CONTEXT

Biodegradable and biocompatible poly(alpha-hydroxy acids) polymers have been interestingly investigated as biomaterials for applications such as drug delivery, surgery (surgical suture) as well as othopedic surgery (implant). Nevertheless, if one wishes to develop a specific polymer for a specific application, many obstacles are encountered. For example, any drug delivery vector based on poly(alpha-hydroxy acids) will have to have a specific physical and chemical structure allowing the crossing of physiological barriers and the recognition of a specific target.

PGA poly(glycolic acid) and PLA poly(L-lactic acid) which are based respectively on the copolymerisation of cyclic diesters of glycolic acid, glycolide, and of lactic acid, lactide, through the catalytic opening of the cycle are widely used. However the process of opening said cycle are practically only limited to these diesters and to reach specific properties, it is required to go through hard to settle copolymerisation with other monomers. Moreover, said polymer usually do not have functional groups.

Thus, it has recently been investigated polymers based on O-carboxy anhydrides (OCAs) due to many potential applications. Their obtention is well known and requires phosgenation. As for the polymerisation of said OCAs, until now, existing process could not control all the parameters such as the polymer molar mass which is a key parameters for potential applications.