Creating a spectrum of fibrocartilages through different cell sources and biochemical stimuli.
In this study a scaffoldless approach was employed with two different cell sources and biochemical stimuli to engineer a spectrum of fibrocartilages representative of the different regions of the knee meniscus. Constructs composed of 100% fibrochondrocytes (FC) or a 50:50 co-culture of fibrochondrocytes and chondrocytes (CC) were cultured in 10% fetal bovine serum medium or serum-free "chondrogenic" medium, each +/-10 ng/mL TGF-beta1 (+T). Constructs from these two cell groups and four culture conditions were cultured for 6 weeks. By varying the cell type and presence of the growth factor, GAG per dry weight of the constructs spanned that of native tissue, ranging 16-45% and 1-7% in the CC and FC groups, respectively. Collagen density was most dependent on cell type and was significantly lower than tissue values. The collagen I/II ratio could be manipulated by cell type and serum presence to span the native range, from 3.5 in the serum-free CC group to over 1,000 in the FC groups treated with serum-containing medium. Using the CC cell group in the presence of serum-free medium dramatically increased the compressive stiffness to 128 +/- 34 kPa, similar to native tissue. Similarly, serum-free medium or TGF-beta1 treatment enhanced the tensile modulus by an order of magnitude, up to 3,000 kPa. Using two cell sources and manipulating biochemical stimuli, a range of fibrocartilaginous neotissues was engineered. Fibrocartilages such as the knee meniscus are characterized by heterogeneity in matrix and functional properties, and this work demonstrates a strategy for recreating these heterogeneous tissues.
Hoben
Gwendolyn M
GM
Department of Bioengineering, Rice University, 6100 Main St, Keck Hall Suite 116, Houston, Texas 77005, USA.
Athanasiou
Kyriacos A
KA
D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects; D018920:Coculture Techniques; D003094:Collagen / Q000032:analysis; D003470:Culture Media / Q000737:chemistry; D051445:Fibrocartilage; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
D003470:Culture Media; D053773:Transforming Growth Factor beta1; D003094:Collagen