Bioprinting of MSC Exosomes for Bone Regeneration

摘要 间充质干细胞（MSC）衍生的外泌体是具有免疫调节和免疫调节功能的多功能试剂。 再生特性，并可被工程化以增强组织特异性活性。为了扩大优势， 在这些工程化的外泌体中，需要解决靶向、递送和生物材料负载的挑战 在空间和时间上都是。解决这一知识差距将是我独立工作的一个主要方面。 研究和本提案旨在为我提供培训和经验，以过渡到一个 独立调查员我建议在水凝胶中3D封装和生物打印工程外泌体 运营商可以解决其中一些挑战。在我的博士和博士后工作的基础上，我 我建议设计一种可调的水凝胶系统，可以作为一种通用的外泌体载体和递送系统， 平台为了检验这一假设，设计了两个具体目标。在目标1中，我将 本发明涉及一种新型水凝胶系统中的工程化骨诱导性外来体，所述水凝胶系统含有外来体结合基序， 已经在初步研究中得到确认。包封的药物的结合、释放动力学和功能性 将对外来体进行定量分析，并基于应用特异性（此处为骨再生）选择 根据标准，将为目标2挑选一名候选人。在目标2中，3D生物打印的条件将标准化， 产生具有包封的工程化外泌体的光交联生物打印3D支架。效价 将在大鼠颅骨缺损模型中体内评价这些支架再生骨的能力。成功 该项目的完成将为工程控制释放提供基础知识 外泌体，并使用3D生物打印技术在再生医学中定制使用。 这是一个新兴的领域，为我提供了一个机会，建立一个公认的专业知识和培养 一个学术生涯，专注于使用工程外泌体的生物打印再生。

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.