Antibacterial rifampicin-loaded electrospun polycaprolactone membranes for ureteral regeneration

Author of the study: Nowadays partial or complete ureteral loss following resection or injuries of various etiology is managed with different surgical techniques involving local tissue flaps or autologous tissues interposition. In the last years ureteral tissue engineering using membranes, tubular scaffolds or decellularized matrices has shown promising results for ureteral substitution. The aim of this study is to evaluate the use of antibacterial electrospun polycaprolactone/ rifampicin (PCL/RIF) membranes for the production of ureteral scaffolds with antibacterial properties. Materials and methods: Electrospinning processwas used to produce the membranes that were subsequently impregnated with rifampicin. Membranes stability was evaluated by immersion in Simulated Body Fluid (SBF) at 37 °C. Mechanical properties were evaluated by uniaxial tensile tests, Young’s modulus was calculated for each sample. UV spectrophotometry was used to evaluate in vitro release of rifampicin. The ability of PCL/Rif membranes to sustain cell adhesion and proliferation was evaluated by seeding human urothelial bladder carcinoma cells on the membranes. In order to investigate the antibacterial effect of PCL/Rif membranes, in vitro antibacterial tests were performed using bacterial strains belonging to the “ESKAPE” group. Results: PCL/Rif membranes are characterized by a random distribution of fibers with an average diameter of 0.52 μm.Water contact angle for PCL and PCL/Rif membranes is around 125° and decreases to 0° after air-plasma treatment. When culture medium is used as testing fluid PCL and PCL/Rif contact angles are 116° and 12° respectively. Membranes are deformable up to 300% of their initial dimension and possess an elastic Young modulus of about 20 kPa; after 3 weeks membranes gain the property to sustain a 100% deformation before rupture. The 72% of rifampicin load is released by the membranes in the first 24 hours. Proliferation assay showed a seven-fold increase of cell number adhered on the membranes after 7 days of culture. At the same time in presence of PCL/Rif membranes, rates of bacterial proliferation inhibition ranged from 75 to 94% compared to controls. Conclusions: PCL/Rif membranes represent a promising starting point in the production of ureteral scaffolds with antibacterial properties for ureteral substitution.