Biomedical Engineering Reference
In-Depth Information
of patents that have been awarded recently are highlighted here. h ese pat-
ents form the basis of technology that is currently being developed in the
hope of commercialisation.
h e utility of chitosan as a i nal coating has found widespread biomedi-
cal application. A chitosan-based coating process for ophthalmic lenses has
recently been reported. h is coating allows the lenses to move freely with-
out adhering to the eye and has antimicrobial properties making this an
appealing product [91]. Halada and co-workers reported on a method for
the electrochemical deposition of metal NPs (ruthenium, rhodium, pal-
ladium, silver, osmium, iridium, platinum and gold) together with a chito-
san coating on a stainless steel surface [92]. h is coating has antimicrobial
properties and can potentially be used to confer antimicrobial activity to
the surface of medical implants [92]. A patent i led by Filee and colleagues
described the preparation of chitosan-based biomimetic scaf olds consist-
ing of two layers, a nanoi bre scaf old membrane and a porous support
layer (sponge) [93]. h ese scaf olds can potentially be utilized in wound
dressing, tissue engineering and other biomedical applications [93].
h ixotropic hydrogels have found widespread application in the cos-
metic market, thus allowing the delivery of water soluble actives. However,
it is the ability to control gelation using external stimuli or chemical change
on demand that is particularly useful in biomedical applications. Yu
et al.
described the application of a dextran-chitosan based
in-situ
gelling hydro-
gel in the biomedical sector [94]. Potential uses of this hydrogel include
controlled drug release, bioi lm prevention, tissue in-growth prevention
(tissue engineering) and as a matrix for cell proliferation [94]. Wang
et al.
used gelatin, i broin,
chitosan, collagen or sodium alginate in the prepara-
tion of electrospun natural material nanoi bres which were loaded with
inorganic nanoparticles (mesoporous silica or dye, growth factor, nucleic
acid, bioenzyme or drug-coated mesoporous silica) [95]. h ese nanoi bres
are biocompatible, simple to prepare and relatively cheap for potential
applications in tissue engineering (growth factor and gene release) and
other biomedical i elds such as cancer treatment, drug delivery, etc [95].
Arab merchants brought cotton cloth to Europe about 800 A.D. Cotton,
which comprise of cellulose, a structurally related polymer to chitosan his-
torically has a very long lead in technology improvements. Over the past
decades, much ef ort has gone into making cotton fabrics more resistant to
microbial degradation. It is only in recent times that the inherent antimi-
crobial nature of chitosan has drawn attention. An example of successful
technology commercialisation is that of Crabyon
®
i bre, is a blend of chito-
san and viscose manufactured by the textile company Swicoi l. h is i bre
is based on the patent i led by the company Omikenshi which developed a
