Hyaluronan coatings

Other carbohydrate polymers consist of repeating oligosaccharide units. Thus, in hyaluronan irnits of glucuronic acid and N-acetyl-D-glucosamine alternate (Fig. 4-11). The "O antigens" of bacterial cell coats (p. 180) contain repeating subunits made up of a "block" of four or five different sugars. In these and... 

As described above, cancer cells produce or induce other cells to produce hyaluronan. This halo of hyaluronan protects the cells against macrophages or leukocytes and shields them from cytostatics. Several studies have dealt with the addition of hyaluronidase to chemotherapy in order to degrade the hyaluronan coating and to render the cells more accessible to the cytostatic drugs. 

HA is a ubiquitous nonsulfated GAG characterized by its long length and unique mode of synthesis that occurs at the plasma membrane of the cell via a hyaluronan synthase (HAS) (75). Because of its mode of synthesis, HA is extruded directly into the extracellular space and can be retained as a cell coat (76). It is likely that... 

The hyaluronan in the component of pseudoexfoliation material from human donor eyes has been analyzed histochemically. Hyaluronan was found to coat the fibrillar exfoliation material on the lens, zonules, iris epithelium, and ciliary body (85). The major component of the pseudoexfoliation material on the posterior surface of the iris was histochemically verified as chondroitin sulfate, while the minor component was hyaluronan (86). A polarization microscopic analysis demonstrated the presence of more sulfated glycosaminoglycans in exfoliation syndrome than in control subjects. 

Thierry B, Winnik FM, Merhi Y, Silver J, Tabrizian M. Radionuclides-hyaluronan-conjugate thromboresistant coatings to prevent in-stent restenosis. Biomaterials 2004 25 3895-3905. 

Wang YW, Mo W, Yao H, Wu Q, Chen J, Chen GQ (2004) Biodegradation studies of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). Polym Degrad Stab 85 815-821 Wang YW, Wu Q, Chen GQ (2003) Reduced mouse fibroblast cell growth by increased hydro-philicity of microbial polyhydroxyalkanoates via hyaluronan coating. Biomaterials 24 4621 629... 

Skardal A, Sarker S, Crabbe A, Nickerson C A and Prestwich G D (2010a), Hyaluronan-gelatin coated microcarriers for spherical microtissue culture and recovery . Biomaterials, 31, 8426-35. 

Sondrup C, Liu Y, Shu X Z, Prestwich G D and Smith M E (2006), Cross-linked hyaluronan-coated stents in the prevention of airway stenosis , Otolaryngol Head... 

Several hydrophilic coatings were applied to PUs to increase surface hydrophilicity, including poly(ethylene glycol) (PEG), hyaluronan, dermatan sulfate, and heparin. 

Other hydrophilic coalings have been proposed to reduce bacterial adhesion onto Morra et al. studied in vitro the adhesion of S. epidermidis onto bare PU catheters and PU catheters coated with hyaluronan. A significant reduction in bacterial adhesion was found by using the soft, hydrated surface of the modified PU. ° Highly sulfonated hyaluronan as PU coating resulted in the inhibition of S. epidermidis adhesion with respect to the unmodified PU. ... 

PHBHHx Hyaluronan coating Improved hydrophilicity, low fibroblast L929 cellular growth 1.6x10 (4x10 ) cells per ml. Could be employed in biomaterial selection and design. 77... 

A separate attempt has also been made to use the LbL coating method to form self-assembling chitosan/hyaluronan (CS/HA) coatings for endovascular stents... 

Heublein B, Evagorou EG, Rohde R et al (2002) Polymerized degradable hyaluronan - a platform for stent coating with inherent inhibitory effects on neointimal formation in a porcine coronary model. Int J Artif Organs 25 1166-1173... 

Several cell types exhibit highly hydrated, hyaluronan-dependent, pericellular matrices or coats that are destroyed by treatment with hyaluronan-specific hyalur-onidase [16, 17]. In culture, these matrices cannot be analyzed readily by conventional light microscopy. However the coats can be visualized indirectly by exclusion of particles and are usually 5-10 pm in thickness (Figure 2). These pericellular matrices provide the milieu in which numerous cellular activities take place and they influence the behavior of cells in many circumstances. For example, during tissue formation or remodeling, such matrices would provide a hydrated, fluid pericellular environment in which assembly of other matrix components and presenta-... 

With respect to muscle differentiation in the limb, mononucleated myoblasts are also initially separated from each other by a hyaluronan-rich matrix in vivo and express pericellular matrices in culture [49] (Figure 2E). However during the processes of condensation and fusion to give myotubes these coats are lost [49] (Figure 2F), thus allowing the interactions required for these cells to differentiate. 

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