Targeted Photoactivable Nanocells: Image-based Drug Delivery and Dosimetry in GBM

描述(由申请人提供)：这一合作应用程序寻求通过将使用新型纳米结构的药物输送与我们用于图像分析的独特的磁共振引导光学成像量化(MROQ)系统相结合，来创建用于治疗多形性胶质母细胞瘤(GBM)的图像引导平台。我们使用靶向光动力疗法(PDT)，这是一种基于光化学的技术，可以有效地治疗GBM。PDT正在进行GBM治疗的临床研究，PDT试剂也可以发出荧光，从而使药物的在线成像能够同时用于图像引导药物传递(IGDD)和光剂量学(IGLD)。这里测试的基本论点是，当靶向递送治疗和显像剂与定量成像相结合以提供指导PDT治疗计划的药代动力学结合(PKB)模型时，治疗结果更好。其策略是制造基于纳米技术的靶向表皮生长因子受体(EGFR)的荧光纳米细胞(TNC)，其中包括PDT试剂(苯并卟啉衍生物，BPD)、生物试剂阿瓦斯丁和表面连接的MRI造影剂Gd-DTPA(Gd-DTPA)。EGFR的靶向是使用单抗(Mab)西妥昔单抗C225，该单抗用近红外染料LICOR 800CW进行荧光标记，以实现IGDD和随后开发成像和治疗药物与肿瘤细胞结合的PK模型。BPD荧光将为IGLD的研究提供依据。EGFR在&gt；50%的GBM中过度表达，主要用于传递高有效载荷的探针。TNC将与非特异性靶向纳米细胞(NNC)进行比较，在NNC中，C225被不相关的针对U87 GBM细胞上不表达的前列腺特异性膜抗原(PSMA)的单抗取代。研究目标将在四个具体目标上实现，包括TNC/NNC的制造、2D细胞培养、新开发的3D GBM模型(概括肿瘤结构)和体内原位肿瘤模型结合MROQ定量成像。目标1将合成和表征TNC和NNC。目的：在体外建立的人肾小管上皮细胞(U87细胞)三维细胞模型中检测TNC/NNC的选择性和光毒性，为进一步研究IGDD/IGLD奠定基础。AIM 3将使用我们的MROQ系统在体内开发预测性PKB模型，以量化药物输送并在体内建立TNC的细胞相关部分以指导AIM 4，这将在短期(肿瘤负担)和长期(生存)研究中建立体内定量IGDD/IGLD和PKB模型对原位小鼠GBM治疗结果的影响。本研究的意义在于，通过与TNC和NNC的直接对比研究，提供了新的多功能药物传递结构、新的3D GBM模型、定量成像的双模式系统，确立了IGDD/IGLD对治疗结果的影响，并解决了大分子载体靶向价值的争议。如果IGDD/IGLD显示出更好的结果，这项研究形成了患者定制治疗的基础，其中照射的时间和数量根据个人情况进行调整。

DESCRIPTION (provided by applicant): This collaborative application seeks to create an image-guided platform for the treatment of glioblastoma multiforme (GBM) by combining drug delivery using novel nanoconstructs with our unique magnetic resonance guided optical imaging quantification (MROQ) system for image analysis. We use targeted photodynamic therapy (PDT), a photochemistry-based technology to effectively treat GBM. PDT is in clinical studies for GBM treatment and PDT agents can also fluoresce thus enabling online imaging of drug for both image-guided drug delivery (IGDD) and light dosimetry (IGLD). The basic thesis being tested here is that treatment outcomes are superior when targeted delivery of therapeutic and imaging agents is combined with quantitative imaging to provide pharmacokinetic binding (PKB) models that guide treatment planning for PDT. The strategy is to fabricate nanotechnology-based, epidermal growth factor receptor (EGFR) targeting, fluorescent nanocells (TNC) that incorporate a PDT agent (benzoporphyrin derivatve, BPD), a biologic agent, Avastin and a surface conjugated MRI contrast agent Gadolinium-DTPA (Gd-DTPA). The EGFR is targeted using the monoclonal antibody (Mab) Cetuximab, C225, which is fluorescently labeled with an NIR dye LICOR 800CW for enabling IGDD and subsequent development of PK models of binding of the imaging and therapeutic agents to tumor cells. BPD fluorescence will provide the basis for IGLD. EGFR, overexpressed in >50% of GBMs is used as a molecular target primarily for delivering high payloads of probes. The TNC will be compared with non-specifically targeted nanocells (NNC) where the C225 is replaced by an irrelevant Mab targeted to prostate specific membrane antigen (PSMA) not expressed on U87 GBM cells. The study goals will be achieved in 4 specific aims that include TNC/NNC fabrication, 2D cell culture, newly developed 3D GBM models (recapitulating tumor architecture) and in vivo orthotopic tumor models combined with quantitative imaging using MROQ. Aim 1 will synthesize and characterize TNC and NNC. Aim 2: will test the TNC/NNC selectivity and phototoxicity in 3D cellular models of GBM (U87 cells) in vitro for establishing the basis for IGDD/IGLD by determining cell associated fractions. Aim 3 will develop predictive PKB models in vivo using our MROQ system for quantifying drug delivery and establishing cell-associated fractions of TNC in vivo to guide Aim 4, which will establish the impact of quantitative IGDD/IGLD and PKB models in vivo on treatment outcomes in orthotopic murine models of GBM in short-term (tumor burden) and long-term (survival) studies. The significance of this study is that it provides new multifunctional drug delivery constructs, new 3D GBM models, a dual modality system for quantitative imaging, establishes the impact of IGDD/IGLD on treatment outcome and resolves the controversy of the value of targeting of macromolecular carriers by direct comparative studies with TNC and NNC. If IGDD/IGLD show superior outcomes, the study forms the basis for patient-customized treatments where the timing and amount of illumination is adjusted to individuals.