在癌细胞上明确过表达的受体的基于配体的靶向代表了增强化疗功效的有效药物递送方法。前蛋白转化酶枯草杆菌蛋白酶/kexin9型(PCSK9)是一种主要由肝细胞产生的丝氨酸蛋白酶,可以潜在地用作靶向配体。PCSK9与肝细胞表面的LDL-r结合,导致内吞作用和内体降解。高LDL-r表达,这被认为可以满足胆固醇和磷脂的更高需求,以建立增殖的癌细胞膜,确保PCSK9缀合的脂质体的选择性摄取。在目前的工作中,PCSK9偶联脂质体系统用于将紫杉醇(PTX)递送至癌细胞.该蛋白质通过EDC和NHS在两步偶联反应中与含有COOH-PEG2000-COOH脂质的脂质体偶联。共轭通过NMR确认,和脂质体进一步通过SEM和zetasizer进行表征。PCSK9缀合的脂质体具有69.1%的高包封率,直径为90.0±4.9nm。长期稳定性(30天)研究(Zeta电位:-9.88)证实了优异的恒定性和显著的药物保留(58.2%)。在人胚肾细胞(HEK293)中使用MTS测定法探索了体外细胞毒性和靶向效率,肝细胞(HEPG2),和人结肠癌细胞系(HCT116)持续24小时。PCSK9缀合的脂质体在HCT116细胞系中表现出比未缀合的(对照)脂质体显著更高的生长抑制(p<0.001)。新型PCSK9偶联脂质体具有有效和精确的体外抗癌活性,因此,首次提出作为癌症治疗的有前途的靶向递送系统。
Ligand-based targeting of the receptors that are overexpressed explicitly on cancer cells represents an effective drug delivery approach to enhance the chemotherapeutic efficacy. Proprotein convertase subtilisin/kexin type 9 (PCSK9) which is a serine protease enzyme primarily produced by the liver cells, can potentially be used as a targeting ligand. PCSK9 binds to the LDL-r on hepatocytes\' surface, leading to endocytosis and endosomal degradation. High LDL-r expression, which is believed to meet the higher demand of the cholesterol and phospholipids to build proliferating cancer cell membrane, ensures selective uptake of the PCSK9 conjugated liposomes. In the present work, the PCSK9 conjugated liposomal system was developed to deliver paclitaxel (PTX) to cancer cells. The protein was conjugated by EDC and NHS in a two-step coupling reaction to the liposomes containing COOH-PEG2000-COOH lipid. Conjugation was confirmed by NMR, and liposomes were further characterized by SEM and zeta sizer. PCSK9-conjugated liposomes showed high encapsulation efficiency of 69.1% with a diameter of 90.0 ± 4.9 nm. Long-term stability (30 days)
study (Zeta potential: -9.88) confirmed excellent constancy and significant drug retention (58.2%). Invitro cytotoxicity and targeting efficiency was explored using MTS assay in human embryonic kidney cells (HEK293), liver hepatocellular cells (HEPG2), and a human colon cancer cell line (HCT116) for 24 h. PCSK9 conjugated liposomes exhibited significantly higher growth inhibition than the unconjugated (control) liposomes in HCT116 cell line (p < 0.001). The novel PCSK9 conjugated liposomes presented potent and precise in vitro anticancer activity and, therefore, are suggested for the first time as a promising targeted delivery system for cancer treatment.