Two constitutional structural schemes are proposed attempting to unify and rationalize a series of focused NMR and chromatographic determinations aimed at providing an integrated picture for the structure of softwood kraft lignin.

Lignin is the second most abundant natural polymer. Its use and targeted functionalisation within biomass refinery processes, however, still needs to be further explored and devel- oped. The oxidative functionalisation, and thus valorisation of lignin, is a very promising way to go, since it holds the possibilities to yield highly functionalised, monomeric or olig- omeric products that can serve as starting materials for other valorisation processes in the chemical and pharmaceutical industries. Gaining a profound knowledge about the struc- ture of lignin, being able to analyse structural features, and understanding the mechanisms that guide the reactions leading to the oxidative derivatisation, depolymerisation and func- tionalisation of lignin samples from different renewable sources are key requirements for developing successful valorisation protocols for lignin. In this review, we wish to revisit, and set into context, some important achievements in the field of oxidatively upgrading lignin. We will focus on organometal catalyses (MTO, salen complexes, POMs), biomimetic catalyses (porphyrins), and enzymatic catalyses (laccase, peroxidase) for upgrading lignin and lignin model compounds. Details of mechanistic implications and means of potential manipulations of reaction outcomes are discussed

To liberate society from its dependence on fossil‐based fuels and 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. Herein, 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 is reviewed. In addition, 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 are critically discussed.

The mechanism of lignin nanoprecipitation and subsequent self-assembly was elucidated by studying generation of lignin nanoparticles (LNPs) from aqueous ethanol. LNP formation was found to follow a kinetically controlled nucleation-growth mechanism in which large lignin molecules formed the initial critical nuclei. Using this information, we demonstrate entrapment of budesonide in LNPs and subsequent pH-triggered and surfactant-responsive release of this synthetic anti-inflammatory corticosteroid. Overall, our results not only provide a promising intestinal delivery system for budesonide, but also deliver fundamental mechanistic understanding for the entrapment of actives in LNPs with controlled size and release properties.