Bioprinting of MSC Exosomes for Bone Regeneration

摘要 间充质干细胞(MSC)来源的外切体是一种多功能的试剂，具有免疫调节和 具有再生性能，并可设计用于增强组织特异性活动。要扩大优势， 对于这种工程化的外切体，需要解决靶向、递送和生物材料装载方面的挑战 无论是在空间上还是时间上。解决这一知识差距将是我独立工作的一个主要方面 研究和此建议旨在为我提供过渡到 独立调查员。我建议在水凝胶中对工程外切体进行3D封装和生物打印 运营商可以应对其中的一些挑战。在我博士和博士后工作的基础上，我 建议设计一种可调节的水凝胶系统，作为一种多功能的外切体载体和递送 站台。已经设计了两个具体的目标来检验这一假设。在目标1中，我将概括 一种新型水凝胶系统中的工程化骨诱导外切体，该系统包含外切体结合基序， 已在初步研究中确定。包封剂的结合、释放动力学和功能性 外切体将被定量分析，并基于特定的应用(此处为骨再生)选择 在目标2中，3D生物打印的条件将标准化为 生成具有封装的工程外切体的照片交联型生物打印3D支架。它的效力 这些支架中再生骨的能力将在大鼠颅骨缺损模型中进行活体评估。成功者 该项目的完成将为工程化药物的控制释放提供基础知识 利用3D生物打印技术在再生医学中定制使用Exosome。 这是一个新兴的领域，为我提供了一个建立公认的专业知识和培养 专注于利用工程外切体的生物打印进行再生的学术生涯。

Abstract Mesenchymal stem cell (MSC) derived exosomes are versatile agents that possess immunomodulatory and regenerative properties and can be engineered for enhanced tissue-specific activity. To extend the advantages of such engineered exosomes, challenges to targeting, delivery and biomaterial loading need to be addressed both spatially and temporally. Addressing this knowledge gap will be a primary aspect of my independent research and this proposal is designed to provide me with the training and experience to transition into an independent investigator. I propose that 3D encapsulation and bioprinting of engineered exosomes in hydrogel carriers can address some of these challenges. On the foundations of my doctoral and postdoctoral work, I propose to engineer a tunable hydrogel system that can serve as a versatile exosome carrier and delivery platform. Two specific aims have been designed to test this hypothesis. In aim 1, I will encapsulate engineered osteoinductive exosomes in a novel hydrogel system that contains exosome binding motifs that have been identified in preliminary studies. The binding, release kinetics and functionality of the encapsulated exosomes will be quantitatively analyzed and based on application-specific (bone regeneration here) selection criteria, one candidate will be selected for aim 2. In aim 2, conditions for 3D bioprinting will be standardized for generation of photo crosslinked bioprinted 3D scaffolds with encapsulated engineered exosomes. The potency of these scaffolds to regenerate bone will be evaluated in vivo in a rat calvarial defect model. The successful completion of this project will provide a foundational knowledge for the controlled release of engineered exosomes and for their customized use in regenerative medicine using 3D bioprinting technology. This is a newly emerging field that provides an opportunity for me establish a recognized expertise and foster an academic career that focuses on regeneration using bioprinting of engineered exosomes.