Item

Abstract

Diagnostic procedures seek to provide measures of analytes, cells and their components, morphological structures or molecular fingerprints to guide therapy. Such procedures are limited by the concentration of analytes or cells, the dimension of morphological structures and the identification of a given molecular state with a distinct state of health or disease. To improve diagnostic procedures the increase of analyte and cell concentration in blood, tissue or other body fluid samples is desirable. Material science and engineering could construct new devices that may enable the enrichment of analytes and cells in vivo or ex vivo for subsequent testing. We functionalized two kinds of substrates with specific antibodies (IgG) that were directed against distinct cell surface antigens. One substrate was characterized by nano-patterned gold dots, the other by a solid gold surface. Mouse monoclonal IgG, directed either against CD4 or HLA-G cell surface epitopes, was covalently bound to gold islands or solid gold surfaces using linker chemistry. With both kinds of substrates and three types of linker specific cells were enriched and collected out of samples that resemble in vivo conditions: CD4+ lymphocytes in blood samples and trophoblasts under flow conditions. Using 125J-labelled IgG we demonstrated stable binding of antibodies to substrate (5,6 to 10,2 ng/mm2, depending on linker type) with less than 10 % loss of 125J-IgG over a time frame of 30 days. We conclude that nano-patterned and solid gold surfaces could be functionalized with antibodies for collecting of rare cell populations in biological samples. Biopsy devices may be constructed for the enrichment of cells in vivo, if unspecific reactions could be ruled out.