Antibacterial Coatings Based on Bioinspired Polymer Systems

Abstract

This work mainly focuses on the antibacterial treatment of the biomedical materials based on the mussel-inspired polymers. In the last few decades, there has been a tremendous interest in the study of the antibacterial materials. However, due to the emergence of drug resistant bacteria, the design of antibacterial materials has met with more challenges. In this work, the silver and Cu NPs were applied as antibacterial materials combined with the mussel-inspired polymers. In addition, a new supramolecular material was developed as good alternative to antibacterial compounds. The positively charged nanoaggregates based on zwitterionic pillar[5]arene were designed in this work combating the planktonic bacteria and disrupting the biofilm. In the first project, a Cu NPs-incorporated MI-dPG coating was designed. Based on the antibacterial tests, surface characterization, and stability test, the universal coating presented excellent antibacterial ability against the Gram-negative bacteria (E. coli, DH5α), Gram-positive bacteria (S. aureus, SH1000), and the drug resistant bacteria (kanamycin resistant E. coli, MG1655). This coating approach can be realized by a simple dip-coating method. Furthermore, the coating is available on versatile substrates, such as ceramic, metal, polymers, etc. In the second project, the zwitterionic Pillar[5]arene presented excellent antibacterial ability against the Gram-negative bacteria (E. coli, DH5α), Gram-positive bacteria (S. aureus, SH1000). This supramolecular system can self-assemble into weakly positively charade nanoaggregates. Pillar[5]arene combined with the zwitterion showed excellent antibacterial ability. Meanwhile, it also presented the ability to eradicate both the young biofilm and pre-established biofilm, which did not lead to rapid generation of resistance. In the third project, the antibacterial and antifouling surfaces based on the antibacterial agent (Ag NPs) and antifouling surfaces with superwettability were produced. One important advantage of the work is that the system was based on the same polymer, MI-dPG, which makes the different wettability more comparable. The comparison between different wettability showed that the Ag NPs incorporated onto the superamphiphobic surface presented better stability. This study demonstrated that the superamphiphobic wettability helped stabilize the Ag NPs incorporated on the surface because there was an air film between the surface and the outside environment, which could reduce the release of the Ag NPs. In summary, the work aimed to modify the biomedical materials with antibacterial ability based on the bio-inspired polymers. Besides the antibacterial effect, more biological functions were meanwhile combined (antifouling, osteogenic ability) in the later study to promote the integration of the biomaterials. The simple and rapid fabrication of antibacterial surfaces showed great potential in the biofunctional materials and need to be further tested in vivo.