PEG-Silane Surface Modification of PDMS for Effective Gastruloid Formation in Microfabricated Shapes

Abstract

We have a hypothesis that mechanical constraints imposed by shaped culture well could enhance the efficiency of gastruloid formation. However, when cell aggregates are seeded on a polydimethylsiloxane (PDMS) device containing shaped wells, the cells tend to adhere to the top surface of the PDMS. Few aggregates get into the microwells. We expected that surface modification with polyethylene glycol (PEG) would reduce cell adhesion to PDMS and therefore more cell aggregates would fall into wells. PEG surface modification is performed using a silanization reaction, and successful modification is demonstrated by significantly reduced cell adhesion to the top of the PDMS device when dissociated cells are seeded. However, the number of cell aggregates falling into the shaped wells remains low. To address this problem, possible strategies include designing a device containing funneled shaped wells and seeding dissociated cells in a PEG modified device to enable cell aggregate formation in shaped well in situ.