Lignin was fractionated using EtOH or acetone before particle preparation to ensure that the obtained LNPs differ in size. Therefore, around 10 g of Amallin A and BioPiva 100 were dissolved in 100 mL of EtOH or acetone (10 % w/v), respectively. After dissolution for 4 h, the soluble fraction was separated by filtration and lignin was isolated by evaporation of the solvent. For samples LNP1 and LNP-3, the acetone soluble fraction of Amallin A and BioPiva 100 was used, respectively. LNP-2 and LNP-4 were prepared using the EtOH solublef fraction of BioPiva 100 and unfractionated BioPiva, respectively. The lignin nanoparticles were then prepared by the solvent shifting approach. In brief, an 8 % w/v lignin solution was prepared by dissolving lignin in aqueous acetone (75 %v). After complete dissolution, the solution was rapidly poured into a threefold amount of vigorously stirred H2O. After particle formation, acetone was removed by rotary-evaporation. The concentration of LNPs in H2O was determined gravimetrically.