6 research outputs found
Fluorescence-Magnetism Functional EuS Nanocrystals with Controllable Morphologies for Dual Bioimaging
Multiple
functions incorporated in one single component material
offer important applications in biosystems. Here we prepared a divalent
state of rare earth EuS nanocrystals (NCs), which provides luminescent
and magnetic properties, using both 1-Dodecanethiol (DT) and oleylamine
(OLA) as reducing agents. The resultant EuS NCs exhibit controllable
shapes, uniform size, and bright luminescence with a quantum yield
as high as 3.5%. OLA as a surface ligand plays an important role in
tunable morphologies, such as nanowires, nanorods, nanospheres et
al. Another attractive nature of the EuS NCs is their paramagnetism
at room temperature. In order to expand the biological applications,
the resultant EuS NCs were modified with amphiphilic block copolymer
F127 and transferred from oil to water phase. The excellent biocompatibility
of EuS NCs is demonstrated as well as preservation of their luminescence
and paramagnetic properties. The EuS NCs offer multifunction and great
advantages of bright luminescence, paramagnetic, controllable morphologies,
and good biocompatibility promising applications in the field of simultaneous
magnetic resonance and fluorescence bioimaging
Nanoparticle Counting by Microscopic Digital Detection: Selective Quantitative Analysis of Exosomes via Surface-Anchored Nucleic Acid Amplification
Exosomes
are nanosized vesicles secreted by cells, with a lipid
bilayer membrane and protein and nucleic acid contents. Here, we present
the first method for the selective and quantitative analysis of exosomes
by digital detection integrated with nucleic acid-based amplification
in a microchip. An external biocompatible anchor molecule conjugated
with DNA oligonucleotides was anchored in the lipid bilayer membrane
of exosomes via surface self-assembly for total exosome analysis.
Then, specific antibody–DNA conjugates were applied to label
selective exosomes among the total exosomes. The DNA-anchored exosomes
were distributed into microchip chambers with one or fewer exosomes
per chamber. The signal from the DNA on the exosomes was amplified
by a rapid isothermal nucleic acid detection assay. A chamber with
an exosome exhibited a positive signal and was recorded as 1, while
a chamber without an exosome presented a negative signal and was recorded
as 0. The 10100101 digital signals give the number of positive chambers.
According to the Poisson distribution, the exosome stock concentration
was calculated by the observed fraction of positive chambers. The
findings showed that nanoscale particles can be digitally detected
via DNA-mediated signal amplification in a microchip with simple microscopic
settings. This approach can be integrated with multiple types of established
nucleic acid assays and provides a versatile platform for the quantitative
detection of various nanosomes, from extracellular vesicles such as
exosomes and enveloped viruses to inorganic and organic nanoparticles,
and it is expected to have broad applications in basic research areas
as well as disease diagnosis and therapy
Self-Sterilizing and Regeneratable Microchip for the Precise Capture and Recovery of Viable Circulating Tumor Cells from Patients with Cancer
Cancer
cells metastasize and are transported in the bloodstream, easily reaching
any site in the body through the blood circulation. A method designed
to assess the number of circulating tumor cells (CTCs) should be validated
as a clinical tool for predicting the response to therapy and monitoring
the disease progression in patients with cancer. Although CTCs are
detectable in many cases, they remain unavailable for clinic usage
because of their high testing cost, tedious operation, and poor clinical
relevance. Herein, we developed a regeneratable microchip for isolating
CTCs, which is available for robust cell heterogeneity assays on-site
without the need for a sterile environment. The ivy-like hierarchical
roughened zinc oxide (ZnO) nanograss interface was synthesized and
directly integrated into the microfluidic devices and enables effective
CTC capture and flexible, nontoxic CTC release during incubation in
a mildly acidic solution, thus enabling cellular and molecular analyses.
