Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien 97401, Taiwan.
Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65409-1120, USA.
J Nanosci Nanotechnol. 2019 Feb 1;19(2):613-621. doi: 10.1166/jnn.2019.15751.
Cell-penetrating peptides (CPPs) containing a preponderance of basic amino acids are able to deliver biologically active macromolecules and nanomaterials into live cells. Quantum dots (QDs) are nanoparticles with unique fluorescence properties that have found wide application in biomedical imaging. In this study, we demonstrate transduction of an L6 CPP (RRWQWR) derived from bovine lactoferricin (LFcin) into human lung cancer cells. L6 noncovalently interacts with QDs to form stable complexes. L6/QD complexes enter cells most efficiently when prepared at a nitrogen/phosphate ratio of 60. Mechanistic studies indicate that L6/QD complexes enter cells by endocytosis. Treatment with 1,2-benzisothiazol-3(2)-one (BIT), an industrial preservative that enhances uptake of certain CPPs, does not affect L6 CPP-mediated protein transduction efficiency. L6 and L6/QD complexes are not cytotoxic. These results indicate that L6 LFcin might be an efficient and safe nanoshuttle for nanoparticles or nanomedicines in biomedical applications.
细胞穿透肽（CPPs）富含碱性氨基酸，能够将生物活性大分子和纳米材料递送到活细胞中。量子点（QDs）是具有独特荧光性质的纳米颗粒，已在生物医学成像中得到广泛应用。在这项研究中，我们展示了源自牛乳铁蛋白（LFcin）的 L6 CPP（RRWQWR）转导进入人肺癌细胞。L6 与 QD 非共价相互作用形成稳定的复合物。当氮/磷比为 60 时，L6/QD 复合物进入细胞的效率最高。机制研究表明，L6/QD 复合物通过内吞作用进入细胞。用 1,2-苯并异噻唑-3（2）-酮（BIT）处理，一种增强某些 CPP 摄取的工业防腐剂，不影响 L6 CPP 介导的蛋白转导效率。L6 和 L6/QD 复合物没有细胞毒性。这些结果表明，L6 LFcin 可能是生物医学应用中纳米颗粒或纳米药物的有效且安全的纳米载体。
