Non-foldable pouch for forming an implantable artificial organ

Abstract

The present invention relates to an implantable pouch which contains a rigid plate in its inner volume, thereby preventing said pouch to be folded.

Claims

1. A pouch for forming an implantable artificial organ/device wherein said pouch is a closed envelope made from two semi-permeable membranes that are sealed all over the perimeter of the pouch, thereby defining an inner volume and an outer volume of the pouch, wherein said pouch contains a substantially planar rigid plate in its inner volume, wherein the rigid plate is made from a material selected from the group consisting of a biocompatible metal and a biocompatible alloy, wherein the rigid plate is made of titanium or of an alloy containing titanium.

2. The pouch of claim 1, wherein the rigid plate has the same shape as the pouch and the surface of the rigid plate is at least 60% of the surface of the pouch.

3. The pouch of claim 1, wherein the rigid plate has the same shape as the pouch and the surface of the rigid plate is at least 80% of the surface of the pouch.

4. The pouch of claim 1, wherein the surface of the plate is smooth.

5. The pouch of claim 1, wherein the surface of the plate is not smooth.

6. The pouch of claim 1, wherein the thickness of the plate is comprised between 0.01 mm and 2 mm.

7. The pouch of claim 1, wherein the surface of the plate bears holes.

8. The pouch of claim 1, wherein the plate is made of a porous biocompatible material.

9. The pouch of claim 1, wherein the surface of plate is covered with a biocompatible elastomer.

10. The pouch of claim 1, wherein the plate presents protuberances at its surface.

11. The pouch of claim 9, wherein the biocompatible elastomer is silicone.

12. The pouch of claim 1, wherein the plate surface is covered with a surface treatment as to avoid cell adhesion thereon.

13. The pouch of claim 1, wherein the alloy is nitinol.

14. The pouch of claim 1, wherein the porous biocompatible material is porous titanium.

15. The pouch of claim 11, wherein the silicone coat presents protuberances at its surface.

16. The pouch of claim 1, wherein the thickness of the plate is comprised between 0.1 mm and 0.6 mm.

17. The pouch of claim 9, wherein the elastomer coat surface is covered with a surface treatment as to avoid cell adhesion thereon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: upper view of a titanium sheet embedded in silicon according to one embodiment

(2) FIG. 2: implantable pouch after implantation and recovery without (A) or with (B) the presence of a rigid plate therein.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(3) This description provides examples not intended to limit the scope of the appended claims. The figures generally indicate the features of the examples, where it is understood and appreciated that like reference numerals are used to refer to like elements. Reference in the specification to “one embodiment” or “an embodiment” or “an example” means that a particular feature, structure, or characteristic described is included in at least one embodiment described herein and does not imply that the feature, structure, or characteristic is present in all embodiments described herein.

(4) FIG. 1 is a representation of a rigid plate intended to be associated to semi-permeable membranes for forming an implantable chamber which can be used for encapsulating secreting cells producing at least one substance of interest.

(5) This plate (or plate), referenced 100 is herein disclosed as embedded within an elastomer (here silicon) layer 110.

(6) The silicon layer comprises protuberances (111), that are in staggered rows, thus creating channels (112) in which the cells can settle.

(7) The plate (100) further comprises holes (101, 102) that are useful for overmolding the silicon over the plate and allow communication of fluid between the two half-volumes delimited by the plate within the pouch. It can be seen that holes (101) have been pierced within the silicon layer, wherein holes 102 have not been filled with elastomer.

EXAMPLE

Example 1—Device Implantation in Pigs and Subsequent Retrieving

(8) Landrace pigs were implanted with device with or without reinforcing plate.

(9) Landrace pigs were implanted with device featuring implantable chambers described earlier or another system that is only placed on upper membrane.

(10) Briefly, a premedication was performed by intramuscular injection of Azaperone (Stresnil®—2 mg/Kg) and Ketamine (Imalgene®−10 mg/Kg). Anesthesia was induced with intravenous injection of 0.4 mg/Kg of Propofol and completed by a muscle relaxant Pancuronium at 0.1 mg/Kg. Immediately after induction, an oro-tracheal intubation was performed and a pulmonary ventilation was set up using a semi-closed circular system connected on a respirator in a controlled-pressure mode. The maintenance of anesthesia was ensured on the inhalatory mode using isoflurane (inspired fraction=2 vol %) with a fresh gas debit of 2 L/min of a mixture of O2/N2O 50%/50% that serves as a vector gaz.

(11) After shaving and disinfection of swine's abdomen, a midline incision was performed and a pouch was carefully dissected between the peritoneum and abdominal muscles. Device was then wetted with sterile saline solution and inserted into the pouch and attached at 4 points on abdominal muscles using 3/0 absorbable thread. Abdominal muscles and subcutaneous tissue were then sutured by simple overlock using 1/0 and 3/0 absorbable thread respectively.

(12) Finally, skin was closed by intradermal suture using 3/0 absorbable thread. Animals were followed after surgery to ensure complete recovering of the animals with administration of Paracetamol (500 mg), Tramadol (50 mg) and Ketoprofen (50 mg) every 6 hours.

(13) Once pre-determined implantation time is passed, pigs were anesthetized according to the same protocol as used for implantation. Device was retrieved and animals were sacrificed by injection of a lethal dose of potassium chloride.

(14) It is clear from FIG. 2 that the presence of the rigid plate within the pouch (FIG. 2.B) makes it possible to protect the shape of the pouch upon implantation wherein such pouch is torn in the absence of the plate (FIG. 2.A).

Example 2—Punching Test

(15) Using a dedicated bench test, the device was tested with or without a titanium sheet overmolded with silicone. In this test, the device was a circle with a 120 mm diameter and the plaque was circular with a 96 mm diameter (corresponding to 80% of the device's diameter).

(16) The test consists in a punching test with a penetration of 5 mm.

(17) The test was performed at 37° C. in liquid solution.

(18) When no titanium sheet present, the device could support 500 cycles, before breakage.

(19) By comparison, when the device is reinforced with a titanium sheet, the device could achieve up to 7000 cycles.

(20) In these “in vivo” mimicking conditions (at 37° C. in liquid), presence of a titanium plaque makes the device 14 times more resistant to punching.