Fig. 1From: Novel hyaluronic acid–methotrexate conjugate suppresses joint inflammation in the rat knee: efficacy and safety evaluation in two rat arthritis modelsChemical structure of DK226 [37]. DK226 consists of four parts: MTX, peptide, linker, and HA. MTX binds through its α-carboxylic acid. Peptide and linker are α–Phe–Phe and –NH–(CH2)2–NH–, respectivelyBack to article page