Chondrogenesis of hMSC in affinity-bound TGF-beta scaffolds.
Herein we describe a bio-inspired, affinity binding alginate-sulfate scaffold, designed for the presentation and sustained release of transforming growth factor beta 1 (TGF-β1), and examine its effects on the chondrogenesis of human mesenchymal stem cells (hMSCs). When attached to matrix via affinity interactions with alginate sulfate, TGF-β1 loading was significantly greater and its initial release from the scaffold was attenuated compared to its burst release (>90%) from scaffolds lacking alginate-sulfate. The sustained TGF-β1 release was further supported by the prolonged activation (14 d) of Smad-dependent (Smad2) and Smad-independent (ERK1/2) signaling pathways in the seeded hMSCs. Such presentation of TGF-β1 led to hMSC chondrogenic differentiation; differentiated chondrocytes with deposited collagen type II were seen within three weeks of in vitro hMSC seeding. By contrast, in scaffolds lacking alginate-sulfate, the effect of TGF-β1 was short-term and hMSCs could not reach a similar differentiation degree. When hMSC constructs were subcutaneously implanted in nude mice, chondrocytes with deposited type II collagen and aggrecan typical of the articular cartilage were found in the TGF-β1 affinity-bound constructs. Our results highlight the fundamental importance of appropriate factor presentation to its biological activity, namely - inducing efficient stem cell differentiation.
The Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
Tali
T
Re'em
Yael
Y
Kaminer-Israeli
Emil
E
Ruvinov
Smadar
S
Cohen
D000464:Alginates / Q000737:chemistry; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000187:drug effects*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020935:MAP Kinase Signaling System; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D051899:Smad2 Protein / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*; D016212:Transforming Growth Factor beta / Q000737:chemistry* / Q000494:pharmacology
D000464:Alginates; D006603:Hexuronic Acids; D051899:Smad2 Protein; D016212:Transforming Growth Factor beta; D020723:Glucuronic Acid