Preparation of gold nanoparticles by novel bacterial exopolysaccharide for antibiotic delivery.
OBJECTIVE
To develop potent drug delivery agents to treat multidrug resistant (MDR) bacterial infections using gold nanoparticles (AuNPs) prepared by bacterial exopolysaccharide (EPS) being a reducing and stabilizing agent.


METHODS
Gold nanoparticles were prepared by EPS, extracted from Lactobacillus plantarum. AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), zeta potential and Fourier transform infrared spectroscopy. Antibiotics used for functionalization of AuNPs were levofloxacin, cefotaxime, ceftriaxone and ciprofloxacin. The resulted functionalized AuNPs were tested against various MDR bacteria by employing different assays such as well diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time killing assay.


RESULTS
The nanostructures exhibited excellent bactericidal activity and reduced MIC and MBC against MDR Gram positive and Gram negative bacteria compared to free drugs. Escherichia coli was the most susceptible MDR bacteria followed by Klebsiella pneumoniae and Staphylococcus aureus. TEM results revealed that the bactericidal activity of nanostructures could be mediated by penetration, loss of cytoplasmic contents and cell lysis.


CONCLUSIONS
Antibiotic functionalized nanostructures were more potent than free drugs and could be used as potent drug delivery vehicles.
Department of Biotechnology, N.M.A.M. Institute of Technology, Nitte-574110, India.
Pradeepa
Department of Biotechnology, N.M.A.M. Institute of Technology, Nitte-574110, India. Electronic address: drvidyasm@nitte.edu.in.
S M
SM
Vidya
Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal 576104, India.
Srinivas
S
Mutalik
Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Mangalore-575025, India.
K
K
Udaya Bhat
Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Mangalore-575025, India.
Prashant
P
Huilgol
Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal 576104, India.
Kiran
K
Avadhani
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D006046:Gold / Q000737:chemistry*; D007778:Lactobacillus / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D011134:Polysaccharides / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared
D000900:Anti-Bacterial Agents; D011134:Polysaccharides; D006046:Gold
Bactericidal activity; Drug delivery; Exopolysaccharide; Functionalized gold nanoparticles; Multidrug resistant