Enhanced antibiofilm activity of ciprofloxacin-loaded quatsomal gel against Multidrug-Resistant Staphylococcus aureus (MRSA)

MRSA biofilms remain a major challenge in clinical settings because they reduce antibiotics susceptibility and contribute to persistent infections. This current study was designed to evaluate quatsomal gel as a proof-of-concept topical ciprofloxacin delivery platform aimed at enhancing localized antimicrobial and antibiofilm activity against MRSA. The ciprofloxacin loaded quatsomes were prepared using a probe-sonication method with CTAB and cholesterol and were then incorporated in a hydroxypropyl methylcellulose-based gel. The resulting formulation was characterized by particle size, zeta potential, TEM, entrapment efficiency, and FTIR spectroscopy. A HPMC-based gel was developed for topical delivery and its antimicrobial and antibiofilm activities were assessed. An in vivo wound excision model in mice was used to evaluate the therapeutic efficacy of this formulation. The loaded formulation exhibited a mean particle size of 153 ± 1.3 nm, a zeta potential of + 34.6 ± 1.4 mV, and 79 ± 0.4% ciprofloxacin entrapment efficiency. FTIR confirmed drug incorporation, while the pH, spreadability, and viscosity were remained within appropriate ranges for skin application. The optimized formulation significantly reduced MRSA growth, with a minimum inhibitory concentration of 64 µg/mL and 91.32 ± 0.14% biofilm inhibition. In vivo studies showed that the ciprofloxacin-loaded quatsomes treated group had 98% wound contraction and ~ -4 log 10 CFU reduction, compared with 82% wound contraction and ~ -1.8 log 10 CFU reduction in ciprofloxacin treated group. Ciprofloxacin-loaded quatsomes showed significant antimicrobial and antibiofilm activity against MRSA in both in vitro and in vivo analysis, representing a promising proof-of-concept approach for localized ciprofloxacin delivery in biofilm-associated skin infections. Further studies should focus on pharmacokinetic evaluation, safety profiling and clinical evaluation to facilitate translation into an effective nanomedicine.