Balancing surface chemistry and biocompatibility: an analysis of poly(dimethylsiloxane) and polyethylene terephthalate membrane bonding methods in Lab-on-a-Chip systems for cell culture.

Next to the poly(dimethylsiloxane) (PDMS), polyethylene terephthalate (PET) is the material increasingly used in the fabrication of Lab-on-a-Chip (LoC) systems. It results from their excellent biocompatibility and straightforward fabrication of microstructures. The integration of PDMS and PET requires chemical modification of surfaces, such as the use of silane-based coupling agents (3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTMS). However, this method is often ineffective in achieving stable, leak-proof bonding, with the potential for high cytotoxicity. In response to these challenges, we tested whether polydopamine (PDA) could be a promising alternative method for PDMS and PET bonding. We compared two PDMS-PET surface bonding methods, such as APTES/GPTMS and PDA, and we proved that PDA coatings created strong, stable bonds between PDMS and PET, providing a biocompatible surface that supports cell adhesion and culture without cytotoxic effects. The results highlight the significant advantages of PDA in developing PDMS-PET-based LoC systems, allowing for more reliable and complex in vitro models for drug testing and disease research.