Strategies to allow the in vivo monitoring of aerogels after their implantation are currently under research. Different nanocomplexes have been designed for this purpose but the stability and the biocompatibility of the final system are still important concerns. Upconversion nanoparticles (UCNPs) have excellent luminescent and optical properties to trace aerogels in vivo.

In this work, highly luminescent UCNPs were synthesized by a novel approach combining co-precipitation and sol-gel methods and were then incorporated into 3D-printed aerogels. Fluorescence and stability properties of the UCNPs-decorated aerogels were studied as part of the physicochemical characterization. Different in vitro and in vivo tests were also performed to study the long-term biocompatibility of the 3D-printed aerogel scaffolds. The resulting UCNPs-decorated implants were biocompatible and able to promote cell adhesion and migration. Also, in vivo monitoring capability of aerogels after their subcutaneous implantation was first-time demonstrated for three weeks.

The work entitled “3D-printed aerogels as theranostic implants monitored by fluorescence bioimaging” has been published in the Bioactive Materials journal (IF: 18, August 2024). This work is the result of a collaboration between the University of Lisbon, the University of Coimbra and the AerogelsLab.