Influence of Cross-Linking on the Physical Properties and Cytotoxicity of Polyhydroxyalkanoate (PHA) Scaffolds for...

In this study, an unsaturated copolyester, poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxy-10-undecenoate] (PHBU), was produced by an engineered strain of Escherichia coli, cross-linked via thiol-ene click chemistry, and analyzed for improved physical properties and biocompatibility with human mesenchymal stem cells. By cross-linking the PHBU polymer, an increase in tensile strength of greater than 200% to 26.2 MPa was observed, resulting in a material with physical properties closer to those relevant for soft tissue replacement. Results showed that this chemically cross-linked polyester did not exhibit significant cytotoxicity toward human cells after chemical modification. The chemically modifiable copolyester described here could potentially be used as a replacement for an assortment of tissues currently without viable material alternatives in the field of tissue-engineering.