# Novel Biofilm Inhibitors of Oral Streptococci

> **NIH NIH K08** · UNIVERSITY OF ILLINOIS AT CHICAGO · 2021 · $138,254

## Abstract

PROJECT SUMMARY/ABSTRACT
Dental caries is the most common childhood disease in today’s society. Untreated dental caries contributes to
oral pain, abscess development, tooth loss and poor esthetics affecting both the health and self-esteem of
children. Restorative dental procedures are the standard of care in the treatment of dental caries yet often are
not feasible for those children of low socioeconomic status. Long lasting preventive methods are the treatment
of choice in such patients that cannot routinely see dental professionals. The etiology of dental caries in pediatric
patients is attributed to tooth-borne biofilms comprising Streptococcus mutans and Streptococcus sobrinus. This
bacteria-based etiology has led clinicians to turn to tooth-applied, bactericidal silver (Ag) agents as a cost-
effective method to arrest dental caries. However, Ag use is associated with tooth staining, tissue toxicity and
disruption of the microbiota calling into question their repeated application and long-term use. This proposal
sets forth the first example of cerium oxide nanoparticles (CeO2-NP) as non-bactericidal biofilm inhibitors of oral
Streptococci. Preliminary results demonstrate in vitro biofilm inhibition of S. mutans and S. sobrinus by CeO2-
NP prepared by Ce(IV) ammonium salt hydrolysis. CeO2-NP prepared by the current methodology have exhibited
a higher efficacy in limiting in vitro biofilm formation as compared to AgNO3, the current standard for topical
treatment in pediatric dental caries arrest. Importantly, the mechanism of biofilm inhibition by CeO2-NP is non-
bactericidal as opposed to AgNO3. A significant challenge of tooth-applied agents is maintaining a clinically
effective concentration of the agent at the tooth surface. This proposal is unique in that it sets forth not only non-
bactericidal biofilm inhibitors for tooth application, but a method of retaining them at the enamel surface for an
extended period of time. Cerium salts have a well-known affinity for hydroxyapatite and have been shown to
limit demineralization (erosion) of the enamel surface with acidic challenge. Hydroxyapatite is a dynamic
structure that facilitates surface chemical exchange of ions and nanoparticles of varying size with simple topical
administration. Given the known affinity of Ce-agents for the enamel surface, we propose the incorporation of
the novel biofilm inhibiting CeO2-NP agents of this proposal onto the enamel surface via adsorption. The
objectives of this proposal are to investigate potential extracellular mechanisms of biofilm inhibition by CeO2-NP
as well as the chemical interaction of CeO2-NP with hydroxyapatite surfaces and its efficacy in translation model
studies.

## Key facts

- **NIH application ID:** 10167683
- **Project number:** 5K08DE028009-03
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT CHICAGO
- **Principal Investigator:** Russell P Pesavento
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $138,254
- **Award type:** 5
- **Project period:** 2019-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10167683

## Citation

> US National Institutes of Health, RePORTER application 10167683, Novel Biofilm Inhibitors of Oral Streptococci (5K08DE028009-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10167683. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*