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

Abstract

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.

Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

“…The results (113) demonstrate that POC can outperform other biodegradable elastomers used for cartilage tissue engineering and warrants further in vivo studies. Motivated by their previous studies, these researchers published successive reports to evaluate the coupled effects of 3D POC scaffold pore shape and permeability on chondrogenesis using primary chondrocytes in vivo (114, 115). The results indicated that low-porosity POC scaffolds composed of spherical pores showed a significantly greater increase in cartilage matrix formation over 6 weeks in vivo when compared with highly porous POC scaffolds composed of cuboidal pores.…”

Biodegradable Elastomers for Tissue Engineering and Cell–Biomaterial Interactions

“…For example, thermoset POC elastomers were processed into foams using ordered hydroxyapatite molds. [99] In this technique, SFF methods are used to produce inverse wax molds. The wax molds are used to form sacrificial hydroxyapatite forms, which are then used to mold POC prepolymers.…”

Relationship between micro-porosity, water permeability and mechanical behavior in scaffolds for cartilage engineering

“…Other authors observed the limited role of the macro pores in a PCL scaffold for bone regeneration and suggested further studies of the scaffold properties like interconnectivity and permeability 23 . In other works it is seen that a low permeability in a porous PCL scaffold enhanced chondrogenesis in vitro with primary chondrocytes 24 and by measuring the permeability of the scaffold with cells it is seen how the permeability diminishes from seeding as tissue grows 25 . Other authors have used 3D…”