23 research outputs found
Visualization of melanoma tumor with lectin-conjugated rare-earth doped fluoride nanocrystals
Aim To develop specific fluorescent markers for melanoma
tumor visualization, which would provide high selectivity
and reversible binding pattern, by the use of carbohydrate-
recognizing proteins, lectins, combined with the
physical ability for imaging deep in the living tissues by utilizing
red and near infrared fluorescent properties of specific
rare-earth doped nanocrystals (NC).
Methods B10F16 melanoma cells were inoculated to
C57BL/6 mice for inducing experimental melanoma tumor.
Tumors were removed and analyzed by lectin-histochemistry
using LABA, PFA, PNA, HPA, SNA, GNA, and
NPL lectins and stained with hematoxylin and eosin. NPL
lectin was conjugated to fluorescent NaGdF4:Eu3+-COOH
nanoparticles (5 nm) via zero length cross-linking reaction,
and the conjugates were purified from unbound substances
and then used for further visualization of histological
samples. Fluorescent microscopy was used to visualize
NPL-NaGdF4:Eu3+ with the fluorescent emission at 600-720
nm range.
Results NPL lectin selectively recognized regions of undifferentiated
melanoblasts surrounding neoangiogenic foci
inside melanoma tumor, PNA lectin recognized differentiated
melanoblasts, and LCA and WGA were bound to tumor
stroma regions. NPL-NaGdF4:Eu3+ conjugated NC were
efficiently detecting newly formed regions of melanoma
tumor, confirmed by fluorescent microscopy in visible and
near infrared mode. These conjugates possessed high photostability
and were compatible with convenient xylenebased
mounting systems and preserved intensive fluorescent
signal at samples storage for at least 6 months.
Conclusion NPL lectin-NaGdF4:Eu3+ conjugated NC permitted
distinct identification of contours of the melanoma
tissue on histological sections using red excitation at 590-
610 nm and near infrared emission of 700-720 nm. These
data are of potential practical significance for development
of glycans-conjugated nanoparticles to be used for in vivo
visualization of melanoma tumor
The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes
CdS Dots, Rods and Platelets—How to Obtain Predefined Shapes in a One-Pot Synthesis of Nanoparticles
In recent years, numerous protocols for nanoplatelet synthesis have been developed. Here, we present a facile, one-pot method for controlling cadmium sulfide (CdS) nanoparticles’ shape that allows for obtaining zero-dimensional, one-dimensional, or two-dimensional structures. The proposed synthesis protocol is a simple heating-up approach and does not involve any inconvenient steps such as injection and/or pouring the precursors at elevated temperatures. Because of this, the synthesis protocol is highly repeatable. A gradual increase in the zinc acetate concentration causes the particles’ shape to undergo a transition from isotropic quantum dots through rods to highly anisotropic nanoplatelets. We identified conditions at which synthesized platelets were purely five monolayers thick. All samples acquired during different stages of the reaction were characterized via optical spectroscopy, which allowed for the identification of the presence of high-temperature, magic-size clusters prior to the platelets’ formation
CdS Dots, Rods and Platelets—How to Obtain Predefined Shapes in a One-Pot Synthesis of Nanoparticles
In recent years, numerous protocols for nanoplatelet synthesis have been developed. Here, we present a facile, one-pot method for controlling cadmium sulfide (CdS) nanoparticles’ shape that allows for obtaining zero-dimensional, one-dimensional, or two-dimensional structures. The proposed synthesis protocol is a simple heating-up approach and does not involve any inconvenient steps such as injection and/or pouring the precursors at elevated temperatures. Because of this, the synthesis protocol is highly repeatable. A gradual increase in the zinc acetate concentration causes the particles’ shape to undergo a transition from isotropic quantum dots through rods to highly anisotropic nanoplatelets. We identified conditions at which synthesized platelets were purely five monolayers thick. All samples acquired during different stages of the reaction were characterized via optical spectroscopy, which allowed for the identification of the presence of high-temperature, magic-size clusters prior to the platelets’ formation
Correlation between matrix structural order and compressive stress exerted on silicon nanocrystals embedded in silicon-rich silicon oxide
International audienceSilicon nanocrystals embedded in a silicon oxide matrix were deposited by radio frequency reactive magnetron sputtering. By means of Raman spectroscopy, we have found that a compressive stress is exerted on the silicon nanocrystal cores. The stress varies as a function of silicon concentration in the silicon-rich silicon oxide layers varies, which can be attributed to changes of nanocrystal environment. By conducting the Fourier transform infrared absorption experiments, we have correlated the stresses exerted on the nanocrystal core to the degree of matrix structural order