LBL assembly of [email protected] X and chitosan on PLLA substrate to enhance antibacterial and biocompatibility

Poly L-lactic acid (PLLA) is a non-toxic, biocompatible degradable polymer material with excellent mechanical properties after moulding. However, it faces challenges in the use of biomedical materials because of its intolerance to bacteria. Here, we use an easy-to-operate method to prepare a composite multilayer membrane: PLLA membrane was used as substrates to assemble positively charged chitosan and negatively charged [email protected] on the surface using the layer-by-layer (LBL) method. The assembly process was detected by fluorescein isothiocyanate-labelled chitosan and the thickness of the coating multilayer was also detected as 210.0 ± 12.1 nm for P-M membrane and 460.5 ± 26.5 nm for [email protected] membrane. The surface self-assembled multilayers exhibited 91.27% and 96.11% growth inhibition ratio against Escherichia coli and Staphylococcus aureus strains under 808 nm near-infrared laser radiation with a synergistic photothermal antibacterial effect. Furthermore, best biocompatibility of P-M and [email protected] membranes compare to PLLA membrane motivated us to further explore its application in biomedical materials.