Natural and Naturally Derived Photoinitiating Systems for Light-Based 3D Printing

Photoinitiating systems (PISs) are key components in photoc- urable formulations (inks) for three-dimensional (3D) printing. Natural PISs are promising and more environmentally friendly alternatives to conventional photoinitiators. These systems offer enhanced features such as less toxicity and therefore, higher biocompatibility. Further- more, they can be found in a large “ color palette ” variety (absorbing in the different regions of the UV-visible spectrum) enabling new possibil- ities in the field of 3Dprinting. In this review, we outline the current efforts to implement natural and naturally derived PISs in light-based 3Dprinting. First, recently applied natural PISs and their performance for light-based 3Dprinting are discussed. In a second part, an overview of naturally derived PISs including the most common synthetic strategies are provided. Last, current challenges as well as future perspec- tives of the field are discussed.