Thermosensitive injectable polymer-based stem cell therapy for limb ischemia

热敏可注射聚合物干细胞疗法治疗肢体缺血

• 批准号: 8963562
• 负责人: Hak-Joon Sung
• 金额: $ 23.53万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8963562
• 关键词: Address; Binding; Biomedical Engineering; Blood Vessels; Blood flow; Body Temperature; Bone Marrow; Cell Line; Cell Therapy; Cells; Clinical Trials; Collagen Type IV; Development; Endothelial Cells; Engraftment; Exhibits; Gangrene; Gel; Gene Cluster; Generations; Goals; Grant; Growth Factor; Heart failure; Hindlimb; Human; Hydrogels; In Vitro; Injectable; Integrins; Ischemia; Isolated limb perfusion; LacZ Genes; Laminin; Limb structure; Mediating; Mesenchymal Stem Cells; Methods; Modeling; Molecular; Mus; Operative Surgical Procedures; Pain; Pathway interactions; Patients; Peptides; Perfusion; Peripheral arterial disease; Phenotype; Polymers; Protocols documentation; Recovery; Relative (related person); Reporter; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Stem cells; Testing; Therapeutic; Time; Tissues; Translating; Ulcer; Undifferentiated; Ventricular Function; angiogenesis; base; beta-Galactosidase; clinical practice; combinatorial; foot; implantation; improved; inhibitor/antagonist; innovation; insight; mortality; mouse model; neovasculature; paracrine; progenitor; programs; promoter; public health relevance; regenerative; repaired; scaffold; screening; small molecule; stem cell differentiation; stem cell therapy; vasculogenesis

 DESCRIPTION: Critical limb ischemia (CLI) in patients is characterized by ulceration, pain, and limb loss with associated high mortality. For CLI patients who are not suitable surgical candidates, stem cell therapy represents a promising alternative to increase perfusion. However, results from recent clinical trials with bone marrow-derived stem cells indicate a lack of lasting efficacy due to two major obstacles: poor long-term tissue engraftment and their low potency. This grant addresses these obstacles by parallel development of 1) thermosensitive injectable polymers that enable improved survival and proliferation of stem cells in ischemic tissue 2) efficient generation of MSCs which have been partially preprimed towards the endothelial lineage and exhibit higher potency. To accomplish these goals, a mouse MSC line genetically tagged with a lacZ reporter driven by an endothelial promoter (flk1) was generated to perform high-throughput testing of multiple vascular differentiation protocols. This screen identified laminin I and collagen IV as potent molecular inducers of endothelial differentiation of mouse and human MSCs. Endothelial prepriming of MSCs dramatically improved ischemic perfusion in mice. The hypothesis to be tested is that preprimed MSCs with high reparative potency injected with thermosensitive polymers which gel at body temperature will target stem cells to ischemic foci to promote their engraftment and therapeutic potency. The project seeks to understand the molecular factors and signaling pathways involved in stepwise endothelial differentiation of MSCs and to generate a combinatorial therapy using bioengineered injectable polymer to deliver the preprimed human MSCs with peptide-based therapeutics to improve perfusion in a mouse model of hindlimb ischemia. The long-term goal is to develop a non-invasive stem-cell therapy to augment limb perfusion in patients with CLI.

 描述：严重肢体缺血 (CLI) 患者的特点是溃疡、疼痛和肢体丧失，且死亡率较高，对于不适合手术的 CLI 患者来说，干细胞治疗是增加灌注的一种有希望的替代方案。最近的骨髓源性干细胞临床试验表明，由于两个主要障碍，缺乏持久功效：长期组织移植能力差和效力低。这项资助通过并行开发 1) 热敏可注射聚合物来解决这些障碍。能够改善缺血组织中干细胞的存活和增殖 2) 高效生成 MSC，这些 MSC 已部分向内皮谱系预引发并表现出更高的效力 为了实现这些目标，小鼠 MSC 系在基因上标记了由 lacZ 报告基因驱动的细胞。生成内皮启动子 (flk1) 以对多种血管分化方案进行高通量测试。该筛选确定了层粘连蛋白 I 和胶原 IV 是血管内皮分化的有效分子诱导剂。 小鼠和人类 MSC 的内皮预激发显着改善了小鼠的缺血灌注。要测试的假设是，注射有在体温下凝胶的热敏聚合物的预激发 MSC 会将干细胞靶向缺血灶，以促进其植入和移植。该项目旨在了解间充质干细胞逐步内皮分化所涉及的分子因素和信号通路，并利用其产生组合疗法。生物工程可注射聚合物可通过基于肽的疗法输送预引发的人类间充质干细胞，以改善小鼠后肢缺血模型的灌注。长期目标是开发一种非侵入性干细胞疗法，以增强 CLI 患者的肢体灌注。