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-热学和具体的挑战主题，13-CA-102：用于热学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与光动力疗法(PDT)的组合方案，PDT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。卵巢癌存活率低的主要原因是手术和化疗后残留的肿瘤，导致疾病复发，以及对放射和化疗的抵抗。一种具有灵敏度和分辨率的微创成像方式，在治疗周期的早期发现与复发性疾病有关的亚毫米OvCa结节，将使患者能够及时重新评估疾病，并在必要时启动更多治疗。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手段。我们已经开发了这样一种荧光显微内窥镜，并表明它能够检测出微小的肿瘤结节。我们还证明了光动力疗法使肿瘤对抗血管内皮生长因子(阿瓦斯丁)治疗增敏，并且当阿瓦斯丁以纳米结构形式细胞内传递时，这种组合(光动力疗法和阿瓦斯丁)更有效。这一提议背后的假设是，光动力疗法结合细胞内靶向的血管内皮生长因子池将是一种有价值的联合治疗方法，当与可以监测治疗反应的成像系统结合时，将是最有用的。我们的策略是使用包裹了阿瓦斯丁和PDT试剂苯并卟啉衍生物的Theranostic Nanocell(TNC)作为治疗成分。TNC通过吲哚青绿标记的抗EGFR抗体(西妥昔单抗/C225)靶向OvCa细胞上的表皮生长因子受体(EGFR)，是TNC的诊断组件。将阿瓦斯丁包裹在这些分子靶向的纳米结构中，应该会减少这种药物的严重全身毒性，这种毒性通常是致命的。这些目标将通过3个具体目标来实现：1)TNC的合成和表征，2)研究治疗纳米细胞在3D细胞培养模型中的作用，以获得有效剂量，以及3)评估TNC在体内检测肿瘤结节的效率，并利用显微内窥镜建立TNC在OvCa小鼠模型中的生物分布。为了在两年的资助期内完成该项目，本提案主要集中在体外开发和鉴定具有少量体内成分的TNC。然而，如果成功，这一结果将在广泛的动物/人类研究中得到进一步证实，这项研究的结果将影响到具有多功能平台对其他疾病的适应性的OvCa患者的很大比例。这项建议的主要成果将是i)TNC的制造和剂量，以在3D培养中对体外肿瘤结节进行成像和破坏，以及在体内检测这些播散的结节，以及ii)基于TNC的荧光显微内窥镜，用于敏感和特异地检测微转移的OVCA。 公共卫生相关性：目前治疗Ovca术后的方法未能显著提高患者的存活率和生活质量。我们的方法不仅有助于定位微小的残留病，而且可以用多种药物选择性地摧毁它，并减少副作用。这项研究具有改善患者护理的潜力，并可能导致开发一种新的手术后OvCa患者的管理标准。

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.