Angiogenic growth factor delivery for vascular regeneration in critical limb ischemia using acoustically-responsive scaffolds

使用声响应支架输送血管生长因子以促进严重肢体缺血的血管再生

• 批准号: 10516588
• 负责人: Mario Leonardo Fabiilli
• 金额: $ 69.46万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-12-15 至 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10516588
• 关键词: Acoustics; Advanced Development; Affect; Biocompatible Materials; Blood Vessels; Cardiovascular Diseases; Cell Survival; Cell Therapy; Cells; Clinical; Clinical Trials; Development; Disease; Emulsions; Encapsulated; Endothelial Cells; Engineering; Ensure; Exposure to; FGF2 gene; Focused Ultrasound; Funding; Goals; Growth; Growth Factor; Hydrogels; Implant; Ischemia; Kinetics; Knowledge; Mechanics; Mediating; Microscopy; Modeling; Outcome; Penetration; Perfusion; Pericytes; Peripheral arterial disease; Platelet-Derived Growth Factor; Pre-Clinical Model; Property; Regenerative Medicine; Specificity; Speed; Stromal Cells; Structure; Techniques; Technology; Testing; Therapeutic; Therapeutic Trials; Tissue Engineering; Tissue Viability; Tissues; Translations; Variant; Vascular regeneration; Vascularization; blood perfusion; blood vessel development; cell motility; controlled release; critical limb Ischemia; in vivo; limb ischemia; millimeter; mouse model; permissiveness; platelet-derived growth factor BB; release factor; response; scaffold; spatiotemporal; subcutaneous; success; technique development; therapeutic angiogenesis; tissue regeneration; ultrasound; vaporization

ABSTRACT The development of techniques to generate functional, perfused blood vessel networks is essential for engineering of viable tissues as well as for the treatment of ischemic diseases. Pro-angiogenic growth factors have been used, either as a standalone therapy or in combination with cell-based techniques, to promote vascularization. Unfortunately, conventional approaches for delivery of pro-angiogenic growth factors have yielded disappointing results in clinical, therapeutic trials. This is because optimal growth factor combinations, concentrations, release kinetics, and spatial presentations are unknown. Thus, there is a need to develop translatable technologies for precisely controlling these parameters so optimization can be achieved. Our long- term goal is to develop implantable biomaterials for tissue regeneration that are spatiotemporally manipulated in a non-invasive, on-demand manner using focused ultrasound. Focused ultrasound is a clinically-used technology with sub-millimeter precision that penetrates deeply within the body. During the prior funding period, we developed a paradigm-changing hydrogel, termed an acoustically-responsive scaffold (ARS) that enables the controlled release of multiple, pro-angiogenic growth factors using ultrasound. An ARS consists of an ultrasound-sensitive emulsion embedded within a hydrogel matrix. Growth factors encapsulated within the emulsion are released when an ARS is exposed to focused ultrasound. This non-thermal release mechanism, termed acoustic droplet vaporization (ADV), is driven by the formation of a bubble within each emulsion droplet, thereby releasing the encapsulated payload. We developed techniques to sequentially release basic fibroblast growth factor (bFGF) and platelet derived growth factor-BB (PDGF-BB) from an ARS. We also demonstrated that ADV can release bioactive bFGF with high specificity, thereby leading to the formation of functional vessels in vivo. The kinetics of bFGF release strikingly impacted the formation of perfused blood vessels. ADV-generated bubbles also dramatically altered the permissiveness of the ARS to cell migration. The objective of this proposal is to understand how vascularization is impacted by spatiotemporal variation of release kinetics of bFGF and PDGF-BB from an ARS as well as permissiveness of the ARS. The central hypothesis is that optimal blood vessel formation can be achieved by precisely controlling growth factor release from ARSs using ADV-generated bubble dynamics. Aim 1 will use ADV-generated bubble dynamics to modulate the kinetics of growth factor release from an ARS. Aim 2 will quantify the impact of bFGF release kinetics and ARS permissiveness on the development and inosculation of cell-loaded ARSs. Aim 3 will demonstrate enhanced vascularization in an atherosclerotic model of hind limb ischemia by sequentially delivering bFGF and PDGF-BB from acellular ARSs. Successful completion of these aims will advance the translation of pro-angiogenic growth factors in acellular and cell-based therapies for vascularization as well as propel other biomedical applications of ADV.

摘要 开发产生功能性灌注血管网络的技术对于以下方面至关重要： 活组织的工程化以及缺血性疾病的治疗。促血管生成生长因子 已被用于，无论是作为一个独立的治疗或与细胞为基础的技术相结合，以促进 血管化不幸的是，用于递送促血管生成生长因子的常规方法 在临床治疗试验中的结果令人失望。这是因为最佳的生长因子组合， 浓度、释放动力学和空间呈现未知。因此，有必要发展 可转换的技术，用于精确控制这些参数，从而可以实现优化。我们长久以来- 长期目标是开发用于组织再生的可植入生物材料， 以非侵入性的、按需的方式使用聚焦超声。聚焦超声是一种临床上使用的 这种技术具有亚毫米的精度，可以深入人体。在前期融资中 期间，我们开发了一种改变范例的水凝胶，称为声响应支架（ARS）， 能够使用超声控制释放多种促血管生成生长因子。ARS包括 包埋在水凝胶基质中的超声敏感乳液。生长因子包封在 当ARS暴露于聚焦超声时，释放乳剂。这种非热释放机制， 被称为声学液滴蒸发（ADV），是由每个乳液内形成气泡驱动的 液滴，从而释放包封的有效载荷。我们开发了一种技术， 成纤维细胞生长因子（bFGF）和血小板衍生生长因子-BB（PDGF-BB）。我们也 证明ADV可以高特异性地释放生物活性bFGF，从而导致 体内的功能性血管。bFGF释放动力学显著影响灌流血的形成 船舶. ADV产生的气泡也极大地改变了ARS对细胞迁移的容许性。 本提案的目的是了解血管化如何受到时空变化的影响 从ARS释放bFGF和PDGF-BB的动力学以及ARS的容许性。中央 假设最佳血管形成可以通过精确控制生长因子释放来实现 利用ADV产生的气泡动力学从ARS中分离出来。Aim 1将使用ADV生成的气泡动力学来 调节生长因子从ARS释放的动力学。目标2将量化bFGF释放的影响 动力学和ARS容许性对载细胞ARS的发展和融合的影响。目标3将 在后肢缺血的动脉粥样硬化模型中，通过顺序地 从非细胞ARS递送bFGF和PDGF-BB。这些目标的成功实现将推动 促血管生成生长因子在用于血管形成的无细胞和基于细胞的疗法中的翻译， 推动ADV的其他生物医学应用。