Polyesterurethane and acellular matrix based hybrid biomaterial for bladder engineering

Poly(lactic-co-glycolic acid) (PLGA) based biomaterials for soft tissue engineering have inherent disadvantages, such as a relative rigidity and a limited variability in the mechanical properties and degradation rates. In this study, a novel electrospun biomaterial based on degradable polyesterurethane (PEU) (DegraPol((R))) was investigated for potential use for bladder engineering in vitro and in vivo. Hybrid microfibrous PEU and PLGA scaffolds were produced by direct electrospinning of the polymer onto a bladder acellular matrix. The scaffold morphology of the scaffold was analyzed, and the biological performance was tested in vitro and in vivo using a rat cystoplasty model. Anatomical and functional outcomes after implantation were analyzed macroscopically, histologically and by cystometry, respectively. Scanning electron microscopy analysis showed that PEU samples had a lower porosity (p<0.001) and were slightly thinner (p=0.009) than the PGLA samples. Proliferation and survival of the seeded smooth muscle cells in vitro were comparable on PEU and PLGA scaffolds. After 8 weeks in vivo, the PEU scaffolds exhibited no shrinkage. However, cystometry of the reconstructed bladders exhibited a slightly greater functional bladder capacity in the PLGA group. Morphometric analyses revealed significantly better tissue healing (p<0.05) and, in particular, better smooth muscle regeneration, as well as a lower rate of inflammatory responses at 8 weeks in the PEU group. Collectively, the results indicated that PEU-hybrid scaffolds promote bladder tissue formation with excellent tissue integration and a low inflammatory reaction in vivo. PEU is a promising biomaterial, particularly with regard to functional tissue engineering of the bladder and other hollow organs. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 658-667, 2017.