R- and Z-Axis Patterned Scaffolds Mimic Tracheal Circumferential Compliance and Longitudinal Extensibility.

There remains no routine treatment for congenital tracheal abnormalities affecting more than 1/3 of the length. Natural and artificial prostheses are plagued by mechanical failure and inconsistent outcomes. Mimicking native tissue mechanics in an engineered replacement may improve functional and patient outcomes. We synthesized tubular constructs comprising photo-cross-linked methyl acrylate-co-methyl methacrylate, p(MA-co-MMA), with patterned r- and z-axes in order to achieve mechanical properties similar to lamb tracheae. Hard and soft alternating bands, and a soft vertical section, mimic tracheal architecture. Patterned constructs were capable of 46% elastic longitudinal extension. The construct longitudinal composite modulus, 0.34 ± 0.09 MPa, was not significantly different from ovine tracheae. The superior of two geometries evaluated supports up to a 46% reduction of internal volume within the physiological range of transmural pressures. Thus, these patterned hydrogels yielded longitudinal elasticity and radial rigidity while allowing for radial deformation required for effective coughing.