Bioactive substance immobilization

Immobilization and Controlled Release of Bioactive Substances from Stimuli-Responsive Hydrogels... 

Microstructure and viscosity are dependent on the chemical composition Used as immobilization matrices for cells and enzymes, controlled release of bioactive substances, injectable microcapsules for treating neurodegenerative and hormone deficiency diseases Lacks yield value... 

Increased content of negative-charged sulfonic groups imparts a stable phase state of dilute aqueous dispersions of ANP. Study of rheological properties of aqueous dispersions also showed that with the increase in concentration the viscosity rises, and the 7—8% ANP dispersion has a gel form. Furthermore, the presence of acidic functional groups in the ANP contributes immobilization of bioactive substances containing basic functional groups. 

Plasma-induced grafting of hydrogels offers a possibility to obtain permanent minimization of the surface energy of hydrophobic polymer surfaces. Hydrox-yethylmethacrylate (HEMA) was applied as hydrophilic monomer, the polymer of which is already known in the fabrication of contact lenses [1,112]. Acrylic acid (AAc) was chosen as the hydrogel building monomer to generate a stable, hydrophilic surface with the additional possibility of using the acid functions for further immobilization of bioactive substances. 

In view of further immobilization of bioactive substances via the carboxylic functions of the grafted acrylic acid, investigation of the accessibility of the acidic groups was carried out by means of appropriate derivatization reactions with TFE using the coupling reagent EDC (Eq. (3)) and detection of the reporter element fluorine by means of XPS. 

Bioactive substances designed to act as receptors must be immobilized at an electrode surface. There are some differences depending on the question whether biocatalytic or bioaffinity sensors must be realized. Potentiometric and amperometric sensors also are characterized by different requirements. In principle, with potentiometric sensors a higher impedance can be tolerated, whereas amperometric sensors require a good electric conductivity. Nevertheless, immobilization techniques are similar for both groups. 

Tzevi R, Todorova G, Kossev K, Troev K, Geoigiev EM, Roundhill DM (1993) Immobilization of bioactive substances on poly(alkylene phosphate)s, 1. Immobilization of 2-phenylethylamine. Makromol Chem 194 3261-3269... 

The method has advantages of simple operation, mild reaction conditions and easy division. So it is usually applied to prepare sustained release drugs or immobilized bioactive substances. 

A variety of methods and materials have been proposed and tested to immobilize bioactive substances such as microorganisms, enzymes, and... 

From the above three struetural variants one may infer that the value of 0.03 mole in the eellular lipids strongly indieates the required eoneentration for immobilization of tadpoles . In short, it adequately eonfers the bioactivity of a drug substance to its inherent hydrophobicity and hydrophilicity. 

Polyacrylamide is used in a wide range of cosmetic products such as moisturizers, lotions, creams, self-tanning products, etc. Polyacrylamides were first used as an implantable carrier for sustained delivery of insulin to lengthen the life of diabetic rats. Since then, various drug delivery systems based on polyacrylamide have been developed. It is also used as a carrier for other bioactive macromolecules and cells to produce the desired effects. Polyacrylamide-chitosan hydrogels are biocompatible and are used for sustained antibiotic release. Polyacrylamide is also used in extra corporeal toxin-removing devices, which remove unwanted toxic substances and subsequently returns the detoxified component to the circulation effectively. The function of polyacrylamide in an extracorporeal toxin removal modality is to provide a support matrix for immobilization of the functional parts or ligands. 

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