Diffusion of dimethyl sulfoxide in tissue engineered collagen scaffolds visualized by computer tomography

Cryopreservation is a convenient method for long-term preservation of natural and engineered tissues in regenerative medicine. Homogeneous loading of tissues with CPAs, however, forms one of the major hurdles in tissue cryopreservation. In this study, computer tomography (CT) as a non-invasive imaging method was used to determine the effective diffusion of Me2SO in tissue-engineered collagen scaffolds. The dimensions of the scaffolds were 30 × 30 × 10mm³ with a homogeneous pore size of 100 μm and a porosity of 98%. CT images were acquired after equilibrating the scaffolds in phosphate buffered saline (PBS) and transferring them directly in 10% (v/v) Me₂SO. The Me₂SO loading process of the scaffold could thus be measured and visualized in real time. The experimental data were fitted using a diffusion equation. The calculated effective diffusion constant for Me₂SO in the PBS loaded scaffold was determined from experimental diffusion studies to be 2.4 × 10^-6 cm²/s at 207deg;C.