The Inhibiting Effects Of Nano-ciprofloxacin On Pseudomonas Aeruginosa Biofilm Formation

The P.aeruginosa (PA)is a common opportunistic pathogen,and its biofilm(BF) is one of the reasons for the antibiotic resistance.The dense three-dimensional structure of biofilm has a high density of bacteria and lead to a low permeability to antibiotics, the antibiotics can only be applied to the surface of the biofilm rather than to kill the bacteria inside the biofilm and the infection cannot be cured for a long time.Therefore, to solve the low permeability of antibiotics is a promising way for the treatment of the infectious disease caused by biofilm The volume effect, surface effect, quantum size effect and macroscopic quantum tunneling effect of the drug-loading nanoparticles has the potential penetration to the biofilm. To prepare a nanoparticles drug system which have a simple method, better stability and higher drug-loading efficiency through ion gel technology. The good water soluble chitosan chloride (CS) and P-cyclodextrin sulfate (S-β-CD) were selected as the carrier, and the ciprofloxacin hydrochloride(Cip) was selected as the model drug. The present study aims to prepare an ideal ciprofloxacin nanoparticles that can inhibit P.aerμginosa biofilm formation,as well as control its infections effectively.For the optimal experiment, We can prepare an ideal ciprofloxacin nanoparticles when the concentration of the concentration of CS, S-β-CD and Cip all at 1.0mg/ml,the pH value of CS solution at 5.5, the stirring time at 4 hours and the prepared particles have uniform size and regular surface morphology through Zeta potentiometer,Scanning Electron Microscopy,ultraviolet spectroscopy and other characterization methods.The average particle size of ciprofloxacin nanoparticles is 142.9±1.41nm, the Zeta potentials is+62.47 ± 0.28mV and the drug-loading efficiency is 51.21%. Through crystal violet staining,Scanning Electron Microscopy and Laser Confocal Microscopy,we detected the bacteriostatic and anti-biofilm of ciprofloxacin nanoparticles.The results showed that nano-ciprofloxacin has no sinificant inhibition and no killing effect on plankton P.aeruginosa.But it has the effect on inhibiting biofilm formation and also eradicating its mature biofilm, especially reflected in the impact on the density and thickness of biofilm,which have significant differences.This study showed that chitosan-β-cyclodextrin sulfate as the carrier of the nanoparticles drug system is a relatively promising system.It possesses potential appliance value in the treatment of P.aeruginosa and infectious disease caused by its biofilm.The study will provide a strong theoretical support and useful strategy in the treatment of chronic respiratory infection disease,which is related to P.aeruginosa biofilm, and cannot be cured for a long time.