TISSUE-ENGINEERED CONSTRUCTS
The present invention provides constructs including a tubular biodegradable polyglycolic acid scaffold, wherein the scaffold may be coated with extracellular matrix proteins and substantially acellular. The constructs can be utilized as an arteriovenous graft, a coronary graft, a peripheral artery bypass conduit, or a urinary conduit. The present invention also provides methods of producing such constructs.
1 . A construct comprising a tubular biodegradable non-woven polyglycolic acid scaffold, wherein the density of the polyglycolic acid is about 45 mg/cc to about 75 mg/cc and said density is uniform across the entire tubular scaffold, wherein the thickness of the polyglycolic acid is about 0.8 to about 1.2 mm and wherein the thickness of the fibers within the polyglycolic acid is about 5 to about 20 μm.
2 . The construct of claim 1 , wherein the length of the tubular biodegradable polyglycolic acid scaffold is about 1 cm to about 100 cm.
3 . The construct of claim 1 , wherein the inner diameter of the tubular biodegradable polyglycolic acid scaffold is about 3 mm to about 6 mm.
4 . The construct of claim 1 , further comprising non-biodegradable polyethylene terephthalate supports at each end of the tubular biodegradable non-woven polyglycolic acid scaffold, wherein the porosity of the polyethylene terephthalate is 2≥200 cc/min/cm 2 and the supports permit the attachment and growth of cells.
5 . The construct of claim 1 , wherein the construct is substantially free of heavy metal contaminants.
6 . The construct of claim 5 , wherein the construct comprises trace amounts of heavy metal contaminants selected from the group consisting of: aluminum, barium, calcium, iodine, lanthanum, magnesium, nickel, potassium and zinc.
7 - 13 . (canceled)
14 . A tubular construct comprising extracellular matrix proteins and polyglycolic acid having thickness greater than about 200 μm at the thinnest portion of the construct and having an internal diameter of ≥3 mm, wherein the construct is intimal hyperplasia and calcification resistant, wherein the polyglycolic acid comprises less than 33% of the cross-sectional area of said construct, and wherein the construct is substantially acellular comprising less than 5% intact cells.
15 - 33 . (canceled)
34 . A method of producing a tubular construct comprising:
(a) providing a tubular biodegradable polyglycolic acid construct having an inner diameter of about 3 mm to about 6 mm,
(b) seeding human cells at passage 6 or less on the tubular biodegradable polyglycolic acid construct,
(c) culturing the cells under conditions such that the cells secrete extracellular matrix proteins on the tubular biodegradable polyglycolic acid construct,
(d) decellularizing the construct in step (c) such that the construct is substantially acellular comprising less than 5% intact cells and wherein the construct is intimal hyperplasia and calcification resistant, and
(e) degrading the polyglycolic acid construct in step (c) such that the polyglycolic acid comprises less than 33% of the cross-sectional area of said construct, and wherein the construct has a extracellular matrix protein thickness greater than about 200 μm at the thinnest portion of the construct,
thereby producing a decellularized tubular construct.
35 - 36 . (canceled)
37 . The method of claim 34 , wherein the construct is substantially acellular comprising less than 1% intact cells.
38 . The method of claim 34 , wherein the cells are obtained from a single donor or obtained a cell bank, wherein the cells in the cell bank are pooled from a plurality of donors.
39 . The method of claim 34 , wherein the cells are isolated from human aorta.
40 . The method of claim 34 , wherein the cells comprise smooth muscle cells.
41 . The method of claim 34 , wherein the cells are at passage 3 or less.
42 . The method of claim 34 , wherein the cells are at cultured in medium comprising about 11% to about 30% human serum for the first 2-6 weeks of culture and in medium comprising about 1% to about 10% human serum for at least an additional 4 weeks.
43 . The method of claim 42 , wherein the medium further comprises high glucose, insulin, bFGF and EGF.
44 - 45 . (canceled)
46 . A tissue-engineered vascular conduit, comprising:
a tubular construct, comprising:
an internal diameter of between 3 mm and 20 mm;
a length between 1 cm and 100 cm;
a thickness greater than 200 μm at the thinnest portion of the tubular construct;
less than 5% intact cells; and
human extracellular matrix proteins expressed by human cells during culture in culture medium comprising human serum, the expressed human extracellular matrix proteins comprising hydroxyproline at >60 μg/mg dry weight.
47 . The tissue-engineered vascular conduit of claim 46 , wherein the internal diameter of the tubular construct is between 3 mm and 8 mm.
48 . The tissue-engineered vascular conduit of claim 46 , wherein the length of the tubular construct is between 10 cm and 50 cm.
49 . The tissue-engineered vascular conduit of claim 46 , wherein the expressed human extracellular matrix proteins comprise circumferentially aligned extracellular matrix proteins.
50 . The tissue-engineered vascular conduit of claim 46 , wherein the tubular construct comprises less than 300 ng/cm of beta-actin.