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. • Preparing porous bioactive scaffolds successfully with codoped up-conversion crystals and persistent luminescent phosphors. • Reporting for the first time green light afterglow NIR charged from biophotonic scaffolds. • Demonstrating photoisomeration of PAI molecule induced by biophotonic scaffolds under 980 nm, for in-situ drug delivery systems. • Challenges related to the sintering process on the upconversion properties of the scaffold are discussed