18 research outputs found
Identification of PHB2 as a Potential Biomarker of Luminal A Breast Cancer Cells Using a Cell-Specific Aptamer
Precise
diagnosis of breast cancer molecular subtypes remains a
great challenge in clinics. The present molecular biomarkers are not
specific enough to classify breast cancer subtypes precisely, which
requests for more accurate and specific molecular biomarkers to be
discovered. Aptamers evolved by the cell-systematic evolution of ligands
by exponential enrichment (SELEX) method show great potential in the
discovery and identification of cell membrane targets via aptamer-based
cell membrane protein pull-down, which has been regarded as a novel
and powerful weapon for the discovery and identification of new molecular
biomarkers. Herein, a cell membrane protein PHB2 was identified as
a potential molecular biomarker specifically expressed in the cell
membranes of MCF-7 breast cancer cells using a DNA aptamer MF3Ec.
Further experiments demonstrated that the PHB2 protein is differentially
expressed in the cell membranes of MCF-7, SK-BR-3, and MDA-MB-231
breast cancer cells and MCF-10A cells, and the binding molecular domains
of aptamer MF3Ec and anti-PHB2 antibodies to the PHB2 protein are
different due to there being no obvious competitions between aptamer
MF3Ec and anti-PHB2 antibodies in the binding to the cell membranes
of target MCF-7 cells. Due to those four cells belonging to luminal
A, HER2-positive, and triple-negative breast cancer cell subtypes
and human normal mammary epithelial cells, respectively, the PHB2
protein in the cell membrane may be a potential biomarker for precise
diagnosis of the luminal A breast cancer cell subtype, which is endowed
with the ability to differentiate the luminal A breast cancer cell
subtype from HER2-positive and triple-negative breast cancer cell
subtypes and human normal mammary epithelial cells, providing a new
molecular biomarker and therapeutic target for the accurate and precise
classification and diagnostics and personalized therapy of breast
cancer
Chemiluminescent Labels Released from Long Spacer Arm-Functionalized Magnetic Particles: A Novel Strategy for Ultrasensitive and Highly Selective Detection of Pathogen Infections
Previously, the unique advantages
provided by chemiluminescence
(CL) and magnetic particles (MPs) have resulted in the development
of many useful nucleic acid detection methods. CL is highly sensitive,
but when applied to MPs, its intensity is limited by the inner filter-like
effect arising from excess dark MPs. Herein, we describe a modified
strategy whereby CL labels are released from MPs to eliminate this
negative effect. This approach relies on (1) the magnetic capture
of target molecules on long spacer arm-functionalized magnetic particles
(LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase
(SA-AP) to biotinylated amplicons of target pathogens, (3) the release
of CL labels (specifically, AP tags), and (4) the detection of the
released labels. CL labels were released from LSA-MPs through LSA
ultrasonication or DNA enzymolysis, which proved to be the superior
method. In contrast to conventional MPs, LSA-MPs exhibited significantly
improved CL detection, because of the introduction of LSA, which was
made of water-soluble carboxymethylated β-1,3-glucan. Detection
of hepatitis B virus with this technique revealed a low detection
limit of 50 fM, high selectivity, and excellent reproducibility. Thus,
this approach may hold great potential for early stage clinical diagnosis
of infectious diseases
Multifunctional Yolk–Shell Mesoporous Silica Obtained via Selectively Etching the Shell: A Therapeutic Nanoplatform for Cancer Therapy
Herein,
we fabricated a new yolk–shell-structured mesoporous silica
nanoparticle (YMSN) with multifunctionalities of fluorescence imaging,
photothermal therapy (PTT), and drug delivery by using a fluorescein
isothiocyanate-doped silica nanoparticle partially covered by patchy
gold as the core. Different from the conventional selective etching
procedure, the multifunctional silica core is left intact, and the
alkali etching mainly occurs in a hexadecyl trimethyl ammonium bromide/silica
hybrid layer, which leads to the formation of the void space in YMSNs.
In addition, the utilization of patchy gold as the PTT agent can avoid
the shield against the outer irradiation on the core. Results show
that the as-prepared YMSNs have a good biocompatibility in the concentration
of 0–1000 μg·mL<sup>–1</sup> and a high doxorubicin-loading
capability (8.04 wt %). In vitro and in vivo antitumor experiments
reveal that the resulting YMSNs can be utilized for chemo- and photothermic
combination therapy as well as optical imaging
Action of Gold Nanospikes-Based Nanoradiosensitizers: Cellular Internalization, Radiotherapy, and Autophagy
A major challenge
to achieve effective X-ray radiation therapy
is to use a relatively low and safe radiation dose. Various radiosensitizers,
which can significantly enhance the radiotherapeutic performance,
have been developed. Gold-based nanomaterials, as a new type of nanoparticle-based
radiosensitizers, have been extensively used in researches involving
cancer radiotherapy. However, the cancer therapeutic effect using
the gold nanoparticle-based radiotherapy is usually not significant
because of the low cellular uptake efficiency and the autophagy-inducing
ability of these gold nanomaterials. Herein, using gold nanospikes
(GNSs) as an example, we prepared a series of thiol-polyÂ(ethylene
glycol)-modified GNSs terminated with methoxyl (GNSs), amine (NH<sub>2</sub>-GNSs), folic acid (FA) (FA-GNSs), and the cell-penetrating
peptide TAT (TAT-GNSs), and evaluated their effects on X-ray radiotherapy.
