High-quality water-soluble quantum dots had been synthesized following the one-step method. Furtherly, the impact factors on the optical properties of quantum dots, which were the feed ratio of S/In and the reflux time, had been concerned emphatically. By changing the reaction parameters, we made the fluorescence emission of ZnInAgS quantum dot tunable from green to orange, and the maximum fluorescence quantum efficiency was up to 30%. Then we modified bovine serum albumin (BSA) on the surface of ZnInAgS quantum dot, which was conjugated with BSA-QDs through the linker of 3'3-dimercapto-diacetate DOX. Finally, the reduction-sensitive drug delivery system based on ZnInAgS quantum dots (QBSSD) was successfully constructed. The resultant QBSSD complex were observed to be significantly stable in aqueous solution. In addition, owing to their cellular reduction responsiveness at the cleavable disulfide linker, the QBSSD complex were able to release DOX rapidly. In vitro drug release and cell level release experiments proved that our QBSSD complexes could make a quick drug release in the environment with GSH. The efficacy experiments showed that our QBSSD complexes exhibited a strong killing effect to cancer cells, and low toxic to normal cells. All the results indicated that the reduction-sensitive drug delivery system was a promising model of administration.
KEYWORDS: Tumors, Near infrared, Luminescence, In vivo imaging, In vitro testing, Receptors, Confocal microscopy, Optical properties, Rhodamine B, Microscopy
Cell adhesion molecule integrin αvβ3 is an excellent target for tumor interventions because of its unique
expression on the surface of several types of solid tumor cells and on almost all sprouting tumor vasculatures. In this
manuscript, we describe the synthesis of near-infrared (NIR) fluorochrome ICG-Der-02-labeled dimeric cyclic RGD
peptides (ICG-Der-02-c(RGDyK)2) for in vivo tumor integrin targeting. The optical properties and structure of the probe
were intensively characterized. Afterwards, the integrin specificity of the fluorescent probe was tested in vitro for
receptor binding assay and fluorescence microscopy and in vivo for subcutaneous MDA-MB-231 and U87MG tumor
targeting. The results indicated that after labeling RGD peptide, the optical properties of ICG-Der-02 showed no obvious
change. Besides, in vitro and in vivo tumor targeting experiment indicated that the ICG-Der-02-c(RGDyK)2 probe with
high integrin affinity showed excellent tumor activity accumulation. Noninvasive NIR fluorescence imaging is able to
detect tumor integrin expression based upon the highly potent RGD peptide probe.
Signal transducer and activator of transcription (STAT) 5b is an important protein in JAK-STAT signal pathway and is
responsible for the metastasis and proliferation of tumor cells. The determination of the STAT5b expression provides a
way to study the mechanism of tumor progress. In this study, gold nanoparticles with different diameters were
conjugated to the fluorescein modified STAT5b specific DNA sequence to form the beacon. The procedures for the
beacon with better fluorescence properties were optimized. The fluorescence quenching and the recovery properties after
hybridizing with mRNA of STAT5b were intensively investigated. Results indicate the gold nanoparticle based beacon
is an effective probe for the determination of STAT5b protein expression in JAK-STAT signal pathway and has great
potential in the study of drug screening and discovery.
CdHgTe/SiO2 nanoparticles were prepared by SiO2 capping on the surface of CdHgTe quantum dots
(QDs). The characteristics, such as optical spectra, size and optical stability were investigated. The size
of CdHgTe/SiO2 nanoparticles could be larger than 100 nm after CdHgTe QDs capped with SiO2.
CdHgTe/SiO2 nanoparticles acted as a novel fluorescence probe have a maximum fluorescence
emission of 790 nm and a full width at half-maximum (FWHM) of 50-70 nm. The in vivo fluorescence
imaging of CdHgTe/SiO2 nanoparticles in mouse model indicated the nanoparticles could be passively
targeting to lung and liver. CdHgTe/SiO2 nanoparticles offer new perspectives for size dependent
bio-dstribution studies in living body.
In this paper, we report a new facile method for the synthesis of water-soluble PbS quantum dots (QDs), using
dihydrolipoic acid (DHLA) as a stabilizer. The prepared QDs were characterized by optical techniques and
high-resolution transmission electron microscopy (TEM). Next, these water-soluble luminescent PbS QDs were further
used to detect copper (II). The obtained experimental results show that the fluorescence of the PbS QDs could be
markedly quenched by Cu(II) whereas approximate concentrations of other physiologically relevant cations, such as
Zn(II), Ca(II), Mg(II), Mn(II), Na(I) and K(I) etc., almost did not interfere with the fluorescence quenching progress of
copper ions. Based on this, a simple and rapid method for Cu(II) determination was developed. Under optimal conditions,
the response was linearly proportional to the copper(II) concentration in the range of 1 to 11.5x10-8 mol•L-1, with a correlation coefficient of 0.995. Hence, aqueous DHLA-stabilized PbS QDs may be a promising fluorescent probe in
sensing copper(II) selectively.
