Enzyme-Lignin Nanocapsules Are Sustainable Catalysts and Vehicles for the Preparation of Unique Polyvalent Bioinks.

Reactive lignin nanocapsules catalyze a pigmentation reaction to furnish an innovative type of sustainable polyvalent bioink. In this nanodevice, the pigment, vehicle, binder, and additive are included in a single confined spherical space. Bioinks with different shades of color, black, gray, yellow-like, pink-like, and red/brown hues, have been prepared by selecting the reactants and the pigmentation process. Lignin nanocapsules play multiple functions in the support and activation of the enzyme necessary for the synthesis of pigments. Lignin nanocapsules protected the melanin pigment from alkaline and UV-degradation treatment.