Rigid-rod Peptides as Nanocarriers for Delivery of Cancer Drugs

描述（由申请人提供）：癌症是美国第二大死亡原因。除了手术和放射治疗，化疗和药物联合治疗是提高患者生存率最成功的方法之一。紫杉醇（PTX）是目前临床应用最成功的紫杉醇类药物之一。PTX非常有效 用于治疗多种癌症，包括：卵巢癌、乳腺癌、结肠癌、头颈癌和非小细胞肺癌。不幸的是，目前使用的旨在增加PTX的溶解度并因此增加PTX的生物利用度的制剂与不良过敏反应有关。因此 合成并测试了几种前药，其通常含有与亲水性和可水解基团如多羧酸、糖、聚合物和肽缀合的PTX。尽管有这些努力，但人们对开发用于PTX和其他弱可溶性药物的靶向药物递送的新型前药以提高其治疗效率有相当大的兴趣。这项提案的目标是开发一种新型的局部给药系统用于低溶解度药物的（纳米载体）PTX与THP的缀合提供了许多优于目前使用的前药的潜在优点：（1）它改善了前药溶解度，（2）由于刚性棒状构象，它增加了蛋白酶抗性，（3）它允许掺入药物靶向序列或细胞穿透载体，（4）它允许前药固定在 胶原基质此外，与金属纳米载体不同，THP纳米载体可生物降解为生物安全的产品。该提案旨在开发肽序列以形成基于PTX的水溶性模型前药，所述PTX经由C2 '-OH位置处的琥珀酰连接连接至肽的赖氨酸基团。通过改变肽长度和序列，将调节前药的溶解度。所提出的肽序列将形成THP刚性棒纳米载体，提供针对体内生物降解的增加的稳定性。此外，THP载体将打开从亲水性胶原基质递送疏水性药物的可能性。前药的释放曲线将作为纳米载体结构的函数来测量。通过合成不同长度的THP并将预热（自组装）或非预热（共混）纳米载体并入胶原基质中，我们希望有效地控制前药释放的速率。将细胞穿透载体并入前药的可行性将被研究。还提出了将聚精氨酸序列并入前药序列中以研究优先纳米载体细胞摄取。还将研究拟定Paclitaxel前药的细胞毒性。发展目标是增加PI参与与人类健康直接相关的跨学科研究，并提高PI实验室的生产力。所要求的支持将导致PI实验室开发新的方法和协议，并增加研究生和本科生的参与，包括来自传统上代表性不足背景的学生。如果获得SC-3的支持，将增加PI的研究成果，并提高主要资助支持的竞争力，如NSF和NIH-RO 1类型的赠款。 公共卫生相关性：该提案描述了一类新型的用于低溶解度抗癌药物（例如紫杉醇）的局部药物递送纳米载体，其基于组装成三螺旋肽（THP）的胶原模拟肽。紫杉醇与THP（一种刚性棒纳米载体）的缀合通过增加在水中的溶解度、改善稳定性、允许掺入药物靶向序列或细胞穿透载体以及允许从亲水性胶原基质局部递送疏水性药物而提供了优于目前使用的前药的许多潜在优点。

DESCRIPTION (provided by applicant): Cancer is the second leading cause of death in the United States. Next to surgery and radiation treatments, chemotherapy and combination therapies involving drugs are among the most successful in increasing patient survival rates. Paclitaxel (PTX) is one of the most successful taxoids in clinical use today. PTX is very effective in treatment of several cancers including: ovarian, breast, colon, head and neck, and non small cell lung cancer. Unfortunately, the currently used formulations which are intended to increase the solubility and thus bioavailability of PTX, are linked to adverse allergic reactions. Therefore several prodrugs, typically containing PTX conjugated with the hydrophilic and hydrolyzable groups such as polycarboxylic acids, sugars, polymers and peptides, were synthesized and tested. Despite these efforts there is a considerable interest in developing novel prodrugs for targeted drug delivery of PTX and other weakly soluble drugs to increase their therapeutic efficiency. The goal of this proposal is to develop a novel class of local drug delivery systems (nanocarriers) for low solubility drugs (such as PTX) based on collagen mimetic peptides assembled into triple helical peptide (THP) The conjugation of PTX with THP affords numerous potential advantages over currently used prodrugs: (1) it improves prodrug solubility, (2) it increases protease resistance due to rigid rod conformation (3) it allows incorporation of drug targeting sequence or cell penetrating vector, (4) it allows immobilization of the prodrug within a collagen matrix . Additionally, the THP nanocarrier unlike metallic nanocarriers biodegrades to biologically safe products. The proposal aims at developing peptide sequences to form water soluble model prodrugs based on PTX attached to the peptide's lysine group via succinylic link at C2'-OH position. By varying the peptide length and sequence the solubility of the prodrug will be adjusted. The proposed peptide sequences will form THP rigid-rod nanocarrier providing increased stability against in vivo biodegradation. Moreover, the THP carrier will open the possibility of delivering the hydrophobic drugs from hydrophilic collagen matrix. The release profile of a prodrug will be measured as a function of the nanocarrier structure. By synthesizing different length of THP and incorporating pre-heated (self-assembled) or non-preheated (blended) nanocarrier within collagen matrix we hope to effectively control the rates of the prodrug release. The feasibility of incorporating the cell-penetrating vectors into the prodrug wil be investigated. The incorporation of the polyarginine sequences into the prodrug sequence to study preferential nanocarrier cell uptake is also proposed. The cytotoxicity of the proposed Paclitaxel prodrug will also be studied. The developmental objective is to increase the PI's involvement in interdisciplinary research directly related to human health and to increase the productivity of the PI laboratory. The requested support will result in the development of new methodologies and protocols in the PI's laboratory and increased participation of graduate and undergraduate students, including students from traditionally underrepresented backgrounds. This SC-3 support, if awarded, will increase the PI's research output and improve competitiveness for major grant support such as NSF and NIH-RO1 type grants. PUBLIC HEALTH RELEVANCE: This proposal describes a novel class of local drug delivery nanocarriers for low solubility anti-cancer drugs, such as Paclitaxel, based on collagen mimetic peptides assembled into triple helical peptide (THP). Conjugation of Paclitaxel with THP, a rigid- rod nanocarrier, offers numerous potential advantages over currently used prodrugs by increasing solubility in water, improving stability, allowing incorporation of drug targeting sequence or cell penetrating vector, and allowing local delivery of hydrophobic drugs from hydrophilic collagen matrix.