A novel Drug Delivery System Using HBV Envelop Protein Particles

有许多肝病可能是基因治疗的候选者。基因治疗需要一种载体，它与基因一起被携带到靶细胞或器官中。理想的载体应该是非常安全的，具有良好的转染效率，并表现出对它们的靶标的高特异性。1992年，黑田等人报道了可在酵母细胞中合成的大量HBsAg包膜L颗粒。由酵母菌过量产生的HBV包膜L颗粒是中空纳米颗粒（平均直径80nm），其展示人类肝脏特异性感染所必需的前S1肽。通过电穿孔将GFP（绿色荧光蛋白）表达质粒或荧光染料（钙黄绿素）掺入L颗粒中，并直接用于体外转染各种细胞。GFP或钙黄绿素衍生的荧光仅在人肝衍生的细胞如NuE和HepG2中观察到，但WiDr和A431没有。我们将人肝癌细胞和人结肠癌细胞分别移植到裸鼠和大鼠皮下。粒子与。将GFP表达质粒或癌黄素经尾静脉分别感染荷瘤裸鼠或裸鼠。7天后，在皮下肝细胞癌中特异性地观察到荧光，但在大鼠或小鼠的皮下结肠癌、脑、心脏、肺、肝、脾、肾、肾上腺、肠或肌肉中未观察到荧光。当通过L颗粒将人凝血因子IX基因（血友病B的治疗基因）转移到异种移植物模型中时，在血浆中获得治疗因子IX水平至少1个月。总之，HBsAg L颗粒显示出对人源性肝组织的特异性识别能力，并在体内系统中证明了转基因能力。

There are many hepatopathies that may be candidates for gene therapy. Gene therapy needs a vector that is carried together with its genes into a target cell or organ. Desirable vectors should be extremely safe, have good transfection efficiency, and demonstrate a high specificity for their target. In 1992, Kuroda et al. reported on the large amount of HBsAg envelope L particles that could be synthesized in yeast cells. HBV envelope L particles overproduced by yeast are hollow nanoparticles(average diameter 80nm) displaying the pre-S1 peptide indispensable for human liver-specific infection. Either a GFP(green fluorescence protein)-expression plasmid or a fluorescent dye(calcein) was incorporated into L particles by electroporation, and directly used for the transfection of various cells in vitro. Either GFP- or calcein-derived fluorescence was observed only in human liver-derived cells such as NuE and HepG2 not but WiDr and A431. We transplanted human hepatocellular carcinoma cells and human colon cancer cells subcutaneously in nude rats or nude mice. L particles with. GFP-expression plasmide or carcein were infected into the tumor-bearing nude rats or mice through tail vein. After 7 days, fluorescence was observed specifically in the subcutaneous heptocellular carcinoma, but not was observed in the subcutaneous colon cancer, brain, heart, lung, liver, spleen, kidney, adrenal gland, intestine, or muscle of rats or mice. When the human clotting factor IX gene, a therapeutic gene for hemophilia B, was transferred into the xenograft model by the L particles, therapeutic factor IX levels were obtained in the plasma for at least 1 month. In conclusion, HBsAg L particles showed a specific recognition ability for human-derived liver tissue and demonstrated a transgenie ability in an in vivo system.