Chitosan

DNase, phorbol 12-myristate 13-acetate (PMA), and high molecular weight sodium hyaluronate were procured from Sigma-Aldrich. Chitosan (deacetylation degree of 95%) and sulfo-cyanine5.5 (Cy5.5) was procured from Energy Chemical (Shanghai, China). Sodium periodate (NaIO₄) was procured from KeLong Chemical (Chengdu, China). Anti-neutrophil elastase was procured from Abcam Co., Ltd. 4′,6-diamidino-2-phenylindole (DAPI), Bicinchoninic acid (BCA) kit, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT), and nitric oxide (NO) probe were procured from Beyotime Biotechnology (Nantong, China). PE-labelled anti-CD86 antibodies and FITC-labelled CD80 antibodies were obtained from BioLegend. RAW264.7 cells were procured from the Shanghai Cell Bank (Shanghai, China) and were cultured in Dulbecco’s modified eagle’s medium with high glucose, supplemented with 10% heat-inactivated fetal bovine serum, 2 mM glutamine, nonessential amino acids, and sodium pyruvate. The medium and supplements were procured from Thermo Fisher Scientific. Cells were cultured at 37 °C in a humidified chamber with 5% carbon dioxide. The solvents used in the studies were analytically pure and used directly without treatment.

Chitosan (medium viscosity, 200–400 mPa·s), zinc acetate (99.9%), and acetic acid (99.5%) were purchased from Energy Chemical. Ruthenium chloride trihydrate was purchased from Shanxi Kaida Chemical. Commercial cellulase (NS22086, 1000 BHU (2) g^-1) was obtained from Novozymes. Birch wood (Betula), beech wood (Zelkova), eucalyptus grandis (Eucalyptus), poplar (Populus tomentosa carr.), pine wood (Pinus), spruce wood (Picea), and miscanthus (Miscanthus lutarioriparius) were screened into powders in size of 2–5 mm, extracted by toluene/ethanol for 5 h and dried at 60 °C before use. Dimeric and polymeric lignin model compounds were prepared following the literature reports^{45 (link),49 (link)}. All reagents and solvents were used as received without additional purification.

L-Carvone, chitosan (medium viscous, 200~400 mPa·s), and aryl aldehydes were purchased from Energy Chemical (Shanghai, China). 4-Methyl-thiosemicarbazide was provided by TCI (Tokyo, Japan). Ethyl bromoacetate, 5-amino-1,3,4-thiadiazole-2-thiol, chloroacetyl chloride, and other reagents/solvents were obtained from Macklin (Shanghai, China).