AVS 47th International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeP

Paper BI-WeP7
Vesicle -> Supported Bilayer Transformation Kinetics; Influence of Support Material, Vesicle Size and Temperature

Wednesday, October 4, 2000, 11:00 am, Room Exhibit Hall C & D

Session: Poster Session
Presenter: E. Reimhult, Chalmers University of Technology, Sweden
Authors: E. Reimhult, Chalmers University of Technology, Sweden
F. Höök, Chalmers University of Technology, Sweden
B. Kasemo, Chalmers University of Technology, Sweden
Correspondent: Click to Email
Supported phospholipid bilayers (SPB) on a solid surface are biologically functional components of high current interest, e.g., for biosensors, tissue engineering, and basic science (Sackman, Science 271:43 (1996); Stelzle et al., J. Phys. Chem. 97:2974 (1993)). We have recently reported the kinetics of SPB formation from sonicated, unilamellar vesicles (SUV) of average size 25 nm, on a SiO@sub 2@ support, using the quartz crystal microbalance - dissipation (QCM-D) technique (Keller and Kasemo, Biophysical Journal 75:1397 (1998); Keller et al., Phys. Rev. Lett. 84:5443 (2000)). Several interesting questions arose from the latter results; how does the vesicle -> bilayer transformation kinetics depend on the vesicle size, on temperature, and on the support. In the present study we are addressing these questions, whose answers are important for future sensor, biomaterial and micro-patterning applications. Already obtained results reveal a (vesicle) size-dependent kinetics, where also the end result (the final bilayer) may have different properties for different sizes of extruded unilamellar vesicles (EUV). The dependence on temperature is currently studied and will be reported. An exploratory study shows a strong temperature dependence for the vesicle -> bilayer transition. Different surfaces also cause different kinetics. So far, SiO@sub 2@ surfaces have been the dominating support used to promote complete bilayer formation. Vesicle adsorption, but no bilayer formation, is observed for oxidized Ti and Au surfaces , while partial bilayer formation may occur on Pt. The above results constitute a platform from which more complex functional supported bio-membranes can be constructed (Höök et al, to be published).