Biomedical Engineering Reference
In-Depth Information
Henderson et al. (2009)
report that ROS play a significant role in cellular systems, especially
with regard to physiological and pathological processes, and have been the focus of much
research interest (
Babior et al., 1973; Babior, 1984; Aitken et al., 2007; Brechard and
Tschirhart, 2008; Drose and Brandt 2008; Goud et al., 2008
). ROS are important for the
immune system (
De Ravin et al., 2008; Feld et al., 2008; Kang and Malech, 2009
).
Henderson et al. (2009)
show that during periods of oxidative stress, the levels of ROS
increase, and the increased ROS levels lead to negative effects. The tissues are unable to deal
effectively with this, and this leads subsequently to migraine, ischemic injury, and cardiovas-
cular disease (
Cross et al. 1987; Bindokas et al. 1996; Zulueta et al., 1997; Khalil and Khodr,
2001; Khodr and Khalil, 2001
).
Henderson et al. (2009)
report that analytical systems have
been developed to directly monitor ROS in real time (McNeil et al., 1989,
1992; Manning
et al., 1998; Scheller et al., 1999; McNeil and Manning, 2002; Chang et al., 2005a,b
).
They also report that
Clark et al. (1998)
had developed a nanosensor technology called
PEBBLE that was capable of detecting changes in the intracellular environment using a fluo-
rescent probe. The PEBBLE technology has been used to detect quite a few different analytes
(
Clark et al., 1999a,b; Summer et al., 2002; Xu et al., 2002
; Hammond et al., 2008). They
have recently used the commercially available fluorescent probe 123 DHR to monitor ROS
as indicated above. This probe was previously used to detect a number of analytes including
superoxide, hydrogen peroxide, and peroxynitrite (
Roesler et al., 1991; Henderson and
Chappell, 1993; Crow, 1997; Chang et al., 2005a
,b;
Goud et al., 2008; Qin et al., 2008
).
Henderson et al. (2009)
report that permeable dyes and particle-conjugated probes have been
used in the literature (
Henderson and Chappell, 1993; Jiang et al., 1997; Chang et al., 2005a,b;
Palazolo-Ballane et al., 2007
. They also report that fluorescent dyes encapsulated in PEBBLE
technology offer significant advantages over the conventional dyes used in intracellular
environments (
Clark et al., 1998; Webster et al., 2005
). A big advantage of PEBBLE tech-
nology, according to them, is that its inert matrix protects the intracellular environment,
and interactions between nonspecific interferents are minimized. This limits false positives
(
Summer et al., 2002
).
Webster et al. (2007)
have reviewed the different methods by which
PEBLE technology may be delivered into the intracellular environment.
Henderson et al.
(2009)
in their recent analysis have delivered the ROS sensitive PEBBLE technology into
macrophage cells through phagocytosis.
Henderson et al. (2009)
report that polyacrylamide PEBBLE nanosensors were synthesized
using a modified version of the method available in the literature (Clark et al., 1999;
Webster
et al., 2005; Coupland et al., 2008
). The PEBBLE nanosensor was calibrated using the gen-
eration of the ROS species got by the reaction of the substrate xanthine with the enzyme xan-
thine oxidase (XOD). With regard to PEBBLE delivery into the cellular environment, they
report that confocal microscopy was used to confirm that the NR8383 cell line used in the
study was able to internalize the ROS responsive PEBBLE technology through phagocytosis.
