Biocompatible Slippery Fluid-Infused Films Composed of Chitosan and Alginate via Layer-by-Layer Self-Assembly and Their Antithrombogenicity

Antifouling super-repellent surfaces inspired by Nepenthes, the pitcher plant, were designed and named slippery liquid-infused porous surfaces (SLIPS). These surfaces repel various simple and complex liquids including water and blood by maintaining a low sliding angle. Previous studies have reported the development of fluorinated SLIPS that are not biocompatible. Here, we fabricated fluid-infused films composed of biodegradable materials and a biocompatible lubricant liquid. The film was constructed using a combination of electrostatic interactions between chitosan and alginate and hydrogen-bonding between alginate and polyvinylpyrrolidone (PVPON) via the layer-by-layer self-assembly method. After chitosan and alginate were cross-linked, the PVPON was removed by increasing the pH to generate porosity from the deconstruction of the hydrogen-bonding. The porous underlayer was hydrophobized and covered by biocompatible almond oil. Blood easily flowed over this biodegradable and biocompatible SLIPS without leaving stains on the surface, and the material is environmentally durable, has a high transmittance of about 90%, and is antithrombogenic. The results of this study suggest that this SLIPS may facilitate the creation of nonfouling medical devices through a low-cost, eco-friendly, and simple process.