A simple model for the perfusion of porous hydrogel scaffolds under culture in a sustentation like bioreactor

International audienceOver the last decade hydrogels, and more recently porous hydrogels, have shown to be promising biocompatible, resorbable scaffolds for tissue engineering (Gloria et al, 2010). Such porous scaffolds generally show a poor mechanical behavior which makes them difficult to manipulate. Since one key issue of tissue engineering is to properly perfuse the scaffolds in order to promote cell seeding in 3D scaffold, increase mass transport and mechanically condition by shear and compressive forces the cells under culture, the perfusion strategy has to be adapted for such materials. As a matter of fact the use of such scaffolds in perfusion systems in which the scaffolds are clamped is prohibited and only bioreactors in which the scaffolds are freely suspended are possible. In order to quantify the perfusion performance of porous hydrogel scaffolds in such bioreactors we :1) characterized the free settling velocity, measured the permeability of the scaffolds,2) derived a simple model for the perfusion of the scaffolds under free falling suspension,3) compared the obtained perfusion characteristics with literature,4) designed and built a bioreactor system to host the scaffolds under proper flow conditions performed cell culture experiments. The present work relates to the 4 first steps, details of the 2 later ones can be found in Knapp et al (2012)