Effective and simple one-step strategy for preparation of “clickable” cellulose modules: support to build antibacterial materials

An efficient and simple way to generate “clickable” cellulose modules called alkyne-functionalized cellulose fibers (ACFs) for click reaction was presented. This method is only based on one step reaction: propargyl methacrylate (PMA) with pendant alkynyl groups was grafted onto the surface of cellulose fibers (CFs) using ceric ammonium nitrate as the initiator in aqueous medium. This has been providing a new and versatile platform for the wide utilization of cellulose resources and creation of novel functional materials. The effect of process variables on grafting copolymerization of PMA was investigated and suitable preparation conditions were identified. The clickability of ACFs was evaluated by reacting with two azides. The antibacterial cellulose functional material was achieved through incorporation of a “clickable” handle (alkynyl groups) to cellulose fibers followed by rapid attachment of β-cyclodextrin with an azide tag using copper-catalyzed click reaction and loading with ciprofloxacin hydrochloride (CipHCl). Pure CFs and ACFs showed a little affinity to CipHCl, whereas click products (ACFs@Azide-β-CD) increased the loading amount dramatically because the equilibrium amount was higher than pure CFs and ACFs. Meanwhile, the release process of CipHCl from ACFs@Azide-β-CD was prolonged to reaches the equilibrium. The ACFs@Azide-β-CD loaded with CipHCl showed excellent antibacterial activity against Escherichia coli. The ACFs@Azide-β-CD loading CipHCl have considerably longer bacterial activity against E. coli compared to CFs and ACFs.