title: Optical waveguide lightmode spectroscopy as a new method to study adhesion of anchorage-dependent cells as an indicator of metabolic state.
abstract: Optical Waveguide Lightmode Spectroscopy (OWLS) is based on measurements of the effective refractive index of a thin layer above the waveguide. Its potential as a whole-cell biosensor was demonstrated recently monitoring adhesion and spreading of Baby Hamster Kidney (BHK) cells on-line. In this work the OWLS is shown to be a promising tool to study the adhesion, morphology and metabolic state of fibroblasts in real time. A new design of the measuring chamber allowed simultaneous observation by phase-contrast microscopy and made the adsorbed cell density controllable and reproducible. The OWLS signal correlated quantitatively with the contact-area between the fibroblasts and the waveguide. The OWLS signals for adhesion and spreading of three different fibroblast cell lines were in good agreement with their morphology identified by phase-contrast microscopy. The cell adhesion and cell shape changes were examined in three scenarios: (a) serum-induced spreading of the surface attached fibroblasts was followed until it was completed, and the OWLS signal remained constant for over 12 h; (b) the fully spread cells were exposed to the microtubuli-disrupting colchicine and a decrease of the OWLS signal was monitored; (c) in a similar experiment with benzalkonium chloride, a strong skin irritant, a concentration-dependent response of the signal was found. The results show the strength of the OWLS method for monitoring the adhesion behavior of anchorage-dependent cells such as fibroblasts. It has a great potential as a whole-cell biosensor for high throughput screening in toxicology.
authors.affiliation: Department of Chemical Engineering, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland. hug@tech.chem.ethz.ch
authors.forename: T S
authors.initials: TS
authors.lastname: Hug
authors.forename: J E
authors.initials: JE
authors.lastname: Prenosil
authors.forename: M
authors.initials: M
authors.lastname: Morbidelli
mesh_terms: D016475:3T3 Cells; D000327:Adsorption; D000818:Animals; D001548:Benzalkonium Compounds / Q000494:pharmacology; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology*; D002452:Cell Count; D002460:Cell Line; D003078:Colchicine / Q000494:pharmacology; D006224:Cricetinae; D003470:Culture Media; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007739:L Cells; D051379:Mice; D055095:Optics and Photonics; D013053:Spectrophotometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D001548:Benzalkonium Compounds; D003470:Culture Media; D003078:Colchicine