Dental biofilm is a dynamic and diverse microbial community enmeshed in an equally complex polysaccharide matrix. The extracellular polysaccharides (EPS) are synthesized by microorganisms (Streptococcus mutans, a key contributor) and promote biochemical and structural changes in the matrix enhancing the cariogenicity of the biofilm. Dental caries occurs as a result of persistent low pH environment within biofilms containing elevated amounts of extracellular polysaccharides. The development of novel chemotherapeutic approaches, other than microbiocides, that affect the development of EPS matrix and acidogenicity are promising routes to prevent or reduce oral diseases related to dental biofilm. Recently, we have identified a novel strategy to reduce the development and virulence of dental biofilms and caries by combining two naturally occurring anti- caries/anti-plaque agents (apigenin and tt-farnesol) with fluoride. The putative pathways by which these compounds attenuate the cariogenicity of S. mutans within biofilms involve, at least, three routes: (1) by inhibiting the activity and expression of glucosyltransferases, which are associated with the formation of the polysaccharide matrix in biofilms, (2) by affecting acid production by disrupting S. mutans membrane integrity, and (3) by reducing the synthesis and/or accumulation of IPS. These biological activities influenced the composition of the polysaccharide matrix and acidogenicity of S. mutans biofilms in vitro, which resulted in enhanced cariostatic properties of fluoride without affecting the viability of oral flora population in vivo. Although significant amount of data were generated from our previous USPHS/NIH supported studies, further analyses are required to elucidate the molecular and physiological mechanisms of action of these agents, and to evaluate their effectiveness in vivo. Therefore, we propose a multi-disciplinary, step-wise research project to investigate their influence on: 1) the expression of specific genes associated with the formation of the extracellular polysaccharide matrix using real-time PCR, 2) structure of the polysaccharides matrix in the biofilm using GC-MS, MALDI-TOF-MS and NMR;3) metabolic pathway of S. mutans by specific biochemical assays on PTS system and glycolytic enzymes. Furthermore, we will identify the most effective dosage of our therapeutic approach in vivo, which may also reduce fluoride exposure. By integrating biochemical and molecular techniques with an in vivo model of dental caries, we expect to enhance our understanding of how these compounds modulate the pathogenesis of S. mutans biofilm development, and expand their potential usefulness as a novel chemotherapeutic approach to prevention of biofilm-related diseases, which could be evaluated in future clinical trials. Project Narrative This project proposes a novel therapeutic approach to prevent dental caries, the single most prevalent and costly oral infectious diseases in the United States. Our approach uses natural compounds, is highly effective without suppressing the resident oral flora (non-microbiocidal) and may decrease exposure to fluoride.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE018023-05
Application #
8204775
Study Section
Oral, Dental and Craniofacial Sciences Study Section (ODCS)
Program Officer
Lunsford, Dwayne
Project Start
2008-02-19
Project End
2014-06-30
Budget Start
2012-01-01
Budget End
2014-06-30
Support Year
5
Fiscal Year
2012
Total Cost
$256,213
Indirect Cost
$89,841
Name
University of Rochester
Department
Dentistry
Type
Schools of Dentistry
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Gao, Lizeng; Liu, Yuan; Kim, Dongyeop et al. (2016) Nanocatalysts promote Streptococcus mutans biofilm matrix degradation and enhance bacterial killing to suppress dental caries in vivo. Biomaterials 101:272-84
Hwang, Geelsu; Liu, Yuan; Kim, Dongyeop et al. (2016) Simultaneous spatiotemporal mapping of in situ pH and bacterial activity within an intact 3D microcolony structure. Sci Rep 6:32841
Koo, Hyun; Yamada, Kenneth M (2016) Dynamic cell-matrix interactions modulate microbial biofilm and tissue 3D microenvironments. Curr Opin Cell Biol 42:102-112
Zhou, Jiayi; Horev, Benjamin; Hwang, Geelsu et al. (2016) Characterization and optimization of pH-responsive polymer nanoparticles for drug delivery to oral biofilms. J Mater Chem B Mater Biol Med 4:3075-3085
Benoit, Danielle Sw; Koo, Hyun (2016) Targeted, triggered drug delivery to tumor and biofilm microenvironments. Nanomedicine (Lond) 11:873-9
Niepa, Tagbo H R; Hou, Likai; Jiang, Hongyuan et al. (2016) Microbial Nanoculture as an Artificial Microniche. Sci Rep 6:30578
Klein, Marlise I; Hwang, Geelsu; Santos, Paulo H S et al. (2015) Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms. Front Cell Infect Microbiol 5:10
Horev, Benjamin; Klein, Marlise I; Hwang, Geelsu et al. (2015) pH-activated nanoparticles for controlled topical delivery of farnesol to disrupt oral biofilm virulence. ACS Nano 9:2390-404
Nguyen, Phuong Thi Mai; Falsetta, Megan L; Hwang, Geelsu et al. (2014) α-Mangostin disrupts the development of Streptococcus mutans biofilms and facilitates its mechanical removal. PLoS One 9:e111312
Lemos, José A; Quivey Jr, Robert G; Koo, Hyun et al. (2013) Streptococcus mutans: a new Gram-positive paradigm? Microbiology 159:436-45

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