Pellet culture elicits superior chondrogenic redifferentiation than alginate-based systems.
Although pellet culture and encapsulation of chondrocytes into gel-like biomaterials have lead to major advances in cartilage tissue engineering, a quantitative comparative characterization of cellular differentiation behavior during those cultivation procedures has not yet been performed. Our study therefore aimed at answering the following question: is the redifferentiation pathway of chondrocytes altered by slight changes in the type of alginate biomaterial (pure alginate, alginate-fibrin, alginate-chitosan) and how do the cells behave in comparison to biomaterial-free (pellet) three-dimensional culturing? Monolayer-expanded chondrocytes from healthy adult porcine knee joints were cultivated in alginate, alginate-chitosan, alginate-fibrin beads and as pellets up to 4 weeks. Quantitative PCR and Immunohistology were used to assess chondrogenic markers. Alginate-fibrin-encapsulated chondrocytes behaved almost like monolayer chondrocytes. Alginate- and alginate-chitosan encapsulation lead to a low chondrogenic marker gene expression. Although all 3D-cultured chondrocytes showed a considerable amount of Sox9 expression, only pellet cultivation lead to a sufficient Collagen II expression. This puts the usage of alginate-cultivated cartilage tissue engineering constructs under question. Fibrin addition is not beneficial for chondrogenic differentiation. Sox9 and Collagen II behave differently, depending upon the surrounding 3D-environment.
Bernstein
Peter
P
Department of Orthopaedic Surgery, University Hospital Carl Gustav Carus Dresden, Medical Faculty of the Technical University Dresden, D-01307 Dresden, Germany. peter.bernstein@uniklinikum-dresden.de
Dong
Meng
M
Corbeil
Denis
D
Gelinsky
Michael
M
Günther
Klaus-Peter
KP
Fickert
Stefan
S
D000464:Alginates / Q000737:chemistry; D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008297:Male; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*
D000464:Alginates; D006603:Hexuronic Acids; D055758:SOX9 Transcription Factor; D020723:Glucuronic Acid; D003094:Collagen