In this report, we synthesized multifunctional dye-doped mesoporous silica nanoparticles(MSNs) by encapsulating
near-infrared dyes into the nanoparticles. In order to enhance the targeting property, the surface was modified with amino
group for further conjugation of targeted ligands. In addition, we explored the influence of the synthetic temperature on
the particle morphology. The optical properties, morphology and structure of the as-prepared dye-doped silica
nanoparticles were characterized. Results indicated the dye-doped silica nanoparticles can be used as a good probe for
early tumor diagnosis and have the potential to serve as a targeted carrier for antitumor drugs.
KEYWORDS: Tumors, Near infrared, In vivo imaging, Tissues, Nanoparticles, Luminescence, System on a chip, Cancer, Magnetic resonance imaging, Imaging systems
The development of more selective delivery systems for cancer diagnosis and chemotherapy is one of the most
important goals of current anticancer research. The purpose of this study is to construct and evaluate the folate-decorated,
self-assembled nanoparticles as candidates to deliver near infrared fluorescent dyes into tumors and to investigate the
mechanisms underlying the tumor targeting with folate-decorated, self-assembled nanoparticles. Folate-decorated
N-succinyl-N'-octyl chitosan (folate-SOC) were synthesized. The chemical modification chitosan could self-assemble
into stable micelles in aqueous medium. Micelle size determined by size analysis was around 140 nm in a
phosphate-buffered saline (PBS, PH 7.4). Folate-SOC could maintain their structure for up to 15 days in PBS. Near
infrared dye ICG-Der-01 as a mode drug was loaded in the micelles, and the entrapment efficiency (EE) and drug
loading (DL) were investigated. The targeted behavior of folate-SOC was evaluated by near-infrared fluorescence
imaging in vivo on different groups of denuded mice, with A549 or Bel-7402 tumors. The optical imaging results
indicated that folated-decorated SOC showed an excellent tumor specificity in Bel-7402 tumor-bearing mice, and weak
tumor specificity in A549 tumor bearing mice. We believe that this work can provide insight for the engineering of
nanoparticles and be extended to cancer therapy and diagnosis so as to deliver multiple therapeutic agents and imaging
probes at high local concentrations.
In this paper, we present a new facile and environmental friendly method to prepare water-soluble
near-infrared (NIR)-emitting PbS quantum dots (QDs) at room temperature under ambient conditions, using
dihydrolipoic acid (DHLA) as a stabilizer. The photoluminescence (PL) emissions of the prepared DHLA-capped
PbS QDs are tunable between 870 and 1010 nm. A PL quantum yield (QY) of ~10% can be achieved under
optimized conditions without any post-preparative treatment. Here, we further use the produced DHLA-capped PbS
QDs for NIR fluorescence imaging in a mouse model. The obtained experimental results showed that the NIR
fluorescence of the PbS QDs in living tissues generated from the excitation with semiconductor laser (λmax=765.9
nm) could penetrate living tissues and be detected easily by the noninvasive in vivo NIR fluorescence imaging
system. In addition, the preliminary studies on the cytotoxicity and in vivo toxicity of the QDs also indicates fully
that these water-soluble DHLA-capped PbS QDs are very lowly toxic, and as such they should have greater
potential in biological and medical applications especially in noninvasive in vivo fluorescence imaging of mice,
compared to other existing highly toxic aqueous NIR-emitting quantum dots (CdTe, HgTe, etc).
Near-infrared (NIR) fluorescence imaging possesses many advantages as an in vivo non-invasive optical
imaging modality for studying diseases in preclinical models. In this study, low density lipoprotein(LDL)
fraction was quickly isolated from human plasma by modified heparin-citrate precipitation method and then
conjugated to near infrared fluorescence dye ICG-Der-02 with excitation and emission wavelengths at
760nm and 830nm, respectively. The conjugates LDL-ICG-Der-02 were intravenously injected into the
mice bearing different tumor models. And real time series fluorescence tumor images at different intervals
of post-injection were in vivo acquired by a self-built NIR reflectance fluorescence imaging system.
Results demonstrated that LDL-ICG-Der-02 conjugates could efficiently target to the tumor sites that
over-expressed LDL receptors and could be completely eliminated at last.
In this paper, we investigated carefully the influence of the added L-cysteine on the stability of
mercaptopropionic acid (MPA)-stabilized CdTe nanoparticles (NPs). Transmission electron microscopy (TEM) imaging
revealed that the addition of pH ~11.5 L-cysteine solution could reduce the stability of MPA-capped CdTe NPs, which
resulted in the formation of sheet-shaped nanostructures finally after about seven days of storage in darkness under
ambient conditions. The typical size of these resulting nanosheets was ~6 μm in length, ~1 μm in width and ~50 nm in
thickness. The high-resolution TEM characterization and elemental analysis from energy-dispersed X-ray (EDX)
spectrum indicated that these resulting sheets were made from well-crystallized nanopartilces (~4 nm) of CdS rather than
CdTe. In addition, XRD analysis and optical microscopy also supported further these experimental observations. Hence,
here, the post addition of L-cysteine induced the spontaneous transition and concomitant self-assembly of
MPA-stabilized CdTe nanoparticles into luminescent CdS nanosheets.
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