Improved Biomedical Polyurethanes

Biomedical polyurethane having the formula A-B-C-Bn, wherein A denotes a polyol comprising a prepolymer that is at least partially based on a random copolyester, B denotes a diisocyanate moiety, C denotes a diol component and n denotes the number of recurring units, wherein the B-C-B segment is bioresorbable, wherein at least one of, preferably both the diisocyanate moieties (B) in B-C-B have a different length than the diol component (C), and wherein the B-C-B segment is based on two diisocyanate units and comprises more than 14 linear carbon atoms in the backbone.

Biomedical polyurethane according to any of the previous claims, wherein B is at least partially based on a linear or branched C4 to C11 alkyl diisocyanate, preferably selected from the group consisting of 1,4-butane diisocyanate (BDI), 1,5-pentane diisocyanate (PDI), 1,6-hexyl diisocyanate (HDI), 1,7-heptyl diisocyanate (HpDI), 1,8-octyl diisocyanate (ODI), 1,9-nonyl diisocyanate (NDI), 1,10-decyl diisocyanate (DDI), methylene bis(4-cyclohexylisocyanate), 2,6-diisocyanatohexanoate and esters thereof (L-lysine diisocyanate, LDI), 5-isocyanate-1-(isocyanomethyl)-1,3,3-trimethylcyclohexane (isophorondiisocyanate, IPDI) and combinations thereof.

Biomedical polyurethane according to any of the previous claims, wherein C is at least partially based on C4 to C11 alkyl diols, preferably selected from the group consisting of glycol, diethylene glycol, 1,4-butane diol (BDO), 1,5-pentane diol (PDO), 1,6-hexyl diol (HDO), 1,7-heptyl diol (HpDO), 1,8-octyl diol (ODO), 1,9-nonyl diol (NDO), 1,10-decyl diol (DDO), N-methyl diethanolamine (N-MDEA), 2,2-bis(hydroxymethyl)propanoic acid, tartartic acid, polyethylene glycol, polycaprolactone, poly lactide and combinations thereof.

Biomedical polyurethane according to any of the previous claims, wherein C is at least partially based on a molecule comprising three or more alcohol groups, preferably a triol, more preferably triethanol amine or glycerol, in an amount of 0.01 to 10 mol %.

Biomedical polyurethane according to any of the previous claims, wherein the copolyester is based on lactide, glycolide, trimethylene carbonate and/or ε-caprolactone.

Biomedical polyurethane according to any of the previous claims, for use in a method of the treatment of nasal wounds, nerves, meniscal injuries, skin and/or veins.

Medical device such as a foam or a sheet, comprising the biomedical polyurethane according to any of the previous claims.

Method for the preparation of a biomedical polyurethane in accordance with any of the previous claims, said method comprising the step of:

• i) reacting the polyol A with the diisocyanate B to form an isocyanate terminated polyol B-A-B, followed by;
• ii) determining the amount of isocyanate groups [R—NCO], followed by;
• iii) reacting the isocyanate terminated polyol B-A-B with the diol component C to form the biomedical polyurethane having the formula A-B-C-Bn.