(674b) Particle Targeting Using Antigen-Antibody Interaction for Pharmaceutical Application

This work is concerned with the surface modification of fluorescent silica nanoparticles by a monoclonal antibody IgG-M75 and the specific binding of such particles to surfaces coated by the PG domain of carbonic anhydrase IX (CA IX). CA IX is a trans-membrane protein specifically expressed in stomach but its overexpression is also associated with several types of carcinomas. The adhesion strength of antibody-bearing silica nanoparticles to antigen-bearing surfaces was investigated under laminar flow conditions in a microfluidic cell and compared to the adhesion of unmodified silica nanoparticles and nanoparticles coupled with a nonspecific antibody. Adhesion to HT-29 cancer cells (cell line derived from colorectal carcinoma) using flow cytometry was also investigated and compared with the cell line NIH 3T3 (sarcoma cell line) which does not displayed CA IX on its surface. The specific modification of nano- and microparticles by an antibody-like protein appears to be a feasible approach for the targeting of tumor cells.