Phosphate glass-based microstructured optical fibers with hole and core for biomedical applications

Bioresorbable phosphate glasses are an excellent alternative to conventional silicate-based glass systems for biomedical applications. These glasses can have tailorable bioresorbability and mechanical properties, a wide range of transparency windows (from 300 to 2600 nm), and are of great interest for biophotonic devices. The present work investigates the feasibility of fabricating a microstructured bioresorbable optical fiber combined with a microfluidic channel. Extrusion and stack-and-draw techniques are used to manufacture the microstructured optical fiber capable of guiding light and liquid simultaneously. An optimized extrusion procedure allowed fabricating preforms with the lowest bending and tapering possible. The preform was drawn to 130 and 230 μm diameter fibers. Light guide and attenuation loss were characterized, and the microfluidic channel was tested for liquid delivery. The proposed approach demonstrates the vast potentiality of such microstructured fiber that could be used as a theranostics device to be employed in specific areas inside the body without needing a removal procedure.