Mechanical and morphological description of human acellular dura mater as a scaffold for surgical reconstruction.

As native human dura mater has been successfully used as a transplant, the acellular dura mater scaffold is a promising material for the same purpose, that is less prone to transplant rejection. A detailed knowledge of the dura material properties may also aid to tissue engineer customized scaffolds mechanically mimicking the healthy natural condition. Both native and acellular dura have to date not been satisfactorily described concerning their load-deformation properties and the morphology related to scaffold mechanics. We investigated the tensile properties of 18 acellular human dura samples and compared these to the values of 18 matched native counterparts of the same donors. A highly standardized approach in material testing was used with coupled image correlation, involving 3D-printed clamps and fixtures, and adaptation of the tissue water content. The tensile parameters of acellular dura appeared to differ only minutely from the native condition. The removal of cells appeared not to vastly influence the biomechanics of dura. Lower values of the elastic modulus (36 vs. 74 MPa, p < 0.01) and ultimate tensile strength (4 vs. 7 MPa, p = 0.05) of acellular dura compared to the native counterparts were likely the consequence of tissue swelling related to the acellularization procedure. Collagens and proteoglycans remained intact in the acellular state, whereas glycosaminoglycans appeared to decrease. Fibronectin and elastic fibres were exposed by the removal of cells. Consequently, seeding these acellular scaffolds with cells appears not to be necessary from a biomechanical perspective.