A biocompatible bacterial cellulose/tannic acid composite with antibacterial and anti-biofilm activities for biomedical applications.

Biofilm-associated infections are in a high rate of recurrence and biofilms show formidable resistance to current antibiotics, making them a growing challenge in biomedical field. In this study, a biocompatible composite was developed by incorporating tannic acid (TA) and MgCl2 to bacterial cellulose (BC) for antimicrobial and anti-biofilm purposes. The morphology was investigated by scanning electron microscopy (SEM), and chemical structure were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectra (XPS). In vitro release profiles of tannic acid revealed that the Mg2+ cross-links help impede the release of TA from BC matrix, while composite BC-TA lacked Mg2+ ionic cross-links, thus more TA was released from the hydrogel. The BC-TA-Mg composites also displayed strong antibacterial activity against S. aureus, E. coli and P. aeruginosa. Moreover, the composites significantly reduced biofilm formation of S. aureus and P. aeruginosa after 24 h incubation by ∼80% and ∼87%, respectively. As a consequence, the BC-TA-Mg composites are a very promising material for combating biofilm-associated infections in biomedical and public health fields.