Biomedical Engineering Reference
In-Depth Information
Adhered fibrinogen
Fibrinogen
e
Fibrin monomer
Fibrinopeptides
+
Two fibrin monomer
P
olymer
Cross-lin
k
FIGURE 19.50
Interactions of fi brinogen with a solid via the charge transfer process. (From Chen, J.Y.
et al.,
Biomaterials
, 23, 2545, 2002. With permission.)
19.6 SURFACE MODIFICATION OF POLYMERS FOR
ENHANCED ANTIBACTERIAL PROPERTIES
19.6.1 Cu-I
MPLANTED
P
OLYMERS
Medical polymers are widely used in the treatment of diseases and biomedical implants because of
their excellent mechanical properties and biological properties [185-187]. However, when medical
polymers are implanted inside the human body, they can become places for microbes to adhere and
breed, and thus infection of medical polymers is one of the major clinical complications [188-191].
Nowadays, there is an increasing interest in the development of anti-infective medical polymers
by the biomedical industry. Antimicrobial properties on medical polymers can be achieved by two
main approaches [192-196]. The fi rst technique is the deposition of antibacterial reagents directly
onto the surface of the polymers by means of vapor deposition, sputter coating, or ion beam-assisted
surface modifi cation and deposition. The second method is the direct incorporation of antibacterial
reagents into the polymers.
Researchers in City University of Hong Kong found that Cu could be incorporated into the
surface region of polyethylene (PE) by means of PIII to promote the antimicrobial properties
[197]. Low-energy (several keVs) Cu PIII can introduce a large amount of Cu into the poly-
mer without causing too much damage to the polymer surface [36,63,197
202].
Medical-grade
PE specimens were implanted with Cu in a plasma immersion ion implanter equipped with a
Cu cathodic arc plasma source and nitrogen PIII was performed to change the structure of the
implanted region of the substrate. Compared to the single Cu PIII process, this dual plasma
-
