Qualitative comparison between different biopolymers for usage in two-photon polymerization towards liver regeneration

Abstract

Femtosecond laser-based two-photon polymerization is becoming increasingly popular in biofabrication. One of the key selling points of the technology is the possibility to use a variety of different materials to produce biology-oriented structures, for instance, liver cell regeneration. These include hybrid materials, lithographic resins, and hydrogels to name a few. However, while these materials are investigated separately, there is a severe lack of studies dedicated to directly comparing them in terms of structurability. Therefore, in this work, popular pre-polymers such as SZ2080, SU8, and GelMA are compared side by side in this manner. They are photosensitized using photoinitiators Irgacure 369, Irgacure 2959, and LAP. Structurability is tested using two different popular wavelengths - 800 nm and 515 nm. Acquired differences are subsequently partially explained by two-photon absorption measurement, giving insights into the efficiency of the photopolymerization process. Finally, biocompatibility is compared showing surprisingly small differences between all the tested materials.