Figure 3.

Examples of biomaterials systems for studying macrophage phenotypic changes in response to fibrotic ECMs. (a) Geometric control of murine bone marrow derived macrophages (BMDM) by micropatterning drives macrophage polarization to an M2 phenotype with cellular elongation [40^•] suggesting that microenvironmental control of cell shape influences macrophage function. (b) Interpenetrating network of calcium crosslinked alginate in Matrigel® to control hydrogel stiffness independent of ligand binding density and porosity revealed that stiffness alone induces an invasive phenotype in MCF10A breast epithelial cells [31^••]. (c) Studies comparing cellular stiffness responses on flat hydrogels and synthetic fibrous materials revealed that they were inversely correlated. Unlike 2D hydrogels where greater bulk stiffness increased focal adhesion formation and proliferation, greater stiffness of individual fibers limited the ability of human mesenchymal stem cell (hMSC) to bundle fibers and form focal adhesion complexes [55].

Source: Images were reproduced with permission from the National Academy of Sciences (a) and Nature Publishing Group (b, c).