Main Chain Modified Polylactides. Methods of Synthesis and Applications

Polylactide is an important material in biomedical applications, but its slow degradation rate, low hydrophilicity, and lack of reactive side-chain groups limit its use. To overcome these limitations it is crucial to functionalize it with reactive groups. By introducing reactive functional side groups, biologically active compounds can be attached with the possibility of controlled release. Additionally, introducing suitable functional groups can improve hydrophilicity, which is essential for drug delivery. There are several ways to introduce reactive functional side groups to the polylactide chain, with the most versatile being the introduction of a reactive group into monomeric lactide and its subsequent polymerization or copolymerization with lactide. This approach allows the preparation of polylactides with pendent functional groups via the polymerization of functional (substituted) monomers. Therefore, the synthetic strategy based on functional monomers is considered the primary option to access a broad range of functional polylactides. This review focuses on the modification of polylactide by incorporating functional groups into monomer molecules and their subsequent polymerization. Through this approach, it is possible to improve the properties of polylactide for various biomedical applications. In the following sections, we will discuss the different methods for functionalization and their potential impact on the biomedical field.