Functionalized and crosslinked polymers

A hyaluronic acid polymer derivative comprising one or more modified hydroxyl groups, wherein the hyaluronic acid polymer derivative has the formula:

• A) HA-(OCH2CH2SO2CH2CH2—X—R1—Y)n, where HA is hyaluronic acid, X is S or NH, R1 is an aromatic moiety, and Y is one or more of H, a carboxylic acid group or a salt or ester thereof, a hydroxyl group, a sulfonic acid group or a salt thereof, or an amine group, and n is the number of modified hydroxyl groups where n≥1;
• or
• B) (Y—R2—X—CH2CH2SO2CH2CH2O)m,—HA-(OCH2CH2SO2CH2CH2—X—R1—Y)n, where HA is hyaluronic acid, X is S or NH, R1 and R2 are each a substituted or unsubstituted C1-C20 aliphatic or aromatic moiety, wherein R1 and R2 are different from each other, Y may be the same or different, and Y is one or more of H, a carboxylic acid group or a salt or ester thereof, a hydroxyl group, a sulfonic acid group or a salt thereof, or an amine group, or an amine group, and n≥1 and m≥1;
• or
• C) (CH2═CH—SO2CH2CH2O)m—HA-(OCH2CH2SO2CH2CH2—X—R1—Y)n, where HA is hyaluronic acid, X is S or NH, R1 is a substituted or unsubstituted C1-C20 aliphatic or aromatic moiety Y is one or more of H, a carboxylic acid group or a salt or ester thereof, a hydroxyl group, a sulfonic acid group or a salt thereof, or an amine group, and n≥1 and m≥1.