Investigation of antibacterial effect as In vitro of radiolabeled antibiotic loaded chitosan nanoparticles

The widely use of antibiotics has caused to develop resistance to antibiotics of the bacteria. For this reason, it is necessary to develop new "talented agents" which increase on the effectiveness of antibiotics. Cefpodoxime Proxetil, third generation cephalosporin group, is a broad spectrum antibiotic. Chitosan is an ideal biomaterial because of its properties such biocompatible, cationic, antibacterial, mucoadhesive, natural polymer. The investigations show that the effects of antibacterial drug against microorganisms can be increased by loading them into chitosan nanoparticles. The aim of this work is to investigate on useful potential as a nuclear imaging agent of radiolabeled cefpodoxime proxetil loaded chitosan nanoparticle in the detection of gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) bacterial infections. Chitosan (CS) nanoparticles and Cefpodoxime Proxetil loaded chitosan (CP-CS) nanoparticles were prepared by using ionic gelation method. The nanoparticles were characterized by Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscope (SEM) techniques. The amount of loaded Cefpodoxime Proxetil onto CP-CS nanoparticle was determined by ultraviolet–visible (UV-Vis) spectroscopy. Cefpodoxime Proxetil and Cefpodoxime Proxetil loaded chitosan nanoparticles were radiolabeled with 37 MBq sodium pertechnetate by using 100 μg SnCl2. Radiolabeling yields of radiolabeled Cefpodoxime Proxetil (99mTc-CP) and radiolabeled Cefpodoxime Proxetil loaded chitosan nanoparticles (99mTc-CP-CS) were determined by TLRC method and were found as to be 89±3 % and 94±2 % respectively. While binding efficiency of 99mTc-CP-CS nanoparticles for S. aureus was 99.3 % at 1h; 68.9 % at 2h; 76.9 % at 4h, binding efficiency of 99mTc-CP was 7.2 % at 1h; 9.3 % at 2h; 9.5 % at 4 h. In vitro binding study results indicate that binding efficiencies of 99mTc-CP-CS nanoparticles in S. aureus was higher than that of 99mTc-CP. It was found that binding efficiencies of 99mTc-CP-CS nanoparticles for E. coli (91.2 % at 1 h; 77.9 % at 2h; 58.3 % at 4h) were higher than 99mTc-CP (6.6 % at 1 h; 8.1 % at 2h; 10.3 % at 4 h). These results promise that 99mTc-CP-CS nanoparticles might be an agent for infection nuclear imaging potential. Keywords: chitosan, nanoparticle, cefpodoxime proxetil, antibacterial effect, 99mTc, S. aureus, E.coli