The antiviral activity of a number of fractions of poly(acry1ic acid)s and poly(methacry1ic acid)s with different tacticities, different molecular weights and molecular weight distributions has been investigated. Isotactic poly(acry1ic acid)s are essentially more antiviral active in the whole area of efficacy than the atactic ones. Independent of the tacticity poly(acry1ic acid)s with molecular weights smaller than 5000 show no significant effects, polymers with molecular weights greater than 25000 are toxic in the used doses. The optimum of efficacy is between 6000 and 15000. Isotactic poly(acry1ic acid)s with narrow molecular weight distributions are more active than those with broad distributions. The atactic poly(acry1ic acid)s with lower efficacy do not show this relationship. Atactic poly(methacry1ic acid)s are not antiviral active in vivo compared with untreated controls. Isotactic ones have a just detectable efficacy which is essentially lower than the activity of the atactic poly(acry1ic acid)s.

Isopropyl acrylat~-2,3-'~C and isopropyl acryIat~-2,3-~H were polymerized using anionic initiators. The isotactic polymers were fractionated by fractional precipitation and characterized. The polymer fractions were hydrolysed to polyacrylic acids by trifluoroacetic acid. Aqueous solutions of these radioactive labelled polyacrylic acids were injected intravenously to mice in amounts of 40 to lCOmg/kg. Distribution in organs and the excretion were studied. About two thirds of the dose were excreted within the first two days with a half-life of about 0,s days. Further excretion took place with a half-life of about six weeks. Distribution in the organism was not uniform; the highest concentrations were found in spleen, bones, and liver, i.e. organs being parts of the reticuloendothelial system. A relationship between organ concentration and molecular weight of the polyacrylic acid was only observed in the spleen. Nine weeks after injection about 10% of the dose were still retained in the organism, mainly in the skeleton.

SYNOPSISWith the objective to develop both characterization methods and test systems for blood and tissue compatibility, some polymers, e.g., polyethylene (PE), polypropylene (PP), and ethylene/propylene/diene-ter-polymer (EPDM) of different shapes, e.g., beads, films, tubes, fibers, tubings, and microtome slices, were grafted with a variety of 15 monomers in order to introduce hydrophobic, hydrophilic, and ionizable groups. The grafted surface was characterized morphologically by the surface area (Brunauer-Emmett-Teller: BET value), by scanning electron microscopy (SEM), and by profilographic measurements. Surface grafting was controlled by frustrated multiple internal reflexion (FMIR)-ir measurements, by determination of the critical surface tension, and by energy-dispersive x-ray analysis (EDXA) combined with SEM. The EDXA-SEM method was found to be a helpful tool to characterize the homogeneity and penetration profile of surface grafting. The tissue compatibility was tested by implanting test samples under the skin of rats. Blood compatibility was determined via in vifm test systems based on the determination of single clotting factors. to the preparation of blood-compatible polymeric surfaces involves hydrogels or hydrophilic groups [5]. The second idea to introduce ionizable groups, especially negatively charged ones, is based on the knowledge of the anionic architecture at the vascular wall interface [63. Thirdly, surfaces with so-called LTI (low temperature isotropic) carbons (of Gulf Oil Corp.) and other carbons [7] and fluorinated polymers like polytetrafluoroethylene are known as materials with improved blood or tissue compatibility. Many

No abstract