Biomedical Engineering Reference
In-Depth Information
for eukaryotic cells via generating reactive oxygen species (ROS) and have syner-
gistically
inducing magnetic properties for potential use as controls for cell fate
processes. Although implants with magnetic properties have been shown to be
successful for treatment of bone defect, the cure of malignant bone tissue and the
restoration of large bone defects still provide major clinical challenges. A num-
ber of magnetic biomaterials such as magnetic Ca/P
−
based materials, bioactive
glass ceramics and ferrimagnetic calcium phosphate glass
−
ceramics are reported
prospective materials for malignant bone tumors in hyperthermia therapy. After
discussing these aspects, this chapter concludes with a discussion on the effect
of electric and magnetic fi eld on bacterial adhesion and growth behavior
in vitro
.
−
Keywords:
Magnetic fi eld, electric fi eld, hydroxyapatite, ZnO, Ag, iron oxide
7.1 Introduction
Biomaterials are very important from a healthcare prospective because they
are used to replace lost tissues and treat many diseases. Optimally designed
biomaterials provide temporary scaffolding to facilitate new tissue growth
[1]. In order to cure the bone defects, a variety of synthetic biomaterials
have been anticipated as bone fi llers. Among these biomaterials, bioglass
and calcium
phosphate ceramics represent bioactive materials having the
aptitude to achieve direct biological bond with bone [2]. The biomaterials
must show good mechanical responses as well as bone
−
mimicking proper-
ties in physical terms and must be biocompatible in order to prevent bio-
logical rejection, which hampers device performance. It is therefore highly
preferable that synthetic biomaterial be “inert” and not toxic towards the
host organism [3]. Its host response should be good in order to minimize
the chances of aspect loosening, which may lead to revision surgery. A
good biomaterial should have natural bone
−
like properties [4]. The issues
associated with synthetic biomaterials are summarized in Figure 7.1.
It has been reported that more than 2,00,000 primary hip and 2,00,000
primary knee arthroplasties are performed each year in the USA [5]. Also,
0.5% and 2.5% of them are reported to experience prosthetic infection
within 10 years [5, 6]. A variety of disease
−
causing bacteria have become
antibiotic resistant and this has been a serious threat to public health
worldwide [7]. Among these pathogenic microorganisms,
Enterococcus
,
Staphylococcus
,
Streptococcus
and
coagulase negative
Staphylococci
are com-
mon species that are responsible for a wide variety of infections and dis-
eases [8].
The nosocomial infections have an effect on approximately 10% of all
inpatients, leading to a delay in discharge by an average of 11 days, or
directly causing 5000 deaths/year in the UK [9]. These bacterial strains are
becoming a major cause for hospital
−
acquired infections [10].
Total joint
replacement affected by sepsis can have catastrophic results in the form
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