PATCH FOR SEALING AN AMNIOTIC MEMBRANE AND SYSTEM FOR PLACING AN AMNIOTIC MEMBRANE

Abstract

Patch (1) for sealing an amniotic membrane, wherein the patch (1) comprises a support (11) and an adhesive (12) that is activated in presence of amniotic liquid or a wet environment. Device for placing said patch (1) comprising a cannula (2) for inserting said patch (1) in a rolled-up position, said cannula (2) being provided with a handle (3); and a dipstick (4) provided with a pusher (5), said dipstick (4) being inserted inside the cannula (2) in the use position. The patch adheres efficiently on the amniotic membrane, adapts to the elastic properties of this membrane, and by attaching only to the amnion it does not interfere with the natural sliding movements of one membrane against each other, together with the device to ensure that the patch is placed in the proper position without damaging the membrane.

Claims

1. Patch (1) for sealing an amniotic membrane, characterized in that the patch (1) comprises a support (11) and an adhesive (12) that is activated in presence of amniotic liquid or a wet environment.

2. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the patch (1) also comprises an attachment thread (16).

3. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the support (11) is made from an elastomeric material.

4. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the support (11) comprises an outer layer (14) and an inner layer (15).

5. Patch (1) for sealing an amniotic membrane according to claim 4, wherein the outer layer (14) is made from silicone and the inner layer (15) is made from a thermoplastic material.

6. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the adhesive (12) is based in a formulation of hydroxypropyl methylcellulose (HPMC) and hydroxyethylcellulose (HEC).

7. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the support (11) also comprises a mesh (17).

8. Patch (1) for sealing an amniotic membrane according to claim 7, wherein said mesh (17) is a hexagonal mesh.

9. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the support (11) also comprises a micropattern (13), which is in contact with said adhesive (12).

10. Patch (1) for sealing an amniotic membrane according to claim 9, wherein said micropattern (13) is formed by concave hemispheres.

11. Patch (1) for sealing an amniotic membrane according to claim 1, wherein said adhesive (12) is formed by several adhesive coatings.

12. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the patch (1) has a semi-lentil shape.

13. Patch (1) for sealing an amniotic membrane according to claim 1, wherein the adhesive (12) includes a polyvinyl alcohol (PVA) layer.

14. Patch (1) for sealing an amniotic membrane according to claim 1, also comprising a body (18) provided with a plurality of harpoons (19).

15. Patch (1) for sealing an amniotic membrane according to claim 14, wherein said body (18) is made from a plurality of segments (20).

16. Patch (1) for sealing an amniotic membrane according to claim 14, wherein said harpoons (19) protrude from the support (11).

17. System for sealing an amniotic membrane, comprising a patch (1) according to claim 1 and a device for placing said patch (1) on an amniotic membrane, characterized in that the device comprises: a cannula (2) for inserting said patch (1) in a rolled-up position, said cannula (2) being provided with a handle (3); and a dipstick (4) provided with a pusher (5), said dipstick (4) being inserted inside the cannula (2) in the use position.

18. Device according to claim 17, wherein the pusher (5) comprises a hole (23) for placing a fastening thread (6) for fastening said patch (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] For a better understanding the above explanation and for the sole purpose of providing an example, some non-limiting drawings are included that schematically depict a practical embodiment.

[0033] FIG. 1 is a plan view of the patch according to the present invention;

[0034] FIG. 2 is a cross-section view of the patch according to the present invention;

[0035] FIG. 3-5 are views showing the use of the device for inserting the patch inside the cannula;

[0036] FIG. 6 is a perspective view of part of a patch according to the present invention showing a more detailed structure of the patch;

[0037] FIG. 7 is a cross-section view of the patch of FIG. 6;

[0038] FIG. 8 is an elevation view of some segments forming the body; and

[0039] FIG. 9 is a view of an end of the device for inserting the patch where the hole of the pusher can be seen.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0040] According to a first aspect, the present invention refers to a patch 1 formed by a biocompatible elastomeric support 11 and a wet-activation adhesive 12 which is activated in presence of amniotic liquid or a wet environment. The elastomeric support 11 and the adhesive 12 will be introduced into the fetal cavity through a trocar once surgery on the fetus has been completed. The patch will remain adhered to the fetal side of the amniotic membrane until the moment of childbirth, without causing any toxicological reaction, either against the mother or against the fetus.

