Microengineered three-dimensional collagen fiber landscapes with independently tunable anisotropy and directionality

Abstract

Fibrillar collagen is abundant in the extracellular matrix (ECM), and cellular processes including differentiation, proliferation, and migration, have been linked to the directionality and degree of alignment (anisotropy) of collagen fibers. Given the importance of cell-substrate interactions in driving biological functions, several microfluidic approaches have been developed to create threedimensional (3D) collagen gels with defined fiber properties that enable quantitative correlations between structural cues and observed cell responses. Although existing microfluidic methods provide excellent control over collagen fiber anisotropy, independent control over both fiber direction and anisotropy (that we collectively refer to as the "collagen landscape") has not been demonstrated. Therefore, to advance collagen microengineering capabilities, we present a userfriendly approach that uses fluid flows to create well-defined collagen landscapes within a microfluidic channel network. These landscapes include: i) control over fiber anisotropy, ii) spatial gradients in fiber anisotropy, and iii) defined fiber directionality. Finally, we present two approaches to simplify procedures to allow cell interaction with the microengineered collagen landscapes.

Mechano-mediated M2 macrophage polarization and immune suppression in stiffened tumor microenvironment

“…Quantification of the matrix elasticity revealed a significant increase in the elastic modulus of the crosslinked and aligned matrices compared with that of the random matrix (Figure 1F). An increase in the elastic modulus in an aligned matrix compared with a random matrix is well correlated with previous reports [15,17,49,50].…”