Injectable Slippery Lubricant-Coated Spiky Microparticles with Persistent and Exceptional Biofouling-Resistance

Injectable micron-sized particles have historically achieved promising applications, but they continued to suffer from long-term biofouling caused by the adhesions of biomolecules, cells, and bacteria. Recently, a slippery lubricant infusion porous substrate (SLIPS) exhibited robust antiadhesiveness against many liquids; however, they were constructed using a 2D substrate, and they were not suitable for in vivo applications, such as injectable biomaterials. Inspired by SLIPS, here, we report the first case of injectable solid microparticles coated with a lubricating liquid surface to continuously resist biofouling. In our design, microparticles were attached with nanospikes and fluorinated to entrap the lubricant. The nanospikes enabled the lubricant-coated spiky microparticles (LCSMPs) to anomalously disperse in water despite the attraction between the surfaces of the microparticles. This result indicated that the LCSMPs exhibited persistent anomalous dispersity in water while maintaining a robust lubricating surface layer. LCSMPs prevented the adhesion of proteins, mammalian cells, and bacteria, including Escherichia coli and Staphylococcus aureus. LCSMPs also reduced in vivo fibrosis while conventional microparticles were heavily biofouled. This technology introduced a new class of injectable anti-biofouling microparticles with reduced risks of inflammation and infections.