Nanoconjugate based on polymalic acid for brain tumor treatment

描述（由申请人提供）：纳米技术的最新进展可能为癌症治疗的显著改善和成功提供新的希望，特别是在预防肿瘤生长和进展方面。这与预后非常差的脑胶质瘤特别相关，目前的治疗在很大程度上无法治愈，因此需要新的治疗方式。本研究以多头绒泡菌（Physarumpolycephalum）为原料，以聚（p-L-苹果酸）（PMLA）为纳米平台，制备了一种新型的纳米级（20-30 nm）抗肿瘤药物载体（Polycefin）。这种通用平台可以容易地被修饰以包括共价连接到PMLA骨架的新部分，例如抑制肿瘤细胞靶标的抗癌药物。当前版本的递送平台包含：可生物降解的、无毒的和非免疫原性的PMLA;药物释放单元;靶向血管生成胶质瘤增加的蛋白层粘连蛋白411的两条链的吗啉代反义寡核苷酸（AON）单元;用于特异性组织靶向和内体摄取的抗转铁蛋白受体抗体;生物聚合物保护剂聚乙二醇（PEG）;用于内体膜破坏的疏水释放单元;和荧光跟踪染料。开发纳米平台以抑制具有全身递送的复杂蛋白质的合成。这些蛋白质，如三聚体层粘连蛋白在肿瘤生长、侵袭和转移中起重要作用，但以前不能被常规药物阻断。初步数据表明，药物直接递送到脑肿瘤部位，抑制胶质瘤分子靶点（层粘连蛋白链），并且在体内没有可见的毒性。结果，实现了携带胶质瘤的动物的存活率增加60%（p<0.01），肿瘤大小减小10倍（p<0.01）。将在本提案中评价和开发该静脉全身给药系统。该项目将专注于含有AON的基础纳米缀合物平台的临床前测试，该平台针对我们的特征性胶质瘤标志物层粘连蛋白411，一种对肿瘤血管发育重要的蛋白质。最终目标是通过详细的化学、化学-物理和临床前评价，从几种基于聚合物的缀合物中选择一种先导载体-药物化合物，这将为临床使用建立坚实的理论基础。我们的目标包括：（1）通过改变AON和靶向抗体分子的数量，对Polycefin变体进行化学优化，以最有效地阻断层粘连蛋白411;（2）对平台进行化学、物理和药代动力学表征，包括研究稳定性、体内半衰期和组织蓄积;（3）优化注射次数和剂量，以最有效地治疗肿瘤;以及（4）药物药理学性质（毒性、分布、代谢和排泄）的GLP合规性研究。相关性（参见说明）：本项目与NIH公告RFA-CA-05-026“癌症纳米技术平台伙伴关系”（UOl）相关。我们的多学科团队创建了一个新的纳米级（20-30 lun）抗肿瘤药物输送系统的基础上聚（P-L-苹果酸）（PMLA）。该通用平台可以容易地被修饰以包括共价连接到PMLA骨架的新部分，例如抑制肿瘤细胞靶标的抗癌药物。这与预后非常差的脑胶质瘤特别相关，目前的治疗在很大程度上无法治愈，因此需要新的治疗方式。该纳米平台的开发是为了抑制几种肿瘤特异性靶点的合成，这些靶点在肿瘤生长、侵袭和转移中起着重要作用，但以前无法被常规药物阻断。

DESCRIPTION (provided by applicant): Recent advances in nanotechnology may offer a new hope for a significant improvement and success of cancer treatment, especially in preventing tumor growth and progression. This is particularly relevant to brain gliomas that have very poor prognosis, are largely incurable by current therapy, and therefore, need novel treatment modalities. Our research is dealing with a new nanoscale (20-30 nm) anti-tumor drug delivery system (Polycefin) based on naturally derived nanoplatform, poly(p-L-malic acid) (PMLA) fi-om a slime mold, Physarum polycephalum. This universal platform may be easily modified to include new moieties covalently attached to PMLA backbone, such as anti-cancer drugs inhibiting tumor cell targets. The current version of the delivery platform contains: biodegradable, non-toxic, and non-immunogenic PMLA; a drug releasing unit; Morpholino antisense oligonucleotide (AON) unit targeting two chains of angiogenic glioma-increased protein laminin 411; anti-transferrin receptor antibody for specific tissue targeting and endosomal uptake; biopolymer protector polyethylene glycol (PEG); a hydrophobic release unit for endosomal membrane disruption; and a fluorescent tracking dye. The nanoplatform was developed to inhibit the synthesis of complex proteins with systemic delivery. These proteins, such as trimeric laminins play a significant role in tumor growth, invasion and metastasis, but previously could not be blocked because by conventional drugs. Preliminary data demonstrated drug delivery directly to the brain tumor site, inhibition of glioma molecular targets (laminin chains), and lack of visible toxicity in vivo. As a result, a 60% increase in survival of glioma bearing animals (p<0.01) with 10-fold tumor size reduction (p<0.01) was achieved. This I.V. systemic delivery system will be evaluated and developed in this proposal. The project will focus on the preclinical testing of basic nanoconjugate platform containing AON against our characterized glioma marker, laminin 411, a protein important for tumor vessel development. The ultimate goal is to select a lead vehicle-drug compound from several polymer-based conjugates by detailed chemical, chemical-physical and preclinical evaluation, which would establish a solid rationale for clinical usage. Our Aims include (1) chemical optimization of Polycefin variants for the most efficient blocking of laminin 411 by varying the number of AON and targeting antibody molecules; (2) chemical, physical and pharmacokinetic characterization of the platform including studies of stability, in vivo half-life and tissue accumulation; (3) optimization of the number of injections and dosage for the most effective tumor treatment; and (4) GLP-compliant study of drug pharmacological properties (toxicity, distribution, metabolism and excretion). RELEVANCE (See instructions): This project is relevant to the NIH announcement RFA-CA-05-026 "Cancer Nanotechnology Platform Partnerships" (UOl). Our multidisciplinary team created a new nanoscale (20-30 lun) anti-tumor drug delivery system based on poly(P-L-malic acid) (PMLA). This universal platform may IK easily modified to include new moieties covalently attached to PMLA backbone, such as anti-cancer drugs inhibiting tumor cell targets. This is particularly relevant to brain gliomas that have very poor prognosis, are largely incurable by current therapy, and therefore, need novel treatment modalities. The nanoplatform was developed to inhibit the synthesis of several tumor specific targets that play a significant role in tumor growth, invasion and metastasis, but previously could not be blocked by conventional drugs.