Development of a Hybrid NIR-II Thermometer Suitable for Drug Release

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Accurate temperature monitoring is crucial for diagnosing conditions like cancer and inflammation, as localized thermal variations are key indicators.
• The second biological window (NIR-II, 1000-1700 nm) is advantageous for deep tissue imaging due to reduced light scattering and absorption by biological tissues.
• Neodymium (Nd³⁺) and Ytterbium (Yb³⁺) doped materials offer efficient energy transfer under 808 nm excitation, producing emissions in the NIR-II range.

Purpose of the Study:

• To develop a novel hybrid thermometer for temperature sensing and imaging within the NIR-II biological window.
• To investigate the potential of these hybrid thermometers for theranostic applications, including drug delivery.

Main Methods:

• Fabrication of a hybrid thermometer using a silica core and a periodic mesoporous organosilica (PMO) shell.
• Decoration of the PMO shell with LiLuF₄:Nd³⁺, Yb³⁺ nanoparticles for luminescence-based temperature sensing.
• Loading the hybrid nanostructures with doxorubicin to evaluate drug release capabilities.

Main Results:

• The hybrid thermometer successfully enabled temperature sensing and imaging in the NIR-II spectral region.
• The material demonstrated efficient luminescence properties suitable for deep tissue penetration.
• The hybrid nanostructures showed potential for controlled drug release when loaded with doxorubicin.

Conclusions:

• The developed hybrid thermometer offers a promising platform for non-invasive temperature monitoring and deep tissue imaging in the NIR-II window.
• These findings highlight the potential of the Nd³⁺-Yb³⁺ system in hybrid nanostructures for theranostic applications, combining diagnostics with targeted therapy.