A Novel Device for Direct Permeation Measurements of Hydrogels and Soft Hydrated Tissues

The goal of this study was to develop a system to reliably measure the intrinsic hydraulic permeability of hydrogels and soft hydrated tissues. Such a device can be used to assess the development of functional properties in tissue engineered constructs [1]. The design parameters for such a device include ease of assembly and the ability to measure hydraulic permeability over a range of specimen deformations. To meet these criteria, a device was designed that could quantify the hydraulic permeability of a sample under different levels of deformation, allowing characterization of strain-dependent effects. The device was tested on both agarose and articular cartilage specimens, yielding permeability values consistent with published data [2]. The intrinsic hydraulic permeability of a tissue is an important parameter that governs fluid exudation during deformational loading. The ability of articular cartilage, which exhibits non-linear strain dependent hydraulic permeability [3], to generate and sustain interstitial fluid pressurization is essential to its functional properties (e.g., load bearing and lubrication). This novel device allows for direct and reliable measurement of these physical properties.