Targeted Photoactivatable Nanocells to Image and Treat Metastic Ovarian Cancer

描述（由申请人提供）：本申请涉及广泛的挑战领域（13）智能生物材料-治疗诊断学和特定的挑战主题，13-CA-102：用于治疗诊断应用的基于纳米技术的多功能材料。这项研究的长期目标是开发基于机制和纳米技术的图像引导组合方案与光动力疗法（PDT），这是FDA批准的用于某些癌症的治疗方法，并用于卵巢癌（OvCa）的临床试验。OvCa的生存率差在很大程度上是由于手术和化疗后的残留肿瘤导致疾病复发以及对放疗和化疗的抵抗。具有灵敏度和分辨率的微创成像模式可在治疗周期早期检测与复发性疾病相关的亚毫米OvCa结节，这将允许及时进行疾病重新评估，并在需要时开始额外的治疗。光学显微内窥镜是一种具有高灵敏度和微米级分辨率的微创成像方式。我们已经开发了这样一种荧光显微内窥镜，并表明它能够检测小肿瘤结节。我们还证明了PDT使肿瘤对抗VEGF（Avastin）治疗敏感，并且当Avastin在纳米构建体中细胞内递送时，这种组合（PDT和Avastin）更有效。该提议的假设是PDT与VEGF池的细胞内靶向组合将是有价值的组合治疗，当与可以监测治疗反应的成像系统结合时将是最有用的。我们的策略是使用Theranostic Nanocell（TNC），其封装Avastin和PDT剂苯并卟啉衍生物作为治疗组分。TNC通过荧光吲哚菁绿标记的抗表皮生长因子受体（EGFR）抗体（西妥昔单抗/C225）靶向OvCa细胞上的EGFR，并作为TNC的诊断组分。将阿瓦斯丁封装在这些分子靶向纳米结构中应该可以降低这种药物的严重全身毒性，这种毒性通常是致命的。这些目标将在3个具体目标中实现：1）TNC的合成和表征，2）研究治疗诊断纳米细胞在3D细胞培养模型中的作用以获得有效剂量，以及3）使用显微内窥镜在OvCa的鼠模型中评价TNC检测肿瘤结节和建立TNC生物分布的体内功效。为了在两年的供资期内完成该项目，本提案主要侧重于体外开发和表征TNC，其中含有少量体内成分。但是，如果成功，将在广泛的动物/人体研究中进一步证实结果，并且本研究的结果将影响大部分OvCa患者的多功能平台对其他疾病的适应性。该提案的主要交付成果将是i）TNC制造和给药，以在3D培养物中体外成像和破坏肿瘤结节，以及在体内检测这些播散性结节，以及ii）用于微转移OvCa的基于TNC的灵敏和特异性检测的荧光显微内窥镜。 公共卫生相关性：目前手术后治疗OvCa的方法未能显著改善患者的生存率和生活质量。我们的方法不仅有助于定位微观残留疾病，而且可以选择性地用多种药物破坏它，减少副作用。这项研究有可能改善患者的护理，并可能为手术后OvCa患者制定新的管理标准。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (13) Smart Biomaterials - Theranostics and specific Challenge Topic, 13-CA-102: Nanotechnology-based multi-functional materials for theranostic applications. The long term goal of this research is to develop mechanism and nanotechnology-based image-guided combination regimens with photodynamic therapy (PDT), an FDA approved treatment for certain cancers and in clinical trials for Ovarian Cancer (OvCa). The poor survival for OvCa stems in large part from residual tumor following surgery and chemotherapy leading to the disease recurrence and due to resistance to radiation and chemotherapy. A minimally invasive imaging modality with sensitivity and resolution to detect sub-millimeter OvCa nodules associated with recurrent disease, early in the treatment cycle would allow for timely disease re-assessment and the initiation of additional treatments if needed. Optical microendoscopy is a minimally invasive imaging modality with high sensitivity and micron-scale resolution. We have developed such a fluorescence microendoscope and shown it is capable of detecting small tumor nodules. We have also demonstrated that PDT sensitizes tumors to anti-VEGF (Avastin) treatment and that this combination (PDT and Avastin) is more effective when Avastin is delivered intracellularly in a nanoconstruct. The hypothesis underlying this proposal is that PDT combined with intracellular targeting of the VEGF pool will be a valuable combination treatment that will be most useful when incorporated with an imaging system that can monitor treatment response. Our strategy is to use a Theranostic Nanocell (TNC) that encapsulates Avastin and the PDT agent benzoporphyrin derivative as therapeutic components. The TNC targets Epidermal Growth Factor Receptor (EGFR) on OvCa cells via fluorescent indocyanine green-labeled anti-EGFR antibody (Cetuximab /C225) and serves as the diagnostic component of TNC. Encapsulation of Avastin inside these molecularly targeted nano-constructs should reduce the severe systemic toxicity of this drug, which is often lethal. The goals will be realized in 3 specific aims: 1) Synthesis and characterization of TNC, 2) Investigate the effect of theranostic nanocell in 3D cell culture models to obtain effective doses and 3) Evaluate the in vivo efficacy of the TNC to detect tumor nodules and establish TNC biodistribution in a murine model of OvCa using microendoscopy. In order to complete the project in the two year funding period, this proposal is focused primarily on developing and characterizing the TNC in vitro with a minor in vivo component. However, if successful, the results will be further substantiated in an extensive animal/human study and the findings of this study will impact a large proportion of OvCa patients with adaptability of the multifunctional platform to other diseases. Major deliverables of this proposal will be i) TNC fabrication and dosing to image and destroy tumor nodules in vitro in 3D cultures as well as detect these disseminated nodules in vivo, and ii) Fluorescence microendoscope for TNC-based sensitive and specific detection of the micrometastatic OvCa. PUBLIC HEALTH RELEVANCE: Current methods to treat OvCa following surgery have failed to drastically improve patient survival and quality of life. Our method will not only help locate the microscopic residual disease but also selectively destroy it with multiple drugs and with reduced side-effects. This study has the potential to improve patient care and could result in the development of a new standard of management for the patients with OvCa following surgery.