Optimized photoinitiator for fast two-photon absorption polymerization of polyester-macromers for tissue engineering

The efficiency of two-photon polymerization (TPP) techniques depends on the photoinitiator (PI) systems. Objective of this study was to enhance the performance of a cyclopentanone-based PI by introducing polar side chains in order to increase the solubility of the PI in the investigated macromonomers urethanedimethacrylate (UDMA) and lactide-caprolactone-methacrylate (LCM). The conditions for TPP were investigated in writing power/speed arrays. To confirm the high reactivity of the new PI a maximum speed experiment at a concentration of 2% was performed and a TPP structure in the dimensions of several centimeters could be written, which to our knowledge has not yet been reported elsewhere.