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Articular Cartilage Development
Published in Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi, Articular Cartilage, 2017
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi
While similar to fibronectin in action and containing the integrin RGD interacting sequence, vitronectin is a 75 kDa cell adhesion glycoprotein with an N-terminal somatomedin B domain (Keijer et al. 1991; Kost et al. 1992; Tomasini-Johansson et al. 1998) and central and C-terminal hemopexin homology (Jenne and Stanley 1985). Vitronectin has a critical role in coagulation and inhibition of cell damage during complement activation and has been linked to regulation of cell migration and adhesion during cancer metastasis. In vitro, chondrocytes bind readily to vitronectin or fibronectin-coated surfaces.
Human-Induced Pluripotent Stem Cells: Banking and Characterization
Published in Deepak A. Lamba, Patient-Specific Stem Cells, 2017
Uthra Rajamani, Lindsay Lenaeus, Loren Ornelas, Dhruv Sareen
Vitronectin is a serum glycoprotein that is a component of ECM basement membranes and promotes cell adhesion and spreading (11). It has been used widely as an ECM for hESC and iPSC culture. Specifically, two variant forms of vitronectin have been identified to support stem cell attachment and survival when grown in defined E8 media, namely, VTN-N and VTN-NC (12). It has been shown that vitronectin better supports initial attachment and survival of cells when passaged in small clumps using EDTA as a passaging method (12).
Cell Adhesion in Animal Cell Culture: Physiological and Fluid-Mechanical Implications
Published in Martin A. Hjortso, Joseph W. Roos, Cell Adhesion, 2018
Manfred R. Koller, Eleftherios T. Papoutsakis
The major extracellular protein of focal adhesions is vitronectin. Although both fibronectin and vitronectin are capable of forming focal adhesions independently (30), fibronectin is specifically cleared from these sites over time and is replaced by vitronectin (31). The majority of adhesion-promoting activity in serum is accounted for by vitronectin (30), which is present at a concentration of ~ 300 μg/ml in serum. Without these serum proteins, or in the presence of nonspecific proteins such as BSA, cells will not form focal adhesions, although eventually some cells will synthesize and secrete enough fibronectin onto the surrounding substratum to allow their attachment (32). Fibronectin and vitronectin have several properties that allow them to act as attachment proteins. For instance, fibronectin is a very sticky molecule which may bind to fibrin, heparan, collagen, cell receptors, DNA, IgG, plasminogen, and even to another fibronectin molecule (33). The essential features of these molecules in the formation of focal adhesions are the heparan sulfate proteoglycan binding and the cell receptor binding domains (22). Heparan sulfate is a glycosaminoglycan, which is a repeating polymer of -(N-acetylglucosamine-uronic acid)n-disaccharide units. The sugars in the polymer chain are sulfated to varying degrees, and many heparan sulfate chains bind to a core protein to form a heparan sulfate proteoglycan. Proteoglycans are a very diverse group of large macromolecules that fill up much extracellular space and interact with many other molecules through their charged moieties. Proteoglycans also exist on the surface of cells, and it is probably these cell surface proteoglycans that play an augmenting role in the attachment of cells to fibronectin and vitronectin (34). The segment of fibronectin and vitronectin that binds to cell receptors contains the tripeptide sequence Arg-Gly-Asp (RGD), which is responsible for recognition (35). When coated onto a surface, short synthetic polypeptides containing the RGD sequence have been shown to promote cell attachment, whereas in solution they competitively inhibit cell attachment to a surface coated with either fibronectin or the polypeptides themselves (33). The RGD sequence is the cell recognition site of a number of extracellular matrix proteins, including: fibronectin, vitronectin, collagen types I, III, IV, V, and VI, and laminin (36).
Preparation, characterization and bioactivities of nano anhydrous calcium phosphate added gelatin–chitosan scaffolds for bone tissue engineering
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Yogendra Pratap Singh, Sudip Dasgupta, Rakesh Bhaskar
The release of Ca2+ ions and PO43− ions from more soluble DCPA phase cause a local increase in ion concentration, faster super saturation leading to higher amount of Ca-P precipitation and promoted better protein absorption, which in turn promoted better osteogenesis. Cell adhesive proteins such as fibronectin and vitronectin can specifically wind with integrin protruding from cell membrane to anchor cells with ECM to initiate different kind of cell behaviors such as adhesion, proliferation and even osteogenic differentiation [36, 37]. In turn, this increased protein adsorption orchestrated better binding of integrins α5β1 and α5β3, as well as osteoblast precursor cells [38]. As a whole, RGD domains of fibronectin on Ca-P surfaces influenced the spreading of osteo progenitor cells, thus contributing to the osteoconductivity of corresponding scaffold surfaces [39]. Moreover, generally, osteoblasts tend to adhere more and spread better on onosteoinductive calcium phosphate.
The improvement of calvarial bone healing by durable nanogel-crosslinked materials
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Pornkawee Charoenlarp, Arun Kumar Rajendran, Rie Fujihara, Taisei Kojima, Ken-ichi Nakahama, Yoshihiro Sasaki, Kazunari Akiyoshi, Masaki Takechi, Sachiko Iseki
To compensate this issue, one suitable approach is to functionalize the surface of the material by cell adhesion properties to recruit and retain increased number of osteoblasts in the durable scaffold in addition to the GFs. RGD widely exists in extracellular matrix proteins such as fibronectin, vitronectin, osteopontin and bone sialoprotein [26] It interacts with integrin cell surface receptors to initiate cell adhesion and cell spreading [27]. For bone tissue engineering applications, it has been shown that surface modification with RGD sequence can enhance bone marrow stromal cell adhesion [28], promote osteoblast differentiation in vitro [29] and stimulate bone formation in vivo [30]. As expected, RGD-NanoCliP-GFs discs showed a remarkable improvement on bone healing and RGD-NanoCliP showed better osteoblast-like cell attachment. This result was also consistent with the previous reports that showed synergistic effect of RGD and hBMP2 on enhanced bone formation in vivo intramuscular and subcutaneous models [31,32]. Moreover, there are many reports from in vitro studies that showed synergistic effect of RGD and BMP2 on osteogenic differentiation and mineralization of bone marrow stromal cells (BMSCs) [33,34] as well as mesenchymal stem cells [32].
Effect of micro-roughening of poly(ether ether ketone) on bone marrow derived stem cell and macrophage responses, and osseointegration
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Akira Tsuchiya, Naoyuki Fukuda, Riki Toita, Kanji Tsuru, Kunio Ishikawa
Several studies have reported the effect of surface roughness and topography on cell behavior, including cell attachment, morphology, proliferation and differentiation [30,31,35–42]. In this study, we found that the attachment and proliferation of RMSCs on R-PEEK was significantly higher than that on M-PEEK (Figures 4 and 5). Cell adhesion proteins such as fibronectin, vitronectin, osteopontin and bone sialoprotein, have an arginine-glycine-aspartate peptide sequence which is the integrin-binding domain and plays pivotal roles in initial cell attachment, morphology and proliferation [43]. Owing to the larger surface area of R-PEEK, more proteins can be adsorbed on R-PEEK, attributing to superior initial cell attachment and proliferation in R-PEEK [44]. The OD450 of R-PEEK was decreased at 3 days compared to that at 3 h (Figures 4 and 5) probably because these experiments were performed using different bath of RMSCs having different level of dehydrogenases activity depending on an individual, culture time, passage number, and so on. This assay is based on that cell number is proportional to amount of WST-8 formazan which is produced WST-8 upon multiple chemical reactions including reduction of substrate by dehydrogenases.