3 research outputs found
High Order Gap Modes of Film-Coupled Nanospheres
Tailoring
coupled plasmonic structures is an alternative way to
obtain new optical properties of plasmonic materials. Recently, film-coupled
nanoparticle systems with high stability and controllability have
been used to probe the ultimate limits of field enhancement/confinement
and near-field interaction with other quantum emitters. When the gap
between particles and films is below a few nanometers, induced high
order (HO) gap modes become significant. In this report, we investigate
these HO modes associated with the system of a gold nanosphere positioned
above a gold film, separated by a nanometer-scale spacer layer. The
shift in far-field scattering profile under different excitation conditions
and collection wavelengths indicates the influence of HO modes, and
the results are compared to the corresponding simulations. In addition,
the far-field scattering spectra/patterns by multipole expansion and
the near-field distributions by FEM, both calculated with the dielectric
function of the low damping factor, are utilized to resolve the individual
HO modes. These findings not only identify the HO gap modes but also
clarify their excitation conditions and far-field/near-field scattered
field distribution. The effect of HO modes should be taken into account
when the interaction between the gap field and quantum emitters nearby
is investigated for active plasmonic devices
Glycol Chitosan Engineered Autoregenerative Antioxidant Significantly Attenuates Pathological Damages in Models of Age-Related Macular Degeneration
Age-related
macular degeneration (AMD) is the foremost cause of
irreversible blindness in people over the age of 65 especially in
developing countries. Therefore, an exploration of effective and alternative
therapeutic interventions is an unmet medical need. It has been established
that oxidative stress plays a key role in the pathogenesis of AMD,
and hence, neutralizing oxidative stress is an effective therapeutic
strategy for treatment of this serious disorder. Owing to autoregenerative
properties, nanoceria has been widely used as a nonenzymatic antioxidant
in the treatment of oxidative stress related disorders. Yet, its potential
clinical implementation has been greatly hampered by its poor water
solubility and lack of reliable tracking methodologies/processes and
hence poor absorption, distribution, and targeted delivery. The water
solubility and surface engineering of a drug with biocompatible motifs
are fundamental to pharmaceutical products and precision medicine.
Here, we report an engineered water-soluble, biocompatible, trackable
nanoceria with enriched antioxidant activity to scavenge intracellular
reactive oxygen species (ROS). Experimental studies with <i>in
vitro</i> and <i>in vivo</i> models demonstrated that
this antioxidant is autoregenerative and more active in inhibiting
laser-induced choroidal neovascularization by decreasing ROS-induced
pro-angiogenic vascular endothelial growth factor (VEGF) expression,
cumulative oxidative damage, and recruitment of endothelial precursor
cells without exhibiting any toxicity. This advanced formulation may
offer a superior therapeutic effect to deal with oxidative stress
induced pathogeneses, such as AMD
Glycol Chitosan Engineered Autoregenerative Antioxidant Significantly Attenuates Pathological Damages in Models of Age-Related Macular Degeneration
Age-related
macular degeneration (AMD) is the foremost cause of
irreversible blindness in people over the age of 65 especially in
developing countries. Therefore, an exploration of effective and alternative
therapeutic interventions is an unmet medical need. It has been established
that oxidative stress plays a key role in the pathogenesis of AMD,
and hence, neutralizing oxidative stress is an effective therapeutic
strategy for treatment of this serious disorder. Owing to autoregenerative
properties, nanoceria has been widely used as a nonenzymatic antioxidant
in the treatment of oxidative stress related disorders. Yet, its potential
clinical implementation has been greatly hampered by its poor water
solubility and lack of reliable tracking methodologies/processes and
hence poor absorption, distribution, and targeted delivery. The water
solubility and surface engineering of a drug with biocompatible motifs
are fundamental to pharmaceutical products and precision medicine.
Here, we report an engineered water-soluble, biocompatible, trackable
nanoceria with enriched antioxidant activity to scavenge intracellular
reactive oxygen species (ROS). Experimental studies with <i>in
vitro</i> and <i>in vivo</i> models demonstrated that
this antioxidant is autoregenerative and more active in inhibiting
laser-induced choroidal neovascularization by decreasing ROS-induced
pro-angiogenic vascular endothelial growth factor (VEGF) expression,
cumulative oxidative damage, and recruitment of endothelial precursor
cells without exhibiting any toxicity. This advanced formulation may
offer a superior therapeutic effect to deal with oxidative stress
induced pathogeneses, such as AMD