Injectable Hydrogels to Deliver Gene Therapy for Myocardial Infarct

可注射水凝胶为心肌梗塞提供基因治疗

基本信息

批准号：
10163255
负责人：
Sarah C Heilshorn
金额：
$ 39.63万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-15 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10163255
关键词：
Address Animals Anterior Arteries Biocompatible Materials Blood capillaries Cardiac Cardiac Myocytes Catheters Cause of Death Chemicals Chemistry Chronic Clinical Contracts DNA Diffuse Diffusion Dose Drug Delivery Systems Echocardiography Elastin Elements Exertion Family Female Firefly Luciferases Formulation Future Gel Gene Delivery Gene Expression Gene Expression Profiling Genes Geometry Growth Factor Heart Heart Contractilities Histologic Hyaluronic Acid Hydrazones Hydrogels Immune response In Situ In Vitro Infarction Inflammation Injectable Injections Kinetics Left Ligation Matrix Metalloproteinases Measurement Mechanics Modeling Molecular Weight Myocardial Infarction Myocardium Necrosis Operative Surgical Procedures Peptide Nucleic Acids Performance Pharmaceutical Preparations Plasmids Property Proteins Prunella vulgaris Randomized Rattus Recombinants Recovery of Function Reporter Genes Rheology Saline Site Stress Stromal Cells Surgeon Surgical sutures Therapeutic Thinness Tissues Validation Variant Ventricular Viscosity Wistar Rats angiogenesis base bioluminescence imaging biomaterial compatibility chemokine clinical translation clinically relevant combinatorial crosslink density design dosage endothelial stem cell experimental group fluorescence imaging gene therapy heart function hemodynamics improved in vivo local drug delivery male mathematical model mechanical properties minimally invasive novel therapeutics placebo group pre-clinical preclinical study pressure prevent programs protein aminoacid sequence regenerative repaired therapeutic gene therapeutic protein therapeutically effective tissue regeneration treatment group treatment strategy viscoelasticity

项目摘要

Following myocardial infarction (MI), local tissue remodeling leads to chronically worsening heart function that is a major cause of death in the US. Several preclinical studies have shown that local delivery of growth factors or growth factor-encoding genes can significantly improve cardiac function. Unfortunately, effective delivery of therapeutics to the beating heart remains a formidable challenge, impeding clinical translation of novel drug therapeutics. The ideal MI drug-delivery system would be catheter injectable, would prevent extrusion out of the contractile myocardium, and would provide sustained delivery of an effective therapeutic dosage. Unfortunately, most catheter-injectable biomaterials are weak hydrogels that are rapidly extruded out of contractile heart tissue. To overcome this clinical challenge, we propose the design of injectable gels that are crosslinked by dynamic covalent chemistry (DCC) bonds that are strong yet reversible. Thus, these DCC hydrogels combine the clinically desired properties of being injectable and having the mechanical integrity required for retention in the beating heart. Specifically, our gels are formed through DCC hydrazone bonds between a chemically modified hyaluronic acid and a recombinant, elastin-like protein. The resulting gel is enzymatically biodegradable and fully chemically defined for future potential in FDA studies. In Aim 1, a family of 20 gels with distinct viscoelastic mechanical properties will be synthesized and characterized for ease of catheter injection and retention in the contracting heart. We will modulate the viscosity of the gels by altering the molecular weight of hyaluronic acid and the yield stress of the gel by varying the concentration of a DCC crosslink competitor and perform in vitro and in vivo quantifications of injectability. In parallel in Aim 2, we evaluate the hypothesis that sustained release of a regenerative payload can be achieved through combinatorial mixing of drug tethers with distinct cleavage kinetics. Specifically, our payload is minicircle genes encoding stromal cell-derived factor-1α (SDF-1α), which is known to induce angiogenesis and improved heart function following MI. This payload is tethered to the injectable gel via DNA hybridization with peptide nucleic acid (PNA)-peptides. In Aim 3, the gel formulation from Aim 1 with optimal in vivo retention properties and the drug tether design from Aim 2 with sustained gene release will be combined into an injectable MI therapy. Functional performance will be evaluated in a preclinical rat MI model using minicircle genes carrying both SDF-1α and a firefly luciferase reporter gene. Following induction of MI through ligation of the left anterior descending (LAD) artery, animals will be randomly assigned into either sham or treatment groups. Treatment animals will receive a 60-μL intramyocardial injection of saline only, hydrogel only, untethered genes in saline, untethered genes in gel, or tethered genes in gel. Bioluminescence imaging (days 0, 1, 4, 7, 21, 42, 60, and 90) will be used to monitor gene expression. Functional recovery after MI will be assessed using echocardiography (days 7, 21) and hemodynamic measurements (day 90). Finally, heart explants will be analyzed for evidence of necrosis, inflammation, angiogenesis, and tissue regeneration (day 90).

心肌梗死 (MI) 后，局部组织重塑会导致心脏功能长期恶化，一些临床前研究表明，生长因子或局部给药是导致死亡的主要原因。生长因子编码基因可以显着改善心脏功能，不幸的是，有效传递。心脏跳动的治疗仍然是一个巨大的挑战，阻碍了新药的临床转化理想的 MI 药物输送系统是导管注射式的，可以防止药物被挤出体外。不幸的是，收缩性心肌将提供持续的有效治疗剂量。大多数导管注射生物材料是弱水凝胶，会迅速从收缩性心脏组织中挤出。为了克服这一临床挑战，我们提出了通过动态交联的可注射凝胶的设计共价化学 (DCC) 键牢固且可逆，因此，这些 DCC 水凝胶结合了临床应用。所需的可注射特性以及具有保留在打浆中所需的机械完整性具体来说，我们的凝胶是通过化学改性透明质酸之间的 DCC 腙键形成的。产生的凝胶可通过酶促生物降解并完全化学降解。在 Aim 1 中，定义了 20 种具有独特粘弹性力学性能的凝胶的未来潜力。将综合和表征特性，以便于导管注射和在收缩中保留我们将通过改变透明质酸的分子量和产量来调节凝胶的粘度。通过改变 DCC 交联竞争剂的浓度来调节凝胶的应力，并在体外和体内进行在目标 2 中，我们同时评估了持续释放的假设。再生有效负载可以通过具有不同裂解的药物系链的组合混合来实现具体来说，我们的有效负载是编码基质细胞衍生因子-1α（SDF-1α）的小环基因，即已知可在心肌梗死后诱导血管生成并改善心脏功能。该有效负载与注射剂相连。通过 DNA 与肽核酸 (PNA)-肽杂交形成凝胶在目标 3 中，使用来自目标 1 的凝胶制剂。具有持续基因释放的 Aim 2 的最佳体内保留特性和药物系链设计将是结合到可注射的 MI 治疗中，将在临床前大鼠 MI 模型中评估功能表现。在诱导 MI 后，使用携带 SDF-1α 和萤火虫荧光素酶报告基因的小环基因。通过结扎左前降支（LAD）动脉，动物将被随机分配到假手术组或治疗组将仅接受60μL盐水、水凝胶的心肌内注射。仅盐水中的未束缚基因、凝胶中的未束缚基因或凝胶中的束缚基因。（第 0、1、4、7、21、42、60 和 90 天）将用于监测 MI 后的功能恢复。使用超声心动图（第 7、21 天）和血流动力学测量（第 90 天）进行评估。将分析外植体的坏死、炎症、血管生成和组织再生的证据（第90天）。