Mechanical and Biochemical Assessments of Three-Dimensional Poly(1,8-Octanediol-co-Citrate) Scaffold Pore Shape and Permeability Effects onIn VitroChondrogenesis Using Primary Chondrocytes

Poly(1,8-octanediol-co-citrate) (POC) is a biocompatible, biodegradable elastomer with potential application for soft tissue applications such as cartilage. For chondrogenesis, permeability is a scaffold design target that may influence cartilage regeneration. Scaffold permeability is determined by many factors such as pore shape, pore size, pore interconnectivity, porosity, and so on. Our focus in this study was to examine the effects of pore shape and permeability of two different POC scaffold designs on matrix production, mRNA gene expression, and differentiation of chondrocytes in vitro and the consequent mechanical property changes of the scaffold/tissue constructs. Since type I collagen gel was used as a cell carrier in the POC scaffolds, we also examined the effects of collagen gel concentration on chondrogenesis. We found that lower collagen I gel concentration provides a favorable microenvironment for chondrocytes promoting better chondrogenic performance of chondrocytes. With regard to scaffold design, low permeability with a spherical pore shape better enhanced the chondrogenic performance of chondrocytes in terms of matrix production, and mRNA gene expressions in vitro compared to the highly permeable scaffold with a cubical pore shape.