Demonstration of improved tissue integration and angiogenesis with an elastic, estradiol releasing polyurethane material designed for use in pelvic floor repair.

Abstract

Pelvic organ prolapse and stress urinary incontinence affect 40-50% of postmenopausal women worldwide. Polypropylene meshes have been extensively used for the surgical intervention of these disorders; however, these meshes can lead to severe complications in some patients. The need for synthetic materials more suited for use in pelvic floor repair is widely accepted. This study aims to develop an electrospun 17-β-estradiol releasing polyurethane (PU) scaffold that not only provides the appropriate mechanical support but can also stimulate new extracellular matrix (ECM) production and angiogenesis. PU scaffolds with and without 17-β-estradiol (25 and 50 mg/g) were prepared by blend electrospinning. Mechanical properties of scaffolds were assessed by uniaxial cyclic and non-cyclic testing. The viability and ECM production of human adipose derived mesenchymal stem cells (hADMSCs) cultured on 17-β-estradiol releasing PU scaffolds was evaluated. Angiogenic potential of estradiol releasing scaffolds was demonstrated by using an ex ovo chick chorioallantoic membrane (CAM) assay. The inclusion of estradiol in PU scaffolds did not change the ultrastructure but it significantly increased the ultimate tensile strength of scaffolds. hADMSCs on estradiol-releasing PU scaffolds showed more ECM production. The CAM assay revealed a significantly higher angiogenic potential of estradiol-releasing PU scaffolds with an additive effect seen when hADMSCs cultured on estradiol scaffolds. Histological examination of CAM tissue sections showed extensive cellular infiltration and a good tissue integration for all constructed scaffolds. This study shows the angiogenic potential of estradiol-releasing PU scaffolds with appropriate strength and elasticity desirable to support the pelvic floor.