VIABLE BIOENGINEERED SKIN CONSTRUCTS
The present disclosure is directed to viable bioengineered skin constructs.
1 . A viable, bioengineered skin construct comprising
a fully stratified epithelial layer having a top surface and a bottom surface, wherein the fully stratified epithelial layer comprises human keratinocytes;
a dermal equivalent layer having a top surface and a bottom surface, wherein the dermal equivalent layer comprises human dermal fibroblasts within a matrix, the matrix comprising human collagen and optionally murine type I collagen;
wherein the bottom surface of the epithelial layer is adhered to the top surface of the dermal equivalent layer over at least 98% of one of the layers; and
wherein a dog bone-shaped sample of the skin construct fails at a load of about 0.5 N to about 1.0 N (“the failure load”) and a displacement of about 30 mm to about 45 mm when pulled to failure in uniaxial tension at a constant strain rate of 100% per minute with continuous hydration using Dulbecco's phosphate-buffered saline, and wherein the fully stratified epithelial layer fails at the same point in the load-displacement curve as the skin construct and the dermal equivalent layer fails at a displacement of about 12-18 mm or about 14-16 mm;
wherein the dog bone-shaped sample has a gauge width of 4 mm and a gauge length of 25 mm, as measured by a thickness gauge.
2 . The skin construct of claim 1 , wherein the load drops less than 10% of the failure load when the dermal equivalent layer fails.
3 . The skin construct of claim 2 , wherein the load drops less than 5% of the failure load when the dermal equivalent layer fails.
4 . The skin construct of claim 2 , wherein the load drops less than 1% of the failure load when the dermal equivalent layer fails.
5 . The skin construct of claim 1 , wherein the dermal equivalent layer fails at a displacement of about 14-16 mm and a load of about 0.1 N to about 0.5 N.
6 . The skin construct of claim 1 , wherein the skin construct has a thickness of about 100 μm to about 250 μm, or about 120 μm to about 200 μm, as measured by histology.
7 . The skin construct of claim 6 , wherein the fully stratified epithelial layer has a thickness of about 75 μm to about 120 μm and/or the dermal equivalent layer has a thickness of about 20 μm to about 80 μm, as measured by histology.
8 . The skin construct of claim 1 , wherein the keratinocytes of the epithelial layer are from a single human donor and/or the dermal fibroblasts of the dermal equivalent layer are from a single human donor, optionally different from the human donor of the keratinocytes.
9 . The skin construct of claim 8 , wherein the keratinocytes are NIKS cells or the dermal fibroblasts are normal human dermal fibroblasts.
10 . The skin construct of claim 8 , wherein the keratinocytes are NIKS cells and the dermal fibroblasts are normal human dermal fibroblasts.
11 . The skin construct of claim 1 , wherein the skin construct has a surface area of about 40 cm 2 to about 100 cm 2 .
12 . The skin construct of claim 11 , wherein the skin construct comprises human type I collagen.
13 . The skin construct of claim 12 , wherein the skin construct has at least 5 mg of human type I collagen.
14 . The skin construct of claim 12 , wherein the skin construct has at least 5.5 mg of human type I collagen or at least at least 5.8 mg of human type I collagen.
15 . The skin construct of claim 1 , wherein about 98% or more of the human type I collagen is produced by cells of the skin construct.
16 . The skin construct of claim 15 , wherein about 100% of the human type I collagen is produced by cells of the skin construct.
17 . The skin construct of claim 12 , wherein the skin construct comprises human type I collagen and murine type I collagen, wherein the murine type I collagen is not more than 90% by weight of total collagen in the skin construct.
18 . The skin construct of claim 12 , wherein the skin construct comprises human type I collagen and murine type I collagen, wherein the murine type 1 collagen is about 60% to about 90% by weight of the total type collagen in the skin construct.
19 . The skin construct of claim 1 , wherein the skin construct has a total collagen content of about 0.25 mg to about 0.45 mg per cm 2 of surface area, or about 0.29 mg to about 0.39 mg per cm 2 of surface area.
20 . A viable, bioengineered skin construct comprising
a fully stratified epithelial layer having a top surface and a bottom surface, wherein the fully stratified epithelial layer comprises human keratinocytes;
a dermal equivalent layer having a top surface and a bottom surface, wherein the bottom surface of the epithelial layer is adhered to the top surface of the dermal equivalent layer over at least 98% of one of the layers,
wherein the dermal equivalent layer comprises human dermal fibroblasts within a matrix, the matrix comprising human type I collagen, human type III collagen, human type IV collagen, and human type VI collagen and optionally murine type I collagen; and
a total collagen content of about 0.25 mg per cm 2 of surface area to about 0.45 mg per cm 2 of surface area and at least 0.05 mg per cm 2 of surface area of human type I collagen.