Transwell?Integrated 2 µm Thick Transparent Polydimethylsiloxane Membranes with Controlled Pore Sizes and Distribution to Model the Blood?Brain Barrier

Traditional Transwell inserts with track-etched 10 ?m thick polymer membranes have been intensively used for studying cellular barriers. However, their thickness hampers direct cell-cell interaction between the adjacent cells which has shown to critically influence barrier formation. Therefore, here effect of reduced distance by using fivefold thinner (2 ?m) optically transparent polydimethylsiloxane (PDMS) is studied and compared polycarbonate (PC) membranes. The authors validate applicability as an alternative substrate study blood–brain performing a monoculture brain endothelial (hCMEC/D3) co-culture astrocytes in Transwells. PDMS supported protrusions through well-defined pores allowed control over transmigration varying pore size. Cellular localization tight adherens junction proteins ZO-1, Claudin-5, VE-cadherin similar PC while expression levels are affected function membrane material astrocytes. Additionally, permeability assay indicated tighter formation on membrane. These results suggest potential use 2 vitro modeling biological barriers improved models enhanced visibility cell culture.