Thermally Triggered Multivalent Targeting of Tumors

热触发肿瘤多价靶向

• 批准号: 8339991
• 负责人: Ashutosh Chilkoti
• 金额: $ 33.13万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8339991
• 关键词: Adverse effects; Antineoplastic Agents; Arginine; Biodistribution; Blood; Cells; Chemicals; Clinic; Clinical; Dorsal; Dose; Drug Carriers; Drug Delivery Systems; Drug Kinetics; Drug or chemical Tissue Distribution; Elastin; Evaluation; Exhibits; Fever; Flow Cytometry; Fluorescence Microscopy; Goals; Heating; Heterogeneity; Imagery; Implant; In Situ; In Vitro; Investments; Label; Length; Malignant Neoplasms; Mediating; Methods; Micelles; Microscopy; Modality; Mus; Organ; Patients; Penetration; Peptides; Pharmaceutical Preparations; Polymers; Radiolabeled; Recombinants; Research; Serum; Solid Neoplasm; Source; Specificity; System; Technology; Temperature; Testing; Therapeutic; Tissues; Tumor Burden; United States National Institutes of Health; Variant; cancer type; clinically relevant; cytotoxicity; density; design; di-block copolymer; digital; effective therapy; gemcitabine; innovation; nanoparticle; nanoscale; neoplastic cell; overexpression; polypeptide; radiotracer; receptor; scaffold; self assembly; small molecule; subcutaneous; success; therapeutic target; trafficking; tumor; uptake

DESCRIPTION (provided by applicant): The overall goal of this competing NIH R01 renewal application is to create a tumor-targeted cell-penetrating peptide (CPP) nanoscale drug delivery system to target therapeutic payloads to a wide range of solid tumors. This proposal builds upon the observation that oligoarginine peptides display a strong threshold effect in their cell penetration ability; below a threshold of 6 consecutive arginine (Arg) residues in the CPP, little cell uptake is observed, while above this threshold number of Arg residues, there is significant cell uptake. We hypothesized that this threshold effect is not related to the number of sequential Arg residues in the oligoarginine CPP, but instead is reflective of the local Arg residue density. This hypothesis predicts that the triggered self-assembly of a diblock copolymer, that presents < 6 Arg residues on its hydrophilic end, into a micelle should provide a system that exhibits digital "off-on" cell uptake. To test this hypothesis and develop an externally triggered CPP drug delivery system, thermally responsive diblock copolymers of an elastin-like polypeptide (ELPBCs) will be synthesized such that the number of Arg residues on the hydrophilic terminus of the ELPBC will be below the threshold required for efficient cellular uptake of ELPBC unimers at 37 ¿C. In tumors that are externally heated to 39-42 ¿C, which is greater than the critical micellization temperature of the ELPBC, the ELPBC will self-assemble into micelles decorated with Arg residues, and the local Arg residue density in the corona of the ELPBC will exceed the threshold required for efficient cellular uptake, thereby resulting in efficient intracellular uptae within the tumor. Arg-presenting ELPBC with a range of architectural variables will be synthesized, tested for self-assembly and stability between 39 and 42 ¿C in serum, and their temperature-triggered cellular uptake will be quantified by flow cytometry and visualized by fluorescence microscopy. Optimal Arg-presenting ELPBC selected from these studies will then be tested for their pharmacokinetics, tissue distribution and their ability to regress tumors, when they are fused to gemcitabine that is sequestered within the core of the ELPBC micelles. The significance of this proposal is that it will provide a receptor independent method of actively targeting tumors that is applicable to a broad range of cancer types and circumvents the limitations of receptor targeting; furthermore this targeting modality piggybacks on to existing hyperthermia technology, so that it can be readily deployed in the clinic. The drug carrier design presented here is innovative because it is, to our knowledge, the first attempt to control cellular uptake of cancer therapeutics by manipulating the local density of Arg residues on a nanoscale scaffold by externally triggered self-assembly under clinically relevant conditions. PUBLIC HEALTH RELEVANCE: The proposed research will develop a biodegradable, temperature sensitive polymer that will morph into nanoparticles in tumors that are mildly heated by an external source. These nanoparticles will be decorated with arginine residues on their exterior and will contain a cancer drug. The arginine's will allow efficient uptake of the nanoparticles by cells in the tumor, thereby leading to selective and effective treatment of the tumor by the drug with few side-effects.

描述（由申请人提供）：这项竞争性 NIH R01 更新申请的总体目标是创建一种肿瘤靶向细胞穿透肽 (CPP) 纳米级药物递送系统，以将治疗有效负载靶向广泛的实体瘤。该提议基于这样的观察：寡精氨酸肽在其细胞渗透能力方面表现出很强的阈值效应；低于 CPP 中 6 个连续精氨酸 (Arg) 残基的阈值，观察到很少的细胞摄取，而高于此阈值数量的 Arg 残基，则观察到显着的细胞摄取。我们假设这种阈值效应与寡精氨酸 CPP 中连续 Arg 残基的数量无关，而是反映了局部 Arg 残基密度。该假设预测，在其亲水端呈现 < 6 个 Arg 残基的二嵌段共聚物触发自组装成胶束，应提供一个具有数字功能的系统。 “关-开”细胞摄取。为了测试这一假设并开发外部触发的 CPP 药物递送系统，将合成弹性蛋白样多肽 (ELPBC) 的热响应二嵌段共聚物，使得 ELPBC 亲水末端上的精氨酸残基数量将低于 37℃ 下细胞有效摄取 ELPBC 单聚体所需的阈值。在外部加热至39-42℃的肿瘤中，高于ELPBC的临界胶束化温度，ELPBC将自组装成带有Arg残基修饰的胶束，并且ELPBC冠部的局部Arg残基密度将超过细胞有效摄取所需的阈值，从而导致肿瘤内有效的细胞内摄取。将合成具有一系列结构变量的精氨酸呈递 ELPBC，测试其在血清中 39 至 42°C 之间的自组装和稳定性，并且将通过流式细胞术定量并通过荧光显微镜观察其温度触发的细胞摄取。然后将从这些研究中选出的最佳 Arg 呈递 ELPBC 进行药代动力学、组织分布及其消退肿瘤的能力测试，当 它们与吉西他滨融合，吉西他滨被隔离在 ELPBC 胶束的核心内。该提案的意义在于，它将提供一种不依赖受体的主动靶向肿瘤的方法，适用于广泛的癌症类型，并规避受体靶向的局限性；此外，这种靶向方式依赖于现有的热疗技术，因此可以很容易地在诊所中部署。这里介绍的药物载体设计具有创新性，因为据我们所知，这是控制细胞的首次尝试。 通过在临床相关条件下外部触发的自组装来操纵纳米级支架上精氨酸残基的局部密度，从而吸收癌症治疗药物。 公共健康相关性：拟议的研究将开发一种可生物降解的温度敏感聚合物，该聚合物将在外部来源轻微加热的肿瘤中转变成纳米颗粒。这些纳米颗粒的外部将装饰有精氨酸残基，并含有抗癌药物。精氨酸将使肿瘤细胞有效摄取纳米粒子，从而导致药物选择性且有效地治疗肿瘤，且副作用很少。