Solid-state cryomilling for porogen mixing and porous scaffold fabrication - biomed 2011

Several widely used techniques for the fabrication of three dimensional (3D) scaffolds utilize the particulate leaching method to achieve a porous structure. This method involves the selective leaching of a mineral or an organic compound to generate pores. However, scaffolds prepared by this technique tend to exhibit limited interconnectivity. Therefore, to enhance the interconnectivity of the scaffolds fabricated by particulate leaching, a polymeric porogen can be added during processing. Typically porogens are mixed into a polymer solution, powder, or melt. The mixture is subsequently cast, molded, or extruded, and then leaching the porogens results in porous scaffolds. Still, even though scaffold interconnectivity is improved through the addition of polymer porogens, particulate leaching does not yield scaffolds with uniform properties. This research introduces a new solventless approach, cryomilling, to blend porogens and attain interconnected porous scaffolds with uniform morphologies. To validate the efficacy of the suggested approach a comparison of the effect of various solid-state mixing approaches on scaffold morphology and mechanical properties will be made. In this study, salt particles and poly(ethylene oxide) (PEO) were mixed (manually or through cryomilling) with poly(e-caprolactone) (PCL) for the preparation of porous 3D PCL scaffolds, the mixtures were then compression molded, and subsequently, water was used to leach the porogens. Morphological and compressive properties of the resulting scaffolds will be discussed. This simple, novel, economical, organic solvent-free approach for the fabrication of 3D interconnected porous scaffolds holds promise for tissue engineering applications.