Reinforced biological tissue
View Patent ↗The present invention provides for an implantable medical device comprising a hybrid composite material including a first biological component such as an acellular tissue matrix and a second non-biological component for strengthening the device after implantation.
1. An implantable medical device, comprising:
a composite material comprising:
a sheet of an acellular tissue matrix; and
a non-biological component including an upper portion, a lower portion, and a neck portion between the upper portion and the lower portion,
wherein the sheet of the acellular tissue matrix wraps around the neck portion of the non-biological component between the upper portion and the lower portion and covers at least a portion of a surface of the non-biological component to form an elongated composite having a predetermined target load capacity approximating the load capacity of a native human ligament to be replaced by the elongated composite,
wherein at least one of (i) the upper portion of the non-biological component is folded over in the direction of the lower portion of the non-biological component or (ii) the lower portion of the non-biological component is folded over in the direction of the upper portion of the non-biological component, to overlap a portion of the wrapped sheet of the acellular tissue matrix with the non-biological component while maintaining a central portion of the wrapped sheet of the acellular tissue matrix exposed between the upper and lower portions of the non-biological component, and
wherein the non-biological component has a higher tensile load capacity than the sheet of the acellular tissue matrix at the time of implantation, and the sheet of the acellular tissue matrix has a higher load capacity than the non-biological component after implantation and following growth of native cells within the acellular tissue matrix, such that the load capacity of the composite material is within the target load capacity range at the time of implantation and also following growth of native cells within the acellular tissue matrix.
2. The medical device of claim 1 , wherein the sheet of the acellular tissue matrix overlays the non-biological component for substantially all of the composite material.
3. The medical device of claim 1 , wherein the non-biological component comprises a bioabsorbable polymer.
4. The medical device of claim 1 , wherein the non-biological component comprises a biocompatible metal.
5. The medical device of claim 1 , wherein the non-biological component comprises polyhydroxybutyrate, polyactic acid, polyactideglycolide acid, polydioxanone or polycaprolactone.
6. The medical device of claim 1 , wherein the non-biological component is a textile including non-biologic material, the textile being a knit, a weave, a braid, a nonwoven structure, or a combination of knit, weave, braid or nonwoven structures.
7. The medical device of claim 6 , wherein the non-biological component comprises a monofilament of non-biological material.
8. The medical device of claim 6 , wherein the non-biological component further comprises a braided or spun multifilament yarn.
9. The medical device of claim 6 , wherein the sheet of the acellular tissue matrix is integrated into the textile structure of the non-biological component.
10. The medical device of claim 1 , wherein the composite material forms a sheet, a cylinder, a solid tube, a hollow tube or a rolled sheet.
11. The medical device of claim 1 , further comprising a tether portion.
12. The medical device of claim 1 , wherein the non-biological component has a higher stiffness than the sheet of biological component at the time of implantation.
13. The medical device of claim 12 , wherein the stiffness of the composite material substantially matches the stiffness of the native human ligament to be replaced by the composite material.
14. The medical device of claim 13 , wherein the native human ligament is an anterior cruciate ligament.
15. The medical device of claim 1 , further comprising at least one screw.
16. The medical device of claim 15 , further including multiple tethers wrapped around an outer surface of the composite material.
17. The medical device of claim 1 , wherein the target load capacity approximates the load capacity of a native anterior cruciate ligament to be replaced by the composite material.
18. The medical device of claim 1 , wherein the non-biological component comprises polyhydroxybutyrate.
19. The medical device of claim 1 , wherein at least one of the upper portion or the lower portion of the non-biological component folded over and overlapping the portion of the wrapped sheet of the acellular tissue matrix imparts a compressive force on the sheet of biological component to maintain the sheet of the acellular tissue matrix wrapped around the portion of the surface of the non-biological component.
20. The medical device of claim 1 , wherein the non-biological component defines a longitudinal axis, and wherein at least one of (i) the upper portion of the non-biological component or (ii) the lower portion of the non-biological component, is folded over along the longitudinal axis to overlap the portion of the wrapped sheet of the acellular tissue matrix with the non-biological component while maintaining the central portion of the wrapped sheet of the acellular tissue matrix exposed between the upper and lower portions of the non-biological component.