AVS 50th International Symposium
    Biomaterial Interfaces Thursday Sessions
       Session BI+SS-ThA

Paper BI+SS-ThA10
Chitosan - A Biomaterial Interface that can be Selectively Deposited onto Micropatterned Surfaces and Conjugated to Sensing Biomolecules

Thursday, November 6, 2003, 5:00 pm, Room 318/319

Session: Biodiagnostics
Presenter: L.-Q. Wu, University of Maryland Biotechnology Institute
Authors: L.-Q. Wu, University of Maryland Biotechnology Institute
H. Yi, University of Maryland Biotechnology Institute
M.J. Kastantin, University of Maryland
S. Li, University of Maryland
D.A. Small, University of Maryland
J.J. Park, University of Maryland
T. Chen, University of Maryland Biotechnology Institute
G.W. Rubloff, University of Maryland
R. Ghodssi, University of Maryland
W.E. Bentley, University of Maryland Biotechnology Institute
G.F. Payne, University of Maryland Biotechnology Institute
Correspondent: Click to Email
We are examining the amino-polysaccharide chitosan as a biomaterial interface. Chitosan's pH-dependent electrostatic properties allow it to be selectively deposited (i.e. "templated") onto micropatterned electrodes in response to an applied voltage. Deposition of chitosan, or chitosan-containing conjugates, is rapid (about 2 minutes) and can be performed under mild conditions. After neutralization, the films are retained without the need for an applied voltage. These films can also be removed from the electrode using mildly acidic conditions (pH<6). Chitosan's amine groups are also nucleophilic and can readily react with a variety of reagents. In particular, standard coupling chemistries can conjugate proteins and oligonucleotides with chitosan. We are exploiting glutaraldehyde coupling chemistries to anchor nucleic acids and proteins onto chitosan surfaces. In one study, we tethered oligonucleotide probes onto an electrochemically deposited chitosan surface and examined the bio-detection of mRNA by a hybridization-based assay. In a second study, we selectively deposited chitosan on an electode surface embedded in the base of a microfluidic channel. The green fluorescent protein (GFP) was subsequently anchored to this chitosan surface. In summary, chitosan is unique interface biomaterial - it can be templated onto a microfabricated surface and conjugated to bio-molecules. We are currently exploiting these capabilities in biosensor and bio-MEMS applications.