Abstract
Bionanocapsules (BNCs) are hollow nanoparticles composed of L protein of the hepatitis B virus surface antigen that represent specific affinity for human hepatocytes. BNC is useful for delivering genes, siRNAs and drugs to the human liver as drug delivery system (DDS) carrier (Nat Biotech 21, 885 (2003)). Brain tumor is difficult to be extirpated widely and liable to recurrence because a brain is an extremely important part. Although a precise radiotherapy using three-dimensional image diagnosis such as gamma knife has proceeded, the recurrence rate is still high. Therefore, it is important to develop DDS targeting to brain tumor.In the present study, we developed a novel DDS to brain tumor using BNCs, which selectively targeted to brain tumor. Epidermal growth factor receptor (EGFR) is overexpressed in human glioma. The pre-S1 peptide displays on the surface of BNC as the specific ligand for receptor binding on human hepatocytes. We replaced the pre-S1 peptide with antibody affinity motif of proteinA and made hybrid BNC binding anti-human EGFR antibody. The hybrid BNCs were efficiently delivered in glioma cells but not normal glial cells. Moreover, we confirmed the specific delivery of the hybrid BNC to brain tumor in vivo model of brain tumor. These results suggest that this new approach using BNCs provides a promising system for brain tumor-targeted drug delivery. [J Physiol Sci. 2007;57 Suppl:S119]
