Biomedical Engineering Reference
In-Depth Information
microbial contamination is to coat susceptible surfaces with antimicrobial
agents including polymers, which inhibit growth of microorganisms.
h e research discoveries reported in this chapter revise and focus
the recent advances in the preparation and characterization of stimuli-
responsive materials used as medical devices in loading and eluting of
drugs. Additionally, some strategies are described that might help improve
performance of these biomedical devices.
2.2 Classii cation of Materials for Bioapplications
2.2.1 Polymers
Polymers are widely used in various bioapplications because they are avail-
able in a variety of compositions, properties, and forms (solids, i bers, fab-
rics, i lms, and gels), and can be fabricated readily into complex shapes and
structures [1]. In recent years, there has been remarkable growth in the
research and development of synthetic polymers for biomedical, micro-
electronics, and other advanced technological applications. Temperature-
sensitive polymers have gained much attention because of their intelligent
and reversible behavior in response to environmental stimuli, in particu-
lar to temperature variation. Such a behavior, on the one hand, is of great
importance for theoretical and basic research, on the other hand, it can
be utilized to form intelligent materials with nano- or micro- dimen-
sions, such as gels, particles, micelles, and capsules. h ese materials in
various physical formats have shown intelligent loading and release capa-
bilities for drugs, proteins, nanoparticles, and DNAs under the modula-
tion of temperature, ionic strength, pH values, solvents, and even light
[2, 3]. Some polymers used for biomedical applications are high density
polyethylene, ultrahigh molecular weight poly(ethylene), poly(urethane),
poly(sulfone), poly(ethylene), poly(propylene), poly(methylmethacrylate),
poly(etheretherketone), poly(acetal), poly(ethylene terephthalate) and sili-
cone rubber.
2.2.2 Ceramics
Traditional ceramics are of high compressive but low tensile strength. As
compared to metals, ceramics ot en are regarded as favorable materials
for joints or joint surface materials. Most types of ceramics are inherently
hard and brittle materials with higher elastic moduli compared to bone.
Several ceramics have been investigated as bone substitute materials due
