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IET Nanobiotechnol. 2015 Dec;9(6):342-8. doi: 10.1049/iet-nbt.2014.0078.

Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria.

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BIOTYC Foundation, C/ Blasco de Garay, 27., 02003 Albacete, Spain.
Institute of Drug Research, School of Pharmacy-Faculty of Medicine, Center for Nanoscience and Nanotechnology and The Alex Grass Center for Drug Design and Synthesis, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, C/ Almansa, 14., 02006 Albacete, Spain.
Department of Nephrology, Complejo Hospitalario Universitario, C/ Hermanos Falco., 02006 Albacete, Spain.
Department of Pathology, Complejo Hospitalario Universitario, C/ Hermanos Falco., 02006 Albacete, Spain.
Prosthodontics Unit, Faculty of Dentistry, The Hebrew University Jerusalem, Jerusalem 91120, Israel.
Division of Infectious Diseases and Clinical Microbiology, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Ave. Reyes Católicos, 2, 28040 Madrid, Spain.
Department of Research and Development, Nanocustom S.L., 02007 Albacete, Spain.


Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 µg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. coli isolates were 12.5 and 25 µg/ml, respectively, whereas the MIC for S. viridans was 100 µg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 µg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 μg/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria.

[Indexed for MEDLINE]

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