ELESTOMERIC FIBROUS HYBRID SCAFFOLD FOR IN VITRO AND IN VIVO FORMATION
Biocompatible hybrid fibrous scaffold, derived from a synthetic polymer and a natural hydrogel, and methods of use thereof in tissue engineering.
1 . An elastomeric scaffold for soft tissue engineering comprising a poly-4-hydroxybutyrate (P4HB) matrix.
2 . The scaffold of claim 1 , further comprising a hydrogel, preferably a photocrosslinkable hydrogel.
3 . The scaffold of claim 2 , wherein the photocrosslinkable hydrogel is gelatin or methacrylated gelatin (GelMa).
4 . The scaffold of claim 2 , comprising a P4HB matrix, wherein the hydrogel is distributed throughout the matrix.
5 . The scaffold of claim 2 , comprising an inner layer of a gelatin/P4HB composite, and an outer layer of P4HB on either side of the inner layer.
6 . The elastomeric scaffold of claim 1 , which is fabricated by dry spinning to generate aligned fibers of P4HB.
7 . The elastomeric scaffold of claim 1 , wherein the P4HB matrix has an average fiber diameter of 5-20 μm, preferably 8-10 μm.
8 . The elastomeric scaffold of claim 1 , which has a porosity of 10-15 μm.
9 . The scaffold of claim 2 , wherein the hydrogel encapsulates a plurality of cells, preferably stem cells, preferably mesenchymal stem cells (MSCs) or Valvular Interestitial Cells.
10 . The scaffold of claim 9 , wherein the surface of the scaffold comprises cells, preferably cells of a second cell type, preferably endothelial progenitor cells (EPCs), preferably derived from circulating blood.
11 . A method of forming an artificial tissue, comprising culturing the scaffold of claim 10 in a cyclic stretch/flexure bioreactor or in a bioreactor that delivers flow, flexion, and shear signals to the scaffold.
12 . An artificial tissue formed by the method of claim 11 .
13 . An artificial tissue formed by the method of claim 11 , wherein the tissue is a heart valve leaflet, vascular conduit or blood vessel, or a portion thereof.
14 . A method of replacing a tissue in a subject, the method comprising implanting into the subject the scaffold of claim 1 .
15 . A method of replacing a tissue in a subject, the method comprising implanting into the subject the tissue of claim 12 .
16 . A method of replacing a heart valve leaflet, vascular conduit or blood vessel, or a portion thereof, in a subject, the method comprising implanting into the subject the heart valve leaflet, vascular conduit or blood vessel of claim 13 .
17 . A method of forming an artificial tissue, the method comprising:
fabricating or providing an elastomeric scaffold comprising poly-4-hydroxybutyrate (P4HB), wherein the scaffold is fabricated by dry spinning to generate aligned fibers of P4HB to form an anisotropic matrix;
contacting the elastomeric scaffold with a hydrogel, preferably a photocrosslinkable hydrogel, wherein the hydrogel encapsulates a first plurality of cells, preferably stem cells, preferably mesenchymal stem cells (MSCs), under conditions such that the hydrogel is distributed throughout the scaffold;
optionally seeding the surface of the hydrogel-scaffold with a second plurality of cells, preferably cells of a different origin from the first plurality, preferably EPCs, preferably isolated from circulating blood;
exposing the cell-seeded scaffold to light sufficient to crosslink the hydrogel; and
culturing the scaffold under conditions sufficient to allow proliferation and optionally differentiation of the cells, thereby forming an artificial tissue.
18 . The method of claim 17 , wherein the artificial tissue is shaped to be used as a heart valve leaflet, vascular conduit or blood vessel.
19 . The method of claim 17 , wherein the photocrosslinkable hydrogel is methacrylated gelatin (GelMa).
20 . A method of forming an artificial tissue, the method comprising:
fabricating or providing an elastomeric scaffold comprising a poly-4-hydroxybutyrate (P4HB)/gelatin matrix comprising an inner layer of a gelatin/P4HB composite, and an outer layer of P4HB on either side of the inner layer, wherein the scaffold is fabricated by:
generating a first layer of aligned fibers of P4HB;
forming a layer comprising a P4HB/gelatin composite on the matrix; and
generating a second layer of aligned fibers of P4HB;
preferably wherein the gelatin encapsulates a first plurality of cells, preferably stem cells, preferably mesenchymal stem cells (MSCs);
optionally seeding the surface of the hydrogel-scaffold with a second plurality of cells, preferably cells of a different origin from the first plurality, preferably EPCs, preferably isolated from circulating blood;
exposing the cell-seeded scaffold to light sufficient to crosslink the hydrogel; and
culturing the scaffold under conditions sufficient to allow proliferation and optionally differentiation of the cells, optionally comprising culturing the scaffold of claim 10 in a cyclic stretch/flexure bioreactor or in a bioreactor that delivers flow, flexion, and shear signals to the scaffold,
thereby forming an artificial tissue.
21 . A method of replacing a tissue in a subject, the method comprising implanting into the subject the tissue of claim 20 .
22 . A method of replacing a heart valve leaflet, vascular conduit or blood vessel, or a portion thereof, in a subject, the method comprising implanting into the subject the heart valve leaflet, vascular conduit or blood vessel of claim 22 .