Tunable cellulose-polylysine hydrogels via dual dynamic crosslinking: Breaking the resistance barrier in comman bacteria and Vibrio parahaemolyticus infections.

This study develops a dual-dynamic-crosslinked hydrogel via Schiff base and borate ester networks using dialdehyde cellulose (DAC) and ε-polylysine (ε-PL), with tunable properties and breakthroughs in combating drug resistance. DAC (3.83 ± 0.25 mmol/g aldehyde content, 80.21 % yield) crosslinked with ε-PL at 1:0.45 M ratio yields DAC-ε-PL-3 (92.37 % productivity, 8.26 mg/g lysine). The PVA-DAC-ε-PL hydrogel features 1.05-8.10 μm pores, 85.56-93.19 % water retention, shear-thinning rheology, and excellent mechanical properties. It shows broad-spectrum activity against 9 pathogens, including multidrug-resistant (MDR) Vibrio parahaemolyticus (HG9G, HG3G, HC3G), with an 8.75 mg/mL MIC against HG9G and 12.35-16.97 mm inhibition zones. The antibacterial mechanism against MDR strains involves membrane disruption (membrane disruption observed by scanning electron microscopy, elevated conductivity, AKP leakage), respiratory chain inhibition, and downregulation of toxR, tetA, and sul2. Sustained activity inhibits MDR strains for 24 h. This eco-friendly platform addresses antibiotic resistance, with promise for wound dressings and food packaging.