Effect of chitosan particles and dexamethasone on human bone marrow stromal cell osteogenesis and angiogenic factor secretion

• Published in: Bone (New York, N.Y.) N.Y.), 2009-10, Vol.45 (4), p.617-626
• Main Authors: Guzmán-Morales, Jessica, El-Gabalawy, Hani, Pham, Minh H, Tran-Khanh, Nicolas, McKee, Marc D, Wu, William, Centola, Michael, Hoemann, Caroline D
• Format: Article
• Language: English
• Subjects: Angiogenesis; Angiogenesis Inducing Agents - metabolism; Biological and medical sciences; Bone Marrow Cells - cytology; Bone Marrow Cells - drug effects; Bone Marrow Cells - enzymology; Bone Marrow Cells - secretion; Bone marrow stromal cells; Calcification, Physiologic - drug effects; Cell Adhesion - drug effects; Cell Differentiation - drug effects; Cell physiology; Cell Proliferation - drug effects; Cells, Cultured; Chitin/chitosan; Chitosan - pharmacology; Collagen - metabolism; Cytokines - secretion; Dexamethasone; Dexamethasone - pharmacology; Fundamental and applied biological sciences. Psychology; Gelatinases - metabolism; Humans; Inflammation Mediators - metabolism; Matrix Metalloproteinase 2 - metabolism; Mineralization, calcification; Molecular and cellular biology; Orthopedics; Osteogenesis; Osteogenesis - drug effects; Skeleton and joints; Stromal Cells - cytology; Stromal Cells - drug effects; Stromal Cells - enzymology; Stromal Cells - secretion; Vascular Endothelial Growth Factor A - secretion; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2009.06.014

Abstract Chitosan is a polysaccharide scaffold used to enhance cartilage repair during treatments involving bone marrow stimulation, and it is reported to increase angiogenesis and osteogenesis in vivo . Here, we tested the hypotheses that addition of chitosan particles to the media of human bone marrow stromal cell (BMSC) cultures stimulates osteogenesis by promoting osteoblastic differentiation and by favoring the release of angiogenic factors in vitro . Confluent BMSCs were cultured for 3 weeks with 16% fetal bovine serum, ascorbate-2-phosphate and disodium β-glycerol phosphate, in the absence or presence of dexamethasone, an anti-inflammatory glucocorticoid commonly used as an inducer of BMSC osteoblast differentiation in vitro . As expected, dexamethasone slowed cell division, stimulated alkaline phosphatase activity and enhanced matrix mineralization. Added chitosan particles accumulated intra- and extracellularly and, while not affecting most osteogenic features, they inhibited osteocalcin release to the media at day 14 and interfered with mineralized matrix deposition. Interestingly, dexamethasone promoted cell attachment and suppressed the release and activation of matrix metalloprotease-2 (MMP-2). While chitosan particles had no effect on the release of angiogenic factors, dexamethasone significantly inhibited ( p < 0.05 to p < 0.0001) the release of vascular endothelial growth factor (VEGF), granulocyte-macrophage colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-α), interleukins 1β, 4, 6, and 10 (IL-1β, IL-4, IL-6, IL-10), and a host of other inflammatory factors that were constitutively secreted by BMSCs. These results demonstrate that chitosan particles alone are not sufficient to promote osteoblast differentiation of BMSCs in vitro , and suggest that chitosan promotes osteogenesis in vivo through indirect mechanisms. Our data further show that continuous addition of dexamethasone promotes osteoblastic differentiation in vitro partly by inhibiting gelatinase activity and by suppressing inflammatory cytokines which result in increased cell attachment and cell cycle exit.