Recent advances in the production of biomedical systems based on polyhydroxyalkanoates and exopolysaccharides.

In recent years, growing attention has been devoted to naturally occurring biological macromolecules and their ensuing application in agriculture, cosmetics, food and pharmaceutical industries. They inherently have antigenicity, low immunogenicity, excellent biocompatibility and cytocompatibility, which are ideal properties for the design of biomedical devices, especially for the controlled delivery of active ingredients in the most diverse contexts. Furthermore, these properties can be modulated by chemical modification via the incorporation of other (macro)molecules in a random or controlled way, aiming at improving their functionality for each specific application.

Synthesis and Self-Assembly of Poly(-Vinylcaprolactam)--Poly(ε-Caprolactone) Block Copolymers via the Combination of RAFT/MADIX and Ring-Opening Polymerizations.

Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(-vinylcaprolactam)--poly(ε-caprolactone) (PNVCL--PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(-vinylcaprolactam) containing xanthate and hydroxyl end groups (X-PNVCL-OH) was first synthesized by RAFT/macromolecular design by the interchange of xanthates (RAFT/MADIX) polymerization of NVCL mediated by a chain transfer agent containing a hydroxyl function. The xanthate-end group was then removed from PNVCL by a radical-induced process.

Synthesis of amphiphilic pullulan-graft-poly(ε-caprolactone) via click chemistry.

Chemical modification of natural polymers has been commonly employed for the development of new bio-based materials, aiming at adjusting specific properties such as solubility, biodegradability, thermal stability and mechanical behavior. Among all natural polymers, polysaccharides are promising materials, in which biodegradability, processability and bioreactivity make them suitable for biomedical applications. In this context, this work describes the synthesis and characterization of a novel amphiphilic pullulan-g-poly(ε-caprolactone) (Pull-g-PCL) graft copolymer.