Curcumin loaded starch-based aerogels interfere with quorum sensing regulated virulence functions and biofilm of bacterial pathogens

Abstract

Over the last two decades, the sharp escalation of antimicrobial resistance (AMR) has emerged as a formidable threat to human health. This pressing situation demands innovative interventions to combat infectious diseases. Aerogels, characterized by their nanostructured composition and high porosity, present a promising avenue. In this study, we manufactured curcumin loaded starch-based aerogels (CSA) and evaluated their impact on the quorum sensing (QS) mechanism in Gram-negative bacteria. Fourier-transform infrared (FTIR) analysis highlighted the presence of cellulose hydroxyl groups engaged in hydrogen bond formation. Thermogravimetric analysis (TGA) revealed that over 50 % of the initial mass was lost when CSA underwent heating to 350 °C. Microscopic examination showcased a uniform and compact pattern, suggesting reduced pore distribution. The elemental composition analysis indicated that carbon and oxygen constituted 23.00 % and 77.00 % of the weight, respectively. The presence of CSA resulted in over 30.4 % inhibition of violacein pigment production. Furthermore, CSA modulated pyocyanin production, pyoverdin production, LasB elastase activity, and rhamnolipid production by 34.4 %, 31.07 %, 22.7 %, and 19.7 %, respectively. The total exoproteases, cell surface hydrophobicity and exopolysaccharide production in E. coli, L. monocytogenes, S. marcescens, and P. aeruginosa, experienced a significant decrease at sub-MICs. Production of biofilms as well as the mature biofilms in test bacteria were reduced in dose-dependent manner significantly. Due to their antibiofilm and anti-quorum sensing properties, these CSAs could prove to be functional biomaterials with versatile applications, particularly in the food industry.

Keywords

• Aerogel
• Biofilm
• Quorum sensing
• Virulence
• Antimicrobial resistance