A comparative study on poly(xylitol sebacate) and poly(glycerol sebacate): mechanical properties, biodegradation and cytocompatibility

Abstract

In order to develop degradable elastomers with a satisfactory combination of flexibility and enzyme-mediated degradation rate, the mechanical properties, enzymatic degradation kinetics and biocompatibility of poly(xylitol sebcate) (PXS) has been systematically investigated in comparison with poly(glycerol sebacate) (PGS). Under the same level of crosslinked density, the PXS elastomer networks have approximately twice the stretchability (elongation at break) of their PGS counterparts. This observation is attributable to the relatively longer and more orientable xylitol monomers, compared with glycerol molecules. Although xylitol monomers have two more hydroxyl groups, we, surprisingly, found that the hydrophilic side chains did not accelerate the water attack on the ester bonds of the PXS network, compared with their PGS counterpart. This observation was attributed to a steric hindrance effect, i.e. the large-sized hydroxyl groups can shield ester bonds from the attack of water molecules. In conclusion, the use of polyols of more than three -OH groups is an effective approach enhancing flexibility, whilst maintaining the degradation rate of polyester elastomers. Further development could be seen in the copolymerization of PPS with appropriate thermoplastic polyesters, such as poly(lactic acid) and polyhydroxyalkanoate.

Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

“…By titration, 97.0 ± 0.1% conversion of carboxyl groups is calculated. 20 Table 3 summarizes the 13 C NMR analyses of the PXS gel and suggests the possibility of 1,4-diacyl species. Figure 10 shows the methylene and methine region of the 2D ( 13 …”

“…According to our previous comparative investigation of PGS and PXS networks, 20 at the same level of crosslinking, the PXS elastomer networks have approximately twice the elongation at break and have considerably lower in vitro degradation rates than their…”

“…20 However, very little characterization work has been performed on the PXS prepolymer system at the molecular level. To the best of our knowledge, only 1 H NMR spectroscopy has been used in some analyses of a PXS prepolymer by Bruggeman et al 2 to integrate the sebacic acid and the ester regions of a 1:1 xylitol-sebacic acid prepolymer as a way of confirming the stoichiometry.…”

Synthesis of Shape Memory Poly(glycerol sebacate)-Stearate Polymer

“…The optimization of the melting point and the degree of cross‐linking by trying different curing time and by using different fatty acids could be the next step of this work. Our expectations are that these parameters will affect the shape memory efficiency (shape fixity and shape recovery ratio), the mechanical performances, and will help to control the degradation kinetic of these materials into a buffer …”

Reactions of H3PO4 forming polymers. Apparently simple reactions leading to sophisticated structures and applications

“…Important products -polyesters of glycerol can be obtained in a two-step reaction, first described in a pioneering work by Langer [82], based on the reaction of glycerol with dicarboxylic acid to the stage of highly branched and still soluble product. Then, after casting, in the second stage, three dimensional network (gel) is formed [80,83,84]. These gels are elastomeric and already serve as "scaffolds" in regenerative medicine.…”