Self-assembly of bacteria cellulose hydrogels carrying multiple carbohydrate appendages to visualize carbohydrate-carbohydrate interactions.

Nata de coco was chemically modified to afford the bacterial cellulose hydrogels carrying terminal alkynes. The resultant hydrogels were then converted into hydrogels carrying lactosides or those carrying α-2,3-sialyllactosides by the Cu ⁺ -catalyzed alkyne-azide cyclization. The stable homo association of the hydrogels carrying lactosides was observed in an aqueous solution containing Ca ²⁺ , thereby demonstrating the Ca ²⁺ -mediated lactoside-lactoside interactions. Ca ²⁺ also stabilized the hetero associations among the hydrogels carrying lactosides and those carrying α-2,3-sialyllactosides, thereby also demonstrating the Ca ²⁺ -induced interactions between the lactosides and the α-2,3-sialyllactosides. The sizes of these hydrogels were of the order of ca. 5 mm, and their associations could thus be readily monitored with the naked eye.
(Copyright © 2019 Elsevier Ltd. All rights reserved.)