Flavonoids and omega-3 fatty acid-loaded lipid nanocarriers as promising antimicrobial biofilm strategies

Introduction: Biofilms are 3D microorganism clusters adhered to a biotic (host tissue) or abiotic (inert material) surface or interface and encased in a protective self-produced hydrated extracellular matrix of proteins, polysaccharides, and extracellular DNA. Biofilms on medical devices and body tissues cause many antibiotic treatment failures and chronic infections. Biofilm removal is hard, and new strategies are required to eliminate it. Nanocarriers (NC) can transport antibiofilm agents. NCs' small size, large surface, adhesion, and deformability can be tuned to enhance passage of antibiofilm agents through the biofilm barrier. Methodology: Lipid NC, containing flavonoids (quercetin and resveratrol) and omega-3 fatty acids, were produced by lipid film hydration and high-shear homogenization techniques, and characterized regarding size, surface charge and shelf stability. Biofilm susceptibility trials assessed NC's effect on S. aureus biofilms using colony-forming unit (CFU) counting. Biofilms formed by adding 1 mL of S. aureus (1 × 106 CFU mL−1) to 24-well tissue culture plates with coverslips, incubating for 2 hours at 37°C and 100 rpm. After rinsing with 0.9% NaCl, fresh medium containing NC was added for further incubation (24 and 48 hours, 37°C, 100 rpm). Tryptic soy broth without NC served as a positive control. Sessile populations were detached via 1-minute sonication. Results and conclusions: Lipid nanocarriers were homogeneous, with hydrodynamic size 70%. Preliminary results show that flavonoid-loaded lipid nanocarriers may be a promising strategy as anti-biofilm agent.