Integral to the production of safe and biocompatible medical devices is the determination of interfacial properties that affect or control strong biofilm adhesion. The laser spallation technique has recently emerged as an advantageous method to quantify biofilm adhesion across candidate biomedical surfaces. However, there is a possibility that membrane tension is a factor that contributes to the stress required to separate biofilm and substrate. In that case, the stress amplitude, controlled by laser fluence, that initiates biofilm rupture would vary systematically with location on the biofilm. Film rupture, also known as spallation, occurs when film material is ejected during stress wave loading. To determine effects of membrane tension on the laser spallation process, we present a protocol that measures spall size with increasing laser fluence (variable fluence) and with respect to distance from the biofilm centroid (iso-fluence). Streptococcus mutans biofilms on titanium substrates serve as our model system. A total of 185 biofilm loading locations are analyzed in this study. We demonstrate that biofilm spall size increases monotonically with laser fluence and apply our procedure to failure of nonbiological films. In iso-fluence experiments, no correlation is found between biofilm spall size and loading location, thus providing evidence that membrane tension does not play a dominant role in biofilm adhesion measurements. We recommend our procedure as a straightforward method to determine membrane effects in the measurement of adhesion of biological films on substrate surfaces via the laser spallation technique.
|Number of pages||8|
|Journal||ACS Applied Bio Materials|
|State||Published - Mar 16 2020|
Bibliographical noteFunding Information:
This work was supported by National Institutes of Health COBRE Phase III pilot funding under number 5P30GM110788-04. We thank the Center for Pharmaceutical Research and Innovation (CPRI) for use of bacterial culture equipment. CPRI is supported, in part by the University of Kentucky College of Pharmacy and Center for Clinical and Translational Science (UL1TR001998).
This work was supported by National Institutes of Health COBRE Phase III pilot funding under number 5P30GM110788-04. We thank the Center for Pharmaceutical Research and Innovation (CPRI) for use of bacterial culture equipment. CPRI is supported, in part, by the University of Kentucky College of Pharmacy and Center for Clinical and Translational Science (UL1TR001998). We thank Dr. Natalia Korotkova for sharing expertise and donation of the bacterial strain. We would also like to thank Dr. Craig Miller from the University of Kentucky College of Dentistry for guidance.
© 2020 American Chemical Society.
- film separation
- laser spallation
- membrane tension
ASJC Scopus subject areas
- Biochemistry, medical
- Chemistry (all)
- Biomedical Engineering