Pedrosa Lília R Cordeiro, Ten Hagen Timo L M, Süss Regine, van Hell Albert, Eggermont Alexander M M, Verheij Marcel, Koning Gerben A
Section Surgical Oncology, Department of Surgery, Laboratory Experimental Surgical Oncology, Room Ee151b, Erasmus MC, 3000CA, Rotterdam, PO Box 2040, The Netherlands.
Pharm Res. 2015 Apr;32(4):1354-67. doi: 10.1007/s11095-014-1539-4. Epub 2014 Oct 16.
To improve therapeutic activity of mitoxantrone (MTO)-based chemotherapy by reducing toxicity through encapsulation in nanoliposomes and enhancing intracellular drug delivery using short-chain sphingolipid (SCS) mediated tumor cell membrane permeabilization.
Standard (MTOL) and nanoliposomes enriched with the SCS, C8-Glucosylceramide or C8-Galactosylceramide (SCS-MTOL) were loaded by a transmembrane ammonium sulphate gradient and characterized by DLS and cryo-TEM. Intracellular MTO delivery was measured by flow cytometry and imaged by fluorescence microscopy. In vitro cytotoxicity was studied in breast carcinoma cell lines. Additionally, live cell confocal microscopy addressed the drug delivery mechanism by following the intracellular fate of the nanoliposomes, the SCS and MTO. Intratumoral MTO localization in relation to CD31-positive tumor vessels and CD11b positive cells was studied in an orthotopic MCF-7 breast cancer xenograft.
Stable SCS-MTOL were developed increasing MTO delivery and cytotoxicity to tumor cells compared to standard MTOL. This effect was much less pronounced in normal cells. The drug delivery mechanism involved a transfer of SCS to the cell membrane, independently of drug transfer and not involving nanoliposome internalization. MTO was detected intratumorally upon MTOL and SCS-MTOL treatment, but not after free MTO, suggesting an important improvement in tumor drug delivery by nanoliposomal formulation. Nanoliposomal MTO delivery and cellular uptake was heterogeneous throughout the tumor and clearly correlated with CD31-positive tumor vessels. Yet, MTO uptake by CD11b positive cells in tumor stroma was minor.
Nanoliposomal encapsulation improves intratumoral MTO delivery over free drug. Liposome bilayer-incorporated SCS preferentially permeabilize tumor cell membranes enhancing intracellular MTO delivery.
通过将米托蒽醌（MTO）封装在纳米脂质体中来降低毒性，并利用短链鞘脂（SCS）介导的肿瘤细胞膜通透性增强细胞内药物递送，从而提高基于MTO的化疗的治疗活性。
通过跨膜硫酸铵梯度加载标准（MTOL）以及富含SCS、C8-葡萄糖神经酰胺或C8-半乳糖神经酰胺的纳米脂质体（SCS-MTOL），并通过动态光散射（DLS）和冷冻透射电子显微镜（cryo-TEM）进行表征。通过流式细胞术测量细胞内MTO递送，并通过荧光显微镜成像。在乳腺癌细胞系中研究体外细胞毒性。此外，活细胞共聚焦显微镜通过追踪纳米脂质体、SCS和MTO的细胞内命运来探讨药物递送机制。在原位MCF-7乳腺癌异种移植模型中研究肿瘤内MTO与CD31阳性肿瘤血管和CD11b阳性细胞的定位关系。
与标准MTOL相比，开发出了稳定的SCS-MTOL，其增加了MTO向肿瘤细胞的递送和细胞毒性。这种效应在正常细胞中不太明显。药物递送机制涉及SCS向细胞膜的转移，与药物转移无关且不涉及纳米脂质体的内化。在MTOL和SCS-MTOL治疗后在肿瘤内检测到MTO，但游离MTO治疗后未检测到，这表明纳米脂质体制剂在肿瘤药物递送方面有重要改善。纳米脂质体MTO递送和细胞摄取在整个肿瘤中是异质的，并且与CD31阳性肿瘤血管明显相关。然而，肿瘤基质中CD11b阳性细胞对MTO的摄取较少。
纳米脂质体封装比游离药物更能改善肿瘤内MTO递送。脂质体双层掺入的SCS优先使肿瘤细胞膜通透化，增强细胞内MTO递送。
