Oxygen diffusion through collagen scaffolds at defined densities: implications for cell survival in tissue models.

For the success of any biomaterial for tissue engineering, its mechanical properties and ability to support nutrient diffusion will be critical. Collagen scaffolds are ideal candidates, due to their ability to immerse cells in a biomimetic nanofibrous matrix. We have established O(2) diffusion coefficients through native, dense collagen scaffolds at two tissue-like densities, with and without photo-chemical crosslinking, by adapting an optical fibre-based system for real-time core O(2) monitoring deep within collagen constructs. Using a Fick's law model, we then derived O(2) diffusion coefficients; 4.5 × 10(-6) cm(2) /s for 11% density collagen scaffolds; 1.7 × 10(-6) cm(2) /s for 34% collagen scaffolds; 3.4 × 10(-6) cm(2) /s for photochemically crosslinked collagen scaffolds at 11%. Both O(2) diffusion coefficients of the 11% collagen fall within the range of native intestinal submucosa. The high diffusion coefficients of these collagen scaffolds, as well as their material properties, render them viable tissue-engineering matrices for tissue replacement.