[0041] As shown in FIG. 2, the patch 1 is formed by the elastomeric support 11 and the adhesive 12 that is deposited on said support 11, said patch 1 having a flat, curved or semi-lentil shape.

[0042] Said support comprises preferably a micropattern 13 with concave hemispheres, e.g. with a deep of 100 μm on one of their sides. In particular, in the case of a semi-lentil patch 1, the micropattern 13 can be located on the outer ring of the inner side, i.e. the side where the adhesive 12 is deposited.

[0043] According to a first example, the support 11 is made from a bi-component medical grade silicone (NuSil MED-4950P) which can be colored with dyes for medical use.

[0044] According to a second example, the support 11 comprises an outer layer 14 of medical grade silicone and an inner layer 15 without micro-pattern of an electrospinned thermoplastic poly-carbonate/poly-urethane copolymer, both perfectly joined.

[0045] Both examples have an attachment thread 16 (FIG. 1) on its internal part that acts as an attachment point, which is introduced before injecting the silicone. An hexagonal mesh 17 with flexible properties that acts as an internal skeleton can be added.

[0046] The adhesive 12 used in the patch 1 according to the present invention can be an adhesive based in hydroxypropyl methylcellulose (HPMC) or hypromellose (H7509, Sigma-Aldrich). Pharm grade Hypromelose (USP, EP, JP) Metolose® SR, ShinEtsu.

[0047] The adhesive 12 used in the patch 1 according to the present invention can be an adhesive based in Hydroxyethylcellulose (HEC) crosslinked with citric acid. Pharm grade Hydroxyethilcellulose (USP, EP, JP) Natrosol™ 250, Ashland™.

[0048] The adhesive 12 used in the patch 1 according to the present invention can be an adhesive based in other cellulose derivates and other formulations of the commented cellulose derivatives.

[0049] The adhesive 12 used in the patch 1 according to the present invention can be adhesive derivates from the reticulation of poly-vinylalcohol (PVA) with boric tetraborate or other salts.

[0050] The patch 1 according to the present invention can also include bioadhesive coatings. These bioadhesives are composed, by one side, for various thin films of polymers and copolymers made with Chemical Vapor Deposition (CVD) techniques, and for the other side by the activations of dopaminated Hyaluronic Acid (dHA) and dopaminated polymers.

[0051] Said polymeric or copolymeric coatings have different thickness of reactive molecules as glycidyl methacrylate (GMA), pentafluorophenyl methacrylate (PFM), allylisothiocyanate (AITC), and crosslink molecules as hydroxyethylmethacrylate (HEMA), allylamine and diethyleneglycol diacrylate (EGDA) and ethyleneglycol dimethacrylate (EGDMA).

[0052] The adhesive 12 can also be based on dopaminated hyaluronic acid (dHA). In this case, the dHA can be modified to increase the percent of chain dopamination. The adhesive properties start when the catechol groups are oxided and become to quinone. Quinones are reactive to make covalent bonds between the other chains and proteins of the amniotic membrane.

[0053] Different concentrations and formulations of dHA can be used, e.g. a concentration of 10 mg/ml of synthetized dHA and 6 mg/ml of FeCl.sub.3 as an oxidant, periodate sodic and other possible oxidants both dissolved in sterilized mQ water.

[0054] The adhesive 12 used in the patch 1 according to the present invention can include a poly-vinylalcohol (PVA) thin layer on top to protect it from the friction and the environment. This layer dissolves quickly in contact with the amniotic fluid and is biocompatible.

