AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP9
Micropatterned Substrate Screening under Shear Flow (MiSSUS): Direct Comparison of Receptor-ligand Binding

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: K.A. Burridge, Boston University
Authors: K.A. Burridge, Boston University
M.A. Figa, Boston University
J.Y. Wong, Boston University
Correspondent: Click to Email
Microfluidic patterning has been combined with a parallel plate flow chamber to enable screening of combinatorial variations in targeted drug delivery carrier surface properties under tunable physiologically-relevant shear conditions. Carriers containing either drugs or imaging agents must have surface properties that promote binding to targets yet at the same time block rapid immune system clearance. In addition, ligand-receptor mediated attachment must overcome shear flow in the vasculature which decreases contact times and applies forces on bonds. Patterned bilayers which mimic the surface of liposomal delivery vehicles are created by injecting pre-mixed vesicle solutions into lanes formed by a polydimethylsiloxane stamp reversibly sealed to a glass slide. After removing the stamp in an albumin solution to form protein barriers that prevent bilayer expansion, the slide is assembled into a flow chamber for binding studies. MiSSUS provides direct quantitative comparison of the effects of variations in ligand architecture such as relative molecular weights of liganded and unliganded polyethylene glycol. Experiments using MiSSUS revealed that ligand spacer length is an important factor in maintaining adhesion under flow, i.e. that longer spacers confer higher detachment resistance.