Aliphatic poly(ester)s are an interesting class of polymers that are widely applied in the biomedical field as a consequence of their ability to undergo degradation in physiological conditions. The most commonly used aliphatic poly(ester)s are synthesized via the ring-opening polymerization (ROP) of cyclic monomers such as β-butyrolactone, δ-valerolactone, ε-caprolactone and cyclic diesters including lactide and glycolide in the presence of a catalyst and/or an initiator. Poly(ε-caprolactone) (PCL) has well been studied and applied in the biomedical field as a consequence of its excellent mechanical strength, thermal properties, bio-compatibility and non-toxicity, which makes it an ideal polymer candidate as an implantable carrier or in tissue engineering applications. PCL is typically synthesized by anionic or metal-catalysed ROP of ε-caprolactone, a process that requires rigorous synthetic procedures to produce polymers of predictable molecular weights. We have been interested (through collaboration with the Dove group) in the development of an alternative route for the synthesis of a PCL-like polymer by the radical ring-opening polymerization (rROP) of the 7-membered cyclic ketene acetal (CKA), 2-methylene-1,3-dioxepane (MDO). We have reported the first example of controlled copolymerization of the CKA, MDO with vinyl acetate (and its derviatives) and other vinyl monomers to produce well-defined, side-chain functional biodegradable polymers via a facile radical polymerization method. Furthermore, we have also demonstrated the extension of this methodology to facilitate the synthesis of fully-degradable hyperbranched copolymers and polymer nanoparticles with the inclusion of reactive pendant groups.
Amphiphilic Block Copolymer Self-Assemblies of Poly(NVP)-b-poly(MDO-co-vinyl esters): Tunable Dimensions and Functionalities, G. G. Hedir, A. Pitto-Barry, A. P. Dove, R.K.O'Reilly, J. Polym. Sci. Part A: Polym. Chem, 2015, 53, 2699-2710, DOI: 10.1002/pola.27915
Controlling the synthesis of degradable vinyl polymers by xanthate-mediated polymerization, C. A. Bell, G. G. Hedir, R. K. O'Reilly and A. P. Dove, Polymer Chemistry, 2015, 6, 7447-7454. DOI: 10.1039/c5py01156f
Functional Degradable Polymers by Radical Ring-Opening Copolymerization of MDO and Vinyl Bromobutanoate: Synthesis, Degradability and Post-Polymerization Modification, G. G. Hedir, C. A. Bell, R. K. O’Reilly, A. P. Dove, Biomacromolecules, 2015, 7, 2049–2058, DOI: 10.1021/acs.biomac.5b00476
Functional Degradable Polymers by Xanthate-Mediated Polymerization, G.G. Hedir, C. Bell, N.S. Ieong, E. Chapman, I. Collins, R.K. O'Reilly, A.P. Dove, Macromolecules, 2014, 47, 2847-2852, DOI: 10.1021/ma500428e