Affiliations: Division of Experimental Orthopaedics, Orthopaedic University Hospital, Heidelberg, Germany | ALVITO Biotechnologie GmbH, Kleinmachnow, Germany
Note: [] Andreas Fehrenbacher and Eric Steck contributed equally.
Note: [] Address for correspondence: Prof. Dr. Wiltrud Richter, Division of Experimental Orthopaedics, Orthopaedic University Hospital, Schlierbacher Landst. 200a, 69118 Heidelberg, Germany. Tel.: +49 6221 969253; Fax: +49 6221 969288; E-mail: wiltrud.richter@ok.uni-heidelberg.de.
Abstract: One major problem in cartilage tissue engineering is the insufficient biochemical composition of the generated biocomposites. The aim of this study was to improve the collagen and proteoglycan deposition in tissue engineering constructs by application of long-term mechanical loading in culture. Chondrocyte-seeded chitosan biocomposites revealed a homogenous cell distribution, high viability (>95%) and maintenance of a rounded cell shape typical for chondrocytes over 3 weeks of load-free culture. Cyclic compression of chitosan biocomposites (0.1 Hz, amplitude 5–15%, 45 min on and 315 min off) was applied after two different preculture times (3, 21 days) for 3 weeks. At day 42 this resulted in enhanced mRNA levels for aggrecan and a significantly higher specific proteoglycan (5-fold, p<0.0002) and collagen type II (2-fold, p<0.02) deposition compared to unloaded controls. In sum, the chitosan scaffold was highly attractive for cartilage tissue engineering approaches and mechanical loading allowed to further improve the biochemical composition of these biocomposites.
