1 research outputs found
Core/Shell Quantum Dots Encapsulated in Biocompatible Oil-Core Nanocarriers as Two-Photon Fluorescent Markers for Bioimaging
Highly fluorescent quantum dots (QDs)-loaded
nanocapsules, intended
for fluorescent cell imaging, were prepared via an emulsification/solvent-evaporation
method. CdSe/ZnS core/shell quantum dots were applied as cargo; Poloxamer
403 as the polymer component; Cremophor EL as the nonionic surfactant;
and mineral oil, oleic acid, or silicone oil were applied as the oil
phases. Transmission electron microscopy, atomic force microscopy,
dynamic light scattering, and zeta potential measurements were used
to characterize the novel QDs-labeled nanoparticles by particle size,
distribution, and morphology, as well as by ζ-potential and
physical stability. The fabricated long-lasting nanocapsules exhibit
good luminescence properties upon both one-photon and two-photon excitation.
The potential of the encapsulated QDs for fluorescent imaging was
evaluated in cytotoxicity studies as well as in imaging of intracellular
localization, accumulation, and distribution of QDs delivered to well-characterized
human cancer cell linesdoxorubicin-sensitive breast (MCF-7/WT)
and alveolar basal epithelial (A549)as well as on normal human
umbilical vein endothelial (HUVEC) cells, as investigated by confocal
laser scanning microscopy (CLSM). The colloidal CdSe/ZnS-loaded nanocapsules
are shown to exhibit strong two-photon-induced luminescence upon excitation
in the NIR optical transmission window spectral range, making them
ideal markers for bioimaging application. The total two-photon cross
section of a single nanocapsule was determined to be about 4.1 ×
10<sup>6</sup> GM at 800 nm