Design and development of dual drug-loaded liposomes encapsulating gentamicin and curcumin via microfluidic synthesis: A Box-Behnken experimental approach

Curcumin (Cur), a bioactive compound from Curcuma longa , is known for its antimicrobial activity, and its combination with gentamicin (Gen) has shown addictive effects against Pseudomonas aeruginosa, Enterococcus faecalis , and Staphylococcus aureus by reducing their minimum inhibitory concentrations (MIC). However, the development of a dual-drug delivery system faces challenges, such as the modification of liposome bilayer properties by hydrophobic drugs, which can affect drug penetration and in vivo release, as well as achieving optimal encapsulation efficiency. This study aimed to optimize gentamicin/curcumin-loaded liposomes (GenCur-Lips) for enhanced antibacterial therapy. To achieve this, a microfluidic synthesis approach was employed, and optimization was carried out using the Box-Behnken Design (BBD). The independent variables were curcumin concentration (X1), lipid concentration (X2), and flow rate (X3), while the dependent variables included particle size (Y1), curcumin encapsulation efficiency (Y2), and gentamicin encapsulation efficiency (Y3). The optimized GenCur-Lips formulation exhibited a particle size of 173.03 ± 0.75 nm, a polydispersity index (PDI) of 0.121 ± 0.012, and encapsulation efficiencies of 94.69% ± 0.08% for curcumin and 95.06% ± 0.31% for gentamicin. In vitro studies demonstrated that GenCur-Lips displayed enhanced drug release kinetics and antibacterial activity against E. coli and S. aureus compared to free-drug formulations. The application of the Design of Experiments (DoE) approach using BBD successfully optimized the GenCur-Lips formulation, which significantly enhanced drug permeability and antibacterial activity, making it a promising delivery system for effective antibacterial therapy.