Permeability of polymeric scaffolds with defined pore micro-architecture and interconnectivity fabricated by solid freeform microprinting

Three-dimensional (3D) microprinting is a computerized fabrication technique that can produce porous objects with highly complicated pore micro-architecture using data generated by computer aided design (CAD) or other imaging modalities [1]. This technique has been used for fabrication of porous biodegradable polymeric scaffolds that are intended, by design, to have reproducible and well-defined pores and connections for skeletal tissue engineering applications [2-4]. Scaffold porosity and interconnectivity are important design variables for tissue regeneration [5,6]. One measure related to pore interconnectivity is hydraulic permeability, the flow velocity through a porous material at a fixed pressure gradient [7]. The objective of this work was to study the effect of pore size and interconnectivity (defined as the fraction of cubic empty spaces connected to the outside air) on hydraulic permeability of polymeric scaffolds with well design-defined interconnectivity and pore micro-architecture.