Zou Peng, Stern Stephan T, Sun Duxin
Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, Michigan, 48108, USA.
Pharm Res. 2014 Mar;31(3):684-93. doi: 10.1007/s11095-013-1190-5. Epub 2013 Sep 25.
Rapid premature release of lipophilic drugs from liposomal lipid bilayer to plasma proteins and biological membranes is a challenge for targeted drug delivery. The purpose of this study is to reduce premature release of lipophilic short-chain ceramides by encapsulating ceramides into liposomal aqueous interior with the aid of poly (lactic-coglycolicacid) (PLGA).
BODIPY FL labeled ceramide (FL-ceramide) and BODIPY-TR labeled ceramide (TR-ceramide) were encapsulated into carboxy-terminated PLGA nanoparticles. The negatively charged PLGA nanoparticles were then encapsulated into cationic liposomes to obtain PLGA/liposome hybrids. As a control, FL-ceramide and/or TR ceramide co-loaded liposomes without PLGA were prepared. The release of ceramides from PLGA/liposome hybrids and liposomes in rat plasma, cultured MDA-MB-231 cells, and rat blood circulation was compared using fluorescence resonance energy transfer (FRET) between FL-ceramide (donor) and TR-ceramide (acceptor).
FRET analysis showed that FL-ceramide and TR-ceramide in liposomal lipid bilayer were rapidly released during incubation with rat plasma. In contrast, the FL-ceramide and TR-ceramide in PLGA/liposome hybrids showed extended release. FRET images of cells revealed that ceramides in liposomal bilayer were rapidly transferred to cell membranes. In contrast, ceramides in PLGA/liposome hybrids were internalized into cells with nanoparticles simultaneously. Upon intravenous administration to rats, ceramides encapsulated in liposomal bilayer were completely released in 2 min. In contrast, ceramides encapsulated in the PLGA core were retained in PLGA/liposome hybrids for 4 h.
The PLGA/liposome hybrid nanoparticles reduced in vitro and in vivo premature release of ceramides and offer a viable platform for targeted delivery of lipophilic drugs.
亲脂性药物从脂质体脂质双层快速过早释放到血浆蛋白和生物膜中是靶向给药面临的一项挑战。本研究的目的是借助聚乳酸-羟基乙酸共聚物(PLGA)将神经酰胺包封于脂质体水相内部,以减少亲脂性短链神经酰胺的过早释放。
将硼二吡咯氟化物标记的神经酰胺(FL-神经酰胺)和硼二吡咯-TR标记的神经酰胺(TR-神经酰胺)包封于羧基封端的PLGA纳米颗粒中。然后将带负电荷的PLGA纳米颗粒包封于阳离子脂质体中,以获得PLGA/脂质体杂化物。作为对照,制备了不含PLGA的FL-神经酰胺和/或TR神经酰胺共载脂质体。利用FL-神经酰胺(供体)和TR-神经酰胺(受体)之间的荧光共振能量转移(FRET),比较了PLGA/脂质体杂化物和脂质体中神经酰胺在大鼠血浆、培养的MDA-MB-231细胞以及大鼠血液循环中的释放情况。
FRET分析表明,脂质体脂质双层中的FL-神经酰胺和TR-神经酰胺在与大鼠血浆孵育期间快速释放。相比之下,PLGA/脂质体杂化物中的FL-神经酰胺和TR-神经酰胺释放时间延长。细胞的FRET图像显示,脂质体双层中的神经酰胺迅速转移至细胞膜。相比之下,PLGA/脂质体杂化物中的神经酰胺与纳米颗粒同时被细胞内化。对大鼠静脉给药后,脂质体双层中包封的神经酰胺在2分钟内完全释放。相比之下,包封于PLGA核中的神经酰胺在PLGA/脂质体杂化物中保留了4小时。
PLGA/脂质体杂化纳米颗粒减少了神经酰胺在体外和体内的过早释放,并为亲脂性药物的靶向递送提供了一个可行的平台。