title: Poly(dimethylsiloxane)-poly(ethylene oxide)-heparin block copolymers. I. Synthesis and characterization.
abstract: Amphiphilic block copolymers containing poly(dimethylsiloxane), poly(ethylene oxide), and heparin (PDMS-PEO-Hep) have been prepared via a series of coupling reactions using functionalized prepolymers, diisocyanates, and derivatized heparins. All intermediate steps of the synthesis yield quantifiable products with reactive end-groups, while the final products demonstrate bioactive, covalently bound heparin moieties. Due to the solvent systems required, commercial sodium heparin was converted to its benzyltrimethyl ammonium salt to enhance its solubility. The same procedure was applied to heparin degraded by nitrous acid in order to covalently couple it in solutions with the semitelechelic copolymers. As might be expected, this derivatization reduces the apparent bioactivity of the heparin. However, preliminary findings suggest that the bioactivity can be restored by reforming the heparin sodium salt.
authors: Department of Pharmaceutics, University of Utah, Salt Lake City.
authors: D W
authors: DW
authors: Grainger
authors: S W
authors: SW
authors: Kim
authors: J
authors: J
authors: Feijen
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D001777:Blood Coagulation / Q000187:drug effects; D004129:Dimethylpolysiloxanes; D006493:Heparin / Q000138:chemical synthesis* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D012828:Silicones / Q000138:chemical synthesis*; D012833:Siloxanes / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D012828:Silicones; D012833:Siloxanes; C055740:poly(dimethylsiloxane)-(polyethylene oxide)-heparin copolymer; D006493:Heparin