4 research outputs found
Phoenix
A novel chiral coordination polymer, [CuÂ(C<sub>6</sub>H<sub>5</sub>CHÂ(OH)ÂCOO)Â(ÎĽ-C<sub>6</sub>H<sub>5</sub>CHÂ(OH)ÂCOO)]
(<b>1</b>-L and <b>1</b>-D), was synthesized through a
reaction of copper
acetate with l-mandelic acid at room temperature. Although
previously reported copper mandelate prepared by hydrothermal reaction
was a centrosymmetric coordination polymer because of the racemization
of mandelic acid, the current coordination polymer shows noncentrosymmetry
and a completely different structure from that previously reported.
The X-ray crystallography for <b>1</b>-L revealed that the copper
center of the compound showed a highly distorted octahedral structure
bridged by a chiral mandelate ligand in the unusual coordination mode
to construct a one-dimensional (1D) zigzag chain structure. These
1D chains interdigitated each other to give a layered structure as
a result of the formation of multiple aromatic interactions and hydrogen
bonds between hydroxyl and carboxylate moieties at mandelate ligands.
The coordination polymer <b>1</b>-L belongs to the noncentrosymmetric
space group of C2 to show piezoelectric properties and second harmonic
generation (SHG) activity
Theranostic Nanoparticles for MRI-Guided Thermochemotherapy: “Tight” Clustering of Magnetic Nanoparticles Boosts Relaxivity and Heat-Generation Power
Magnetic-resonance-imaging
(MRI)-guided magnetic thermochemotherapy is a potentially invasive
technique combining diagnosis and treatment. It requires the development
of multifunctional nanoparticles with (1) biocompatibility, (2) high
relaxivity, (3) high heat-generation power, (4) controlled drug release,
and (5) tumor targeting. Here, we show the synthesis of such multifunctional
nanoparticles (“Core–Shells”) and the feasibility
of MRI-guided magnetic thermochemotherapy using the synthesized nanoparticles. “Tight”
iron-oxide nanoparticle clustering to zero interparticle distance
within the Core–Shells boosts the relaxivity and heat-generation
power while maintaining biocompatibility. The initial Core–Shell
drug release occurs in response to an alternating magnetic field (AMF)
and continues gradually after removal of the AMF. Thus, a single Core–Shell
dose realizes continuous chemotherapy over a period of days or weeks.
The Core–Shells accumulate in abdomen tumors, facilitating
MRI visualization. Subsequent AMF application induces heat generation
and drug release within the tumors, inhibiting their growth. Core–Shell
magnetic thermochemotherapy exhibits significantly higher therapeutic
efficacy than both magnetic hyperthermia and chemotherapy alone. More
importantly, there are minimal side effects. The findings of this
study introduce new perspectives regarding the development of materials
for MRI, magnetic hyperthermia, and drug delivery systems. Both conventional
and novel iron-oxide-based materials may render theranostics (i.e.,
techniques fusing diagnosis and treatment) feasible
Organic–Inorganic Hybrid Nanoparticles for Tracking the Same Cells Seamlessly at the Cellular, Tissue, and Whole Body Levels
Techniques
to elucidate the kinetics and distribution of the same
cells in the whole body and in tissues are necessary for further studies
of cancer, immunity, and regenerative medicine. Fluorescent imaging
is a powerful technique for visualization of cells. However, current
fluorescent probes are applicable in either the ultraviolet (UV)–visible
(Vis) region (300–650 nm) or the biological transparency window
(BTW, 650–900 nm), but not both. Thus, they cannot serve as
fluorescent probes for both in vivo and in vitro imaging, and it is
difficult to achieve imaging of the same cells seamlessly from the
cellular level to the whole body and tissue levels using currently
available fluorescent probes. Accordingly, in this paper, we describe
organic–inorganic hybrid nanoparticles (HNPs) that could be
used to achieve seamless tracking of the same cells. Within the HNPs,
a porphyrin molecule, Vis-fluorophore, was surrounded by a siloxane
chain, preventing the aggregation of porphyrin molecules. As a result,
the porphyrin fluorescence was not quenched. Furthermore, indocyanine
green (ICG), a BTW fluorophore, was localized on the HNP surface,
leading to fluorescence resonance energy transfer (FRET) from porphyrin
to ICG only near the HNP surface. Through the above structural design,
the HNPs acquired both excitation (λ<sub>ex</sub>) and emission
(λ<sub>em</sub>) wavelengths in the visible region and BTW,
respectively, as well as large Stokes shifts. The HNP-labeled immune
cells successfully and the labeled cells were separated easily from
unlabeled cells by fluorescence-activated cell sorting. The kinetics
of the labeled cells in the whole body were revealed by fluorescence
imaging within BTW. Furthermore, the distributions of the same labeled
cells were elucidated by histological analysis within the UV–vis
region. Thus, the HNPs served as fluorescent probes for seamless tracking
of the same cells
Red Blood Cell-Shaped Microparticles with a Red Blood Cell Membrane Demonstrate Prolonged Circulation Time in Blood
Prolonging
the circulation time (CT) of microparticles (MPs) in
the blood is key for a successful microparticle-based medicinal approach
to serve as drug delivery systems (DDSs). Previously, we reported
that MPs that mimic the shape of red blood cells (RBCs) avoid accumulation
in the spleen and lungs. We now describe the effectiveness of mimicking
not only the shape of RBCs but also their surface structure for the
prolongation of CT. RBC-shaped MPs (RBC-MPs) were electrosprayed with
cellulose and covered with a native RBC membrane (RBCM) collected
from mouse blood. Seven hours after intravenous injection, approximately
twice as many RBCM-covered RBC-MPs (RBC-MPs@RBCM) were present in
the blood of mice compared to unmodified RBC-MPs. Twenty-four hours
postinjection, the concentration of RBC-MPs@RBCM in the blood was
4 times higher. These findings suggest that an RBCM covering the MPs
contributed to significant CT prolongation, which may positively impact
their applications as DDSs