Lignin for nano- and microscaled carrier systems: applications, trends and challenges

To liberate the society from the dependence on fossil materials it is pivotal to explore components of renewable plant biomass in applications that benefit from their intrinsic biodegradability, safety, and sustainability. Lignin, a byproduct of the pulp and paper industry, is a plausible material for carrying various types of cargo in small- and large-scale applications. We review the possibilities and constraints regarding the physical-chemical properties of the lignin source as well as modifications and processing required to render lignins suitable for the loading and release of pesticides, pharmaceuticals, and biological macromolecules. In addition, we discuss critically the technical challenges, regulatory and toxicological aspects, and future research needed to realize some of the promises that nano- and microscaled lignin materials hold for a sustainable future.