Towards poly(D,L-lactic acid)-based biodegradable and biocompatible polymer optical fiber

We demonstrate a biodegradable and biocompatible unclad optical fiber made from poly(D,L-lactic acid) (PDLLA), which is a well-known and commercially available amorphous polyester. We first deal with the chemical and optical characterization of the bulk polymer material and we report on the influence of the processing on the molecular weight and thermal properties of the polymer, during both the preform preparation and the fiber drawing process. We then proceed to the optical characterization based on spectral attenuation measurements using the cutback method and dispersion measurements. We also determine the thermo-optic coefficient. Finally, we confirm the in vitro degradation in phosphate buffered saline (PBS) of our PDLLA fibers. From the results and considering that PDLLA is an FDA-regulated material, we anticipate that our optical fibers are valid candidates for medical applications involving in vivo light delivery, such as for example photodynamic therapy.