Antimicrobial Coatings to Prevent Biofilm Formation on Medical Devices - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 188

5.2.2 Organoselenium
While reduction of bacterial number in solution is important, cleaning of the case is
the main problem. Most patients replace the cleaning solution every day; however,
many don't clean the case. Thus, in order to prevent bacterial colonization of lenses
and solutions, it is important to reduce the ability of bacteria to form biofilms on
lens cases. Recently, it was shown that a case made with organo-selenium incor-
porated into the polymer of a polypropylene case eliminated biofilm formation on
the case material (Reid et al. 2012 , 2013 ). It was found that organoselenium
completely inhibited biofilm formation by S. aureus , P. aeruginosa , Stenotro-
phomonas maltophilia , and E. coli in vitro. In addition it was found that this
complete inhibition was still present after 8 weeks of soaking the case, and the
same results were obtained when the case was maintained dry. Thus, if the lens case
solution was changed daily, no contamination should occur for a contact lens stored
in the case.
6 Summary
It is now well recognized that biofilm development is a serious problem for medical
devices. Solutions for this problem have progressed over the last 10 years. Initially,
devices were impregnated with materials such as silver and other antimicrobials
that would leach out from the device in order to control bacterial attachment. These
earlier attempts had toxicity problems and led to the development of covalent
attachment of materials such as quaternary amines, furanones, and
organoselenium compounds. These resulted in a more stable device coating with
less toxicity. Recently, it was found that the organoselenium compounds could be
incorporated during the polymerization process and still inhibit microbial attach-
ment. This could provide an antimicrobial that is uniformly distributed throughout
the device. Thus, the device could degrade or wear, with time, and still have an
antimicrobial surface.
Acknowledgments Part of the research was supported by NIH Grant 5R44DK074187-03.
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