Cartilage Matrix Formation by Bovine Mesenchymal Stem Cells in Three-dimensional Culture Is Age-dependent

Abstract

Background Cartilage degeneration is common in the aged, and aged chondrocytes are inferior to juvenile chondrocytes in producing cartilage-specific extracellular matrix. Mesenchymal stem cells (MSCs) are an alternative cell type that can differentiate toward the chondrocyte phenotype. Aging may influence MSC chondrogenesis but remains less well studied, particularly in the bovine system. Questions/purposes The objectives of this study were (1) to confirm age-related changes in bovine articular cartilage, establish how age affects chondrogenesis in cultured pellets for (2) chondrocytes and (3) MSCs, and (4) determine age-related changes in the biochemical and biomechanical development of clinically relevant MSC-seeded hydrogels. Methods Native bovine articular cartilage from fetal (n = 3 donors), juvenile (n = 3 donors), and adult (n = 3 donors) animals was analyzed for mechanical and biochemical properties (n = 3-5 per donor). Chondrocyte and MSC pellets (n = 3 donors per age) were cultured for 6 weeks before analysis of biochemical content (n = 3 per donor). Bone marrow-derived MSCs of each age were also cultured within hyaluronic acid hydrogels for 3 weeks and analyzed for matrix deposition and mechanical properties (n = 4 per age). Results Articular cartilage mechanical properties and collagen content increased with age. We observed robust matrix accumulation in three-dimensional pellet culture by fetal chondrocytes with diminished collagen-forming capacity in adult chondrocytes. Chondrogenic induction of MSCs was greater in fetal and juvenile cell pellets. Likewise, fetal and juvenile MSCs in hydrogels imparted greater matrix and mechanical properties. Conclusions Donor age and biochemical microenvironment were major determinants of both bovine chondrocyte and MSC functional capacity. Clinical Relevance In vitro model systems should be evaluated in the context of age-related changes and should be benchmarked against human MSC data.

Anatomic Mesenchymal Stem Cell-Based Engineered Cartilage Constructs for Biologic Total Joint Replacement

“…Our group has previously shown that increased age decreases the chondrogenic potential of bovine MSCs. 47 Increased age has also been shown to reduce the chondrogenic potential of human MSCs. 48 Recent studies have shown that allogeneic MSCs can be used in humans without increased complication rates, and some companies have marketed allogeneic juvenile chondrocytes for cartilage repair (DeNovo Ò ; Zimmer, Inc.).…”

Hydrostatic pressure acts to stabilise a chondrogenic phenotype in porcine joint tissue derived stem cells

“…They are composed of adipocytes and adipose connective tissue containing collagen and glycosaminoglycans. Its surface is covered with synovial membrane and its role is to facilitate the distribution of synovial fl uid within the joint and act as a cushion protecting exposed articular surfaces (Vahlensieck et al, 2002;Nakano et al, 2004).…”

A Comparison of Self-Assembly and Hydrogel Encapsulation as a Means to Engineer Functional Cartilaginous Grafts Using Culture Expanded Chondrocytes

“…At this age, such animals have not reached skeletal maturity. Chondrocytes from such tissue would probably be more adept at producing cartilage-specific ECM than chondrocytes obtained from an older donor, as seen in bovine 49,50 and human donors. 51 As with many tissue engineering studies, cells were expanded and differentiated in high glucose (25 mM) culture medium.…”