The Effect of Temperature and Acidity on ‎Antimicrobial Activities of Pristine ‎MWCNTs and MWCNTs-Arg

Document Type: Research Paper

Authors

1 ‎Hematology and Oncology Research Center, Shahid Sadoughi Hospital, Shahid Sadoughi ‎University of Medical Sciences and Health Services, Yazd, Iran.‎ ‎

2 Farhangian University at Esfahan, Esfahan, Iran.‎

3 ‎Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of ‎Mashhad, Mashhad, Iran. ‎

4 ‎Department of Nano Biotechnology, Faculty of Biological Sciences, Tarbiat Modares ‎University, Tehran 14115, Iran.‎

5 ‎Department of Reproductive Biology, Yazd Reproductive Sciences Institute, ‎Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical ‎Sciences, Yazd, Iran.‎

6 ‎Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843, ‎United States.‎

7 ‎Pediatric Cell Therapy Research Center, Tehran University of Medical Sciences, ‎Tehran, Iran.‎

8 ‎Department of Pediatrics, Shahid Sadoughi University of Medical Sciences, Yazd, ‎Iran.‎

9 ‎Abadan Faculty of Medical Sciences, Abadan, Iran

10 ‎Reproductive Immunology Research Center, Shahid Sadoughi University of Medical ‎Sciences, Yazd, Iran.‎

11 ‎Department of Microbiology, Faculty of Medicine, Shahid Sadoughi University of Medical ‎Sciences, Yazd, Iran.‎

Abstract

   Carbon nanotubes (CNTs) have very promising applications for inhibition of microbial growth. The aim of this study is investigation and comparison of the effect of temperature and acidity on antimicrobial activities of pristine Multiwalled Carbon nanotubes (MWCNTs) and Multiwalled Carbon nanotubes-Arginine (MWCNTs-Arg). Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were calculated in range of temperature (25, 37 and 42 ºC) and pH (4.2, 7.2, and 10) on Staphylococcus aureus. The results approved that pristine and functionalized MWCNTs have broad-spectrum antimicrobial activities against examined pathogen. Between these agents, MWCNTs-Arg and pristine MWCNTs and have the highest inhibitory activity on microbial growth, respectively. The MBC value of MWCNTs was improved by amino acid functionalization. The optimal pH for antimicrobial activity of pristine MWCNTs and MWCNTs-Arg are 4.2 and 7.2 and optimal temperatures are 42 ºC and 42 ºC, respectively. There is no change on optimal temperature of MWCNTs by this functionalization, but functionalization of MWCNTs by Arg enhanced its antimicrobial activity and led to change of optimal pH of MWCNTs for antimicrobial activity. This changes lead to suitable improvement of antimicrobial activity in neutral and biological pH.

Keywords