378
N. Ashwin Kumar et al.
Fig. 24 Schematic representation PNBL conjugated NBs synthesis and its application in vivo
ultrasound imaging. Nanobubbles (a) and Microfluidic based on-chip development of nanobubbles
and compared with microbubbles and mixed population (b). Adapted from reference [270]
were imaged with 5 MHz US probe periodically at 10, 20, 30, 120, 180, and 300 s
provided good contrast enhancement. Microfluidic chips are MEMS-based devices
with micron channels flows with gas and surfactant to form nanobubbles. Micro
spray flow in one channel and lipids are injected through in another channel at the
pressure set at 15 psi and aqueous flow rate of 90 μL min
−1 by Peyman and his
coworkers [270]. Aorta of the mouse was imaged between 28 and 40 MHz HIFU for
pre-clinical imaging applications. The contrast enhancement of NBs shows better
spatial resolution compared to microbubbles in preclinical imaging, as shown in
Fig. 24. Nanodroplets were generated by rapid vaporization and condensation of
perfluorocarbon as core loaded with optical sensitive NIR dye with lipid shells. These
nanodroplets injected via retro-orbital were demonstrated through US by imaging
the brain undergone craniotomy. Upon exposure of laser, more than 60 min observed
blinking effect from nanodroplets. The transient state of the microbubble to nanobubbles obtain high contrast with reflected waves via the super-resolution technique
[271].
9 Nanomaterials for Optical Imaging
In recent years, optical imaging has become a powerful technique for in vivo and
in vitro biomedical imaging [272, 273]. Different methodologies based on varying
light-tissue interactions have been presented for a wide range of applications in
the past decade. The benefits associated with optical imaging include increased
sensitivity, absence of exposure to ionizing radiation, cost-effectiveness, improved
spatial resolution, real-time acquisition [274, 275]. Notwithstanding, the fundamental
impediment associated with optical imaging include light scattering, (auto-) fluorescence and absorption (in the range 400 nm–650 nm) from the nearby tissues. To
overcome the limitations mentioned above focus of near-infrared (NIR), fluorescence imaging has been done in two NIR windows from 650 to 950 nm (NIR I) and
1000 to 1350 nm (NIR II) [276].
Nanoparticles (NP’s) are the new class of contrast agents in size ranging from
1 through 100 nm and has shown promising approach for non-invasive biomedical
N. Ashwin Kumar et al.
Fig. 24 Schematic representation PNBL conjugated NBs synthesis and its application in vivo
ultrasound imaging. Nanobubbles (a) and Microfluidic based on-chip development of nanobubbles
and compared with microbubbles and mixed population (b). Adapted from reference [270]
were imaged with 5 MHz US probe periodically at 10, 20, 30, 120, 180, and 300 s
provided good contrast enhancement. Microfluidic chips are MEMS-based devices
with micron channels flows with gas and surfactant to form nanobubbles. Micro
spray flow in one channel and lipids are injected through in another channel at the
pressure set at 15 psi and aqueous flow rate of 90 μL min
−1 by Peyman and his
coworkers [270]. Aorta of the mouse was imaged between 28 and 40 MHz HIFU for
pre-clinical imaging applications. The contrast enhancement of NBs shows better
spatial resolution compared to microbubbles in preclinical imaging, as shown in
Fig. 24. Nanodroplets were generated by rapid vaporization and condensation of
perfluorocarbon as core loaded with optical sensitive NIR dye with lipid shells. These
nanodroplets injected via retro-orbital were demonstrated through US by imaging
the brain undergone craniotomy. Upon exposure of laser, more than 60 min observed
blinking effect from nanodroplets. The transient state of the microbubble to nanobubbles obtain high contrast with reflected waves via the super-resolution technique
[271].
9 Nanomaterials for Optical Imaging
In recent years, optical imaging has become a powerful technique for in vivo and
in vitro biomedical imaging [272, 273]. Different methodologies based on varying
light-tissue interactions have been presented for a wide range of applications in
the past decade. The benefits associated with optical imaging include increased
sensitivity, absence of exposure to ionizing radiation, cost-effectiveness, improved
spatial resolution, real-time acquisition [274, 275]. Notwithstanding, the fundamental
impediment associated with optical imaging include light scattering, (auto-) fluorescence and absorption (in the range 400 nm–650 nm) from the nearby tissues. To
overcome the limitations mentioned above focus of near-infrared (NIR), fluorescence imaging has been done in two NIR windows from 650 to 950 nm (NIR I) and
1000 to 1350 nm (NIR II) [276].
Nanoparticles (NP’s) are the new class of contrast agents in size ranging from
1 through 100 nm and has shown promising approach for non-invasive biomedical