Control of Polymicrobial Biofilms: Recent Trends - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 335

and disadvantages to each. Specifically, high-powered nonthermal plasma can kill
very effectively and quickly, but the rate at which it etches the biofilms is so fast
that often living cells are removed, potentially resulting in contamination of other
areas such as a bodily surface or medical devices. Conversely, low power plasma
takes a longer exposure time to both kill and remove cells, but because etching
happens at a much later stage in treatment, all cells are much more likely to have
been killed before they are removed (Traba et al. 2013 ).
These above-described characteristics make plasma a very alluring candidate for
various applications in the medical field. One major potential application is for the
cleaning of medical devices. A study done by Rupf and colleagues illustrated the
proficiency of plasma to successfully kill biofilms on titanium surfaces (Rupf
et al. 2011 ). This is significant because titanium is often used for medical implants
due to its unique surface properties which allows for great biocompatibility.
Unfortunately, this same surface also makes it a prime target for biofilm develop-
ment, and it can be challenging to sterilize without degrading the integrity of the
surface (Burgers et al. 2010 ; Traba et al. 2013 ). Another exciting avenue is the use
in wound treatment. Early clinical trials in humans have indicated that nonthermal
plasma can decrease bacterial load in chronic wound infections (Isbary et al. 2010 ),
and similar results have been reported in animal models (Ermolaeva et al. 2011 ).
4.3 Nanotechnology-Based Technologies
The field of nanotechnology offers a promising avenue of research in the fight
against biofilms. An example of such technology is based upon nanoparticles of
nanoparticles. Nanoparticles are extremely small bead-like structures with sizes
generally ranging between 1 and 100 nm although most are under 50 nm (Haynes
et al. 2002 ). A key advantage to using nanoparticles is that their physicochemical
properties (e.g., size, structure, composition, hydrophobicity, charge, etc.) may be
“tuned” by varying the precursors and procedures in their construction (Bagwe
et al. 2006 ; Wang et al. 2009 ; Cheng et al. 2013 ). As a consequence, nanoparticles
have found places for use in biomolecular sensing, microbiological and macro-
biological imaging (e.g., quantum dots), drug delivery, and disease therapy
(Bhardwaj et al. 2009 ; Wang et al. 2009 ). Numerous different types of
nanoparticles for use as antimicrobial agents have been documented and often
involve the use of metals. While these can be individual metals or combinations,
the most notable appears to be silver for microbial control. This is not surprising
considering that silver has long been known to have antimicrobial properties
(Slawson et al. 1992 ). Sondi et al. have shown that silver nanoparticles created
via the reduction of silver ions using ascorbic acid are able to prevent growth of
E. coli (Sondi and Salopek-Sondi 2004 ). Rather than using the nanoparticle itself as
the antimicrobial source, there are also other ways of using biologically inert
nanoparticles to deliver the antimicrobial agents. In most of these cases, the active
agent(s) are attached to the surface of the nanoparticles which acts as a carrier