MEMBRANE TO RE-ESTABLISH CONTINUITY OF INJURED BIOLOGICAL TISSUES
A membrane for re-establishing the continuity of injured biological tissues includes a non-woven fabric of fibres of a polyhydroxyalkanoate (PHA) containing 3-hydroxybutyrate monomer units, wherein the fibers have an average diameter between 800 nm to 3500 nm. Preferably, the PHA is a poly-3-hydroxybutyrate homopolymer and at least one active ingredient is associated with the fibers of the non-woven fabric. The membrane has the advantages of promoting the healing of injured biological tissues relatively quickly, without inducing excessive inflammatory or rejection reactions, thus demonstrating a high biocompatibility, thereby providing a valid support in the healing process of biological tissue injuries and preventing the formation of dehiscences and incisional hernias.
1 . A membrane for re-establishing the continuity of injured biological tissues, comprises a non-woven fabric of fibres of a polyhydroxyalkanoate (PHA) containing 3-hydroxybutyrate monomer units, wherein said fibers have an average diameter comprised from 800 nm to 3500 nm.
2 . The membrane according to claim 1 , wherein the PHA is a poly-3-hydroxybutyrate homopolymer (P3HB) or a copolymer containing at least 20 mol % of 3-hydroxybutyrate monomer units, the remainder being hydroxyalkanoates monomer units other than 3-hydroxybutyrate.
3 . The membrane according to claim 2 , wherein the hydroxyalkanoate monomer units other than 3-hydroxybutyrate derive from: 4-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxyundec-10-enoate, 4-hydroxyvalerate.
4 . The membrane according to claim 2 , wherein the PHA is a poly-3-hydroxybutyrate homopolymer (P3HB).
5 . The membrane according to claim 1 , wherein the PHA has a weight average molecular weight (M W ) comprised in the range from 5,000 to 1,500,000 Da.
6 . The membrane according to claim 1 , wherein the PHA fibers of the non-woven fabric are produced by electrospinning.
7 . The membrane according to claim 1 , wherein the non-woven fabric has dimensions comprised from 1 cm 2 to 50 cm 2 , a rectangular, rhomboidal, square, oval, round or irregular shape and a thickness comprised from 10 μm to 700 μm.
8 . The membrane according to claim 1 , wherein at least one active ingredient is associated with the fibers of the non-woven fabric.
9 . The membrane according to claim 8 , wherein the at least one active ingredient is selected from the group consisting of: pentoxifylline, doxycycline, ibuprofen, cefazolin, rifampicin, paclitaxel, itraconazole, mefoxin, tetracycline hydrochloride, and mixtures thereof.
10 . The membrane according to claim 9 , wherein the active ingredient is doxycycline.
11 . The membrane according to claim 10 , wherein the doxycycline has a concentration comprised from 0.1% w/w to 4% w/w, with respect to the weight of the PHA.
12 . The method for producing a membrane comprising a non-woven fabric according to claim 1 , the method including the following steps:
preparing a spinning solution by solubilization of the polyhydroxyalkanoate (PHA) containing 3-hydroxybutyrate monomeric units in an organic solvent, and
subjecting the spinning solution to an electrospinning process by means of a spinneret and a rotating support placed substantially perpendicular to the spinning direction, using a configuration called horizontal arrangement, so as to obtain the non-woven fabric.
13 . The method according to claim 12 , wherein the organic solvent usable for the preparation of the spinning solution is selected from the group consisting of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), chloroform, N,N-dimethylformamide (DMF), and mixtures thereof.
14 . The method according to claim 12 , wherein in the spinning solution, the PHA containing 3-hydroxybutyrate monomer units has a concentration comprised from 1% to 20% w/v.
15 . The method according to claim 12 , wherein the spinning solution further comprises at least one active ingredient.