Poly(ethylene glycol)-modulated cellular biocompatibility of polyhydroxyalkanoate films

Polyhydroxybutyrate (PHB) and its copolymer with hydroxyvalerate, P(HB-co-HV), are widely used biomaterials. In this study, improvements of their biological properties of degradability and compatibility were achieved by blending with low-molecular-weight poly(ethylene glycol) (PEG106) approved for medical use. Surface morphology and chemistry are known to support cell attachment. Attachment and proliferation of neural olfactory ensheathing cells increased by 17.0 and 32.2% for PHB and P(HB-co-HV) composite films. Cell attachment was facilitated by increases in surface hydrophilicity, water contact angles decreased by 26 +/- 2 degrees and water uptake increased by 23.3% depending upon biopolymer and PEG loading. Cells maintained high viability (>95%) on the composite films with no evidence of cytotoxic effects. Assays of mitochondrial function and cell leakage showed improved cell health as a consequence of PEG loading. The PEG component was readily solubilised from composite films, allowing control of degradation profiles in the cell growth medium. Promotion of biopolymer compatibility and degradability was not at the expense of material properties, with the extension to break of the composites increasing by 5.83 +/- 1.06%. Similarly, crystallinity decreased by 36%. The results show that blending of common polyhydroxyalkanoate biomaterials with low-molecular-weight PEG can be used to promote biocompatibility and manipulate physiochemical and material properties as well as degradation.(c) 2013 Society of Chemical Industry