Snamprogetti

Eniricerche S.p.a.

Eni-ente Nazionale Idrocarburi

Anic S.p.a.

Francesco Pittalis

Francesco Bartoli

Walter Marconi

Franco Morisi

Otello Farias

Guido Giovannoni

An asymmetrical membrane for use in dialysis and ultra-filtration is prepared using a polyester-amide (TATE).sub.n, wherein T represents a radical of terephthalic acid, A represents a radical of hexamethylenediamine, and E represents a radical of hexanediol, in a solvent of formic acid or in a solvent comprising a solution of lithium chloride in dimethylformamide or dimethylacetamide. The polyester-amide (TATE).sub.n is formed into a thin layer and placed into an aqueous coagulation bath to coagulate the resulting membrane. The membrane has a thickness of from 15 to 190 .mu.m, a water permeability of from about 3 up to about 9 liters/m.sup.2 /hour for a .DELTA.P of 300 mm.sub.HG and is permeable for substances having a molecular weight of up to about 17,000.

Asymmetrical membrane of polyester-amide and process for preparing it

A hollow fibre of polyester-amide, useful in the process of dialysis and in ultra-filtration processes in general, is formed by a polyester-amide with repetitive units (TATE).sub.n (wherein T is the terephthalic acid radical; A is the ethylenediamine radical; and E is the hexanediol radical). Such a fibre is obtained by a process which comprises the following steps, carried out sequentially:

Process for preparing a polyester-amide hollow fiber membrane

This invention relates to chemical products of general formula ##STR1## wherein R is an amino group, mono or bi-hydroxyalkyl substituted, or a thio group, mono hydroxyalkyl substituted, in which one or more of the available --OH groups have been esterified with acids containing 2 to 18 carbon atoms. It is also described a process for the preparation of said products, which comprises reacting a corresponding starting compound, N or S-hydroxyalkyl substituted, with the chloride or the anhydride of the acid concerned.

Treating pain, inflammation and/or platelet aggregation

Hollow chitosan fibres for use in ultrafiltration processes are described, and which can be plasticized by the addition of glycerin such that they contain this latter in a quantity variable between 0.5 and 5% by weight with respect to the polymer. Said fibres are prepared by the wet spinning of acid chitosan solutions, using an alkali solution as the external fibre coagulant and a gaseous phase containing a basic gaseous component as the internal fibre coagulant.

Process for the preparation of chitosan fibers

A prosthetic polymer material is made non-thrombogenic by immobilizing apyrase on its surface. Immobilization is preferably carried out by hydrolytically activating the surface of a polyamide polymer or a polyethylene terphthalate polymer, and treating the hydrolyzed polymer with a solution of cross-linking agent and a solution of apyrase. The apyrase converts adenosine diphosphate to adenosine monophosphate and adenosine whereby the formation of thrombi is inhibited.

Preparation of biocompatible materials by immobilization of apyrase

Fibres for biological uses can be produced by adding to a spinnable solution of a polymer selected from among many of the most common polymers and copolymers, a substance selected from among anti-platelet aggregation substances, anticoagulants and substances having a similar action. The substances can also be applied as a surface outer layer to articles made with the polymeric substances.

Bio-compatible porous fibres and materials for occluding biologically

Polyamide materials for the construction of protheses and surgical sundries are made biocompatible by inducing a superficial hydrolysis by treating such materials, either raw or in the form of shaped articles, with a normal multiple solution of hydrogen chloride. Thrice normal or fourfold normal solutions are preferred and the treatment time being a function of the temperature. At human body temperature (37.degree. C.) a treatment time from 30 to 60 minutes will do.

Superficially hydrolyzed biocompatible polyamide material

Biocompatible articles are obtained by treating a polymeric material with a hydrolyzing agent on its surface and covalently binding thereon a biological agent, such as an anti-platelet-aggregation agent.

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Rome, Italy

Francesco Pittalis