IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Monday Sessions
       Session BI-MoP

Paper BI-MoP9
Examination of Bacterial and Protein Attachment and Release Using Tunable Poly(N-Isopropylacrylamide) as a Switchable Hydrophobic/Hydrophilic Substratum

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Biorecognition Poster Session
Presenter: L.K. Ista, The University of New Mexico
Authors: L.K. Ista, The University of New Mexico
S. Mendez, The University of New Mexico
S. Balamurugan, The University of New Mexico
G.P. Lopez, The University of New Mexico
Correspondent: Click to Email
Poly(N-isopropylacrylamide), or PNIPAAM, undergoes a critical solubility transition in response to temperature. Below 32°C, the polymer is freely water soluble, whereas above this temperature it is insoluble in water. When PNIPAAM is immobilized this property translates to an increase in surface hydrophobicity above the transition temperature (T@sub t@). The process is fully reversible, with restoration of the original degree of solubility or hydrophilicity occurring upon cooling to temperatures below T@sub t@. This switchable characteristic of grafted PNIPAAM has been exploited in the creation of fouling release surfaces. It has been discovered that when thin layers of PNIPAAM are grown from initiator-derivatized. alkanethiolate self-assembled monolayers (SAMs), the range of wettabilities observed above and below T@sub t@ can be tuned by altering the hydrophobicity of the underlying SAM. Because the hydrophobic/hydrophilic transition happens in situ, and rapidly over a short temperature range, tunable PNIPAAM substrata are ideal for examining the effect of changing surface hydrophobicity on the attachment and detachment of biofilm components, i.e. microbes and proteins. We report here the results of attachment and detachment studies on patterned tunable PNIPAAM surfaces using two bacteria which normally exhibit different and opposite responses to subtratum hydrophobicity (Halomonas marina and Staphylococcus epidermidis) as well as studies on adsorption and desorption of a variety of proteins known to play a role in biofilm formation.