The effects of glycosaminoglycan content on the compressive modulus of chondrocyte seeded type II collagen scaffolds

Abstract

This study examines glycosaminoglycan (GAG) density and aggregate compressive modulus HA of engineered cartilaginous implants. Culture parameters were developed to cause the goat articular chondrocyte seeded type II collagen scaffolds to generate 25 and 50% of the natural biochemical content of articular cartilage, with an overall goal of identifying construct compositions that might provide the most favorable response when implanted into defects in articular cartilage. Several scaffold cross-link densities were compared across constructs cultured in vitro to several time-points. The compressive modulus HA was measured through unconfined compression. One group of scaffolds averaged a compressive modulus one order of magnitude below that of natural tissue. Histological analysis verified that a chondrogenic phenotype was maintained and revealed a concentration of tissue development in the center of most scaffolds. This work includes a design for an original mechanical test apparatus for measuring the Poisson's ratio of the samples, enabling meaningful interpretation of indentation test results.