In Vitro and in Vivo Growth Factor Delivery to Chondrocytes and Bone-Marrow-Derived Stromal Cells in Cartilage and in Self-Assembling Peptide Scaffolds

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Abstract

The inability of articular cartilage to repair itself after acute injury has been implicated in the development of osteoarthritis. The objective of this work was to develop methods for delivering growth factors to cartilage and to test the ability of a selfassembling peptide scaffold, (KLDL)3, with or without growth factors to augment repair. Delivery methods included growth factor adsorption, scaffold-tethering, and modification of growth factor structure.

(KLDL)3 was modified to deliver IGF-1 and TGF-β1 to chondrocytes and bone-marrow-derived stromal cells (BMSCs), respectively, by adsorption and by biotinstreptavidin tethering. This study showed that while TGF-β1 can be effectively delivered by adsorption, IGF-1 can not. Additionally, while tethering these factors provided longt-erm sequestration, tethering did not stimulate proteoglycan production in vitro.

A full-thickness, critically sized, rabbit cartilage defect model was used to test the ability of (KLDL)3 with or without chondrogenic factors (TGF-β1, dexamethasone, and IGF-1) and BMSCs to stimulate cartilage regeneration in vivo. (KLDL)3 alone showed the greatest repair after 12 weeks with significantly higher Safranin-O, collagen II immunostaining, and cumulative histology scores compared to untreated contralateral controls. Ongoing studies include the evaluation of (KLDL)3 in a clinically relevant sized equine defect co-treated with microfracture and subjected to strenuous exercise.

A fusion protein was created by adding a heparin-binding domain to IGF-1 (HBIGF-1), converting IGF-1 from a short-acting growth factor to one that can be retained and locally delivered in articular cartilage in vivo. It was shown that HB-IGF-1 is retained in cartilage through binding to negatively charged glycosaminoglycan chains, with chondroitin sulfate the most prevalent type in cartilage. HB-IGF-1 was shown to bind adult human cartilage and to be preferentially delivered and retained in rat articular cartilage after intra-articular injection. In contrast, unmodified IGF-1 was not detectable after intra-articular injection. These results suggest that modification of growth factors with heparin-binding domains may be a clinically relevant strategy for local delivery to cartilage.

Taken together, these results show that (KLDL)3 self-assembling peptide hydrogels are customizable for growth factor delivery and can promote cartilage repair in vivo. In addition, the fusion protein HB-IGF-1 is preferentially retained in cartilage tissue compared to un-modified IGF-1.

Cited Works (16)

Year	Entry
1993	Shapiro F, Koide S, Glimcher MJ. Cell origin and differentiation in the repair of full-thickness defects of articular cartilage. J Bone Joint Surg. April 1993;75A(4):532-553.
1992	Hardingham TE, Fosang AJ. Proteoglycans: many forms and many functions. FASEB J. February 1992;6(3):861-870.
1975	Mankin HJ, Thrasher AZ. Water content and binding in normal and osteoarthritic human cartilage. J Bone Joint Surg. January 1975;57A(1):76-80.
2004	Knutsen G, Engebretsen L, Ludvigsen TC, Drogset JO, Grøntvedt T, Solheim E, Strand T, Roberts S, Isaksen V, Johansen O. Autologous chondrocyte implantation compared with microfracture in the knee: a randomized trial. J Bone Joint Surg. March 2004;86A(3):455-464.
2000	Ragan PM, Chin VI, Hung H-HK, Masuda K, Thonar EJ-MA, Arner EC, Grodzinsky AJ, Sandy JD. Chondrocyte extracellular matrix synthesis and turnover are influenced by static compression in a new alginate disk culture system. Arch Biochem Biophys. November 15, 2000;383(2):256-264.
1982	Mankin HJ. The response of articular cartilage to mechanical injury. J Bone Joint Surg. March 1982;64A(3):460-466.
1987	Poole CA, Flint MH, Beaumont BW. Chondrons in cartilage: ultrastructural analysis of the pericellular microenvironment in adult human articular cartilages. J Orthop Res. 1987;5(4):509-522.
2007	Lohmander LS, Englund PM, Dahl LL, Roos EM. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med. October 2007;35(10):1756-1769.
1996	Hunziker EB, Rosenberg LC. Repair of partial-thickness defects in articular cartilage: cell recruitment from the synovial membrane. J Bone Joint Surg. May 1996;78A(5):721-733.
2001	Bonassar LJ, Grodzinsky AJ, Frank EH, Davila SG, Bhaktav NR, Trippel SB. The effect of dynamic compression on the response of articular cartilage to insulin-like growth factor-i. J Orthop Res. January 2001;19(1):11-17.
1976	Maroudas A. Transport of solutes through cartilage: permeability to large molecules. J Anat. November 1976;122(pt 2):335-347.
2001	Poole AR, Kojima T, Yasuda T, Mwale F, Kobayashi M, Laverty S. Composition and structure of articular cartilage: a template for tissue repair. Clin Orthop Relat Res. October 2001;391(suppl):S26-S33.
1988	Kim Y-J, Sah RLY, Doong J-YH, Grodzinsky AJ. Fluorometric assay of DNA in cartilage explants using Hoechst 33258. Anal Ciochem. October 1988;174(1):168-176.
2002	Hunziker EB. Articular cartilage repair: basic science and clinical progress. a review of the current status and prospects. Osteoarthritis Cartilage. June 2002;10(6):432-463.
1998	Johnstone B, Hering TM, Caplan AI, Goldberg VM, Yoo JU. In vitro chondrogenesis of bone marrow-derived mesenchymal progenitor cells. Exp Cell Res. January 10, 1998;238(1):265-272.
1982	Farndale RW, Sayers CA, Barrett AJ. A direct spectrophotometric microassay for sulfated glycosaminoglycans in cartilage cultures. Connect Tissue Res. 1982;9(4):247-248.