Investigation of Lignin-Loaded Cinnamaldehyde Nanoparticles as Antibacterial Material and Their Sustained Release Mechanism

In this study, lignin-loaded cinnamaldehyde nanoparticles (Lig-CIN NPs) were successfully developed as high-efficiency nanoantibacterial materials through antisolvent precipitation loading of the natural antimicrobial agent cinnamaldehyde (CIN). The results demonstrate that Lig-CIN NPs achieved efficient encapsulation of CIN while significantly enhancing its thermal stability and storage stability. The synergistic antibacterial effect between lignin and CIN yielded sustained inhibition rates of 83% against <i>E. coli</i> and 90% against <i>S. aureus</i>, markedly surpassing the efficacy of individual components. Release kinetics and molecular simulation studies revealed that the sustained release behavior of CIN is primarily regulated by hydrophobic interactions and hydrogen bonding between the hydrophobic cavities of lignin and CIN molecules, elucidating the interaction mechanism at the molecular level. This research provides a novel strategy for designing efficient and sustainable phytogenic antibacterial delivery systems.