Biomedical Engineering Reference
In-Depth Information
8.3.5 Neural, Mesothelial, and Other Cells
Mesothelial cells (MSTO) are more sensitive to ferric oxide and cerium
oxide nanoparticles than fibroblasts (3T3), while the cytotoxicity of zinc
oxide nanoparticles are not different between those two cell types [23].
Unmodified quantum dots increased both extracellular calcium influx and
internal calcium release from endoplasmic reticulum and caused cell death
in rat primary hippocampal neurons [24]. TiO
2
nanoparticles caused intra-
cellular formation of ROS in mouse neuronal and glial cells, whereas expo-
sure to carbon black and superparamagnetic Fe
2
O
3
nanoparticles induced
no significant changes in free radical levels [25]. Silver nanoparticles were
more cytotoxic than molybdenum nanoparticles, and nanoparticulates were
more cytotoxic than the corresponding soluble salts in mouse spermatogo-
nial stem cell line for identical concentrations [26].
8.4 Nanomaterial-Based Approach
Nanomaterials are categorized into several groups according to their chemi-
cal properties. The most important category is a group of carbon substances
such as fullerenes, single-walled carbon nanotubes and MWCNTs, carbon
black, and silicon carbide. Other groups of industrial or manufactured nano-
materials are metals such as nanosilver, nanogold, and nanoplatinum; metal
oxides such as titanium dioxide, silicon dioxide, and zinc oxide; ceramics
such as nanoclay; and organic substances such as dendrimers. Several lines
of evidence indicate that the acute toxicity of nanoparticles linearly correlates
to the surface area and a classic mass-based dose (mg mL
-1
or mg cm
-2
) may
not be an appropriate metric for nanoparticles [27,28]. It should also be noted
that the adverse effects of pure silica zeolites largely depend on the aspect
ratio (length vs. width) and the external surface area [27]. It was established
that the cytotoxicity of silica particles of different sizes and shapes could be
estimated by the following relation:
-ln(1 -
y
) =
ktm
(8.3)
where
y
= cell growth inhibition rate (0 ≤
y
≤ 1,
y
= 1, when
m
has no effect)
k
= constant
t
= time of culture with dusts
m
= dust property (surface area, aspect ratio, radical release, length, etc.)
The high correlation coefficient was obtained in the relation between cyto-
toxicity and external surface area (
r
= 0.953) or aspect ratio (
r
= 0.909). The