For the in vitro study, it was found that the ionizing radiation effects
of these GNSs were well correlated with their cellular uptake amounts,
with the same order of GNSs < NH<sub>2</sub>-GNSs < FA-GNSs
< TAT-GNSs. The sensitization enhancement ratio (SER), which is
commonly used to evaluate how effectively radiosensitizers decrease
cell proliferation, reaches 2.30 for TAT-GNSs. The extremely high
SER value for TAT-GNSs indicates the superior radiosensitization effect
of this nanomaterial. The radiation enhancement mechanisms of these
GNSs involved the increased reactive oxygen species (ROS), mitochondrial
depolarization, and cell cycle redistribution. Western blotting assays
confirmed that the surface-modified GNSs could induce the up-regulation
of autophagy-related protein (LC3-II) and apoptosis-related protein
(active caspase-3) in cancer cells. By monitoring the degradation
of the autophagy substrate p62 protein, GNSs caused impairment of
autolysosome degradation capacity and autophagosome accumulation.
Our data demonstrated that autophagy played a protective role against
caner radiotherapy, and the inhibition of protective autophagy with
inhibitors would result in the increase of cell apoptosis. Besides
the above in vitro experiments, the in vivo tumor growth study also
indicated that X-ray + TAT-GNSs treatment had the best tumor growth
inhibitory effect, which confirmed the highest radiation sensitizing
effect of TAT-GNSs. This work furthered our understanding on the interaction
mechanism between gold nanomaterials and cancer cells and should be
able to promote the development of nanoradiosensitizers for clinical
applications
Selection of HBsAg-Specific DNA Aptamers Based on Carboxylated Magnetic Nanoparticles and Their Application in the Rapid and Simple Detection of Hepatitis B Virus Infection
Aptamers
are short single-stranded DNA or RNA oligonucleotides and can be selected
from synthetic combinatorial libraries in vitro. They have a high
binding affinity and specificity for their targets. Agarose gels,
nitrocellulose membranes, and adsorptive microplates are often used
as carriers to immobilize targets in the SELEX (systematic evolution
of ligands by exponential enrichment) process, but the subsequent
separation step is tedious and time-consuming. Therefore, we used
magnetic nanoparticles (MNPs) as carriers to immobilize the target,
hepatitis B surface antigen (HBsAg), which is convenient for fast
magnetic separation. In this study, we first selected DNA aptamers
against HBsAg by immobilizing HBsAg on the surface of carboxylated
MNPs. The ssDNA library of each selection round was prepared by asymmetric
PCR amplification for the next selection round. To obtain aptamer
sequences, the final selected products were purified by gel electrophoresis,
then cloned, and sequenced. DNA aptamers that specifically bind to
HBsAg were successfully obtained after 13 selection rounds. The selected
aptamers were used to construct a chemiluminescence aptasensor based
on magnetic separation and immunoassay to detect HBsAg from pure protein
or actual serum samples. There was a linear relationship between HBsAg
concentration and chemiluminescent intensity in the range of 1–200
ng/mL. The aptasensor worked well even in the presence of interfering
substances and was highly specific in the detection of HBsAg in serum
samples, with a detection limit 0.1 ng/mL lower than the 0.5 ng/mL
limit of an ELISA in use at the hospital. This aptasensor can contribute
to better detection of hepatitis B virus infection
Effective Integration of Targeted Tumor Imaging and Therapy Using Functionalized InP QDs with VEGFR2 Monoclonal Antibody and miR-92a Inhibitor
Rapid
diagnosis and targeted drug treatment require agents that possess
multiple functions. Nanomaterials that facilitate optical imaging
and direct drug delivery have shown great promise for effective cancer
treatment. In this study, we first modified near-infrared fluorescent
indium phosphide quantum dots (InP QDs) with a vascular endothelial
growth factor receptor 2 (VEGFR2) monoclonal antibody to afford targeted
drug delivery function. Then, a miR-92a inhibitor, an antisense microRNA
that enhances the expression of tumor suppressor p63, was attached
to the VEGFR2–InP QDs via electrostatic interactions. The functionalized
InP nanocomposite (IMAN) selectively targets tumor sites and allows
for infrared imaging in vivo. We further explored the mechanism of
this active targeting. The IMAN was endocytosed and delivered in the
form of microvesicles via VEGFR2–CD63 signaling. Moreover,
the IMAN induced apoptosis of human myelogenous leukemia cells through
the p63 pathway in vitro and in vivo. These results indicate that
the IMAN may provide a new and promising chemotherapy strategy against
cancer cells, particularly by its active targeting function and utility
in noninvasive three-dimensional tumor imaging
Coating Carbon Nanosphere with Patchy Gold for Production of Highly Efficient Photothermal Agent
Gold-
or carbon-based photothermal therapy (PTT) agents have shown encouraging
therapeutic effects of PTT in the near-infrared region (NIR) in many
preclinical animal experiments. It is expected that gold/carbon hybrid
nanomaterial will possess combinational NIR light absorption and
can achieve further improvement in photothermal conversion efficiency.
