Solid lipid templating of macroporous tissue engineering scaffolds

Macroporous biodegradable cell carriers (scaffolds) provide the three-dimensional matrix for tissue formation in vitro. In this study, we present the fabrication of macroporous scaffolds with high inter-pore connectivity from different biodegradable polymers using the recently developed solid lipid templating technique. Starting from a polymer solution and solid lipid microparticles, a dispersion is prepared and subsequently transferred into molds, which are finally submerged in warm hexane to precipitate the polymer and extract the porogens. The study shows how to control pore structure, pore size and porosity of the scaffold using this technique. The process parameters dispersion viscosity, porogen size and type of polymer are considered. Limits of viscosity are examined by macroscopic and microstructure evaluation of the scaffolds prepared at different viscosities. An approach to rationalize these data by oscillation rheometry is shown. Pore size can be controlled by porogen particle size and adaptation of the viscosity of the polymer solution. Porosity can be modified by changing the ratio of porogen to polymer. The suitability of the resulting scaffolds was shown using an established cartilage cell culture model.