Targeted Photoactivatable Nanocells to Image and Treat Metastic Ovarian Cancer

描述（由申请人提供）：该申请涉及广泛的挑战领域（13）智能生物材料-治疗学和特定挑战主题，13- ca -102：基于纳米技术的多功能材料用于治疗应用。这项研究的长期目标是开发基于机制和光动力疗法（PDT）的基于纳米技术的图像引导联合方案，PDT是FDA批准的用于某些癌症和卵巢癌（OvCa）临床试验的治疗方法。OvCa的低生存率主要是由于手术和化疗后残留的肿瘤导致疾病复发，以及对放疗和化疗的抵抗。在治疗周期的早期，一种具有灵敏度和分辨率的微创成像方式可以检测与复发性疾病相关的亚毫米OvCa结节，这将允许及时重新评估疾病并在需要时开始额外的治疗。光学显微内镜是一种具有高灵敏度和微米级分辨率的微创成像方式。我们研制了这样一种荧光显微内窥镜，并证明它能够检测出小的肿瘤结节。我们还证明了PDT使肿瘤对抗vegf（阿瓦斯汀）治疗增敏，并且当阿瓦斯汀以纳米结构在细胞内传递时，这种组合（PDT和阿瓦斯汀）更有效。该建议的假设是PDT联合细胞内靶向VEGF池将是一种有价值的联合治疗，当与可以监测治疗反应的成像系统结合使用时，将是最有用的。我们的策略是使用治疗纳米细胞（TNC）封装阿瓦斯汀和PDT剂苯并卟啉衍生物作为治疗成分。TNC通过荧光吲哚菁绿色标记的抗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），作为TNC的诊断成分。将阿瓦斯汀包封在这些分子靶向纳米结构物中，可以减少这种药物严重的全身毒性，这种毒性通常是致命的。具体目标将在3个方面实现：1)TNC的合成与表征；2)在三维细胞培养模型中研究治疗性纳米细胞的作用，以获得有效剂量；3)利用显微内镜评估TNC在体内检测肿瘤结节的功效，并建立TNC在小鼠OvCa模型中的生物分布。为了在两年的资助期内完成该项目，该提案主要侧重于在体外发展和表征TNC，其中少量的体内成分。然而，如果成功，该结果将在广泛的动物/人体研究中得到进一步证实，该研究的发现将影响很大一部分具有多功能平台对其他疾病适应性的OvCa患者。该提案的主要成果将是i) TNC制造和给药，在体外3D培养中成像和破坏肿瘤结节，以及在体内检测这些弥散性结节，以及ii)荧光显微内镜，用于基于TNC的微转移性OvCa的敏感和特异性检测。

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.