Hybrid lanthanide-doped rattle-type thermometers for theranostics

Abstract

The development of top-down hybrid rattle-shaped thermometers based on Hollow Periodic Mesoporous Organosilica (HPMO) and either a β-NaYF₄ or a CaF₂ inorganic host is presented in this work. We show that these kinds of hybrid materials allow preparing efficiently emitting lanthanide-based nanothermometers for potential use for future in vivo applications, where the thermometer is excited in the near-infrared region and emits in the visible or near-infrared region, in which human tissue is most transparent. The Yb–Er upconversion system and the tri-doped Yb–Er–Tm thermometry system were both explored. The hybrid materials were shown to be non-toxic to normal human dermal fibroblasts tested as an example of healthy human cells. The HPMO material, and further the hybrid HPMO@NaYF₄:Er,Yb rattle structures, were also explored for drug loading and release ability using doxorubicin (DOX) as a model drug. This work shows that such HPMO-inorganic rattles can serve as a vehicle for drug delivery and release together with thermometry, potentially leading to a new generation of theranostic nanomaterials.