Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
ACS Biomater Sci Eng. 2021 Dec 13;7(12):5690-5705. doi: 10.1021/acsbiomaterials.1c01131. Epub 2021 Nov 11.
Cancer-associated fibroblasts (CAFs) were believed to establish a tight physical barrier and a dense scaffold for tumor cells to make them maintain immunosuppression and drug resistance, strongly hindering nanoparticles to penetrate into the core of tumor tissues and limiting the performance of tumor cell-targeted nanoparticles. Here, we fabricated the substrate Z-Gly-Pro of fibroblast activation protein α (FAPα) and folic acid-codecorated pH-responsive polymeric micelles (dual ligand-modified PEOz-PLA polymeric micelles, DL-PP-PMs) that possessed nanodrill and tumor cell-targeted functions based on Z-Gly-pro-conjugated poly(2-ethyl-2-oxazoline)-poly(D,l-lactide) (ZGP-PEOz-PLA), folic acid (FA)-conjugated PEOz-PLA (FA-PEOz-PLA), and PEOz-PLA for cancer therapy. The micelles with about 40 nm particle size and a narrow distribution exhibited favorable pH-activated endo/lysosome escape induced by their pH responsibility. In addition, the enhancement of in vitro cellular uptake and cytotoxicity to folate receptors or FAPα-positive cells for doxorubicin (DOX)/DL-PP-PMs compared with DOX/PP-PMs evidenced the dual target ability of DOX/DL-PP-PMs, which was further supported by in vivo biodistribution results. As expected, in the human oral epidermal carcinoma (KB) cells xenograft nude mice model, the remarkable enhancement of antitumor efficacy for DOX/DL-PP-PMs with low toxicity was observed compared with DOX/FA-PP-PMs and DOX/ZGP-PP-PMs. The possible mechanism was elucidated to be the dismantling of the stromal barrier by nanodrill-like DOX/DL-PP-PMs via the deletion of CAFs evidenced by the downregulation of α-SMA and inhibition of their functions proved by the decrease in the microvascular density labeled with CD31 and the reduction in the extracellular matrix detected by the collagen content, thereby promoting tumor penetration and enhancing their uptake by tumor cells. The present research offered an alternative approach integrating anticancer and antifibrosis effects in one delivery system to enhance the delivery efficiency and therapeutic efficacy of anticancer drugs.
癌症相关成纤维细胞 (CAFs) 被认为为肿瘤细胞建立了紧密的物理屏障和密集的支架,使它们保持免疫抑制和耐药性,强烈阻碍纳米颗粒渗透到肿瘤组织的核心,并限制肿瘤细胞靶向纳米颗粒的性能。在这里,我们基于 Z-Gly-Pro 修饰的成纤维细胞激活蛋白α(FAPα)和叶酸编码的 pH 响应性聚合物胶束(双配体修饰的 PEOz-PLA 聚合物胶束,DL-PP-PMs)构建了基质,该胶束具有纳米钻头和肿瘤细胞靶向功能,基于 Z-Gly-pro 共轭的聚(2-乙基-2-恶唑啉)-聚(D,L-丙交酯)(ZGP-PEOz-PLA)、叶酸(FA)-修饰的 PEOz-PLA(FA-PEOz-PLA)和 PEOz-PLA 用于癌症治疗。胶束的粒径约为 40nm,分布较窄,表现出良好的 pH 激活的内体/溶酶体逃逸能力,这是由其 pH 响应性引起的。此外,与 DOX/PP-PMs 相比,DOX/DL-PP-PMs 对叶酸受体或 FAPα阳性细胞的体外细胞摄取和细胞毒性增强,证明了 DOX/DL-PP-PMs 的双重靶向能力,这一结果进一步得到了体内生物分布结果的支持。正如预期的那样,在人口腔表皮癌(KB)细胞异种移植裸鼠模型中,与 DOX/FA-PP-PMs 和 DOX/ZGP-PP-PMs 相比,具有低毒性的 DOX/DL-PP-PMs 的抗肿瘤疗效显著增强。可能的机制是通过纳米钻头样的 DOX/DL-PP-PMs 破坏基质屏障,通过下调α-SMA 并抑制其功能来证明这一点,其功能通过 CD31 标记的微血管密度降低和胶原含量检测到的细胞外基质减少来证明,从而促进肿瘤渗透并增强肿瘤细胞对其的摄取。本研究提供了一种替代方法,即将抗癌和抗纤维化作用整合到一个递药系统中,以提高抗癌药物的递药效率和治疗效果。