Superabsorbent crosslinked bacterial cellulose biomaterials for chronic wound dressings

•Bacterial cellulose (BC) was crosslinked using citric acid along with novel catalysts.•Crosslinked BC had over 5 times greater water capacity as compared to unmodified BC.•Crosslinked BC had over 6 times slower water release as compared to unmodified BC.•Crosslinked BC had over 1.5x higher water capacity than modern commercial dressings.•Crosslinked BC may find application as a biomaterial for superabsorbent dressings. In this work, we present a novel ex situ modification of bacterial cellulose (BC) polymer, that significantly improves its ability to absorb water after drying. The method involves a single inexpensive and easy-to-perform process of BC crosslinking, using citric acid along with catalysts, such as disodium phosphate, sodium bicarbonate, ammonium bicarbonate or their mixtures. In particular, the mixture of disodium phosphate and sodium bicarbonate was the most promising, yielding significantly greater water capacity (over 5 times higher as compared to the unmodified BC) and slower water release (over 6 times as compared to the unmodified BC). Further, our optimized crosslinked BC had over 1.5x higher water capacity than modern commercial dressings dedicated to highly exuding wounds, while exhibiting no cytotoxic effects against fibroblast cell line L929 in vitro. Therefore, our novel BC biomaterial may find application in super-absorbent dressings, designed for chronic wounds with imbalanced moisture level.