Blood interactions with synthetic polymers

Although the surf ce energy is probably not the only parameter which determines the state of adsorbed FN, it does appear to be important. An understanding of how surface energetics effect the interaction of FN with polymer surfaces would be an important contribution in the areas of cell growth and the interaction of blood proteins with synthetic polymers. 

Effect of Chemical Structure and Surface Properties of Synthetic Polymers on the Coagulation of Blood. II. Protein and Platelet Interaction with Polymer Surfaces, Trans. Amer. Soc. Artif. Int. Organs (1968) 14, 250. 

A scientific breakthrough in order to design USCAs on demand can be seen in the third generation (Myomap, Quantison, BiSphere and Sonavist). Compared to the more or less free bubbles of the first and second generations, the novel type of USCAs consist of encapsulated microbubbles with a shell formed by a biopolymer (like human albumin) and/or a biocompatible synthetic polymer (like copolymers of poly-lactide and polyglycolide or derivatives of polycyanoacrylate). In addition to the prolongation of the lifetime in the blood stream, these polymer-stabilized microbubbles can be manufactured to fulfill certain needs, and to interact with diagnostic ultrasound in a defined and optimal manner. 

To increase the residence time of drug carriers in the blood, the carriers are modified with hydrophilic synthetic polymers, such as PEG [62-64]. Coating nanoparticles with PEG sterically disrupts the interactions of blood components with the carrier surface and subsequently decreases the binding of plasma proteins. This minimizes opsonin adsorption onto the carrier and carrier uptake rates by the reticuloendothelial system (RES) [65-67]. Repulsive interactions [68] and poor permeability of proteins through PEG coating [69] may contribute to this observation. 

In order to reduce the interaction of dextran with blood components, the negatively charged dextran sulfate (DS) was used to prepare polyelectrolyte complexes (PECs) together with cationic natural or synthetic polymers, such as chitosan or PEI. PECs can be synthesized by direct interaction of oppositely charged polyelectrolytes in solution. In PECs, the outer coat of dextran sulfate minimizes electrostatic interactions, while the inner posi-... 

This is still a very confused field. An excellent introduction to the questions of tissue and blood response to implanted polymers has been written by Bagnall together with a lead to key references in this field. Review papers by Bruck dealing with the interaction of both natural and synthetic surfaces with blood. 

Lyman DJ, Brash JL, Chaikin SW, Klein KG, Carini M. Effects of chemical structure and surface properties of synthetic polymers on coagulation of blood. 2. Protein and platelet interaction with polymer surfaces. Trans Am Soc ArtifIntOrg 1968 14 250-5. 

In this paper, we examine the Interactions of pyran copolymer with model biomembranes of two kinds 1) the human red blood cell membrane (or red cell "ghost") and 11) multilamellar suspensions (liposomes) of dlpalmltoylphosphatldylchollne (DFPC), a pure synthetic phospholipid. Each of these systems offers advantages In studies of polymer-cell surface Interaction The red cell membrane, idille complex. Is still the most readily Isolated and best understood of the membranes of nonnal human cells, and Its molecular architecture Is, In a general way at least, typical of such membranes. The pure phospholipids provide a much simpler biomembrane model, with the prospect of yielding more complete Interpretation of experimental observations. 

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