Enhanced up/down-conversion luminescence and heat: Simultaneously achieving in one single core-shell structure for...

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Near-infrared (NIR) light offers advantages for bio-imaging and photothermal therapy (PTT).
• Concentration quenching in Nd(3+)-doped materials hinders simultaneous optimization of down-conversion luminescence (DCL) and thermal effects.
• Developing single-particle systems with dual NIR-responsive properties is challenging.

Purpose of the Study:

• To design and synthesize a core-shell nanoparticle capable of simultaneous NIR-to-NIR DCL, NIR-to-Vis up-conversion luminescence (UCL), and photothermal effect.
• To overcome concentration quenching issues for enhanced DCL and thermal properties.
• To develop an imaging-guided cancer therapy platform combining photothermal therapy (PTT) and photodynamic therapy (PDT).

Main Methods:

• Fabrication of a unique NaGdF4:0.3%Nd@NaGdF4@NaGdF4:10%Yb/1%Er@NaGdF4:10%Yb @NaNdF4:10%Yb multiple core-shell structure.
• Utilizing inert layers to mitigate quenching effects and enhance luminescence and thermal properties.
• Integrating Au25 nanoclusters for PDT activation via UCL, and employing NIR DCL for deep-tissue imaging.

Main Results:

• Achieved significantly enhanced NIR-to-NIR DCL, NIR-to-Vis UCL, and photothermal effect under a single 808 nm light excitation.
• Demonstrated effective synergistic cancer inhibition in vitro and in vivo through combined PTT and PDT.
• Successfully performed multimodal imaging (fluorescence imaging, photothermal imaging, photoacoustic imaging) for monitoring therapy and drug delivery.

Conclusions:

• The designed core-shell nanoparticle effectively overcomes concentration quenching, enabling simultaneous DCL, UCL, and PTT.
• The platform shows great potential for imaging-guided synergistic cancer therapy.
• This approach offers a promising strategy for advanced theranostic applications in oncology.