Affibody-displaying bionanocapsules for specific drug delivery to HER2-expressing cancer cells.

A novel HER2-targeted carrier was developed using bionanocapsules (BNCs). Bionanocapsules (BNCs) are 100-nm hollow nanoparticles composed of the L-protein of hepatitis B virus surface antigen. An affibody of HER2 was genetically displayed on the BNC surface (Z(HER2)-BNC). For the investigation of binding affinity, Z(HER2)-BNC was incubated with the cancer cell lines SK-BR-3 (HER2 positive), and MDA-MB-231 (HER2 negative). For analysis of HER2 targeting specificity, Z(HER2)-BNC or Z(WT)-BNC (without affibody) was incubated with both SK-BR-3 and MDA-MB-231 cells by time lapse and concentration. For the delivery of encapsulated molecules (calcein), fluorescence of Z(HER2)-BNC mixed with liposomes was also compared with that of Z(WT)-BNC and nude liposomes by incubation with SK-BR-3 cells. As a result, Z(HER2)-BNC-liposome complex demonstrated the delivery to HER2-expressing cells (SK-BR-3) with a high degree of specificity. This indicates that genetically engineered BNCs are promising carrier for cancer treatment.