Abstract
This study aims to investigate the bioactivity of collagen II/hyaluronan/chondroitin‐6‐sulfate tri‐copolymer as bionic scaffold for nucleus pulposus (NP) tissue engineering. Collagen II (C II) (pH 1–2) was mixed with hyaluronan (HyA) and lyophilized to prepare C II/HyA matrices. Chondroitin 6‐sulfate (6‐CS) was covalently attached to the C II/HyA matrices using 1‐ethyl‐3‐(3‐dimethyl aminopropyl) carbodiimide (EDC) and N‐hydroxysuccinimide (NHS). Then, cells were expanded from rabbit NP and seeded in the tri‐copolymer scaffold. Cell‐scaffold hybrids were maintained for up to 28 days in culture. Cell viability/proliferation, extracellular matrix (ECM)‐related gene expression, and the content of sulfated glycosaminoglycans (s‐GAG) were evaluated. Our results are as following: when cultured for 28 days, the cell‐scaffold hybrids maintained active cell viability/proliferation and exhibited a significantly increased s‐GAG content. In addition, rabbit NP cells cultured in the scaffold demonstrated a significantly higher level of C II and aggrecan gene expression and a significantly lower level of Collagen I (C I) gene expression when compared with that of monolayer cells. Histological studies and scanning electron microscopy (SEM) further indicated newly secreted ECM deposits in the scaffolds. In conclusion, the C II/HyA‐CS scaffold may be an alternative material for NP tissue engineering due to its satisfactory bioactivity, and it deserves further in vivo investigation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010