Interaction of VariousEncapsulated Antipathogenic Drugs with Phospholipid Liposomes

Abstract

Antibiotics are so important for treating bacterial infections. Yet, unfortunately bacteria nowadays are capable of mutating and developing resistance to these antibiotics by time. They can easily evolve and change their structure by self-encoding a new set of modified genes programmed to combat the drug so the antibiotic becomes less effective towards it. This antimicrobial resistance problem is becoming a global issue because infections caused by these resistant microorganisms often fail to respond to the standard treatment, resulting in prolonged illness and greater risk of death. Therefore, the search for a new drug delivery system was an obligation. That is why liposomes were introduced as an effective drug carrier. Liposomes have proved to be an efficient drug delivery system. They are capable of targeting drugs into desired tissues. This can decrease or even demolish the cytotoxic effect of those drugs on healthy tissues and increase the overall efficiency of those administrated drugs. In this study, different antibiotics from the aminoglycosides and cephalosporins families were encapsulated into diverse formulations of phosphatidylcholine liposomes. Their size distributions and zeta potentials were measured. Their physical characterization was followed by testing the efficiency of the incorporated drug delivery on both gram +ve and gram –ve bacteria. It was observed that DMPC liposomes had the most efficient drug delivery into bacterial cells due to their very small size distributions. FTIR spectroscopy also proved that all of the examined antibiotics could be intercalated in both the aqueous moiety and the bilayer membrane of the DMPC liposomes. To conduct these experiments, various techniques were used. Dynamic light scattering technique was used for the physical characterization of liposomes in the Institute of Complex Systems ICS7 in Forchungszentrum Jülich, Germany. The FTIR measurements were carried out in the research institute of ophthalmology, Giza, Egypt. Finally, the microbiological Abstract VIII experiments were carried out in the microbiology department, faculty of science, Ain shams university, Cairo, Egypt. All of the DMPC liposomal-antibiotics inspected had the smallest size distributions and a higher antibacterial efficiency than the traditional antibiotics in their free state. Aminoglycosides and cephalosporins proved their ability to intercalate themselves in both the aqueous moiety and the bilayer membrane of DMPC liposomes. FTIR spectroscopy proved that most of the antibiotics interactions with the liposome happened in the head (NH-OH) and phosphate group regions and that cefotaxime induced the biggest interactions with the bilayer membrane of the DMPC liposome prompting the highest conformational changes in it. The encapsulated antibiotics concentrations could even be reduced into 2 and 4 times fold and still had better antibacterial effect than the traditional free antibiotics.