Research in our group focuses on interfacial
reactions and applications. The area where gases,
liquids and solids interact with solid surfaces
is called the interfacial region. This is a
chemically complex region that is difficult
to define and control. Reactions and interactions
in this area are important in applications such
as corrosion control, biomaterials, heterogeneous
catalysis, proteomics and biosensors. In our
group, we aim to control this region through
chemical modification of the surface which is
specific to the application.
Biomaterials
Biomaterials are synthetic materials placed
in the body to replace or reinforce bones and
tissues. The interaction of these materials
with the body is integral to their long-term
success. Situations where these interactions
are crucial is the in-growth of bone into joint
replacements, tissue reactions to catheters
and IVs, the encapsulation of stabilization
implements by healthy tissue. In order to study
these systems, we must understand the problem
that a bad interaction can cause. Second, we
try to understand both the biological and chemical
nature of the interaction. Finally we try to
design chemical modifications which can aid
these interactions and reduce the problems caused
by the biomaterials.
Our initial
interest is in the interaction of stainless
steel stents with the artery or vein. Stents
are tube shaped implants which are used to reinforce
the walls of the artery and allow continued
blood flow. These surfaces are sites for colonization
of bacteria leading to infection. More commonly
the stents are sites for adhesion of fibrous
tissue and cells leading to the restenosis or
reclosure of the artery and veins. Blood clots
caused by the insertion of the stent are due
to the non-specific adsorption of platelets
on the surface. These problems could be reduced
if the stents were coated to resist the non-specific
adsorption of bacteria, tissue and platelets.
Our approach is to reduce the non-specific adsorption
through chemical modification via monolayers
and polymers. Students on these projects gain
experience in a wide variety of skills including
synthesis, spectroscopy, surface analysis and
tissue culture.
Biofouling
Biofouling is the adhesion of bacteria and other
small organisms to the surface of structural
materials. The biofouling leads to the corrosion
of "corrosion-resistant" materials
such as stainless steel and titanium alloys
through the sequestering of oxygen at the surface.
Marine structures such as ships, oil rigs and
docks are particularly susceptible to biofouling.
Fouling-resistant paints and coatings are used
but the search for more effective coatings continues.
In our laboratory, we approach this problem
through surface modification of the metal oxide
surfaces. We are attempting to resist the micro-organism
attachment on the metal oxide surface. Model
systems have been particularly successful in
using monolayers for this purpose but not on
metal oxide surfaces. We will combine monolayer,
polymer and small molecule synthesis to develop
new coatings in this area.
