Biologically active polymers discussion

The hydrolytic release of 5-chloro-8-hydroxyquinoline from 5-chloro-8-quinolinylacrylate containing polymers was studied under physiological conditions (pH 7.2 and 37 C) as well as in acidic and alkaline medium. The relationship between composition, polymer microstracture, type of the comonomer unit, hydrolysis behaviour, and biological activity is discussed. 24 refs. 

In the extraction of biologically active compounds, care must be taken to avoid the loss of activity that often occurs by contact with organic diluents. Thus a series of systems have been developed specifically with these compounds in mind. The first of these uses mixtures of aqueous solutions containing polymers and inorganic salts that will separate into two phases that are predominately water. A second system uses supercritical conditions in which the original two-phase system is transformed into one phase under special temperature-pressure conditions. Also the active organic compound can be shielded from the organic diluent by encapsulation within the aqueous center of a micelle of surface active compounds. AU these systems are currently an active area for research as is discussed in Chapter 15. 

In this review we first summarize methods of synthesis of ECM analogs as graft copolymers. The modification of supermolecular structure (crystallinity, crosslink density, porosity) is then discussed. Finally, the relationships between polymer structure and biologic activity are summarized. 

Dual Analytical-Bioassay. Many of the reports of polymer applications include dual analytical and bioassay features because these integrated studies help to focus attention on those compound classes and individual compounds that have the highest biological activity. These dual-purpose reports were counted in both categories to arrive at an application distribution of 85 analytical and 15 bioassay. The results given in these two report groups are discussed separately in the following sections. 

Methods for preparing heparin-containing polymeric materials by means of ionic and covalent immobilization of heparin on various polymers are surveyed. The data on the biological activity of heparin are discussed as well as the probable mechanisms of thromboresistance enhancement endowed to polymeric materials by this anticoagulant. Some approaches toward an increased efficiency of anticoagulant properties of immobilized heparin are analyzed, and the position of heparin-containing polymers among other biomedical polymers is discussed. 

Polymers grafted at the surface at a density below the brush regime (see Figure 1) do not frustrate subsequent particle deposition. Still, the surface will dynamically respond to the indwelling particles. For instance, the conformation and orientation and, hence, the biological activity of adsorbed protein molecules may be manipulated. Two cases are discussed below. 

The system discussed in this paper also has biological relevance. Owing to the C(=0)-NH- bonds, the polymer chain of the PNIPA can be considered as a model protein, while phenol is a frequent substituent of amino acids or other biologically active molecules.11... 

Natural bloactive polymers are essential to life and Include the proteins, nucleic acids and polysaccharides. Synthetic bioactive polymers are a more recent development but hundreds of possible examples have been reported with potential biological activity. In this brief, introductory review, the history, philosophy, mode of activity and the advantages of bloactive polymers are discussed emphasizing synthetic polymers. 

The 1 2 copolymer of dlvlnyl ether and maleic anhydride ("pyran copolymer," I) exhibits a broad range of biological activity, and has been discussed elsewhere in this volume and in earlier reviews (JL, 2) Of particular interest is the polymer s antitumor activity after initial clinical testing and then withdrawal from clinical use due to severe toxicity, the drug is again under evaluation as an agent for the treatment of human cancer. ... 

Electrostatic interactions resulting from the polarity of the carbon-fluorine bond play an important role in the binding of fluorinated biologically active compounds to their effectors [22] (discussed in detail in Sections 4.5 and 4.6) and for the me-sophase behavior of fluorinated liquid crystals [23] (Section 4.4). The consequences of the low polarizability of perfluorinated molecular substructures have been put into commercial use for chlorofluorocarbon (CFG) refrigerants, fire fighting chemicals, lubricants, polymers with anti-stick and low-friction properties, and fluorosur-factants. 

These dendrimers have been additionally modified with biologically active molecules, which can react with the available amidic functional groups. Result from the first photophysical and biochemical investigations of the new structurally modified dendrimers are discussed. The comparison between the bio-modified PAMAM dendrimers and some linear polymers is given (Grabchev et al. 2007a). 

Triterpene dimers and trimers discussed in the present review probed to be inactive as cytotoxic [91,8]. According to Gonzalez et al., this fact is due that the size of this type of compound plays an important role in their activity and that they could be stored in the plant as polymers, which could release biologically active units, like the quinone methides. 

Which of these four potential advantages, if any, actually occurs with the platinum polymers is currently being studied. Approximately two dozen platinum polyamines have been synthesized, and some show biological activity while others do not (126-128). Several of the polymers properties are being explored and correlated with polymer activity in an effort to discover why certain polymers are active while others are inactive. Such factors as the nature of the diamine component, the extent to which a polymer is transported into the cell, the rate of aquation, etc., could all influence the biological activity of a polymer. Two other properties that could control polymer activity are the size of a polymer and the tendency of a polymer to degrade, and these will be the subject of discussion here. 

The use of polymers for the immobilization of enzymes and other bio-logically-active molecules has been discussed. The advantages of polymeric support materials and rules for their selection according to the type of use have been discussed. A review of various types of polymers which can serve as support matrices has been given. They are, e.g., polymeric carbohydrate derivatives, poly(allyl carbonate) and poly(allyl alcohol), polymers of acrylamidosalicylic acids, polyacrylamide derivatives, etc. Some examples of the use of immobilized enzymes and other biologically-active molecules were mentioned. 

---