Femtosecond laser-made 3D micro-chainmail scaffolds towards regenerative medicine

Regenerative medicine is a rapidly developing field with far-reaching potential. To sustain progress in this field, new advanced structures are needed. These include scaffolds for cell growth. Direct laser writing (DLW) based on femtosecond laser multi-photon polymerization (MPP) was shown to be an attractive technology for such structure fabrication as it combines vast selection of materials and the possibility to choose feature size in scaffold to be smaller, bigger, or around the same size as a cell. At the same, there are issues related to throughput which limit the widespread implementation of MPP for scaffold manufacturing. It is further compounded by some material limitations making it difficult to print mechanically flexible scaffolds for soft tissue regeneration. In this paper, we propose printing mechanically flexible scaffolds out of mechanically rigid material SZ2080 by employing chainmail architecture. We explore capabilities to optimize the printing procedure of this kind of scaffold, achieving printing times of less than 10 min for a 1 × 1 mm scaffold while maintaining micro-level precision. The superb biocompatibility of such scaffolds is shown both qualitatively and quantitatively and is proven to be independent of the used photoinitiator. Finally, manipulations of scaffolds with cells are performed with no adverse impact on the cell viability or proliferation after such procedures. Overall, this work proposes a methodology for rapid printing of shape-shifting scaffolds which could be used in regenerative medicine both for cell cultivation and potential direct implantation into soft tissue.