Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China.
Wisdom Lake Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China.
Nano Lett. 2023 Jun 28;23(12):5859-5867. doi: 10.1021/acs.nanolett.2c04834. Epub 2023 Mar 27.
The so-called "hard-to-transfect cells" are well-known to present great challenges to intracellular delivery, but detailed understandings of the delivery behaviors are lacking. Recently, we discovered that vesicle trapping is a likely bottleneck of delivery into a type of hard-to-transfect cells, namely, bone-marrow-derived mesenchymal stem cells (BMSCs). Driven by this insight, herein, we screened various vesicle trapping-reducing methods on BMSCs. Most of these methods failed in BMSCs, although they worked well in HeLa cells. In stark contrast, coating nanoparticles with a specific form of poly(disulfide) (called PDS1) nearly completely circumvented vesicle trapping in BMSCs, by direct cell membrane penetration mediated by thiol-disulfide exchange. Further, in BMSCs, PDS1-coated nanoparticles dramatically enhanced the transfection efficiency of plasmids of fluorescent proteins and substantially improved osteoblastic differentiation. In addition, mechanistic studies suggested that higher cholesterol content in plasma membranes of BMSCs might be a molecular-level reason for the greater difficulty of vesicle escape in BMSCs.
所谓的“难转染细胞”对细胞内传递提出了巨大挑战，但对其传递行为的详细了解却很缺乏。最近，我们发现囊泡捕获可能是一种难以转染的细胞（即骨髓间充质干细胞，BMSCs）传递的瓶颈。受这一见解的启发，我们在 BMSCs 上筛选了各种减少囊泡捕获的方法。尽管这些方法在 HeLa 细胞中效果很好，但其中大多数方法在 BMSCs 中都失败了。相比之下，用一种特殊形式的聚（二硫键）（称为 PDS1）对纳米颗粒进行涂层，通过巯基-二硫键交换介导的直接细胞膜穿透，几乎完全避免了 BMSCs 中的囊泡捕获。此外，在 BMSCs 中，PDS1 涂层纳米颗粒显著提高了荧光蛋白质粒的转染效率，并大大促进了成骨分化。此外，机制研究表明，BMSCs 质膜中胆固醇含量较高可能是囊泡逃逸更困难的分子水平原因。
