Liu Betty R, Huang Yue-Wern, Korivi Mallikarjuna, Lo Shih-Yen, Aronstam Robert S, Lee Han-Jung
Department of Laboratory Medicine and Biotechnology, Collage of Medicine, Tzu Chi University, Hualien 97004. Taiwan.
Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65409-1120. United States.
Curr Pharm Biotechnol. 2017;18(7):569-584. doi: 10.2174/1389201018666170822125737.
Development of effective drug delivery systems (DDS) is a critical issue in health care and medicine. Advances in molecular biology and nanotechnology have allowed the introduction of nanomaterial-based drug delivery systems. Cell-penetrating peptides (CPPs) can form the basis of drug delivery systems by virtue of their ability to support the transport of cargoes into the cell. Potential cargoes include proteins, DNA, RNA, liposomes, and nanomaterials. These cargoes generally retain their bioactivities upon entering cells.
In the present study, the smallest, fully-active lactoferricin-derived CPP, L5a is used to demonstrate the primary contributor of cellular internalization.
The secondary helical structure of L5a encompasses symmetrical positive charges around the periphery. The contributions of cell-specificity, peptide length, concentration, zeta potential, particle size, and spatial structure of the peptides were examined, but only zeta potential and spatial structure affected protein transduction efficiency. FITC-labeled L5a appeared to enter cells via direct membrane translocation insofar as endocytic modulators did not block FITC-L5a entry. This is the same mechanism of protein transduction active in Cy5 labeled DNA delivery mediated by FITC-L5a. A significant reduction of transduction efficiency was observed with structurally incomplete FITC-L5a formed by tryptic destruction, in which case the mechanism of internalization switched to a classical energydependent endocytosis pathway.
These results support the continued development of the non-cytotoxic L5a as an efficient tool for drug delivery.
开发有效的药物递送系统（DDS）是医疗保健和医学领域的关键问题。分子生物学和纳米技术的进步使得基于纳米材料的药物递送系统得以引入。细胞穿透肽（CPPs）凭借其支持货物转运进入细胞的能力，可构成药物递送系统的基础。潜在的货物包括蛋白质、DNA、RNA、脂质体和纳米材料。这些货物进入细胞后通常会保留其生物活性。
在本研究中，使用最小的、具有完全活性的乳铁蛋白衍生CPP，即L5a，来证明细胞内化的主要因素。
L5a的二级螺旋结构在其外围包含对称的正电荷。研究了细胞特异性、肽长度、浓度、zeta电位、粒径和肽的空间结构的影响，但只有zeta电位和空间结构影响蛋白质转导效率。FITC标记的L5a似乎通过直接膜转位进入细胞，因为内吞调节剂并未阻止FITC-L5a进入。这与FITC-L5a介导的Cy5标记DNA递送中活跃的蛋白质转导机制相同。用胰蛋白酶破坏形成的结构不完整的FITC-L5a观察到转导效率显著降低，在这种情况下，内化机制转变为经典的能量依赖型内吞途径。
这些结果支持将无细胞毒性的L5a继续开发为一种有效的药物递送工具。
