD）是一种X连锁遗传疾病，每3,500名新生男性中就有1人患病， 其特征是进行性肌肉萎缩和虚弱。因此，患者患有非卧床 残疾、心力衰竭和呼吸衰竭，后者是过早死亡的主要原因。 目前的呼吸道护理治疗仍然是姑息性的，因为没有治愈DMD的方法。的根本原因 DMD是功能性肌营养不良蛋白的缺失，肌营养不良蛋白是一种在肌膜之间提供结构支持的蛋白质， 和细胞外基质。恢复肌营养不良蛋白的一种策略是将卫星细胞移植到目标肌肉。 虽然这种策略不是治疗全身DMD的有效方法，但膈肌 由于其在呼吸功能中的重要作用，它为卫星细胞的递送提供了可行的和重要的靶点。 在成功地将卫星细胞移植到膈肌后，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 通过潜在地绕过机械通气的需要。将卫星细胞输送至膈肌 由于移植细胞的次优植入、存活和功能，以及 隔膜的薄尺寸和深位置。本项目旨在通过以下方式克服这些障碍： 工程化合成的基于水凝胶的生物活性细胞可注射载体以将卫星细胞递送至营养不良的 隔膜，促进移植细胞的存活、扩增、分化和植入，提高 隔膜功能本提案的目标将逐步实现。首先，我们将设计 用粘附肽官能化的合成水凝胶，以维持和指导肌肉卫星细胞功能， 3D，包括粘附、存活、扩张和分化。其次，我们将评估 工程水凝胶允许GFP+肌肉卫星细胞在膈肌中的递送和植入， mdx/mTR小鼠和膈肌功能改善的程度。在这项工作中取得的成功 通过展示该策略作为治疗的潜力，将具有广泛的意义和影响。 DMD患者的呼吸衰竭与其依赖机械辅助通气， 这种治疗可以受益于延长和改善的生活质量。此外，这项工作将建立在一个 更广泛的目标是证明设计用于干细胞输送和植入的生物材料， 肌肉骨骼组织是促进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.