Growing Hybrid Cuticles: Metallochitins as an Emerging Family of Bioactive Mimics of Chitin

Inspired by the properties of natural chitin, the present work provides the first solid foundation for growing conformal ultrathin antibacterial films of organic chitin through a solvent-free molecular layer deposition (MLD) process. This work establishes the initial groundwork for growing biomimetic hybrid cuticles by combining sugar-type molecules with vapor-phase metal-organic precursors, which we term metallochitins or, more generally, metallosaccharides. The MLD process, featuring mild temperatures and solvent-free conditions, provides exceptional conformality and thickness precision, ensuring highly conformal coatings on diverse high aspect ratio substrates. In vitro testing confirmed that the MLD-grown metallochitins not only promote the growth of various cell lines but also prevent adhesion of both Gram-negative and Gram-positive bacteria. The choice of the metal in the hybrid enables selective antimicrobial activity against Gram-negative bacteria or comprehensive antibacterial effects, which can be controlled as desired.