Department of Cell Chemistry, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
Department of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan.
J Pharm Sci. 2021 Apr;110(4):1788-1798. doi: 10.1016/j.xphs.2021.01.026. Epub 2021 Jan 30.
The AB-type Lactosome comprised of poly(sarcosine)-block-poly(l-lactic acid), a biocompatible and biodegradable polymeric nanomicelle, was reported to accumulate in tumors in vivo via the enhanced permeability and retention (EPR) effect. Recently, the cellular uptake of Lactosome particles was enhanced through the incorporation of a cell-penetrating peptide (CPP), L7EB1. However, the ability of Lactosome as a drug delivery carrier has not been established. Herein, we have developed a method to conjugate the AB-type Lactosome with ATP-binding cassette transporter G2 (ABCG2) siRNA for inducing in vitro apoptosis in the cancer cell lines PANC-1 and NCI-H226. The L7EB1 peptide facilitates the cellular uptake efficiency of Lactosome but does not deliver siRNA into cytosol. To establish the photoinduced cytosolic dispersion of siRNA, a photosensitizer loaded L7EB1-Lactosome was prepared, and the photosensitizer 5,10,15,20-tetra-kis(pentafluorophenyl)porphyrin (TPFPP) showed superiority in photoinduced cytosolic dispersion. We exploited the combined effects of enhanced cellular uptake by L7EB1 and photoinduced endosomal escape by TPFPP to efficiently deliver ABCG2 siRNA into the cytosol for gene silencing. Moreover, the silencing of ABCG2, a protoporphyrin IX (PpIX) transporter, also mediated photoinduced cell death via 5-aminolevulinic acid (ALA)-mediated PpIX accumulated photodynamic therapy (PDT). The synergistic capability of the L7EB1/TPFPP/siRNA-Lactosome complex enabled both gene silencing and PDT.
AB 型乳剂由聚（肌氨酸）-嵌段-聚（L-乳酸）组成，是一种具有生物相容性和可生物降解的聚合物胶束，据报道，它可以通过增强的通透性和保留（EPR）效应在体内积聚在肿瘤中。最近，通过掺入细胞穿透肽（CPP）L7EB1，乳剂颗粒的细胞摄取得到了增强。然而，乳剂作为药物递送载体的能力尚未得到证实。在这里，我们开发了一种将 AB 型乳剂与 ATP 结合盒转运蛋白 G2（ABCG2）siRNA 缀合的方法，以诱导胰腺癌细胞系 PANC-1 和 NCI-H226 中的体外细胞凋亡。L7EB1 肽促进乳剂的细胞摄取效率，但不能将 siRNA 递送到细胞质中。为了建立 siRNA 的光诱导细胞质分散，制备了负载光敏剂的 L7EB1-乳剂，并且光敏剂 5,10,15,20-四-（五氟苯基）卟啉（TPFPP）在光诱导细胞质分散方面表现出优势。我们利用 L7EB1 增强的细胞摄取和 TPFPP 光诱导的内体逃逸的联合作用，将 ABCG2 siRNA 有效递送到细胞质中以进行基因沉默。此外，ABCG2（原卟啉 IX（PpIX）转运蛋白）的沉默也通过 5-氨基酮戊酸（ALA）介导的 PpIX 积累光动力疗法（PDT）介导光诱导细胞死亡。L7EB1/TPFPP/siRNA-乳剂复合物的协同作用使基因沉默和 PDT 成为可能。
