Bacterial Adhesion and Interaction with Biomaterial Surfaces - Biointerfaces: Where Material Meets Biology - page 378

13.4 Inhibition of Bacterial Adhesion by Textured

Biomaterial Surfaces

13.4.1 Background
Although addition of antibiotics is still the main strategy for prevention of
biomaterial-associated infections, reduction of bacterial adhesion to an
implant without the use of drugs has been increasingly attractive to bio-
material scientists. One promising approach to prevent microbial infection
is the generation of functional material surfaces that significantly reduce the
initial attachment of microorganisms and the number of persistent patho-
gens. 137 Numerous surface modification techniques, such as anti-adhesive
and antibiotic coatings, surface grafting, chemical modification, and bio-
logical methods have been applied to biomaterials for inhibition of mi-
crobial adhesion. 138-140 Along these strategies, altering surface topography
with micro- or nano-textured patterns is highly attractive since the textured
surface applied to biomaterials does not require modification of surface
chemistry and mechanical properties of bulk materials, but does signifi-
cantly reduce bacterial adhesion and biofilm formation.
Clues for the prevention of biofilm formation by surface topography come
from natural antifouling surfaces such as marine organisms (e.g., shark,
mussel) or the lotus leaf. 141-144 The endothelium of a healthy artery is an-
other example of a natural antifouling system. 145 These natural surfaces are
generally microtopographically structured and also may secret bioactive
products that inhibit the adhesion of microorganism or cells. The combin-
ation of chemical and physical structures creates an ideal antifouling sur-
face. 146 With interest in this area and the related research increased,
biomimetic or bio-inspired materials have been developed over the last
two decades. 147 For example, materials with topographical features mim-
icking the skin of sharks at certain length scales have shown increased
resistance to marine biofouling. 146,148 Similar topography applied into a
poly(dimethylsiloxane) (PDMS) elastomer was found to disrupt biofilm for-
mation of S. aureus, providing the possibility for application in biomedical
devices. 149 These bioinspired antifouling materials generally possess mi-
cron-size structured surfaces having dimensions ranging from 1 to 300
mm. 150 The creation of engineered nanoforce gradients on this specific
patterned surface was believed to contribute to the low attachment of
microorganisms in the marine environment. 151
Topographical structure affects the surface contact area and surface phy-
sicochemical properties, and therefore influences the interactions of bac-
terial cells and material surface, and the subsequent biofilm development.
We developed submicron-textured surfaces on polyurethane biomaterials
originally as a means to reduce blood platelet adhesion, 152 but later results
demonstrated that this structure also decreased the adhesion of S. epi-
dermidis and S. aureus to polyurethane and inhibited biofilm formation
under shear or static conditions. 153 Thus, the in vitro success of textured

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