Strategies to Prevent Bacterial Adhesion on Biomaterials - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 182

Bone defects

Hyperthermia &
Local-drug delivery therapy
kills infected tissue cells

Diseased bone
removed

Implanted
Fe-MBG scaffolds

Scaffolds degradation
bone regeneration

Malignant bone
disease

Remained infected
tissue cells

Fe-MBG scaffold
loaded with drug

Figure 7.21 Illustration for the potential applications of Fe MBG scaffolds with

multifunctional properties for the treatment of bone disease and the regeneration
of bone defects [95]. (Copyright (2013), with permission from Elsevier)

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the other two scaffolds, indicating the increased magnetic strength with
increased Fe content. Release of SiO 4 −4 in simulated body fl uid is not found
to be affected by the presence of Fe in MBG scaffold constituted by 80%
SiO 2 . These developed MBG

Fe scaffolds were found to be magnetic, bio-
active and biodegradable, and simultaneously maintained sustained drug
delivery. Therefore, they can be prospective materials for hyperthermia
therapy as well as local drug delivery applications [95]. A schematic of
treatment of bone disease and regereration is shown in Figure 7.21.
Lu et al. prepared the HA/MWCNTs composite with ferromagnetic
properties via an in situ process, where MWCNTs with mean diameter of
40

−

60 nm were used. It was reported that addition of CNTs to HA resulted
in weak ferromagnetic properties with the saturation magnetization,
remanent magnetization and coercivity values of 0.13 emu/g, 0.02 emu
and 354.55 Oe, respectively, at room temperature [103].
Bretcanu et al. synthesized glass ceramic with composition 24.7SiO 2 ,
13.5 Na 2 O, 13.5 CaO, 3.3 P 2 O 5 , 14 FeO and 31Fe 2 O 3 (wt%) by traditional
melting at 1400, 1450, 1500 and 1550

−

C. The sum of the iron oxides is 45
wt%. The melting of the above glass ceramic composite at higher tempera-
ture (1550

°

C) showed the formation of magnetite. The saturation magneti-
zation varies from 18.6 to 31.5 emu/g, while the coercive fi eld varies from
35 to 180 Oe [104]. Ebisawa et al. reported the bioactivity of 36 wt% Fe 3 O 4
incorporated in CaO

°

like apatite crystal
formation in simulated body fl uid showed the in vitro bioactivity of these
ferromagnetic glass ceramics [105].

− SiO 2 − based glass ceramic. Bone −

7.2.6 Infl uence of External Field on Bacterial Adhesion and
Biofi lm Growth

It has now been widely recognized that an immuno −

inflammatory zone is created after any device implantation in the body,
providing a favorable environment for bacterial proliferation which results
in biomaterial

− incompetent, fibro

associated infection [106]. With the use of external fi eld,
this problem of infection can be solved to some extent as shown below.

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