In-reactor engineering of bioactive aliphatic polyesters via magnesium-catalyzed polycondensation for guided tissue regeneration

Aliphatic polyesters have been widely used in biomedicine owning to their combination of biodegradability, biocompatibility and controllable mechanical properties. Polycondensation is certainly one of the most versatile and robust methods for the synthesis of aliphatic polyesters in a large scale. Nevertheless, traditional catalysts for polycondensation, such as Sb2O3, GeO2 and SnCl2, have potential biotoxicity and need to be completely removed before using in biomedicine. Furthermore, pure aliphatic polyesters do not possess the required functionality and additional work is required for increasing their bioactivity in many biomedical applications. Here, a series of magnesium compounds were used as catalysts for the polycondensation of dicarboxylic acids and diols. We confirmed that the in situ formed magnesium dicarboxylate not only serves as the real catalyst but also endows the resultant polyester with bioactivity because of its osteogenic activity and anti-inflammatory property. Finally, the bioactive polyester was applied to guided tissue regeneration, in which the degree of bone regeneration after 16 weeks is higher than commercial PLA film. This work provides a strategy for the in-reactor engineering of bioactive polyesters within one step on a large scale, and shows promising applications for use in the biomaterial field.