The microchip can be regenerated and recycled to capture CTCs with
the remaining ZnO without affecting the efficiency, even after countless
cycles of cell release. Moreover, microbial infection is avoided during
its storage, distribution, and even in the open space usage, which
ideally appeals to the demands of point-of-care (POC) and home testing
and meets to the requirements for blood examinations in undeveloped
or resource-limited settings. Furthermore, the findings generated
using this platform based on the cocktail of antiepithelial cell adhesion
molecule and antivimentin antibodies indicate that CTC capture was
more precise and reasonable for patients with advanced cancer
Self-Sterilizing and Regeneratable Microchip for the Precise Capture and Recovery of Viable Circulating Tumor Cells from Patients with Cancer
Cancer
cells metastasize and are transported in the bloodstream, easily reaching
any site in the body through the blood circulation. A method designed
to assess the number of circulating tumor cells (CTCs) should be validated
as a clinical tool for predicting the response to therapy and monitoring
the disease progression in patients with cancer. Although CTCs are
detectable in many cases, they remain unavailable for clinic usage
because of their high testing cost, tedious operation, and poor clinical
relevance. Herein, we developed a regeneratable microchip for isolating
CTCs, which is available for robust cell heterogeneity assays on-site
without the need for a sterile environment. The ivy-like hierarchical
roughened zinc oxide (ZnO) nanograss interface was synthesized and
directly integrated into the microfluidic devices and enables effective
CTC capture and flexible, nontoxic CTC release during incubation in
a mildly acidic solution, thus enabling cellular and molecular analyses.
The microchip can be regenerated and recycled to capture CTCs with
the remaining ZnO without affecting the efficiency, even after countless
cycles of cell release. Moreover, microbial infection is avoided during
its storage, distribution, and even in the open space usage, which
ideally appeals to the demands of point-of-care (POC) and home testing
and meets to the requirements for blood examinations in undeveloped
or resource-limited settings. Furthermore, the findings generated
using this platform based on the cocktail of antiepithelial cell adhesion
molecule and antivimentin antibodies indicate that CTC capture was
more precise and reasonable for patients with advanced cancer
Self-Sterilizing and Regeneratable Microchip for the Precise Capture and Recovery of Viable Circulating Tumor Cells from Patients with Cancer
Cancer
cells metastasize and are transported in the bloodstream, easily reaching
any site in the body through the blood circulation. A method designed
to assess the number of circulating tumor cells (CTCs) should be validated
as a clinical tool for predicting the response to therapy and monitoring
the disease progression in patients with cancer. Although CTCs are
detectable in many cases, they remain unavailable for clinic usage
because of their high testing cost, tedious operation, and poor clinical
relevance. Herein, we developed a regeneratable microchip for isolating
CTCs, which is available for robust cell heterogeneity assays on-site
without the need for a sterile environment. The ivy-like hierarchical
roughened zinc oxide (ZnO) nanograss interface was synthesized and
directly integrated into the microfluidic devices and enables effective
CTC capture and flexible, nontoxic CTC release during incubation in
a mildly acidic solution, thus enabling cellular and molecular analyses.
The microchip can be regenerated and recycled to capture CTCs with
the remaining ZnO without affecting the efficiency, even after countless
cycles of cell release. Moreover, microbial infection is avoided during
its storage, distribution, and even in the open space usage, which
ideally appeals to the demands of point-of-care (POC) and home testing
and meets to the requirements for blood examinations in undeveloped
or resource-limited settings. Furthermore, the findings generated
using this platform based on the cocktail of antiepithelial cell adhesion
molecule and antivimentin antibodies indicate that CTC capture was
more precise and reasonable for patients with advanced cancer
Prevention of Cyanobacterial Blooms Using Nanosilica: A Biomineralization-Inspired Strategy
Cyanobacterial
blooms represent a significant threat to global
water resources because blooming cyanobacteria deplete oxygen and
release cyanotoxins, which cause the mass death of aquatic organisms.
In nature, a large biomass volume of cyanobacteria is a precondition
for a bloom, and the cyanobacteria buoyancy is a key parameter for
inducing the dense accumulation of cells on the water surface. Therefore,
blooms will likely be curtailed if buoyancy is inhibited. Inspired
by diatoms with naturally generated silica shells, we found that silica
nanoparticles can be spontaneously incorporated onto cyanobacteria
in the presence of polyÂ(diallyldimethylammonium chloride), a cationic
polyelectrolyte that can simulate biosilicification proteins. The
resulting cyanobacteria-SiO<sub>2</sub> complexes can remain sedimentary
in water. This strategy significantly inhibited the photoautotrophic
growth of the cyanobacteria and decreased their biomass accumulation,
which could effectively suppress harmful bloom events. Consequently,
several of the adverse consequences of cyanobacteria blooms in water
bodies, including oxygen consumption and microcystin release, were
significantly alleviated. Based on the above results, we propose that
the silica nanoparticle treatment has the potential for use as an
efficient strategy for preventing cyanobacteria blooms