Sodium monoiodoacetate

Urethane, sodium monoiodoacetate, and rhodamine 6G were obtained from Sigma Aldrich (St. Louis, MO, United States) and were dissolved in 0.9% saline. Pepducin P4pal10 was synthesized by Genscript (Piscataway, NY, United States) and also dissolved in 0.9% saline. Physiological buffer (135 mM NaCl, 20 mM NaHCO3, 5mM KCl, 1 mM MgSO4-7H2O, pH = 7.4) was prepared in the lab.

Chitosan (degree of deacetylation ~ 95%, viscosity 100–200 mPa.s) was obtained from Aladdin (Shanghai, China). Sodium monoiodoacetate (MIA) and sodium periodate (NaIO4) were supplied by Sigma-Aldrich (St. Louis, MO, USA). Enzyme-linked immunosorbent assay (ELISA) kit of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-17 were purchased from Sigma-Aldrich. Hyaluronic acid (100–200 k) and adipic acid dihydrazide (ADH) were produced by Yuanye biology (Shanghai, China). Rat chondrocytes (ATCC-0038) was got from American Type Culture Collection (ATCC, Gaithersburg, MD, USA). Dulbecco’s Modified Eagle’s Medium (DMEM, low glucose), streptomycin–penicillin and fetal bovine serum (FBS) were supplied by Gibco^® Life Technologies (Carlsbad, CA, USA). Cell Counting Kit-8 (CCK-8) and Calcein-AM/Propidium Iodide (PI) were purchased from Beyotime Biotechnology (Shanghai, China). Hematoxylin–Eosin and Safranin O stains were got from Thermo Fisher Scientific Co., Ltd (Shanghai, China). Triton X-100 was supplied by Solarbio Science & Technology Co., Ltd. (Beijing, China). The antibodies enrolled in immunofluorescence were obtained from Abcam (Cambridge, UK).

Sodium monoiodoacetate, rhodamine 6G, and urethane were obtained from Sigma-Aldrich (St. Louis, MO, USA). Sivelestat (neutrophil elastase inhibitor; 4-[[[2-[[(carboxymethyl)amino] carbonyl]phenyl]amino]sulfonyl] phenyl ester 2,2-dimethyl-propanoic acid, monosodium salt, tetrahydrate) was obtained from Caymen Chemicals (Ann Arbor, MI, USA). SerpinA1 (neutrophil elastase inhibitor) was obtained from Abcam, Inc. (Toronto, ON, Canada). GB83 (PAR2 antagonist; N-((S)-3-cyclohexyl- 1-((2S,3S)-1-(2,3-dihydrospiro[indene-1,4′-piperidine]-1′-yl)- 3-methyl-1-oxopentan-2-ylamino)-1-oxopropan-2-yl) isoxazole-5-carboxamide) was obtained from Axon Medchem (Groningen, The Netherlands). Neutrophil Elastase 680 FAST was purchased from PerkinElmer (Waltham, MA, USA). Sodium monoiodoacetate, sivelestat, and rhodamine 6G were dissolved in saline. GB83 was dissolved in vehicle (1:1:8 DMSO/cremophor/saline). Physiological buffer (composition—135 mM NaCl, 20 mM NaHCO3, 5 mM KCl, 1 mM MgSO4*7H2O, pH = 7.4) was prepared in-house.