Construction and characterization of an antibacterial/anticoagulant dual-functional surface based on poly l-lactic...

In this study, a poly l-lactic acid (PLLA) fibrous mat was prepared by electrospinning, followed by surface modification with polydopamine (PDA), based on its strong adhesion performance and self-polymerization of dopamine. The PDA coating on the fibrous mat surface provided a reaction platform for heparin via a Michael-type addition reaction and a reductive surface for Ag⁺ in situ formation of silver nanoparticles (AgNPs) in AgNO₃ solution. The structure and chemical composition of the fibrous mats were determined by scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. All the results confirmed the successful immobilization of heparin and AgNPs on the PLLA fibrous mats. Thermogravimetric analysis (TGA) and energy dispersive X-ray spectrum (EDS) analysis were used to determine the content of AgNPs and their distribution on the fibrous mat surface. Water contact angle measurements showed the hydrophilic improvement after modification. The antibacterial investigation indicated that the fibrous mats could inhibit the growth of both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Protein adsorption, the hemolysis test, the coagulation test, complement activation, and platelet activation were used to confirm the compatibility with blood and the anticoagulation property of the fibrous mats. Finally, cell proliferation and live/dead assays, conducted with cultured fibroblasts on the fibrous mats, showed that the modified fibrous mat surface had good cell compatibility. This antibacterial/anticoagulant dual-functional surface, based on poly l-lactic acid electrospun fibrous mats, would have potential application in blood contacting materials.