Photo-assisted targeting of immunotherapy to the bladder

描述(申请人提供)：膀胱癌是美国第五大常见肿瘤，占所有恶性肿瘤的5%-10%。标准的治疗方法是经尿道切除肿瘤，然后进行膀胱内免疫治疗(卡介苗)。卡介苗会引起长期免疫炎症，从而根除残留的肿瘤细胞。尽管卡介苗有效，但它是一种活生生的病原体，会在大量患者中造成感染和并发症。因此，活体病原体治疗的新的替代方法正在不断地被探索。在卡森实验室，合成的Toll样受体7的配方 配体(TLR7)被发现是膀胱炎症的有效诱因，模拟卡介苗治疗，不会导致卡介苗通常造成的任何问题。膀胱内TLR7配体在膀胱癌小鼠模型中显示出疗效，目前正在进行临床试验。然而，TLR7配体制剂在恶劣的膀胱环境中结合和保留的效率不是很高，这需要长期给药来维持慢性炎症和改善治疗结果。我们提出了一种新的解决方案，以延长TLR-7配体在膀胱内的传递。在摩尔大学癌症中心，我们发现在尿路上皮局部机械损伤(类似于肿瘤切除后的损伤)后，多肽可以有效地穿透尿路上皮。我们假设，使用上述多肽靶向纳米粒中的TLR7配体可以增加递送，并比自由分子更有效地促进炎症。作为额外的步骤，将使用光化学来稳定地将颗粒粘合到膀胱壁上；光交联可以延长含有TLR-7的纳米颗粒在膀胱中的停留时间，从而延长免疫炎症。这个探索性项目将专注于在膀胱中靶向和光化学的概念验证，而主要可测量的结果将是TLR-7激动剂的递送水平、在膀胱中的停留时间以及体内免疫炎症的持续时间。我们将：(1)制备和表征用于靶向传递TLR7配体的光活性纳米颗粒；(2)体外检测细胞结合和免疫刺激作用；(3)进行体内光交联实验，定量测定TLR7配体传递和体内炎症反应。这些目标的成功实现将使我们能够进行全面的肿瘤治疗研究、大型动物研究，并探索使用靶向-光交联方案提供更多的治疗方式。开发一种结合到尿路上皮损伤区域，然后在指定区域长时间化学附着的递送载体，是一种新型的膀胱受控药物递送，可以显著提高泌尿外科患者的护理质量。

DESCRIPTION (provided by applicant): Bladder cancer is the fifth most common tumor in the USA, accounting for 5-10% of all malignancies. The standard treatment is the trans-urethral resection of the tumor, followed by intravesical immunotherapy (Bacillus Calmette-Guerin (BCG)). BCG causes long-term immune inflammation that eradicates residual tumor cells. Despite its efficacy, BCG is a living pathogen that causes infections and complications in a large number of patients. Therefore, novel alternative approaches to the living pathogen therapy are constantly being explored. In the Carson laboratory, formulations of synthetic Toll-like receptor 7 ligands (TLR7) were found to be potent inducers of inflammation in the bladder, mimicking BCG treatment without resulting in any of the problems commonly caused to BCG. Intravesical TLR7 ligands showed efficacy in mouse models of bladder cancer and are currently in clinical trials. However, the binding and retention of the TLR7 ligands formulations in the harsh bladder environment is not very efficient, which requires chronic dosing for maintaining chronic inflammation and improving the therapeutic outcome. We propose a novel solution to prolonged delivery of TLR-7 ligands in the bladder. At the Moores UCSD Cancer Center, we found peptides that efficiently penetrated the urothelium following local mechanical damage to the urothelium (similar to the damage following tumor removal). We hypothesize that targeting TLR7 ligand in nanoparticles using the above peptide can increase the delivery and promote more potent inflammation than free molecules. As an additional step, photochemistry will be used in order to stably "glue" the particles to the bladder wall; photocrosslinking could prolong the residence time of the TLR-7-containing nanoparticles in the bladder and therefore prolong immune inflammation. This exploratory project will focus on the proof-of-concept of targeting and photochemistry in the bladder, whereas the main measurable outcome will be the level of the TLR-7 agonist delivery, time of residence in the bladder, and the duration of the immune inflammation in vivo. We will: (1) Prepare and characterize photoactive nanoparticles for targeted delivery of TLR7 ligands; (2) Test cell binding and immunostimulation in vitro; (3) Perform photocrosslinking experiments in vivo and quantify the TLR7 ligand delivery and inflammatory response in vivo. The successful accomplishment of the goals will allow us to perform full-scale tumor-treatment studies, large animal studies, and to explore the delivery of additional therapeutic modalities using a targeting-photocrosslinking scheme. The development of delivery vehicles that bind to the areas of urothelial damage, and then chemically attach in the specified areas for an extended period of time, is a novel type of controlled drug delivery in the bladder that can dramatically improve quality of care for urological patients.