Bioresorbable Microdroplet Lasers as Injectable Systems for Transient Thermal Sensing and Modulation

Area of Science:

• Biomedical Engineering
• Materials Science
• Optics

Background:

• Minimally invasive temperature sensing and thermal modulation are crucial for biological research and clinical care.
• Bioelectronic devices face limitations; functional nanomaterials offer alternatives with remote sensing and injectability.
• Existing methods lack the integrated sensing and modulation capabilities demonstrated by novel nanomaterials.

Purpose of the Study:

• To introduce a transient, bioresorbable system for minimally invasive temperature sensing and thermal modulation in living tissues.
• To demonstrate the functionality of injectable microparticle lasers as both thermal sensors and distributed thermal modulation vehicles.
• To evaluate the biocompatibility and efficacy of these nanomaterials in biological applications.

Main Methods:

• Development of injectable slurries of microparticles self-assembled from cholesteric liquid crystals doped with fluorophores.
• Encapsulation of microparticle lasers in soft hydrogel shells with tunable bioresorption rates.
• Characterization of particle sensitivity, lasing threshold, size, and photothermal agent functionality.
• Ex vivo temperature measurements in Casper fish and cytotoxicity evaluations.

Main Results:

• Demonstrated injectable, bioresorbable microparticle lasers with temperature-sensitive emission wavelengths (>4-300 nm °C⁻¹).
• Achieved active temperature feedback (ΔT = 1 °C) and potential for remote thermal transport property evaluation.
• Confirmed biocompatibility through cytotoxicity assays and successful ex vivo temperature measurement in biological tissues with 0.01 °C resolution.

Conclusions:

• The developed system offers a novel, multifunctional platform for minimally invasive thermal sensing and modulation in biological applications.
• Injectable, bioresorbable microparticle lasers present a promising alternative to traditional bioelectronic devices.
• This technology holds potential for advancing remote sensing, targeted therapy, and thermal diagnostics in clinical and research settings.