Poloxamer additive as luminal surface modification to modulate wettability and bioactivities of small-diameter polyurethane/polycaprolactone electrospun hollow tube for vascular prosthesis applications

Abstract In regard of engineering small-diameter vascular graft, a stable surface treatment targeting only the tube lumen toward rapid endothelialization and anti-thrombosis without weakening or deconstructing the prosthesis remains a technical challenge. In this study, a bilayer hollow tube with a hydrophilic inner layer polyurethane/polycaprolactone/Poloxamer (PU/PCL/Poloxamer) was fabricated. Poloxamer 407 was blended with PU/PCL as a one-step surface modification to enhance the hydrophilicity and bioactive properties of the electrospun tube’s luminal surface. Hydrophobic polypropylene glycol backbones anchored poloxamer onto based polymer while hydrophilic side chains migrated to the surface to modify the behaviors of electrospun inner surface. The poloxamer blended surface, interestingly, exhibited complicated attraction and repellent behaviors regulated by the dynamic of PEG chains. Moderate grafting density (2 %–8 %) exhibited high bioactive performance of PEG tails to simultaneously modulate cells' adhesion, elongation and proliferation while restricting platelet adhesion in comparison with PU/PCL and super-hydrophilic PU/PCL/Poloxamer surface. The elevation of poloxamer content in composition resulted in a corresponding increase in both hydrophilicity and tensile strength while maintained the homogenous fibrous structure of electrospun mat. Besides, a hydrophobic outer layer PU/PCL was fabricated to prevent the leakage and permeable transmembrane phenomenon toward the sustain application in vascular engineering.