A new biodegradable polyester elastomer for cartilage tissue engineering

Abstract

The objective of this study is to assess whether a new biodegradable elastomer, poly(1,8‐octanediol citrate) (POC), would be a suitable material to engineer elastomeric scaffolds for cartilage tissue engineering. Porous POC scaffolds were prepared via the salt‐leaching method and initially assessed for their ability to rapidly recover from compressive deformation (% recovery ratio). Controls consisted of scaffolds made from other materials commonly used in cartilage tissue engineering, including 2% agarose, 4% alginate, non woven poly(glycolic acid) (PGA) meshes, and non woven poly(L‐lactide‐co‐glycolide) (PLGA) meshes. Articular chondrocytes from bovine knee were isolated and seeded onto porous disk‐shaped POC scaffolds, which were subsequently cultured in vitro for up to 28 days. POC scaffolds completely recover from compressive deformation, and the stress–strain curve is typical of an elastomer (recovery ratio > 98%). Agarose gel (2%) scaffolds broke during the compression test. The recovery ratio of 4% alginate gel scaffolds, PLLA, and PGA were 72, 85, and 88%, respectively. The Young's modulus of POC‐chondrocyte constructs and cell‐free POC scaffolds cultured for 28 days were 12.02 ± 2.26 kPa and 3.27 ± 0.72 kPa, respectively. After 28 days of culture, the recovery ratio of POC‐chondrocyte constructs and cell‐free POC scaffolds were 93% and 99%, respectively. The glycosaminoglycan (GAG) and collagen content at day 28 was 36% and 26% of that found in bovine knee cartilage explants. Histology/immunohistochemistry evaluations confirm that chondrocytes were able to attach to the pore walls within the scaffold, maintain cell phenotype, and form a cartilaginous tissue during the 28 days of culture. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006