Current and Emergent Control Strategies for Medical Biofilms - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 119

efficacy of biomaterial modifications also appears to inhibit Candida biofilms
(Tournu and Dijck 2012 ).
Surface Modifications
The surface properties of medical devices constitute a major factor contributing not
only to their stability in the body but also to their performance and lifetime in vivo
and their colonization by microorganisms. Accordingly, albumin adhesion to sur-
faces is potentially beneficial since it has been shown to prevent binding of
microorganisms, while fibrinogen has the opposite effect (Anderson et al. 2008 ).
Chemical grafting of polyethylene and polypropylene surfaces with functionalized
cyclodextrins changes the protein adsorption profile of these polymers by promot-
ing adsorption of albumin and reducing the adhesion of fibrinogen to the material
surface (Nava-Ortiz et al. 2010 ). These modified substrates were able to incorporate
the antifungal agent miconazole very well and retarded biofilm formation by
C. albicans . Modified polyethylene and silicone rubbers proved to be very efficient
in inhibiting C. albicans biofilm formation (Contreras-Garcia et al. 2011 ). These
materials are cytocompatible and also capable of releasing considerable amounts of
nalidixic acid for several hours. This may further potentiate efficacy of treated
surfaces to prevent formation of biofilms.
Biofilms on voice prostheses consist of mixed populations. Modification of the
silicone surface of the prostheses has been employed to limit C. albicans coloni-
zation, as opposed to incorporation of antimicrobial agents in order to avoid the
occurrence of resistance (De Prijck et al. 2010a ). Silicone disks grafted with C1 and
C8 alkyl side chains demonstrated reduced microbial adherence and inhibited
biofilm formation by C. albicans by up to 92 %. Similarly, grafting of silicone
rubber with cationic peptides, such as the salivary peptide Hst5 and synthetic
variants, inhibited biofilm formation by up to 93 %, in a peptide-dependent manner
(De Prijck et al. 2010b ).
Preconditioning surfaces with surfactants also has potential to prevent bacterial
adhesion and inhibit formation of biofilms. Splendiani et al. ( 2006 ) screened
22 surfactants for their potential to increase the cell wall charge of a Burkholderia
sp. strain and reduce the ability to attach and form biofilms. The authors demon-
strated that some surfactants affected the development of flagella, demonstrating
significant changes in the ability of bacteria to attach in the presence of the
surfactant. In addition to surfactants, biosurfactants synthesized by microbes have
also been used as coating agents for medical implants leading to a reduction in
hospital infections caused by biofilm growth (Rodrigues et al. 2006 ).
Surface Coatings
Microbicidal or static materials have been employed to fabricate or coat the
surfaces of medical devices and have a great potential in reducing or eliminating