Exosomes as carriers of cancer therapeutics

肺癌的有效治疗仍然是一个艰巨的临床挑战。分子学的出现- 靶向疗法和免疫检查点抑制剂在肺癌治疗中显示出前景。然而，在这方面， 只有一部分肺癌患者受益于这些疗法。此外，交付效率低下， 抗癌药物在肿瘤贮库中的积累结合剂量限制性毒性有助于疾病 复发、耐药性和转移，最终导致患者死亡。因此， 肺癌患者<16%。因此，测试新的治疗剂和新的药物递送系统， 有效地将抗癌药物运输到肿瘤库并杀死癌细胞是改善肿瘤的必要条件。 治疗结果。 在本申请中，我们提出测试“外来体”作为癌症治疗的药物载体。的 来源于正常人肺成纤维细胞的外泌体和来源于鼠成纤维细胞的外泌体（Exo）， 装载有携带抗癌药物[多柔比星（Dox）、顺铂（CDDP）]的氧化铁纳米颗粒（IONP）。 化学药物从IONP的释放由pH响应性连接体控制，从而使药物释放最小化。 对正常细胞的相关毒性。此外，负载药物-IONP的外泌体用肿瘤靶向的寡核苷酸修饰。 用于增强肿瘤特异性药物递送和降低对正常细胞的细胞毒性的配体。最后，包括 IONP能够通过磁共振成像（MRI）监测肿瘤生长和治疗反应。 初步研究表明，外泌体可以成功地负载Dox-和CDDP-缀合的IONP。 此外，从外来体证明了优异的药物装载效率和药物释放动力学。在 体外研究表明，装载化学药物的外泌体对癌细胞具有显著的细胞毒性， 正常细胞MRI和SQUID研究显示，载药外泌体提供了良好的对比度图像， 失去了IONP的超顺磁性。此外，肿瘤靶向（tt）外泌体针对 转铁蛋白受体（TfR）过表达的肺癌细胞表现出更大的细胞毒性相比，非 靶向外泌体并在肿瘤异种移植物中积累，导致体内功效。基于我们 令人信服的初步数据，我们假设TT-外泌体将有效地递送化疗药物， 肿瘤细胞，同时能够通过MRI测量治疗反应，对肿瘤细胞的毒性最小， 在体外和体内测试时，正常细胞。我们会根据以下两项建议进行研究 明确的目标。 目标1a。tt-外泌体作为药物载体在体内外研究中的物理生物学特性。 目标1b。确定tt-外泌体对人和小鼠肺癌和正常细胞的功效， 类球体和类器官。 目标2.研究tt-外泌体对肺肿瘤模型的体内抗肿瘤活性。

Effective treatment of lung cancer remains a formidable clinical challenge. The advent of molecularly- targeted therapies and immune checkpoint inhibitors has shown promise in lung cancer treatment. However, only a subset of lung cancer patients benefit from these therapies. Further, inefficient delivery and accumulation of anticancer drugs in tumor depots combined with dose-limiting toxicity contributes to disease relapse, drug resistance, and metastasis culminating in patient death. As a result, the overall survival rate of lung cancer patients is <16%. Thus, testing of new therapeutics and novel drug delivery systems that can efficiently transport anticancer drugs to tumor depots and kill cancer cells are necessary for improving treatment outcomes. In the present application, we propose testing “exosomes” as drug carriers for cancer therapy. The exosomes derived from normal human lung fibroblast and murine fibroblast cell-derived exosomes (Exo) are loaded with iron-oxide nanoparticles (IONP) carrying an anticancer drug [Doxorubicin (Dox), Cisplatin (CDDP)]. The release of the chemodrug from the IONP is controlled by a pH responsive linker thereby minimizing drug- related toxicity to normal cells. Further, the drug-IONP loaded exosome is decorated with a tumor-targeted ligand for enhancing tumor-specific drug delivery and reducing cytotoxicity to normal cells. Finally, inclusion of IONP enables monitoring tumor growth and treatment response by magnetic resonance imaging (MRI). Pilot studies demonstrated exosomes could be successfully loaded with Dox-, and CDDP-conjugated IONP. Further, excellent drug loading efficiency and drug release kinetics was demonstrated from the exosomes. In vitro studies showed chemodrug-loaded exosomes exerted significant cytotoxicity towards cancer cells but not normal cells. MRI and SQUID studies showed drug-loaded exosomes provided good contrast image without losing the superparamagnetic properties of IONP. Furthermore, tumor-targeted (tt) exosomes directed towards transferrin receptor (TfR) overexpressing lung cancer cells exhibited greater cytotoxicity compared to non- targeted exosomes and accumulated in the tumor xenograft resulting in in vivo efficacy. Based on our compelling preliminary data, we hypothesize that tt-exosomes will efficiently deliver chemotherapeutics to tumor cells and concurrently enable measurement of treatment response by MRI with minimal toxicity to normal cell when tested both, in vitro and in vivo. We will conduct the proposed studies under the following two specific aims. Aim 1a. Physico-biological characterization of tt-exosome as drug carriers for use in in vitro and in vivo studies. Aim 1b. Determine the efficacy of tt-exosome against human and mouse lung cancer and normal cells, spheroids and organoids in vitro. Aim 2. Investigate the in vivo antitumor activity of tt-exosome against lung tumor models.