3 research outputs found
Colorimetric Peroxidase Mimetic Assay for Uranyl Detection in Sea Water
Uranyl (UO<sub>2</sub><sup>2+</sup>) is a form of uranium in aqueous
solution that represents the greatest risk to human health because
of its bioavailability. Different sensing techniques have been used
with very sensitive detection limits especially the recently reported
uranyl-specific DNAzymes systems. However, to the best of our knowledge,
few efficient detection methods have been reported for uranyl sensing
in seawater. Herein, gold nanoclusters (AuNCs) are employed in an
efficient spectroscopic method to detect uranyl ion (UO<sub>2</sub><sup>2+</sup>) with a detection limit of 1.86 ÎĽM. In the absence
of UO<sub>2</sub><sup>2+</sup>, the BSA-stabilized AuNCs (BSA-AuNCs)
showed an intrinsic peroxidase-like activity. In the presence of UO<sub>2</sub><sup>2+</sup>, this activity can be efficiently restrained.
The preliminary quenching mechanism and selectivity of UO<sub>2</sub><sup>2+</sup> was also investigated and compared with other ions.
This design strategy could be useful in understanding the binding
affinity of protein-stabilized AuNCs to UO<sub>2</sub><sup>2+</sup> and consequently prompt the recycling of UO<sub>2</sub><sup>2+</sup> from seawater
Hybrid Iron Oxide–Graphene Oxide–Polysaccharides Microcapsule: A Micro-Matryoshka for On-Demand Drug Release and Antitumor Therapy In Vivo
Premature
drug release is a common drawback in stimuli-responsive drug delivery
systems (DDS), especially if it depends on internal triggers, which
are hard to control, or a single external stimulus, which can only
have one function. Thus, many DDS systems have been reported that
combined different triggers; however, limited success has been established
in fine-tuning the release process, mainly due to the poor bioavailability
and complexity of the reported designs. This paper reports the design
of a hybrid microcapsule (h-MC) by a simple layer-by-layer technique
comprising polysaccharides (sodium alginate, chitosan, and hyaluronic
acid), iron oxide, and graphene oxide (GO). Electrostatic assembly
of the oppositely charged polysaccharides and graphene sheets provided
a robust structure in which to load drugs through pH control. The
polysaccharide component ensured high biocompatibility, bioavailability,
and tumor cells targeting. The alternative magnetic field and near-infrared
laser triggerable Fe<sub>3</sub>O<sub>4</sub>@GO component provided
for dual high-energy and high-penetration hyperthermia therapy. On-demand
drug release from h-MC can be achieved by synchronizing these external
triggers, making the release highly controllable. The synergistic
effect of hyperthermia and chemotherapy was successfully confirmed
in vitro and in vivo
Impact of Pore–Walls Ligand Assembly on the Biodegradation of Mesoporous Organosilica Nanoparticles for Controlled Drug Delivery
Porous materials with molecular-scale
ordering have attracted major
attention mainly because of the possibility to engineer their pores
for selective applications. Periodic mesoporous organosilica is a
class of hybrid materials where self-assembly of the organic linkers
provides a crystal-like pore wall. However, unlike metal coordination,
specific geometries cannot be predicted because of the competitive
and dynamic nature of noncovalent interactions. Herein, we study the
influence of competing noncovalent interactions in the pore walls
on the biodegradation of organosilica frameworks for drug delivery
application. These results support the importance of studying self-assembly
patterns in hybrid frameworks to better engineer the next generation
of dynamic or “soft” porous materials