Impact of albumin corona on mucoadhesion and antimicrobial activity of carvacrol loaded chitosan nano-delivery systems under simulated gastro-intestinal conditions

Emerging antibiotic resistance in pathogens has posed considerable challenges to explore and examine the natural antimicrobials (NAMs). Due to the labile nature of NAMs, nano-delivery systems (NDS) are required to protect them from physiological degradation and allow controlled delivery to the targeted site of infection. In this study, corona modified NDS were developed using bovine serum albumin (BSA) on a chitosan core (CS) for sustained delivery of carvacrol (CAR), a natural antimicrobial agent, in the intestine. The optimal nano-formulations of the core (CS-NDS) and corona modified (BSA-CS-NDS) systems were fabricated with an average diameter of 52.4 ± 10.4 nm and 202.6 ± 6 nm, respectively. A shift in zeta-potential (ZP) from positive (+21 ± 3.6 mV) to negative values (-18 ± 2.6 mV) confirmed the electrostatic deposition of BSA corona on CS core. Under the influence of various simulated gastrointestinal conditions, BSA corona provided extra stability to NDS (ZP -38.5 mV), by ensuring delayed release and limited degradation in the gastric conditions. Mucoadhesive studies with quartz crystal microbalance with dissipation (QCM-D) revealed that BSA corona reduced the mucoadhesion of NDS at gastric pH, which enabled the effective delivery of CAR to the intestinal phase for successful eradication of Salmonella enterica.