Original Article Collagen I-Matrigel Scaffolds for Enhanced Schwann Cell Survival and Control of Three-Dimensional Cell Morphology

We report on the ability to control three-dimensional Schwann cell (SC) morphology using collagen I–Matrigel composite scaffolds for neural engineering applications. SCs are supportive of nerve regeneration after injury, and it has recently been reported that SCs embedded in collagen I, a material frequently used in guidance channel studies, do not readily extend processes, instead adopting a spherical morphology indicative of little interaction with the matrix. We have modified collagen I matrices by adding Matrigel to make them more supportive of SCs and characterized these matrices and SC morphology in vitro. Incorporation of 10%, 20%, 35%, and 50 % Matrigel by volume resulted in 2.4, 3.5, 3.7, and 4.2 times longer average SC process length after 14 days in culture than with collagen I–only controls. Additionally, only 35 % and 50 % Matrigel constructs were able to maintain SC number over 14 days, whereas an 88 % decrease in cells from initial seeding density was observed in collagen-only constructs over the same time period. Mechanical testing revealed that the addition of 50 % Matrigel increased matrix stiffness from 6.4 kPa in collagen I–only constructs to 9.8 kPa. Furthermore, second harmonic generation imaging showed that the addition of Matrigel resulted in non-uniform distribution of collagen I, and scanning electron microscope imaging illustrated distinct differences in the fibrillar structure of the different constructs. Collectively, this work lays a foundation for developing scaffolding materials that are concurrently supportive of neurons and SCs for future neural engineering applications