Biomedical Engineering Reference
In-Depth Information
(
a
)
Cell membrane
Cytoplasm
Damaged cell membrane
(
b
)
Cell membrane
Cytoplasm
Figure 7.19
Schematic illustration of proposed TiO
2
nanoparticle
induced
toxicity mechanisms in
Bacillus licheniformis
bacteria under (a) light and (b) dark
conditions, represents TiO
2
nanoparticles and
−
represents generated ROS
(adapted from ref. [92]).
The attachment of nanoparticles on cell wall is also responsible for mem-
brane damage, and a signifi cantly higher concentration of nanoparticles
were attached on bacteria under dark condition, causing higher mem-
brane damage. The toxicity was found to be treatment dose and duration
−
dependent. The difference in the mechanism of nanoparticle interaction
with bacterial in presence of light and in dark condition is schematically
represented in Figure 7.19 [92].
7.2.5.4 HA
−
based Magnetic Biocomposites
Hyperthermia therapy for cancer treatment with the use of magnetic bio-
materials can be a prospective treatment alternative. For the treatment of
bone tumor, the diseased tissue is surgically removed, and thus, bone graft
material is implanted in created bone defect region for treatment [93]. It is
reported that heat, produced by magnetic biomaterial, can be utilized for
treatment of cancer because magnetic scaffold will generate localized heat-
ing inside the tumor when exposed to magnetic fi eld [90]. Cancer cells are
reportedly killed in the temperature range of 43-46
C, whereas normal cells
remain unaffected at these temperatures [94]. Although implants with mag-
netic properties have been shown successful in treatment of the bone defect,
the cure of malignant bone tissue and the restoration of large bone defects
still present major clinical challenges [95]. A number of magnetic biomateri-
als, such as magnetic Ca/P
°
based materials, bioactive glass ceramics, fer-
rimagnetic calcium phosphate glass
−
100].
Ajeesh
et al.
reported the cytocompatibility and enhanced radiopacity of
different composites of magnetic iron oxide and HA. Here, the results were
compared between the HA
−
ceramics, are reported [95
−
−
based composites containing Fe
3
O
4
with that
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