Coagulase negative staphylococci, most notably
Staphylococcus epidermidis, have been identified as a
predominant cause of cardiovascular implant infection, which
begins with the colonization of the device by the bacteria.
One possible approach to reduce this event is to understand
how the physicochemical properties of bacterial surface
influence attachment to biomaterials.
In the present study, the attachment of coagulase negative
Staphylococcus epidermidis expressing capsular
polysaccharide/adhesin (PS/A), the most common etiological
agent of colonization of implantable medical devices, was
assessed in vitro to cellulose diacetate (CDA), to CDA
chemically modified by de-acetylation (CDA-D) and by
phosphorylation (CDA-P), as well as to reference Low Density
Polyethylene (LDPE).
The quantification of S. epidermidis attached to cellulose
diacetate (CDA) in phosphate buffer saline (PBS) elicited
information regarding the interaction between the bacterial
strain and the polymeric biomaterial. There was a significant
difference in the adhesion of RP62A to CDA, compared to
LDPE. Chemical modifications of CDA by de-acetylation and
by phosphorylation were effective in lowering bacterial
attachment. These chemical treatments increased the acidic
parameter of the surface energy and decreased the acid-base
interactions with acidic sites of the capsular PS/A. In other
terms, these treatments also promoted a decrease in
hydrophobicity that linearly correlates with a decrease in the
number of attached cells
