3D printed glass-based biophotonic scaffolds for in situ activation of photoswitchable drugs

The fabrication of porous biophotonic scaffold using a robocasting is reported here. Such material could be used for in-situ activation of photoswitchable drugs, which is essential for improving therapeutic efficacy while minimizing side effects. The scaffold is made of a phosphate glass mixed with CaWO4:Yb3 +,Tm3 + crystals and SrAl2O4:Eu2+,Dy3 + phosphors. Upon 980 nm irradiation, the scaffold emits blue light and green afterglow, enabling in-situ activation post-implantation as NIR light penetrates tissue. The challenges related to the sintering process and its effect on the spectroscopic properties of the scaffold are discussed. The as-3D printed scaffold successfully enables one to activate the muscarinic photoswitchable drug Phthal Azobenzene Iperoxo (PAI) upon NIR excitation, confirming the potential for in-situ phototriggered delivery of drug action using tissue-permeable light stimulus.