In this work, we design and construct a novel PTT agent by coating
a carbon nanosphere with patchy gold. To synthesize this composite
particle with Janus structure, a new versatile approach based on a
facile adsorption–reduction method was presented. Different
from the conventional fabrication procedures, the formation of patchy
gold in this approach is mainly a thermodynamics-driven spontaneous
process. The results show that when compared with the conventional
PTT agent gold nanorod the obtained nanocomposites not only have higher
photothermal conversion efficiency but also perform more thermally
stable. On the basis of these outstanding photothermal effects, the
in vitro and in vivo photothermal performances in a MCF-7 cells (human
breast adenocarcinoma cell line) and mice were investigated separately.
Additionally, to further illustrate the advantage of this asymmetric
structure, their potential was explored by selective surface functionalization,
taking advantage of the affinity of both patchy gold and carbon domain
to different functional molecules. These results suggest that this
new hybrid nanomaterial can be used as an effective PTT agent for
cancer treatment in the future
Efficient and Facile Synthesis of Gold Nanorods with Finely Tunable Plasmonic Peaks from Visible to Near-IR Range
Although
gold nanorods (GNRs) have been prepared with a wide range
of methods for their uses as novel diagnostic and therapeutic agents,
the synthesis of monodispersed GNRs with high yields and size tunability
still requires further improvements. We report on a simple one-pot
method for preparing highly monodispersed GNRs using phenols (e.g.,
hydroquinone, 1,2,3-trihydroxybenzene, and 1,2,4-trihydroxybenzene)
as the reducing agent and NaBH<sub>4</sub> as the initiating reactant.
Fine-tuning of the LSPR peak position of phenols-reduced GNRs from
550 to 1150 nm is accomplished by regulating the silver ion concentrations.
The size of GNRs produced via phenols reduction can also be controlled
by changing the NaBH<sub>4</sub> concentration. By systematically
optimizing the concentrations of the reagents involved in the one-pot
synthesis of GNRs, the yield (in many cases exceeding 90%) is significantly
higher than that prepared with the commonly used reductant (e.g.,
ascorbic acid). The improved efficiency and controllability cut down
the cost and time involved in GNRs production
Intrinsic, Cancer Cell-Selective Toxicity of Organic Photothermal Nanoagent: A Simple Formulation for Combined Photothermal Chemotherapy of Cancer
Nano-agent-mediated
photothermal therapy (PTT) combined with chemotherapy
has been proposed as an effective strategy against cancer. However,
chemotherapeutic agents often cause serious side effects. Herein,
a novel PTT nanoagent (Cy5.5–MSA–G250) with unanticipated
intrinsic tumor-selective cytotoxicity is developed. The Cy5.5–MSA–G250
nanoparticles (NPs) are created by mixing mouse serum albumin (MSA)
and coomassie brilliant blue (G250) and then conjugated with cyanine
5.5 (Cy5.5). As expected, Cy5.5–MSA–G250 NPs can efficiently
kill cancer cells in vitro and in vivo by PTT. Meanwhile, we accidentally
discover that Cy5.5–MSA–G250 have intrinsic specific
cytotoxicity against tumor cells but not against normal cells. Moreover,
the tumor-specific cytotoxicity of Cy5.5–MSA–G250 is
much stronger than that of cytarabine, an FDA-approved anticancer
drug. In vivo experiments also prove that Cy5.5–MSA–G250
NPs can effectively eliminate residual tumor cells and prevent metastasis.
Further study indicates that selective induction of G1 cell cycle
arrest and inhibition of DNA duplication in tumor cells may be the
possible mechanism of the tumor cell-selective cytotoxicity of Cy5.5–MSA–G250
NPs. In addition, direct visualization, low systematic toxicity, good
biodegradation, and efficient body excretion further make Cy5.5–MSA–G250
NPs attractive for in vivo applications. Taken together, Cy5.5–MSA–G250
NPs are proven to be a promising platform for combined photothermal
chemotherapy
Influence factors evaluation to Combined Paternity Index (CPI) based on real sample sequencing data.
<p>(A) The number of effective SNPs and the logarithm of CPI did not relate with the fetal fraction when fetal fraction over 10%. (B) There was no obvious correlation between Paternity Index of each effective SNPs and fetal fraction. (C) The logarithm of CPI had a significant positive correlation with effective sequencing depth, while the number of effective SNPs did not relate with effective sequencing depth. (D) The logarithm of PI had a positive correlation with the effective sequencing depth.</p