[0055] In FIGS. 6 and 7 the patch according to the present invention is shown in more detail.

[0056] In these drawings, the mesh 17 is shown and the patch comprises a body 18, such as a crown, provided with a plurality of harpoons 19 that protrude from the support 11.

[0057] This body 18 has a circular shape and the harpoons 19 are distributed around its periphery and are oriented internally.

[0058] As shown in FIG. 8, the body 18 is made from a plurality of segments 20 engaged to each other by any suitable means, such as tongues 21 that engage in complementary holes 22, this engagement permitting to define the circular shape of the body 18.

[0059] The present invention, according to a second aspect, refers to a system for sealing an amniotic membrane comprising a patch as described previously and a device for placing said patch 1, shown in FIGS. 3-5. The device comprises a cannula 2 with an ergonomic handle 3 and a dipstick 4 with a finger pusher 5.

[0060] According to two alternative embodiments, the ergonomic handle 3 can have a design as a syringe, or a design as a micropipette (shown in FIGS. 3-5).

[0061] Furthermore, the finger pusher 5 can also have different designs, allowing to push the dipstick 4 with the thumb. The first design allows to push the dipstick 4, while the second design (shown in FIGS. 3-5) allows to push and retract the dipstick 4.

[0062] In the use position, the dipstick 4 is placed inside the cannula 2, as will be described hereinafter.

[0063] The method for placing the patch 1 according to the present invention using the disclosed device is the following:

[0064] A first step is inserting the dipstick 4 with the finger pusher 5 into the cannula 2 with the ergonomic handle 3.

[0065] Once the patch 1 is ready with the adhesive 12, a fastening thread 6 is passed through the attached thread 16 of the patch 1, returning in the same direction, forming a double fastening thread, as shown in FIG. 3.

[0066] The two ends of the fastening thread 6 is inserted through the dipstick 4 and go out through a hole 23 at the finger pusher 5. This hole 23 can be seen in FIG. 9, where the handle 3 is connected to the cannula 2 by a threaded piece 24.

[0067] Then, the dipstick 4 is partially removed, and the patch 1 is rolled up (FIG. 4) and inserted into the cannula 2 (FIG. 5), while preserving the tension of the double fastening thread 6.

[0068] Once inserted into the cannula 2, the patch 1 is placed in the desired position on the amniotic membrane, by the following steps:

[0069] 1. Introduction of a trocar to realize the fetal surgery, in a conventional way;

[0070] 2. Extraction of the device with the patch from an esterized blister;

[0071] 3. Introduction of the device into the trocar after the surgical process is finished, until the final position. This final position allows the cannula 2 to protrude through the terminal end of the trocar.

[0072] 4. The finger pusher 5 is pushed until the dipstick 4 pushes out the patch 1, and the patch 1 unfolds.

[0073] 5. Once the adhesive 12 of the patch 1 is rehydrated by the amniotic liquid, the patch 1 is put in contact with the amniotic membrane by a tension of the fastening thread 6 during some time. Then the trocar is removed along with the device, keeping the fastening thread 6 tensioned, so that when the device is removed the thread 6 slides inside the hollow dipstick 4.

[0074] It must be pointed out that during the placement of the patch 1 on the amniotic membrane the device is placed in the positions shown in FIGS. 3-5, but in the inverse order.

[0075] It must also be pointed out that the patch can also comprise an external coating for the patch to slide easily inside the device and for an easier exit, made e.g. by PTFE. Alternatively, the device can also comprise an internal hydrophilic coating.

[0076] Even though reference has been made to a specific embodiment of the invention, it is obvious for a person skilled in the art that the patch and the system described herein are susceptible to numerous variations and modifications, and that all of the details mentioned can be substituted for other technically equivalent ones without departing from the scope of protection defined by the attached claims.