In vitro and in vivo studies on bacteria and encrustation resistance of heparin/poly-L-lysine-Cu nanoparticles coating mediated by PDA for ureteral stent application

Ureteral stents are commonly utilized as a medical device to aid the flow of urine.However,biofilm formation and encrustation complications have been clinical problems.To overcome this challenge,heparin/poly-L-lysine-copper(Hep/PLL-Cu)nanoparticle was immobilized on a dopamine-coated polyurethane surface(PU/NPs).The stability and structural properties of the nanoparticles were characterized by Zeta potential,poly dispersion index,transmission electron microscopy,atom force microscopy and contact angle.The surface composition,antibacterial potency,encrustation resistance rate and biocompatibility of PU/NPs were investigated by scanning electron microscope,X-ray photoelectron spectroscopy,antibacterial assay and MTS assay,respectively.In addition,the antiencrustation property was studied by implanting coated NPs stents in the rat bladder for 7 days.It was shown that the size and distribution of Hep/PLL-Cu nanoparticles were uniform.PU/NPs could inhibit Proteus mirabilis proliferation and biofilm formation,and exhibit no cytotoxicity.Less encrustation(Ca and Mg salt)was deposited both in vitro and in vivo on samples,demonstrating that the NPs coating could be a potential surface modification method of ureteral material for clinical use.