Surface-nanostructured cellulose gauze with terminally aminated low-molecular-weight cellulose for adsorbing bacteria

Abstract Surface nanostructuring of materials is emerging as an antibiotic-free strategy for infection control. We recently demonstrated the decoration of gauze microfibers with nanospike structures via the self-assembly of low-molecular-weight (LMW) cellulose. The resulting nanospiked gauze exhibited bacterial adhesion-promoting effects when protein was present, which were useful for removing pathogenic bacteria from deep burn wounds with protein-containing exudates. However, these effects depend strongly on the presence and concentration of proteins, representing a challenge for reliable clinical implementation. Herein, we present the use of terminally aminated LMW cellulose as a self-assembling building block for the surface nanostructuring of gauze microfibers to achieve bacterial adhesion-promoting effects across a wide range of protein concentrations. Terminally aminated LMW cellulose formed either nanospike or nanofibrillar-network structures, depending on the solvent and coagulant used during self-assembly. Both the aminated nanospikes and the aminated nanofibrillar networks promoted bacterial adhesion under protein-free conditions, likely through electrostatic attraction between the positively charged nanostructures and negatively charged bacterial cells. Moreover, although the effects of the aminated nanospikes were diminished in the presence of proteins with net negative charges, probably because of protein adsorption, the aminated nanofibrillar networks still displayed bacterial adhesion-promoting effects under the same conditions, likely owing to their characteristic nanostructures.