Suturable bioprinted vascularized muscle constructs for treatment of skeletal muscle loss

项目摘要 容积性肌肉损失（VML）通常发生在创伤性损伤后，并导致以下复合损失： 肌肉质量.这些损伤表现为力量下降和功能障碍。临床上，这些 与骨骼肌再生相反，损伤通常通过纤维化愈合。当前现有治疗 VML治疗的选择也不足，并发症通常与手术修复有关 包括神经损伤、过度免疫反应、感染、瘢痕形成和组织移植物供应的限制。 事实上，自然愈合和外科手术在恢复受伤肌肉的功能方面效率低下， 导致生活质量差。因此，使用三维图像来开发临床相关的三维（3D）组织， 患者特异性遗传上相同的细胞已经成为解决上述问题的潜在解决方案。到 要实现这一目标，目前存在两个主要挑战。第一个挑战是获得大量的 患者特异性遗传相同的细胞。使用分化为人多能干细胞（hiPSC）， 肌肉谱系代表了建立在个性化治疗基础上的有希望的候选者。然而，导演 hiPSC向肌肉命运的分化与可重复的分化方案一起沿着， 要有挑战性。第二个挑战是开发高度组织化和血管化的3D骨骼肌 组织，以通过工程化血管网络维持厚组织构建物内细胞的活力。 此外，制造的组织必须通过手术方法牢固地整合到损伤部位。解决 为了应对这些挑战，我们计划从hiPSC衍生的肌源性细胞中开发一种可缝合的3D血管化肌肉组织。 使用生物打印技术将前体细胞（hiPSC-MPC）嵌入生物材料中。将优化 最近开发的方案允许在水凝胶中从hiPSC有效生产功能性肌纤维 具有可调的机械性能和可降解的概况，其模拟了细胞外基质（ECM）， 天然骨骼肌组织为了创造仿生血管化肌肉结构， 生物打印技术将用于精确控制血管网络和对齐肌肉的位置 具有生物相关结构的纤维。使用传统的生物打印系统，很难精确地测量生物打印的质量。 控制材料在Z方向上的位置，以创建独立的水凝胶架构。此外，为了实现 延长植入物保留到受伤部位，并改善肌肉再生，肌肉生长 将开发负载IGF-1因子的可缝合移植物。载有hiPSC-MPC的构建体将被打印在 可缝合的移植物，其由负载IGF-1的PGS/GelMA基质组成，使用静电纺丝。

Project Summary Volumetric muscle loss (VML) usually occurs following traumatic injury and results in a composite loss of muscle mass. These injuries manifest in decreased strength and functional impairments. Clinically, these injuries often heal with fibrosis, as opposed to skeletal muscle regeneration. Current existing therapeutic options are also insufficient for VML treatment, and complications are often associated with surgical repair including nerve injury, excessive immune response, infection, scarring, and limitations of tissue graft supply. Indeed, natural healing and surgical procedures are inefficient in restoring the functionality of injured muscles, resulting in a poor quality of life. Therefore, developing clinically relevant three-dimensional (3D) tissue using patient-specific genetically identical cells has emerged as a potential solution to address the above issues. To achieve this aim, there are two existing main challenges. The first challenge is obtaining large amounts of patient-specific genetically identical cells. The use of human pluripotent stem cells (hiPSCs) differentiated to the muscle lineage represents a promising candidate to build upon personalized therapy. However, directing the differentiation of hiPSCs to the muscle fate along with reproducible differentiation schemes has proven to be challenging. The second challenge is developing a highly organized and vascularized 3D skeletal muscle tissue to maintain the viability of cells inside thick tissue constructs via engineered vessel networks. Furthermore, the fabricated tissues have to strongly integrate into injured site via surgical methods. To address these challenges, we plan to develop a suturable 3D vascularized muscle tissue from hiPSC-derived myogenic precursor cells (hiPSC-MPCs) embedded in biomaterials using bioprinting techniques. We will optimize the recently developed protocols allowing efficient production of functional myofibers from hiPSCs in hydrogels with tunable mechanical properties and degradable profiles, which mimic the extracellular matrix (ECM) of native skeletal muscle tissue. To create biomimetic vascularized muscle constructs, a multi-material embedded bioprinting technique will be used to precisely control the positions of the vascular network and aligned muscle fibers with biologically relevant architectures. With the conventional bioprinting system, it is difficult to precisely control the materials’ position in Z directions to create freestanding hydrogel architectures. Also, to achieve prolonged retention of implants into the injured site and to improve muscle regeneration, a muscle growth factor (IGF-1) laden suturable graft will be developed. hiPSC-MPCs-laden constructs will be printed on the suturable graft consisting of IGF-1-laden PGS/GelMA substrates using electrospinning.