Impact of PDMS surface treatment in cell-mechanics applications

• Published in: Journal of the mechanical behavior of biomedical materials 2020-03, Vol.103, p.103538-103538, Article 103538
• Main Authors: Dogru, Sedat, Aydemir, Duygu, Salman, Naveed, Ulusu, Nuray N., Alaca, B. Erdem
• Format: Article
• Language: English
• Subjects: Cell culture; Cell mechanics; Elasticity; Poisson's ratio; Polydimethylsiloxane (PDMS); Relaxation modulus; Stress, Mechanical; Viscoelastic characterization
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2019.103538

As a widely used elastomer in cell mechanics studies, PDMS is exposed to a variety of surface treatments during cell culture preparation. Considering its viscoelastic nature in particular, effects of the aforementioned treatments on PDMS mechanical behaviour, especially at the relevant length scale of 100 μm, received limited attention. This is despite the fact that significant errors were reported in the quantification of cellular traction forces as a result of minute changes in PDMS mechanical properties. Hence, the effects of plasma oxidation, sterilization and incubation on PDMS modulus of elasticity, relaxation modulus and Poisson's ratio are studied here through tension and stress relaxation tests, with the results of the latter interpreted via the linear viscoelastic formulation. It is observed that although significant deviations from the properties of untreated PDMS are measured through this cycle of surface treatment, properties of untreated PDMS are almost recovered following incubation in cell medium. For example, the modulus of elasticity of treated PDMS was found to be 6% smaller than that of the untreated PDMS. The corresponding deviation was