Antibiofilm and Molecular Effects of Ceftriaxone-loaded PLGA Nanoparticles Against Clinical Haemophilus Influenza

Haemophilus influenzae biofilm-related infections are a significant issue of therapeutic challenge because these infections are resistant to antibiotics and associated with a high recurrence rate. Nanotechnology in drug delivery systems can help improve the antimicrobial efficacy through better penetration and sustained release in biofilms.

The development of a ceftriaxone-loaded poly (lactic-co-glycolic acid) (PLGA) nano-delivery system was done through the double-emulsion solvent evaporation procedure. Nanoparticles have been characterized in terms of size, morphology, and encapsulation efficiency. Minimum inhibitory concentration (MIC) testing and biofilm assays were used to measure the antimicrobial activity. Crystal violet staining was employed to measure biofilm biomass, whereas colony-forming unit (CFU) was used to measure bacterial viability. At 6 and 24 hours, RT-qPCR was done on adhesion/ biofilm-related genes (hia, hmw, hif, luxS) and resistance/ stress genes (blaTEM, blaROB-1, ftsI, acrB).

PLGA-ceftriaxone formulation was found to have better antibiofilm activity than free ceftriaxone. A sharp decrease in biofilm biomass and viable cell counts was observed, and a relationship was found between biofilm inhibition and decreased bacterial viability. The RT-qPCR result showed the down-regulation of adhesion and quorum-sensing genes, as well as the overall decrease in the resistance and stress-related gene expression, especially at 24 hours.

It can be inferred that the enhancement in the performance of the nano-formulation can be explained by the sustained drug release, increased penetration into the extracellular polymeric matrix, and extended exposure to localized antibiotics.

Ceftriaxone-loaded PLGA nanoparticles should be further investigated in in vivo and translational studies as they may be an effective in vitro antibiofilm delivery method against clinical H. influenzae isolates.