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).

遵循心肌梗塞（MI），局部组织重塑导致长期忘记心脏功能美国的主要死亡原因。一些临床前研究表明，生长因子的局部递送或生长因子编码基因可以显着改善心脏功能。不幸的是，有效交付对心脏的治疗方法仍然是一个巨大的挑战，阻碍了新药的临床翻译理想的MI药物输送系统将是导管可注射的，将防止延伸收缩心肌，并将提供有效的治疗剂量的持续提供。很遗憾，大多数可注射导管的生物材料是弱水凝胶，它们迅速从收缩心脏组织中挤出。为了克服这一临床挑战，我们提出了由动态交联的可注射凝胶的设计强大但可逆的共价化学（DCC）键。那就是这些DCC水凝胶结合了诊所可注射的所需特性，并具有在跳动中保留所需的机械完整性心。具体而言，我们的凝胶是通过化学修饰的水流之间的DCC氢唑键形成的酸和重组，弹性蛋白样蛋白。所得的凝胶是可生物降解的，并且完全化学定义为FDA研究的未来潜力。在AIM 1中，一个具有独特粘弹性机械的20个凝胶家族将合成和特征性的物业，以便于签约中的导管注射和保留率心。我们将通过改变氢酸的分子量和产量来调节凝胶的粘度通过改变DCC交叉链接竞争者的浓度并在体外和体内执行凝胶的应力注射性的量化。在AIM 2中并行，我们评估了持续释放a的假设可以通过与不同乳沟的毒品结合混合来实现再生有效载荷动力学。特别是，我们的有效载荷是编码基质细胞衍生因子1α（SDF-1α）的微圆基因，这是已知会在MI后诱导血管生成和改善的心脏功能。此有效载荷已束缚在注射台上通过DNA杂交与肽核酸（PNA） - 肽的凝胶。在AIM 3中，AIM 1的凝胶配方与最佳的体内保留特性和AIM 2带有持续基因释放的药物束系设计将是合并成可注射的MI疗法。功能性能将在临床前大鼠MI模型中评估使用携带SDF-1α和萤火虫荧光素酶报告基因的微量圆基因。诱导MI 通过连接左前降（LAD）动脉，将随机分配到任何一个假或治疗组。治疗动物将仅接受60μl的心膜内注射盐水，水凝胶仅在盐水中，凝胶中的不束缚基因或凝胶中的束缚基因。生物发光成像（第0、1、4、7、21、42、60和90天）将用于监测基因表达。 MI后的功能恢复将是使用超声心动图（第7、21天）和血液动力学测量（第90天）评估。最后，心将分析外植体，以获取坏死，感染，血管生成和组织再生的证据（第90天）。