Reuterin integrated as dynamic imine crosslinks strengthens creatine modified chitosan hydrogel and boosts...

We report a hydrogel platform that integrates a natural antimicrobial as part of the network rather than as a releasable additive. Creatine was first grafted onto methacrylated hydroxybutyl chitosan to obtain an injectable, thermoresponsive, and photocurable backbone (HBC_m_Cre). Reuterin (Reu) was subsequently incorporated through dynamic imine (Schiff-base) coupling, functioning as structural crosslinks that both reinforce the network and sustain local antimicrobial activity. ¹H NMR and FTIR confirmed the successful synthesis. The resulting HBC_m_Cre/Reu hydrogel exhibited smooth injectability, rapid photocuring, and stepwise enhancement in mechanical performance (HBC: 0.45 ± 0.09 N, HBC_m_Cre: 1.27 ± 0.08 N, HBC_m_Cre/Reu: 1.96 ± 0.09 N), indicating that the integration of Reu as a network-forming unit significantly strengthens the gel architecture. The system maintained high biosafety (NIH 3T3 viability >95 %, hemolysis <2 % at 10 mg/mL) and showed potent antibacterial activity, achieving >95 % killing of E. coli and S. aureus and effective biofilm disruption. In vivo rat tail-amputation experiments further demonstrated efficient bleeding control, with creatine grafting markedly reducing bleeding time and blood loss, while Reu primarily contributed to mechanical reinforcement and antibacterial protection rather than direct hemostatic enhancement. These findings establish a distinct structural design strategy where a natural metabolite and antimicrobial are co-integrated into a single hydrogel network, providing a robust and multifunctional platform for potential application in infection-resistant wound care.