Hyaluronic Acid Based Nanoparticles for Targeted Image-Guided Tumor Surgery

描述（由申请人提供）：本提案的总体目标是开发新的荧光造影剂，可以在术中增强肿瘤，指导手术切除肿瘤。本提案中使用的纳米颗粒将来自透明质酸（HLA）的修饰。这些纳米颗粒具有捕获近红外（NIR）荧光染料的能力。捕获后，这些近红外荧光染料被淬灭。此外，HLA是细胞表面受体CD44的配体，可被透明质酸酶降解。理想情况下，透明质酸酶对hla纳米颗粒的特异性降解将释放出荧光的游离染料。透明质酸酶和CD44在多种肿瘤中均过表达，包括浸润性导管癌，本研究对此进行了研究。基于hla的纳米颗粒将包含一类新的纳米颗粒生物传感器，可以专门识别患病细胞。一个关键的创新步骤是，这些近红外生物传感器可以很容易地被新的图像引导手术器械检测到，以提供肿瘤状态的实时图像引导。事实上，已经设计了一个图像引导手术系统，用定向激发光束激发近红外荧光团。近红外发射是通过光谱和CCD探测器在架空多相机探测器。近红外生物传感器和术中成像的结合解决了一个关键的公共卫生问题，即无法在第一次手术中精确地完全切除肿瘤，这可能导致肿瘤复发率很高。肿瘤复发，可降低患者预后，改变治疗方案，并有严重的心理后果，除了额外的手术总费用的卫生保健系统。整合高度创新的技术，以改善接受肿瘤切除的患者的福利，有四个目标：(1)通过改变HLA分子量、引入交联化学和用聚乙二醇包覆纳米颗粒来优化近红外染料的负载和近红外染料的胶体性质；(2)确定荧光激活和CD44靶向的机制；(3)进行体内肿瘤对比研究，包括图像引导手术疗效；(4)对药物进行总体安全性评估，包括详细的生物分布研究。体外炎症和免疫系统激活，以及血液药代动力学。所有的体内研究都将在啮齿动物中进行；携带人类乳腺肿瘤异种移植物的小鼠，健康小鼠和大鼠。据推测，图像引导的肿瘤切除将减少复发性疾病，而纳米颗粒包裹的染料将特异性地增强肿瘤及其边缘，从而使癌症检测比对照组更敏感。

DESCRIPTION (provided by applicant): The overarching goal of this proposal is to develop novel fluorescence contrast agents that can enhance tumors intraoperatively to guide surgical tumor removal. Nanoparticles used in this proposal will be derived from modifications to hyaluronic acid (HLA). These nanoparticles have the ability entrap near infrared (NIR) fluorescent dyes. Upon entrapment, these NIR fluorescent dyes are quenched. In addition, HLA is a ligand for the cell surface receptor CD44 and is degraded by hyaluronidases. Ideally, specific degradation of HLA-based nanoparticles by hyaluronidases will release free dye that is again fluorescent. Both hyaluronidases and CD44 are overexpressed in a variety of tumors, including invasive ductal carcinoma, which is investigated in this proposal. The HLA-based nanoparticles would comprise a new class of nanoparticle biosensors that specifically identify diseased cells. A key innovative step is that these NIR biosensors can be readily detected by new image-guided surgical instrumentation to provide real-time image-guidance on tumor status. Indeed, an image-guided surgery system has been designed that excites NIR fluorophores with a directed excitation beam. NIR emission is detected spectrally and by CCD detectors in an overhead multicamera detector. The combination of NIR biosensors and intraoperative imaging addresses a key public health concern, the inability to exact complete surgical removal during the first surgery, which can result in a high rate of recurrent tumors. Recurrent tumors, can decrease patient prognosis, change therapeutic regimens, and have severe psychological consequences in addition to the overall costs of additional surgery to health care system. The integration of highly innovative technology to improve patient welfare for those undergoing tumor removal is addressed in four aims: (1) optimize the loading of NIR dye and colloidal properties of NIR dyes through modifying HLA molecular weight, introducing crosslinking chemistry, and coating nanoparticles with poly(ethylene glycol), (2) determine the mechanism for fluorescence activation and CD44 targeting, (3) perform in vivo tumor contrast studies, including image-guided surgery efficacy, and (4) an overall safety evaluation of the agents that includes detailed biodistribution studies, inflammatory and immune system activation in vitro, and blood pharmacokinetics. All in vivo studies will be performed in rodents; mice bearing human breast tumor xenografts, healthy mice, and rats. It's hypothesized that image-guided tumor removal will decrease recurrent disease, while nanoparticle entrapped dye will specifically enhance tumors and their margins resulting in more sensitive cancer detection compared to controls.