Details

Autor(en) / Beteiligte

• Rizzo, Riccardo
• Petelinšek, Nika
• Bonato, Angela
• Zenobi‐Wong, Marcy

Titel

From Free‐Radical to Radical‐Free: A Paradigm Shift in Light‐Mediated Biofabrication

Ist Teil von

• Advanced science, 2023-03, Vol.10 (8), p.e2205302-n/a

Ort / Verlag

Germany: John Wiley & Sons, Inc

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• In recent years, the development of novel photocrosslinking strategies and photoactivatable materials has stimulated widespread use of light‐mediated biofabrication techniques. However, despite great progress toward more efficient and biocompatible photochemical strategies, current photoresins still rely on photoinitiators (PIs) producing radical‐initiating species to trigger the so‐called free‐radical crosslinking/polymerization. In the context of bioprinting, where cells are encapsulated in the bioink, the presence of radicals raises concerns of potential cytotoxicity. In this work, a universal, radical‐free (RF) photocrosslinking strategy to be used for light‐based technologies is presented. Leveraging RF uncaging mechanisms and Michael addition, cell‐laden constructs are photocrosslinked by means of one‐ and two‐photon excitation with high biocompatibility. A hydrophilic coumarin‐based group is used to cage a universal RF photocrosslinker based on 4‐arm‐PEG‐thiol (PEG4SH). Upon light exposure, thiols are uncaged and react with an alkene counterpart to form a hydrogel. RF photocrosslinker is shown to be highly stable, enabling potential for off‐the‐shelf products. While PI‐based systems cause a strong upregulation of reactive oxygen species (ROS)‐associated genes, ROS are not detected in RF photoresins. Finally, optimized RF photoresin is successfully exploited for high resolution two‐photon stereolithography (2P‐SL) using remarkably low polymer concentration (<1.5%), paving the way for a shift toward radical‐free light‐based bioprinting. Photoinitiators producing radicals are commonly used to trigger free‐radical crosslinking, raising concerns of potential cytotoxicity. Here, a universal, radical‐free (RF) photocrosslinking strategy is presented. Leveraging RF uncaging and Michael‐addition, cell‐laden constructs are generated by means of one‐ and two‐photon irradiation. With high biocompatibility and negligible reactive oxygen species (ROS), RF‐crosslinking ushers in a new era for light‐mediated bioprinting.