Department of Pharmacology and Institute for Digital Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore.
Department of Surgery, Immunology Programme, Cancer Programme and Nanomedicine Translational Programme, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Singapore.
Theranostics. 2022 Apr 11;12(7):3288-3315. doi: 10.7150/thno.68667. eCollection 2022.
The advent of novel therapeutics in recent years has urged the need for a safe, non-immunogenic drug delivery vector capable of delivering therapeutic payloads specifically to diseased cells, thereby increasing therapeutic efficacy and reducing side effects. Extracellular vesicles (EVs) have garnered attention in recent years as a potentially ideal vector for drug delivery, taking into account their intrinsic ability to transfer bioactive cargo to recipient cells and their biocompatible nature. However, natural EVs are limited in their therapeutic potential and many challenges need to be overcome before engineered EVs satisfy the levels of efficiency, stability, safety and biocompatibility required for therapeutic use. Here, we demonstrate that an enzyme-mediated surface functionalization method in combination with streptavidin-mediated conjugation results in efficient surface functionalization of EVs. Surface functionalization using the above methods permits the stable and biocompatible conjugation of peptides, single domain antibodies and monoclonal antibodies at high copy number on the EV surface. Functionalized EVs demonstrated increased accumulation in target cells expressing common cancer associated markers such as CXCR4, EGFR and EpCAM both and . The functionality of this approach was further highlighted by the ability of targeting EVs to specifically deliver therapeutic antisense oligonucleotides to a metastatic breast tumor model, resulting in increased knockdown of a targeted oncogenic microRNA and improved metastasis suppression. The method was also used to equip EVs with a bifunctional peptide that targets EVs to leukemia cells and induces apoptosis, leading to leukemia suppression. Moreover, we conducted extensive testing to verify the biocompatibility, and safety of engineered EVs for therapeutic use, suggesting that surface modified EVs can be used for repeated dose treatment with no detectable adverse effects. This modular, biocompatible method of EV engineering offers a promising avenue for the targeted delivery of a range of therapeutics while addressing some of the safety concerns associated with EV-based drug delivery.
近年来，新型治疗药物的出现促使人们需要一种安全、非免疫原性的药物传递载体，使其能够将治疗有效载荷专门递送到病变细胞，从而提高治疗效果并降低副作用。近年来，细胞外囊泡（EVs）作为一种潜在的理想药物传递载体引起了人们的关注，这考虑到它们将生物活性货物传递给受体细胞的内在能力及其生物相容性。然而，天然 EVs 在治疗潜力方面存在限制，在工程化 EVs 满足治疗用途所需的效率、稳定性、安全性和生物相容性水平之前，还需要克服许多挑战。在这里，我们证明了酶介导的表面功能化方法与链霉亲和素介导的缀合相结合，可以有效地对 EVs 进行表面功能化。使用上述方法进行表面功能化，可以在 EV 表面以高拷贝数稳定且生物相容地连接肽、单域抗体和单克隆抗体。功能化 EVs 显示在表达常见癌症相关标志物（如 CXCR4、EGFR 和 EpCAM）的靶细胞中的积累增加，以及 和 。这种方法的功能进一步通过靶向 EV 特异性地将治疗性反义寡核苷酸递送到转移性乳腺癌模型的能力得到了突出，导致靶向致癌 microRNA 的敲低增加和转移抑制改善。该方法还用于为 EV 配备一种双功能肽，该肽靶向 EV 并诱导白血病细胞凋亡，从而抑制白血病。此外，我们进行了广泛的测试来验证用于治疗用途的工程化 EV 的生物相容性和安全性，表明表面修饰的 EV 可用于重复剂量治疗，且没有可检测的不良反应。这种模块化、生物相容的 EV 工程方法为靶向递送达一系列治疗药物提供了有前途的途径，同时解决了与 EV 为基础的药物传递相关的一些安全性问题。
