An amide of hyaluronic acid or a derivative thereof which comprises at least one repetitive unit of general formula (I): wherein R═NR6R7, or alcoholic group of the aliphatic, aromatic, arylaliphatic, cycloaliphatic, heterocyclic series, OH, O—, alcoholic group of hyaluronic acid, amino group of deacylated hyaluronic acid; R1, R2, R3, R4═H, SO3—, acyl group derived from a carboxylic acid of the aliphatic, aromatic, arylaliphatic, cycloaliphatic, heterocyclic series, —CO—(CH2)2—COOY; Y═ negative charge, or H; R5═—CO—CH3, H, SO3—, acyl group derived from a carboxylic acid of the aliphatic, aromatic, arylaliphatic, cycloaliphatic, heterocyclic series, acylic group of hyaluronic acid; R6═ is H or a aliphatic, aromatic, arylaliphatic, cycloaliphatic, or heterocyclic group, substituted or unsubstituted; R7═ is H or an aliphatic, aromatic, arylaliphatic, cycloaliphatic, or heterocyclic group, substituted or unsubstituted; wherein at least one of R or R5 forms an amide group.