Enzyme-activated Nanoparticles as Contrast Agents for Optical Detection of Cancer

描述（由申请人提供）：尽管在过去几十年中癌症的检测有了很大的改进，但非侵入性早期检测仍然是一个挑战。光学成像是一种提供高时空分辨率、成像深度为毫米、组织或造影剂信号的光谱分辨率以及允许其在医师办公室或手术室中真实的实时使用的相对简单性的模态。尽管有这些好处，但由于正常组织和癌组织之间缺乏光学对比度，其在检测发展中肿瘤方面的应用受到限制。在本提案中，InnoSense LLC旨在开发和执行可注射的、长循环的、靶向的酶激活纳米颗粒（EANPs）的初步体外和体内评价，这些纳米颗粒作为癌症特异性造影剂用于肿瘤的非侵入性光学成像。这些纳米颗粒基于经证实的生物相容性和生物可降解聚合物，将含有淬灭的近红外（NIR）荧光分子，这些荧光分子在与肿瘤组织中过表达的靶酶相互作用时被激活。这些纳米颗粒对肿瘤的特异性将通过利用允许纳米颗粒在肿瘤组织处积累的增强的渗透性和保留效应以及通过掺入对癌症生物标志物特异性的抗体来增加。与其他造影剂系统相比，使用纳米颗粒来改善荧光分子对肿瘤的生物分布和有效载荷，结合癌症特异性酶触发的NIR信号的产生，预期会导致显著增加的信号背景水平，从而改善非侵入性光学检测的特异性和灵敏度。将在正常细胞和癌细胞中体外评价缺乏抗体和抗体结合的EANP的生物相容性和特异性。光学对比度增强将作为纳米颗粒制剂、浓度和组织模型和癌症动物模型中的深度的函数进行评估。该项目将与Bernard Choi博士合作进行，Bernard Choi博士是生物医学工程系助理教授，也是位于尔湾的加州大学贝克曼激光研究所的助理教授。在第一阶段可行性研究完成后，第二阶段项目将集中在EANP制备的优化，重现性和规模扩大，以及癌症动物模型的严格评估，以确定最佳剂量，NIR开发时间以及可实现的成像深度和空间分辨率。 公共卫生相关性：尽管在过去的几十年中癌症的检测有了很大的改进，但肿瘤的非侵入性早期检测仍然是一个挑战。光学成像是一种提供高空间和时间分辨率的模态，能够检测和分离来自组织或造影剂的信号，成像深度为毫米，并且相对简单，允许其在医生办公室或手术室使用。尽管有这些好处，但由于正常组织和癌组织之间的低对比度，其在检测发展中肿瘤中的应用受到限制。在目前的提案中，InnoSense LLC旨在开发和评估可注射的、长循环的、靶向的酶激活纳米颗粒（EANPs），这些纳米颗粒作为癌症特异性造影剂用于肿瘤的非侵入性光学成像。EANPs基于经证实的无毒聚合物，将含有休眠的荧光分子，这些荧光分子在与肿瘤组织中高水平存在的酶分子相互作用时被激活。EANPs的高有效载荷以及它们的癌症触发激活将导致高信号背景水平，这提高了光学检测的灵敏度。这项研究不仅将为癌组织的非侵入性成像开发一种安全有效的选择，而且还将进一步丰富基于纳米颗粒的造影剂和生物材料领域的科学知识。

DESCRIPTION (provided by applicant): Despite great improvements in the detection of cancer in the last few decades, non-invasive early detection is still a challenge. Optical imaging is a modality that offers high spatio-temporal resolution, millimeters in depth of imaging, spectral resolution of tissue or contrast agent signals, and relative simplicity that would permit its use in real time at a physician's office or operating room. Despite these benefits, its application to the detection of developing tumors is limited due to the lack of optical contrast between normal and cancerous tissue. In the present proposal, InnoSense LLC aims to develop and perform preliminary in vitro and in vivo evaluation of injectable, long-circulating, targeted enzymatically-activated nanoparticles (EANPs) that act as cancer-specific contrast agents for non-invasive optical imaging of tumors. These nanoparticles, based on proven biocompatible and biodegradable polymers, will contain quenched near infra- red (NIR) fluorescent molecules that are activated upon interaction with target enzymes that are overexpressed in tumor tissue. The specificity of these nanoparticles to tumors will be increased by taking advantage of the enhanced permeability and retention effect that permits accumulation of nanoparticles at tumor tissue, and by the incorporation of antibodies specific to cancer biomarkers. The use of nanoparticles to improve the biodistribution and payload of the fluorescent molecules to tumors, combined with the cancer-specific enzyme-triggered development of NIR signal is expected to result in significantly increased signal-to-background levels in comparison to other contrast agent systems, thus improving the specificity and sensitivity of non-invasive optical detection. The biocompatibility and specificity of antibody- lacking and antibody-bound EANPs will be evaluated in vitro in normal and cancer cells. Optical contrast enhancement will be evaluated as a function of nanoparticle formulation, concentration and depth in tissue phantoms and in animal models of cancer. This project will be performed in collaboration with Dr. Bernard Choi, Assistant Professor of the Department of Biomedical Engineering and the Beckman Laser Institute of the University of California, Irvine. Upon completion of the Phase I feasibility study, a Phase II project will center on the optimization of EANP preparation, reproducibility, and scale up, and rigorous evaluation in animal models of cancer to determine optimal dose, NIR development time, and achievable imaging depth and spatial resolution. PUBLIC HEALTH RELEVANCE: Despite great improvements in the detection of cancer in the last few decades, non-invasive early detection of tumors is still a challenge. Optical imaging is a modality that offers high spatial and temporal resolution, the ability to detect and separate signals from tissue or contrast agents, millimeters in depth of imaging, and relative simplicity that would permit its use at a physician's office or operating room. Despite these benefits, its application to the detection of developing tumors is limited due to the low contrast between normal and cancerous tissue. In the present proposal, InnoSense LLC aims to develop and evaluate injectable, long-circulating, targeted enzymatically-activated nanoparticles (EANPs) that act as cancer-specific contrast agents for non-invasive optical imaging of tumors. EANPs, based on proven non-toxic polymers, will contain dormant fluorescent molecules that are activated upon interaction with enzyme molecules that are present in high levels in tumor tissue. The high payload of EANPs, together with their cancer-triggered activation will lead to high signal-to-background levels that improve the sensitivity of optical detection. This research will not only result in the development of a safe and effective option for non-invasive imaging of cancerous tissue, but will also further the body of scientific knowledge in the area of nanoparticle-based contrast agents and biomaterials.