Tri-modal Polymeric Micelles for 'See & Treat' Applications in Surgical Oncology

描述（由申请人提供）：外科肿瘤学的主要目标是完全切除具有足够无瘤边缘和最小手术发病率的肿瘤，注意手术治愈率约为45%，而化疗和放疗治愈率仅为5%。在肺癌、乳腺癌、前列腺癌、结肠癌和胰腺癌中，肿瘤完全切除比部分或不完全手术切除的生存率提高3- 5倍。然而，术中对肿瘤边缘的评估仅仅基于触诊和目视检查，导致肿瘤切除不全（R1切除）的情况时有发生。目标是为外科肿瘤学的“看和治疗”模式开发纳米技术，通过聚合物胶束发射组织穿透近红外光来描绘肿瘤边缘和手术指导；术中光动力治疗（PDT）产生单线态氧；并通过共同递送棉酚（一种天然的BH3模拟物，可抑制抗凋亡Bcl-2蛋白：Bcl-2， Bcl-xL和Mcl-1）促进癌细胞凋亡。我们已经证明，聚乙二醇-嵌段聚e-己内酯（PEG-b-PCL）组装成纳米颗粒，携带近红外染料（DiR）、光敏剂（mTHPP）和棉酚，形成直径为100纳米的胶束，并在24小时内缓慢释放所有3种成分。我们假设充满DiR、mTHPP和棉酚的PEG-b-PCL胶束会通过增强的渗透性和滞留效应在实体瘤中积累，并“照亮”肿瘤边缘，从而实现手术指导，更完整的手术切除，降低肿瘤复发率。我们假设，激光照射到肿瘤床的“点亮”区域（术中PDT）会产生单线态氧，杀死肿瘤细胞，特别是与共递送的棉酚协同作用。具体目的：(1)通过体外物理化学和光物理研究以及体内实验，对填充DiR、mTHPP和棉酚的PEG-b-PCL胶束的稳定性、单线态氧的产生和肿瘤靶向性进行评价：对DiR和mTHPP进行全身光学成像，并对棉酚进行药代动力学研究。(2）. 评估手术后用PEG-b-PCL胶束填充DiR引导手术切除肿瘤和单独手术切除肿瘤作为阳性对照后的肿瘤复发率。(3)。评估手术切除和术中PDT中填充mTHPP的PEG-b-PCL胶束，合并或不合并棉酚后肿瘤的复发率。(4)。评估DiR光学成像、手术切除和术中PDT联合mTHPP和棉酚（三模式治疗）后肿瘤复发率。生物相容性PEG-b-PCL胶束的综合光学成像和治疗能力的进步将使纳米技术在外科肿瘤学中的应用和快速转化为临床试验成为可能。

DESCRIPTION (provided by applicant): The major goal of surgical oncology is the complete resection of tumors with adequate tumor-free margins and minimal surgical morbidity, noting that surgery cures about 45% of patients, whereas chemotherapy and radiation cure only 5% of patients. In lung, breast, prostate, colon, and pancreatic cancers, a complete resection of tumors has a 3- to 5-fold increase in survival over partial or incomplete surgical resection. However, the intraoperative assessment of tumor margins is merely based on palpation and visual inspection, resulting frequently in incomplete tumor resection (R1 resections). The goal is to develop nanotechnology for "see and treat" modalities in surgical oncology, enabled by polymeric micelles that emit tissue penetrating near-infrared light for delineation of tumor margins and surgical guidance; generate singlet oxygen upon intra- operative photodynamic therapy (PDT); and enhance cancer cell apoptosis by the co-delivery of gossypol, a natural BH3 mimetic that inhibits anti-apoptotic Bcl-2 proteins: Bcl-2, Bcl-xL, and Mcl-1. We have proven that poly(ethylene glycol)-block-poly(e-caprolactone) (PEG-b-PCL) assembles into nanoparticles that entrain a near-infrared dye (DiR), a photosensitizer (mTHPP), and gossypol, forming micelles that are 100 nm in diameter and slowly release all 3 components over 24 hrs. We hypothesize that PEG-b-PCL micelles filled with DiR, mTHPP, and gossypol will accumulate at solid tumors via the enhanced permeability and retention effect and "light up" tumor margins, enabling surgical guidance, more complete surgical resection, and lower tumor reoccurrence. We hypothesize that laser light delivered to the "lit up" region of the tumor bed (intraoperative PDT) will generate singlet oxygen that kills tumor cells, especially in concert with co-delivered gossypol. Specific Aims: (1) To assess the stability, generation of singlet oxygen, and tumor targeting of PEG-b-PCL micelles filled with DiR, mTHPP, and gossypol by in vitro physicochemical and photophysical studies and in vivo experiments: whole body optical imaging of DiR and mTHPP and a pharmacokinetics study on gossypol. (2). To assess tumor reoccurrence after surgical guidance by PEG-b-PCL micelles filled with DiR and surgical resection of tumors and after surgical resection of tumors alone as a positive control. (3). To assess tumor reoccurrence after surgical resection and intraoperative PDT with PEG-b-PCL micelles filled with mTHPP, with or without co-incorporated gossypol. (4). To assess tumor reoccurrence after optical imaging of DiR, surgical resection, and intraoperative PDT with mTHPP and gossypol (tri-modal therapy). Advances in integrated optical imaging and therapeutic capability of biocompatible PEG-b-PCL micelles will enable tenable nano-technology applications in surgical oncology and rapid translation into clinical trials. PUBLIC HEALTH RELEVANCE: The goal is to develop a unique tri-functional nanocarrier for surgical oncology that can deliver near-infrared dye, photosensitizer, and gossypol together into solid tumors for intraoperative optical imaging of solid tumors and light-activated cancer cell killing. In a mouse model of neuroblastoma, we will test whether surgical guidance, surgical resection, and intraoperative light-activated cancer cell killing will maximize tumor killing, minimize collateral damage, and prolong survival.