Properties of novel PBC/κ-carrageenan hydrogels: probiotic bacterial cellulose synthesized by co-culture of K. xylinus with L. plantarum or P. pentosaceus.

BACKGROUND: The development of new hydrogels with antimicrobial, biocompatible, and controlled drug-release properties remains a significant challenge for wound-healing applications. The present study primarily focused on the development of PBC/κ-carrageenan composite hydrogels using two different types of probiotic bacterial cellulose (PBC) named as PBC_LP and PBC_PP, which have not been reported previously. METHODS: In this study, two distinct types of probiotic bacterial cellulose (PBC) were synthesized and designated as (PBC_LP) and (PBC_PP). The synthesis of these two distinct types of PBC was accomplished via in situ co-culture of Komagataeibacter xylinus with Lactiplantibacillus plantarum (previously Lactobacillus plantarum) and Pediococcus pentosaceus, separately. "PBC_LP" and "PBC_PP"-based hydrogels were developed by mixing PBCs with κ-Carrageenan using physical and potassium-ion-mediated ionic crosslinking methodologies. The bacterial cellulose (BC)-based hydrogel was selected as a control group for the experimental investigation. RESULTS: Structural characterization by FTIR and XRD confirmed successful integration of BC as well as PBC with κ-Carrageenan through physical and ionic interactions. SEM analysis revealed highly porous, interconnected three-dimensional architectures, which are favourable for biomedical applications. The hydrogels exhibited high porosity, high equilibrium liquid content (>95%), and rapid swelling within 30 min. Ionic crosslinking has been demonstrated to enhance gel fraction and rheological stability, while reducing pore size, porosity, and swelling behavior. Rheological analysis demonstrated stable viscoelastic gel-like behavior and shear-thinning properties, suitable for injectable or adaptable wound-healing materials. In vitro cytocompatibility studies using BALB/3T3 fibroblast cells demonstrated favourable cell viability, particularly for non-crosslinked PBC-based hydrogels, indicating favourable cellular interactions and proliferation. Furthermore, the hydrogels exhibited efficient uptake and a biphasic release profile for Betadine and Gentian Violet, with crosslinked systems showing a more controlled release profile. Importantly, PBC-containing hydrogels exhibited inhibitory activity against Escherichia coli, Staphylococcus aureus, and Candida albicans, which was further enhanced upon loading with antimicrobial agents. CONCLUSION: The PBC/κ-Carrageenan hydrogels developed in this study exhibit a combination of advantageous structural, biological, rheological, antimicrobial, and controlled-release properties. This underscores their potential as multifunctional wound-healing and antimicrobial-delivery systems, making the hydrogel a potential candidate for tissue-engineering and wound-healing applications after in vivo and clinical studies in future work.