Distinguishing anti-PEG antibodies by specificity for the PEG terminus using nanoarchitectonics-based antibiofouling cello-oligosaccharide platforms

Nanoarchitectonics of cello-oligosaccharides: A route toward artificial nanocelluloses

Colloidal cellulose nanoparticles, or nanocelluloses, are derived from natural cellulose sources in a top-down manner via physical and/or chemical treatments that extract naturally occurring cellulose nanostructures. Naturally derived nanocelluloses have been successfully commercialized in various fields, and their potential is still being widely explored in materials science. Moreover, recent advances in nanoarchitectonics of low-molecular-weight cellulose, or cello-oligosaccharides, have opened new avenues for developing "artificial nanocelluloses". Artificial nanocelluloses composed of cello-oligosaccharides synthesized via enzymatic oligomerization or solid-phase glycan synthesis technology are termed "synthetic nanocelluloses". These nanostructures are abiotically constructed in a bottom-up manner at the molecular level via self-assembly of cello-oligosaccharides in vitro. Modulation of the assembly process and molecular design provides control over the molecular alignment, nanomorphology, and surface functionality of artificial nanocelluloses. This review summarizes recent research progress in artificial nanocelluloses, from the preparation and self-assembly of cello-oligosaccharides to their potential applications.

Nanospiked Cellulose Gauze That Attracts Bacteria with Biomolecules for Reducing Bacterial Load in Burn Wounds

Nanostructuring surfaces is an emergent strategy to endow materials with abilities to combat pathogenic bacteria. Nevertheless, it remains challenging to create nanospike structures on the curved surfaces of polymer materials, including gauze and other microfibrous medical materials. Additionally, the effects of nanostructured surfaces on bacteria in the presence of proteins and in vivo remain largely unexplored. Herein, we demonstrated the decoration of gauze microfiber surfaces with nanospike structures via the self-assembly of cello-oligosaccharides and investigated the effects of the nanospiked gauze on bacteria in the presence of proteins. The nanospiked gauze had low bacterial adhesion properties in the absence of proteins, whereas in the presence of proteins, it promoted bacterial adhesion. Analyses suggested that the adsorbed protein layers on the nanospikes were involved in the promoted bacterial adhesion. Furthermore, the bacterial adhesion-promoting effects were exploited to remove pathogenic bacteria from burn wounds with exudate containing proteins using the nanospiked gauze.

Freeze-Dryable, Stable, and Click-Reactive Nanoparticles Composed of Cello-oligosaccharides for Biomolecular Sensing

Nanoparticles have been widely used as platforms for biomolecular sensing because of their high specific surface area and attractive properties depending on their constituents and structures. Nevertheless, it remains challenging to develop nanoparticulate sensing platforms that are easily storable without aggregation and conjugatable with various ligands in a simple manner. Herein, we demonstrate that nanoparticulate assemblies of cello-oligosaccharides with terminal azido groups are promising candidates. Azidated cello-oligosaccharides can be readily synthesized via the enzyme-catalyzed oligomerization reaction. This study characterized the assembled structures of azidated cello-oligosaccharides produced during the enzymatic synthesis and revealed that the terminal azidated cello-oligosaccharides formed rectangular nanosheet-shaped lamellar crystals. The azido groups located on the nanosheet surfaces were successfully exploited for antigen conjugation via the click chemistry. The resultant antigen-conjugated nanosheets allowed for the quantitative and specific detection of a corresponding antibody, even in 10% serum, owing to the antifouling properties of cello-oligosaccharide assemblies against proteins. It was found that the functionalized nanosheets were redispersible in water after freeze-drying. This remarkable characteristic is attributed to the well-hydrated saccharide residues on the nanosheet surfaces. Moreover, the antibody detection capability did not decline after the thermal treatment of the functionalized nanosheets in a freeze-dried state. Our findings contribute to developing convenient nanoparticulate biomolecular sensing platforms.

Surface-mediated self-assembly of click-reactive cello-oligosaccharides for fabricating functional nonwoven fabrics

Polymer fabrics are versatile materials used in various fields. Surface modification methods for hydrophobic polymer fibers have been developed to endow the materials with water wettability and functionality. Nevertheless, it remains a challenge to freely introduce functional groups to polymer fiber surfaces in a simple manner. Herein, we report the decoration of nonwoven fabric surfaces with azidated cello-oligosaccharide assemblies via molecular self-assembly. Cello-oligosaccharides with a terminal azido group were enzymatically synthesized and allowed to self-assemble in polyolefin, polyester, and vinylon nonwoven fabrics. It was found that the functional oligosaccharides formed bark-like assemblies on the nonwoven fiber surfaces, probably through heterogeneous nucleation. The hydrophilic oligosaccharide assemblies made the hydrophobic nonwoven surfaces water-wettable. Moreover, the azido group at oligosaccharide terminal was available for the post-functionalization of the modified nonwovens. In fact, an antigen was successfully conjugated to the modified nonwovens via the click chemistry. The antigen-conjugated nonwovens were useful for the specific and quantitative detection of a corresponding antibody. Our findings demonstrate the great potential of cello-oligosaccharide assembly for the functionalization of fabrics and other polymeric materials.