Novel hyaluronan esters for biomedical applications

A series of novel hyaluronan (HA) esters with aliphatic chains of different length were synthesized. A silylated complex of HA with cetyltrimethylammonium cations (silyl HA-CTA) was used as the starting material. The reactions were performed in xylenes or no solvent with acid chlorides as the acylation agents. The disappearance of all characteristic FT-IR vibration bands associated with the -OSi(CH3)3 groups and the appearance of the strong ester carbonyl peak at 1753 cm-1 demonstrated the success of esterification. Thermoplasticity was achieved with HA esters of high aliphatic acids. It was found that the longer the ester chain, the lower the melting points, so different melting temperatures can be obtained by adjusting the acid chloride chain length to meet various needs.