Expandable aortic or pulmonary root
A support layer for a synthetic root comprises at least a first region and a second region. The pattern, material, density and/or tension of the support layer in the first region is different to that in the second region. The support may be formed from a knitted, woven, braided or 3D-printed material. The support layer may be comprised within a synthetic aortic or pulmonary root. In at least one region the synthetic root may have a multi-layered structure with the support layer disposed between an inner and an outer nanofiber layer.
1 . A synthetic root comprising a support layer having a tubular shape with first and second ends, the support layer being formed of a knitted, woven, braided or 3D-printed material, or a combination thereof, and having a region of increased diameter located between the first and second ends and a crown-shaped region located between the region of increased diameter and the second end;
at least a portion of the support layer being disposed between an inner and an outer nanofiber layer; and
wherein the pattern, material, density and/or tension of the support layer in the region of increased diameter is different to that in the crown-shaped region such that the region of increased diameter and the crown-shaped region are of different stiffness;
the root further comprising one or more leaflets projecting inwardly into the tubular shape.
2 . The synthetic root of claim 1 , wherein the support layer is knitted.
3 . The synthetic root of claim 1 , wherein the support layer is formed from a yarn.
4 . The synthetic root of claim 3 , wherein the yarn is formed from a polymer selected from PCL, polyester, PLA, PLGA, silk (poly (dioxanone), poly (ortho esters), poly (amide esters), poly (anhydrides), polyvinyl esters, (poly (tetrafluoroethylene), poly (ethylene), poly (ethylene glycol), polypropylene oxide, or combinations thereof.
5 . The-synthetic root of claim 1 , wherein the region of increased diameter is formed by three outwardly protruding portions arranged around the circumference of the tube.
6 . The synthetic root of claim 5 , wherein the crown-shaped region comprises three triangular portions connected by a base of circular cross-section, wherein each triangular portion extends between adjacent outwardly protruding portions.
7 . The synthetic root of claim 6 , wherein the stiffness of the outwardly protruding portions is different to the stiffness of the crown-shaped region and/or the stiffness of other regions.
8 . The synthetic root of claim 6 wherein the triangular portions comprise a hydrogel.
9 . The synthetic root of claim 1 , wherein the inner and/or outer nanofiber layer comprises a polymer selected from polycaprolactone (PCL), polyester, (poly(dioxanone), poly(ortho esters), esters), poly(amide poly(anhydrides), polyvinyl esters, (poly(tetrafluoroethylene), poly(ethylene), poly(ethylene glycol), polypropylene oxide, polylactic acid (PLA), poly (lactic-co-glycolic acid (PLGA), silk, or combinations thereof.
10 . The synthetic root of claim 1 , wherein the nanofibers of the inner and/or outer nanofiber layer are aligned.
11 . The synthetic root of claim 1 wherein the inner and/or outer nanofiber layers are bound to bioactive molecules.
12 . The synthetic root of claim 1 , wherein the support layer has different tensions in the region of increased diameter and the crown-shaped region.
13 . The synthetic root of claim 1 , wherein the nanofiber layers of the leaflets have an anisotropic structure.
14 . The synthetic root of claim 13 , wherein the nanofiber layers of the leaflets have a different degree of alignment than nanofiber layers in other regions of the root.
15 . The synthetic root of claim 1 , wherein the leaflets comprise a third support layer region disposed between inner and outer nanofiber layers, and wherein the support layer of the leaflets has regions of different patterning.