DIFFUSION AND TRANSFER OF ANTIBODY PROTEINS FROM A SUGAR-BASED HYDROGEL

Diffusion of antibody protein from hydrogel films and hydrogel encapsu lated in a microcapillary was studied. Thin hydrogel films were formed by crosslinking 6-acryloyl-B-O-methylgalactoside with N,N'-methylene- bis-acrylamide and the diffusive transport of monoclonal antimouse IgG -FITC into and out of the hydrated films was measured. Diffusion coeff icients in 2 and 4% crosslinked hydrogel films were measured. The meas ured diffusion constants determined for IgG in both the 2 and 4% hydro gel films were comparable to the free diffusion of IgG in bulk water ( D-mean similar to 10(-7)cm(2)/s). In addition, 2% crosslinked hydrogel s were prepared in a capillary tube and the transport of antimouse IgG -FITC into and out of the hydrated hydrogel was measured. Kinetic anal ysis indicated that the protein transport through the capillary hydrog el was faster than would be expected for a simple diffusion process. F inally, by utilizing the diffusion of antibody from the capillary hydr ogel, transfer of antibody to a silica surface was demonstrated. A cap illary hydrogel loaded with antimouse IgG-FITC was used to transfer th e protein to a silica surface forming a 30-mu m spot of antibody, whic h was ima,oed using fluorescence microscopy. These results may lead to the development of a nonlithographic method of patterning antibodies on surfaces for use in integrated microimmunosensors.