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Journal of Drug Delivery
Volume 2012 (2012), Article ID 842785, 11 pages
Research Article

Active Targeting to Osteosarcoma Cells and Apoptotic Cell Death Induction by the Novel Lectin Eucheuma serra Agglutinin Isolated from a Marine Red Alga

1Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka 560-8531, Osaka, Japan
2Department of Materials, ETH, Wolfgang-Pauli-Straße 10, 8093 Zürich, Switzerland
3Department of Pathogenomics, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Ehime, Japan
4Department of Bone and Joint Surgery, Graduate School of Medicine, Ehime University, Shitsukawa, Toon 791-0295, Ehime, Japan
5Integrated Center for Science Shigenobu Station, Ehime University, Shitsukawa, Toon 791-0295, Ehime, Japan
6Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577, Ehime, Japan

Received 30 September 2012; Accepted 21 November 2012

Academic Editor: Andreas G. Tzakos

Copyright © 2012 Keita Hayashi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Previously, we demonstrated that the novel lectin Eucheuma serra agglutinin from a marine red alga (ESA) induces apoptotic cell death in carcinoma. We now find that ESA induces apoptosis also in the case of sarcoma cells. First, propidium iodide assays with OST cells and LM8 cells showed a decrease in cell viability after addition of ESA. With 50  g/ml ESA, the viabilities after 24 hours decreased to 54.7 ± 11.4% in the case of OST cells and to 41.7 ± 12.3% for LM8 cells. Second, using fluorescently labeled ESA and flow cytometric and fluorescence microscopic measurements, it could be shown that ESA does not bind to cells that were treated with glycosidases, indicating importance of the carbohydrate chains on the surface of the cells for efficient ESA-cell interactions. Third, Span 80 vesicles with surface-bound ESA as active targeting ligand were shown to display sarcoma cell binding activity, leading to apoptosis and complete OST cell death after 48 hours at 2  g/ml ESA. The findings indicate that Span 80 vesicles with surface-bound ESA are a potentially useful drug delivery system not only for the treatment of carcinoma but also for the treatment of osteosarcoma.