Beam-shaping enhanced two-photon polymerization: towards 3D medical printing

Two-photon polymerization (2PP) based 3D printing is a well-established technique. However, for the vast majority of its existence, 2PP was realized by applying general-purpose setups that were not tailored to any specific field. This resulted in limitations regarding how much 2PP can proliferate in any one particular area. Therefore, in this work, we will explore what can be achieved if a 2PP setup is built from the ground up for usage in one specific field – biomedical 3D printing. To achieve it a special femtosecond (fs) laser-based setup is assembled with integrated dynamic beam-shaping. Removal of zero order maximum in such an optical setup is demonstrated, and main related peculiarities are discussed. Then the beam-shaping is used to elongate voxels allowing to improve manufacturing throughput by more than two orders of magnitude. We then used the setup and developed voxel elongation methodology to produce biology-oriented structures, such as stents, grafts, and organoid scaffolds. We show excellent biocompatibility and cell growth on the later structures. Overall, the presented results show how focusing on 2PP system design to accommodate one particular field, in this case, biomedicine, helps to exploit the system’s capabilities beyond what general purpose 2PP setup could achieve.