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Full text release has been delayed at the author's request until May 31, 2026

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Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles and the Effect of Synthesis pH

Deng, Leyi
http://rave.ohiolink.edu/etdc/view?acc_num=akron1712927443750231

Abstract Details

2024, Master of Science, University of Akron, Polymer Science.
Dental caries are caused by oral microbiota producing acid via sugar metabolism. Streptococcus mutans (S. mutans) is the predominant aerobic cariogenic pathogen within dental plaque, whereas Fusobacterium nucleatum (F. nucleatum) represents anaerobic bacteria associated with periodontal disease and some inflammatory diseases, including irritable bowel syndrome and rheumatoid arthritis. Bacteria may develop antimicrobial resistance to traditional antibiotics and Ag NPs but not Silver-doped hydroxyapatite nanoparticles (AgHAP NPs), making the latter an attractive biocompatible material for dental applications. The Sahai group’s previous studies showed (a) Ag content of AgHAP NPs depends on synthesis pH and (b) AgHAP NPs' antibacterial effects were shown by inhibition zone experiments but, in an apparent contradiction, relatively high MIC values were obtained for anaerobic bacteria F. nucleatum. The goals of the present study were to determine the antibacterial effects of AgHAP NPs with different synthesis pHs (pH7.5, 8, 8.5) on aerobic S. mutans and anaerobic F. nucleatum and to determine why MIC values were unexpectedly high for anaerobic strain F. nucleatum. Antimicrobial tests (MIC, inhibition zone, SEM visualization) showed antibacterial activity of AgHAP NPs which was related to Ag content and Ag+ release from NPs. Ionic conductivity measurements for Ag+ solutions with or without L-Cysteine under anaerobic and aerobic conditions were conducted, showing a dramatic drop in conductivity value only with the presence of L-Cysteine. Accepting the hypothesis that Ag+-thiol complexation reduces the availability of the toxic agent (Ag+) in the growth medium of F. nucleatum, which requires L-Cysteine to maintain anaerobic conditions. Thus, MIC values obtained were spuriously high, while inhibition zone results showed the true efficacy of AgHAP NPs against F. nucleatum.
Nita Sahai (Advisor)
Ali Dhinojwala (Committee Member)
44 p.
Biochemistry; Chemistry; Dentistry; Materials Science
periodontitis, silver-doped hydroxyapatite nanoparticles, pH effect, aerobic and anaerobic bacteria, antimicrobial, oral diseases, Ag+-cysteine complex

Recommended Citations

Citations

  • Deng, L. (2024). Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles and the Effect of Synthesis pH [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1712927443750231

    APA Style (7th edition)

  • Deng, Leyi. Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles and the Effect of Synthesis pH. 2024. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1712927443750231.

    MLA Style (8th edition)

  • Deng, Leyi. "Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles and the Effect of Synthesis pH." Master's thesis, University of Akron, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=akron1712927443750231

    Chicago Manual of Style (17th edition)

akron1712927443750231
© 2024, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.
Release 3.2.12