Figure 4.

Porous polymeric membranes as basement membrane mimic: Depiction of possible combinations regarding cell coculture models using mechanically stable dense porous polymeric membranes: (1A) noncontact cocultures of two spatially separated cell types, (1B) indirect cocultures of two different cell types in contact with the same membrane, and (1C) direct mixture of two different cell types on top of the same membrane; adapted with permission from ref (164). Copyright 2017 Qiaozhi Lu et al. http://creativecommons.org/licenses/by/4.0/ (changes were made). (1D) Alveolar-capillary barrier models on permeable 0.4 μm pore size polyester membranes which can be introduced to an air–liquid interface represents the ease of handling coculture barriers on such mechanically robust platforms; adapted with permission from ref (165). Copyright 2021 Shinjini Chakraborty et al. http://creativecommons.org/licenses/by/4.0/ (changes were made). (2A) Mechanically tunable PDMS membranes and their reduced thickness to 2 μm were used to represent blood-brain barrier, by mono/coculture of endothelial cells and astrocytes where endothelial cells are stained for peripheral tight junctions ZO-1(red), adherens junction protein VE-cadherin (green); reprinted with permission from ref (144). Copyright 2020 Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/ (changes were made). Limitations of porous polymeric membranes are elucidated: (3A) Alveolar-capillary barrier on nanofiber PCL mesh and their cross-section on PC and nanofiber mesh which shows epithelial (green) transmigration toward the endothelial cells across a PC membrane (blue) with 3 μm pores compared to intact alveolar epithelial and endothelial cocultures on a nanofiber mesh, where the epithelial protrusion (green) is clearly seen on opposite side of (3D) PC membrane compared to the (3E) nanofiber mesh; reprinted with permission from ref (41). Copyright 2017 American Chemical Society (changes were made).