Super‐Moisturizing Materials from Morphological Deformation of Suprapolysaccharides

Abstract

The evaporative interface on polysaccharides has evolved to form hierarchical structures with moisture sensitivity to enable organisms to live in drying environments. Here, the discovery of the morphological instability of polysaccharides, especially the reversible self-assembly/disassembly between micron-fibers and microparticles in response to changes in aquatic environments, is reported. This is similar but different to the dynamic instability observed in cytoskeletal proteins, in terms of an accompanying the polymeric deformation. The formation of the polymeric fibers containing crystalline structures can be flexibly controlled by controlling the polymer concentration and salt concentration in aqueous mixtures. Moreover, the microparticles having crosslinking points in the interior acquire the ability to retain a larger number of water molecules in drying environments and behave as super-moisturizing materials.

Cyanobacterial supra‐polysaccharide: Self‐similar hierarchy, diverse morphology, and application prospects of sacran fibers

“…As a result, it was developed as a metal‐adsorbent, a nanocomposite, and a gel bead. [ 74–77 ] For the most recent work in 2022, [ 78 ] it was reported that sacran shows morphological instability, particularly reversible self‐assembly/disassembly between micron‐fibers and micro‐particles in response to changes in aquatic environments. By controlling the polymer concentration and salt concentration in aqueous mixtures, it allows for flexible change of the formation of polymeric fibers with crystalline structures.…”

“…As a result, it was developed as a metal-adsorbent, a nanocomposite, and a gel bead. [74][75][76][77] For the most recent work in 2022, [78] it was reported that sacran shows morphological instability, particularly reversible self-assembly/disassembly between micron-fibers and micro-particles in response to changes in aquatic environments.…”

Structural Analyses of Polysaccharides Extracted from Cyanobacterial Extracellular Gels and Oriented Liquid Crystalline Microfiber Processing by Poly(vinyl alcohol)-Assisted Electrospinning

“…Water-soluble polysaccharides have been conventionally obtained from seaweed with a large amount of gel matrices [1][2][3][4][5]. Gelatinous biomaterials of a freshwater unicellular cyanobacterium, Aphanothece sacrum, are traditionally mass-produced in a local river of Japan [6][7][8][9][10][11][12], which has an abundance of a jelly extracellular matrix (ECM) which is a kind of gel with a high water content (97.5%) [13]. The ECM has good viscoelastic properties to reduce the damage of cell bodies from mechanical shocks in a river flow and to keep the algal body size above the centimeter range.…”

“…We hypothesized that this ECM must mainly contain fibrous materials such as polysaccharides to reinforce itself. Therefore, we extracted polysaccharides, specifically, sacran, as a cotton-like foam from ECM of A. sacrum (Figure 1) and discovered that they consisted of sugar chains with a molecular weight (MW: 16 Mg/mol) [13] much higher than those of other polysaccharides used as superabsorbers [14,15] Most plants contain giant natural polymers such as polysaccharides, lignin, cellulose, hemicellulose, etc., and self-orientation phenomena are observed in plant cell walls, which may play a role in reinforcing plant bodies [16,17]. The extraction of intact celluloses with high MW is challenging due to its high crystallinity and insolubility.…”