Antibacterial activity of cationised and non-cationised placebo lipidic nanoemulsion using transmission electron microscopy

Abstract

The primary aim of the study was to observe the morphological changes taking place on Escherichia coli when treated with non-cationised placebo lipidic emulsion (NCPLE) and cationised placebo lipidic emulsion (CPLE). The particle size of NCPLE and CPLE indicated the mean diameter of 10.77 ± 0.20 nm and 56.98 ± 1.718 nm, respectively. The zeta potential of NCPLE and CPLE depicted the potential of −10.8 ± 0.80 mV and +20.9 ± 3.25 mV, respectively. Agar diffusion study indicated higher inhibition zone of 21.4 ± 0.85 mm for CPLE as evaluated against 14.7 ± 0.76 mm for NCPLE. Transmission electron micrographs of Escherichia coli treated with NCPLE and CPLE showed the potential of blank nanoemulsions as antibacterial, which can be used as a therapeutic agent. The bacterial cell being negatively charged attracts the cationised nanoemulsions from the bulk of dispersion. As the concentration of nanoemulsion increased in the vicinity of the bacterial cell, the degree of collisions increased between the cationised nanoemulsion leading to coalescence and the formation of a pool of emulsion containing bacterial cells leading to cell death. The study demonstrated that placebo lipidic nanoemulsion (NCPLE & CPLE) may itself be used as an active therapeutic agent for the treatment of bacterial infections. Moreover, it can also be used as a carrier system for antibacterial drugs for the two-pronged synergistic effect.

Keywords:

• transmission electron microscopy
• cationic lipids
• photon correlation spectroscopy
• Escherichia coli

Acknowledgements

This research work was financially supported by University Grants Commission, Government of India, vide sanction letter number ‘41-1423/2012 (SR)’, dated 30 July 2012, granted to Mrs Neeru Singh.

Declaration of interest

Authors report no conflict of interest. The authors alone are responsible for the contents and the writing of the paper.