Barium yttrium fluoride based upconversion nanoparticles as dual mode image contrast agents.

Area of Science:

• Materials Science
• Nanotechnology
• Bioimaging

Background:

• Dual-labeled contrast agents offer complementary information for bioimaging.
• Upconversion nanoparticles (UCNPs) are being explored for advanced imaging applications.

Purpose of the Study:

• To investigate Yb³⁺ and Er³⁺-doped BaYF₅ UCNPs as dual-modal contrast agents for optical and X-ray micro computed tomography (μCT).

Main Methods:

• Hydrothermal synthesis of UCNPs with polyethyleneimine (PEI) for aqueous dispersion.
• Characterization using transmission electron microscopy (TEM) and zeta potential measurements.
• In vitro toxicity assessment (MTT assay) and optical/X-ray imaging.

Main Results:

• Synthesized UCNPs with controlled morphology (truncated cuboidal/octahedral), average size of 47±9 nm.
• +51 mV zeta potential indicating good cell permeability; PEI layer aids protein attachment.
• Intense green upconversion photoluminescence and effective X-ray contrast confirmed dual-modality potential.

Conclusions:

• Yb³⁺ and Er³⁺-doped BaYF₅ UCNPs are suitable for dual-modal bioimaging.
• PEI-coated UCNPs demonstrate good biocompatibility, cell permeability, and targeting potential.
• These UCNPs represent a promising platform for advanced diagnostic imaging.