Hwang Jae Youn, Farkas Daniel L, Medina-Kauwe Lali K
Department of Biomedical Engineering, University of Southern California, CA, USA.
J Vis Exp. 2013 Jun 18(76):50396. doi: 10.3791/50396.
The HER2+ tumor-targeted nanoparticle, HerDox, exhibits tumor-preferential accumulation and tumor-growth ablation in an animal model of HER2+ cancer. HerDox is formed by non-covalent self-assembly of a tumor targeted cell penetration protein with the chemotherapy agent, doxorubicin, via a small nucleic acid linker. A combination of electrophilic, intercalation, and oligomerization interactions facilitate self-assembly into round 10-20 nm particles. HerDox exhibits stability in blood as well as in extended storage at different temperatures. Systemic delivery of HerDox in tumor-bearing mice results in tumor-cell death with no detectable adverse effects to non-tumor tissue, including the heart and liver (which undergo marked damage by untargeted doxorubicin). HER2 elevation facilitates targeting to cells expressing the human epidermal growth factor receptor, hence tumors displaying elevated HER2 levels exhibit greater accumulation of HerDox compared to cells expressing lower levels, both in vitro and in vivo. Fluorescence intensity imaging combined with in situ confocal and spectral analysis has allowed us to verify in vivo tumor targeting and tumor cell penetration of HerDox after systemic delivery. Here we detail our methods for assessing tumor targeting via multimode imaging after systemic delivery.
HER2阳性肿瘤靶向纳米颗粒HerDox在HER2阳性癌症动物模型中表现出肿瘤优先蓄积和肿瘤生长消融作用。HerDox由一种肿瘤靶向细胞穿透蛋白与化疗药物阿霉素通过一个小核酸连接子非共价自组装形成。亲电、嵌入和寡聚化相互作用的组合促进自组装成直径约10 - 20纳米的颗粒。HerDox在血液中以及在不同温度下长期储存时均表现出稳定性。在荷瘤小鼠中全身递送HerDox导致肿瘤细胞死亡，而对包括心脏和肝脏在内的非肿瘤组织无明显不良影响（非靶向阿霉素会对这些组织造成明显损伤）。HER2水平升高有助于靶向表达人表皮生长因子受体的细胞，因此，与表达较低水平HER2的细胞相比，HER2水平升高的肿瘤在体外和体内均表现出对HerDox的更高蓄积。荧光强度成像结合原位共聚焦和光谱分析使我们能够在全身递送后验证HerDox在体内的肿瘤靶向性和肿瘤细胞穿透性。在此，我们详细介绍全身递送后通过多模态成像评估肿瘤靶向性的方法。
