In this study, naturally derived cellulose nanofibrils (CNFs), a renewable and easily modified nanomaterial with low cytotoxicity, were rendered bioactive via one-step functionalization with mannopyranoside (CNFs-mannose) for use as a new glyconanomaterial platform for control of bacterial pathogenesis. The recognition affinity of the bioactive surfaces toward fimbriated Escherichia coli was assessed using genetically engineered strains as well as wild-type (WT) MG1655 bacteria. The results revealed high surface coverages of FimH+ (with overexpressed FimH) and WT bacteria on the films of CNFs-mannose due to specific interaction between prevalent mannose on nanofibrils and FimH receptors on E. coli fimbriae. The CNFs-mannose nanofibrils were capable of capturing E. coli from a liquid suspension, as demonstrated either by the nanofibril clusters or by the cellulose filter papers impregnated with CNFs-mannose. More importantly, CNFs-mannose efficiently inhibited adhesion of both FimH+ and WT E. coli to mannosylated surfaces even at a very low concentration, resulting in over 95% reduction of bacterial adhesion. Furthermore, the bioactive nanofibrils showed effective disruption of nonspecific binding of bacteria to abiotic surfaces in flow channel tests. These findings highlight the potential of cellulose nanofibrils as a biocompatible polyvalent nanoscale scaffold and exemplify sugar grafted nanofibrils as novel and effective tools in control of bacterial pathogenesis, bacterial removal, as well as in many other applications.
Keywords: E. coli antiadhesion; bacteria capture; biofunctionalization; cellulose nanofibrils; mannose; nanocellulose.