Organic light-emitting diodes (OLEDs) have been integrated with various extracorporeal and in implantable devices to sense or stimulate specific cellular responses. However, one of the current challenges remains to design a transient OLED that functions effectively and completely dissolves inside human body when no longer needed, without affecting homeostasis. We note that a single report on a biodegradable inorganic LED was found, though the emission is very weak with a broad emission spectrum [1].
Here, we report on the fabrication and optimization of the first biocompatible and transient OLEDs, using chitosan as a substrate, intended to be used in the in-situ detection of doxorubicin (DOXO) via its fluorescence, in the context of the RESORB project. The OLED is intended to be integrated in a compact self-powered device, to be implanted and which, at the end, would undergo degradation upon demand.
Various OLED structures were fabricated and characterized. The ability to detect the DOXO on various substrates by measuring its fluorescence after directly exciting it with OLEDs will be presented. In vitro assays showed that all layers break down under physiological settings and the biocompatibility was confirmed by in vivo tests. Chitosan-based OLED represents a breakthrough in transient electronics and advances implantable light-based biomedical applications.


Acknowledgements: This work was funded by the European Union Horizon Europe programme under grant agreement Nº 101046946 (RESORB). We also acknowledge funding by FCT/MECI through national funds and when applicable co-funded EU funds under UID/50008:Instituto de Telecomunicações (FP,MM, LM and JM) , iBB (UIDB/04565/2020 and UIDP/04565/2020) and Associate Laboratory i4HB (LA/P/0140/2020) (FCF).




Reference:
[1] D. Lu, et al., “Transient Light‐Emitting Diodes Constructed from Semiconductors and Transparent Conductors that Biodegrade Under Physiological Conditions”, Adv. Mater. 2019, 31, 1902739.