Adhesives algin

Thickeners. Thickeners increase the viscosity of the polychloroprene latex adhesives. Amounts up to 1% of polyacrylates, methyl cellulose, alginates and polyurethane thickeners can be used. Particular attention should be paid to fluctuations in pH when thickener is added in the formulations. For low-pH (7-10) formulations, fumed silica or some silicates can be used. 

Polyelectrolyte-based dental cements or restorative materials include zinc polycarboxylates, glass ionomers, a variety of organic polyelectrolyte adhesives as well as alginate-based impression materials. Dental cements are primarily used as luting (cementing) agents for restorations or orthodontic bands, as thermal insulators under metallic restorations, and as sealents for root canals, pits and fissures. They are also sometimes used as temporary or permanent (anterior) restorations. For further introduction to dental materials the reader is referred to standard texts [122,123]. 

A variety of organic adhesives which are capable of forming strong bonds between a polymeric (acrylate) restoration and the hydrophilic tooth material have recently been developed. A number of these monomers, which possess a pendent ionizable group, are polymerized in the mouth to form an adhesive layer. Alginates, which are used as impression materials, are formed by the reaction of the sodium salt of anhydro-beta-d-mannuronic acid with calcium sulfate. Calcium ions crosslink the linear polymer to form a gel. This reaction is carried out inside the mouth, and the gel formed retains the shape of the oral cavity. 

Yong et ah [175] developed an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethyl cellulose was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Magnesium oxide is an alkali stabilizer for omeprazole buccal adhesive tablets. Croscarmellose sodium enhanced the release of omeprazole from the tablets but it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. 

Algin Viscosity stabilizer for starch-dextrin and latex-type adhesives ... 

Tablet binder Substance used to cause adhesion of powder particles in tablet granulations Acacia, alginic acid, carboxymethylcellulose sodium compressible sugar, ethylcellulose gelatin, liquid glucose, metylcellulose povidone, pregelatinized starch...

Miyazaki S, Nakayama A, Oda M, et al. Drug release from oral mucosal adhesive tablets of chitosan and sodium alginate. Int J Pharm 1995 118 257-263. 

To mimic the macromolecular-based ECM in biological tissue, the cell adhesion and proliferation properties of hydrogels are critical parameters. However, various hydrogels that originate from natural resources, such as alginate [87], chitosan [88, 89], and hyaluronic acid [90], and that are synthetically created, such as poly (7V-isopropylacrylamide) (PNIPAAm) [91], PEO [92], PVA [93], and poly(ethylene glycol) (PEG) [94], show a poor cellular viability without modification with cell adhesive proteins or peptides, such as collagen, laminin, fibronectin, and the RGD (Arg-Gly-Asp) sequence. 

The primary methods used in cell immobilization are surface adhesion, covalent attachment and entrapment. Surface adhesion involves adsorption of cells to microcarriers such as calcium alginate beads, collagen-coated plastic beads, diatomite silica, and dextrans [68]. Immobilization can be achieved simply by suspending the cells and microcarrier together under slow agitation. Examples of such systems include immobilized bacteria for waste water treatment and adsorbed Azotobacter vinelandii on Cellex E for nitrogen fixation... 

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