Quantitative analysis of interconnectivity of porous biodegradable scaffolds with micro‐computed tomography

Abstract

Pore interconnectivity within scaffolds is an important parameter influencing cell migration and tissue ingrowth needed to promote tissue regeneration. Methods for assessment of interconnectivity are usually qualitative, restricted to two-dimensional images, or are destructive. Microcomputed tomography nondestructively provides three-dimensional (3D) images of intact specimens at high spatial resolutions. We describe an image analysis technique for quantitative assessment of scaffold interconnectivity. Scaffolds were made via a particulate leaching process with 75%, 80%, 85%, and 88% volumetric porogen fractions. Specimens were scanned and resulting 3D, digital images were analyzed with a custom algorithm. A series of virtual, idealized scaffolds were also created for illustration of the algorithm's analysis approach and for its validation. The program calculated accessible void fractions over a range of minimum connection sizes. In real specimens, nearly 100% of the porous volume was connected with outside air for connections greater than or equal to 20 microm in their smallest dimension. In scaffolds made with 75% porogen, the accessible void fraction decreased to 78% if only those connections greater than or equal to 260 microm were considered. The relationship between accessible void fraction and connection size varied as a function of porogen content. The interconnectivity parameter described here may have implications for cell migration and tissue growth into scaffolds.

Biomaterial Scaffold Fabrication Techniques for Potential Tissue Engineering Applications

“…Pore geometry is control by the selection of the shape for specific porogen agent, where as pore size is control by sieving the porogen particle to the specific dimensional range (Mano et al, 2007). One of the main drawbacks of this technique is that it can only produce thin wafers or membrane up to 3 mm thick and very difficult to design the scaffolds with accurate pore inter-connectivity (Moore et al, 2004).…”

Neural Stem Cell– and Schwann Cell–Loaded Biodegradable Polymer Scaffolds Support Axonal Regeneration in the Transected Spinal Cord

“…5,10,15 Multilumen scaffolds have the mechanical and physical attributes to provide an appropriate microenvironment for regeneration. 17,18 Three broad categories of SCI have been used in animal models: contusion or compression, partial transection, and complete transection. Each offers important contributions to studying repair.…”

Comparison of Osteogenic Potential Between Apatite-Coated Poly(Lactide-Co-Glycolide)/Hydroxyapatite Particulates and Bio-Oss

“…Thirdly, the physical properties and degradation rate of apatitecoated PLGA/HA particulates are easily controlled by adjusting the ratio of lactide and glycolide. In this study, we used a particulate-type material instead of sponge-type material to improve pore interconnectivity within the graft material -an important parameter that influences cell migration and tissue ingrowth needed to promote bone regeneration 24) . Previously, we had observed hindered cell migration and tissue ingrowth in threedimensional sponge-type scaffolds with low interconnectivity that were implanted into bone defects 19) .…”