Spatiotemporal integration of nano-encapsulated phytochemicals during bacterial cellulose biosynthesis for mechanically reinforced antibacterial films

The integration of bioactive compounds into bacterial cellulose (BC) remains challenging due to poor penetration and non-uniform distribution associated with conventional post-synthesis loading methods. This research intends to enhance the physicochemical and bioactive characteristics of bacterial cellulose by the incorporation of nano-encapsulated Anredera cordifolia leaf extract. In this study, a biosynthesis-coupled sequential spray strategy was developed to incorporate nano-encapsulated Anredera cordifolia (NAc) extract into BC during fibril formation ( in situ ) and utilize spatiotemporal incubation period. Nanoencapsulation using Pluronic F127 produced stable nanocarriers with controlled particle size and low polydispersity, enabling effective interaction with the evolving cellulose network. The morphology, FTIR spectra, mechanical properties, and antibacterial properties of the prepared films and bio compound particles were systematically evaluated. SEM results showed that Anredera cordifolia extract was successfully encapsulated, characterized by a smooth molecular surface. In SEM BC/NAc, the integration did not damage the pore structure of BC but strengthened the fibril structure and the fibrils had a thicker layer. In PSA results, the particle size was on the scale of 44-121 nm. Most importantly, the resulting composites exhibited significantly enhanced mechanical properties, with tensile strength increasing by up to six-fold, where pure BC had a tensile strength 5 MPa while modification with NAc increased the tensile strength to 30 MPa relative to pure BC. In addition, strong antibacterial activity from BC/NAc biomaterials, twofold increase compared to NAc, was observed against both Gram-positive and Gram-negative bacteria, confirming the functional effectiveness of the incorporated phytochemicals. Overall, this study demonstrates a process-driven approach for engineering multifunctional BC-based biomaterials and provides new insights into the design of bioactive cellulose composites for wound dressing applications.