Novel Biodegradable Poly(ester−ether)s: Copolymers from 1,4-Dioxan-2-one and d,l-3-Methyl-1,4-dioxan-2-one

Abstract

Synthesis of random copolymers by the nonsequential polymerization of 1,4-dioxan-2-one with D,L-3-methyl-1,4-dioxan-2-one was first investigated using a range of classical initiators. Experimental conditions such as temperature and initiator concentrations were varied to achieve reasonable monomer conversions and molar masses. In general, copolymers were slightly enriched in 1,4-dioxan-2-one. On the basis of block lengths of the respective (co)monomer sequences, it is proposed that the copolymer consists of longer blocks of dioxanone units and a pseudoperiodic pattern with a random distribution of MeDX units. The thermal properties of the copolymer changed significantly with the percentage of MeDX units incorporated. A copolymer with 8% mole percent of MeDX units exhibits a T m of 95.5°C, which is about 15°lower than PDX homopolymer. A range of (PEG) m -b-[(PDX)-co-(PMeDX)] n block copolymers was also successfully prepared using R-methoxy-ω-hydroxy-PEG as macroinitiator. The amphiphilic character of these copolymers is also here demonstrated with spherical core-shell micelles having an average size of 25-30 nm as determined by TEM. The tunable biodegradability characteristics of the hydrophobic core make these polymers interesting candidates as nanocarriers in controlled drug delivery.

Drug Loading and Release from Electrospun Biodegradable Nanofibers

“…The degradation rate of poly(ester-ether)s could also be controlled by copolymerizing dioxanone with methyl dioxanone (MeDX). [127][128][129] Indeed, the introduction of MeDX units in a PDX backbone alters the crystallinity of the resulting copolymer, enhancing hydrolytic cleavage and degradation. In vivo degradation studies conducted on PLCL tubular scaffolds showed a slow degradation (mass loss of 81% noted for an implanted period of 15 weeks), whereby the caprolactone units degraded faster than the lactide units.…”

A review of polymeric biomaterials research for tissue engineering and drug delivery applications at the Centre for Biomedical and Biomaterials Research, Mauritius

“…Inspired by the PLGA family, our group reported on the synthesis and homopolymerisation of a dioxanone analogue, namely MeDX (Lochee et al 2009(Lochee et al , 2010 and its copolymerisation with dioxanone to produce a range of random copolymers (Wolfe et al 2011). Figure 2 gives the structures of 1,4-dioxan-2-one and 3-methyl-1,4-dioxan-2-one.…”

“…Poly(dioxanone-co-methyl dioxanone) [P(DX-coMeDX)] random copolymers were synthesised by procedures previously reported by Lochee et al (2009). Diblock polycaprolactone-b-poly(dioxanone-co-methyl dioxanone) [PCL-b-P(DX-co-MeDX)] polymers were synthesised as described previously (Goonoo et al 2012).…”

An assessment of biopolymer‐ and synthetic polymer‐based scaffolds for bone and vascular tissue engineering

“…The degradation rate of poly(ester‐ether)s could also be controlled by copolymerizing dioxanone with methyl dioxanone (MeDX). Indeed, the introduction of MeDX units in a PDO backbone alters the crystallinity of the resulting copolymer, enhancing hydrolytic cleavage and degradation. In vivo degradation studies conducted on PLCL tubular scaffolds displayed a slow degradation speed (mass loss of 81% noted for an implanted period of 15 weeks), whereby the caprolactone units degraded faster than the lactide part .…”