Holographic microrheology of polysaccharides from Streptococcus mutans biofilms

Fook Chiong Cheong
Department of Physics and Center for Soft Matter Research,
New York University, New York, NY 10003

Simone Duarte
Department of Basic Science and Craniofacial Biology,
College of Dentistry, New York University, New York, NY 10010

Sang-Hyuk Lee
Department of Physics,
University of California, Berkeley, CA 94720-7300

David G. Grier¹
Department of Physics and Center for Soft Matter Research,
New York University, New York, NY 10003

Date: April 6, 2008

Abstract:

We use three-dimensional holographic particle tracking to perform microrheological measurements of model gelled media, including the polysaccharide pellicle of dental biofilms created by the common cariogenic oral pathogen Streptococcus mutans. Nanometer-resolution video-rate holographic tracking of embedded colloidal spheres provides accurate measurements of the gels' complex viscoelastic moduli, including insights into these properties' heterogeneity. When applied to polysaccharides of S. mutans biofilms, these techniques promise quantitative microscopic assays for candidate therapeutic agents against cariogenic dental biofilms.

Key words: video holographic microscopy; microrheology; biofilms; polysaccharide gel; Streptococcus mutans