Biomedical Engineering Reference
In-Depth Information
antibacterial activity against
E. coli
compared to native chitosan and has
been applied in drug delivery, bioimaging, biosensors and gene therapy
[146]. h e review by de Britto
et al.
focused on quaternary ammonium
salts of chitosan, these salts are particularly useful since they are water
soluble and have increased antimicrobial ef ects [147]. Common quater-
nary ammonium salts are trimethyl chitosan chloride (TMC) and 3-tri-
methylammonium-2-hydroxypropyl-
N
-chitosan chloride. h ese polymers
have been applied in a variety of applications and have proven antibac-
terial and antifungal activity [147]. Li and co-workers modii ed chitosan
i lms with antimicrobial
N
-halamine, these i lms were subsequently chlori-
nated to confer biocidal properties [148]. h e i lms were found to be ef ec-
tive against
S. aureus
and
E. coli
within 5-10 minutes at er exposure. h e
authors suggest that these i lms have the potential to be applied as wound
dressings, coatings for medical devices and food packaging [148]. A chito-
san ethylene co-polymer (methyl acrylate and vinyl acetate) synthesized by
Massouda
et al.
was found to be ef ective against
E. coli
,
Salmonella enterica
and
L. monocytogenes
making it a strong candidate for antimicrobial pack-
aging [149]. Dilamian
et al.
produced electrospun membranes of chito-
san/poly(ethylene oxide) in the presence of the broad spectrum antiseptic
poly(hexamethylene biguanide) hydrochloride [150]. h ese nanoi bres
inhibited the growth of
E. coli
and
S. aureus
making these i bres good can-
didates for biomaterials [150]. Similarly, Fouda and co-workers synthesized
carboxymethyl chitosan/poly(ethylene oxide) nanoi bres embedded with
Ag nanoparticles [151]. h ese i bres were tested against
S. aureus
,
P
.
aeru-
ginosa
,
E. coli
and
Candida albicans
and results showed that higher anti-
microbial activity was obtained when nanoi bres with silver nanoparticles
(AgNPs) was tested [151]. h ere are currently a wide variety of bandages
based on chitosan which claim antimicrobial ef ects one such example are
the wound care products marketed by Hemcon. h e company recently
published a report on the antibacterial properties of their products where a
wider range of bacteria was tested and shown to be inhibited by chitosan. A
wide variety of products are on of er which includes haemostatic dressings,
gels, nasal plugs and dental dressings to mention a few [152]. Other prod-
ucts being marketed include the antimicrobial textile i bre Crabyon
®
[96].
Patents and applications of chitosan and its derivatives are based on
the above research. New applications are being reported on a regular basis
making chitosan a highly sought at er commodity. h e future of antimi-
crobial chitosan technology looks promising. Based on the amount and
continued increase in patented innovations, chitosan and its derivatives
are poised to deliver on its untapped commercial potential.
