Tissue scaffold having aligned fibrils, apparatus and method for producing the same, and artificial tissue and methods of use thereof

• US 20050009178A1
• Filed: 06/04/2004
• Published: 01/13/2005
• Est. Priority Date: 06/04/2003
• Status: Active Grant

• Current Assignee: University of South Carolina
• Original Assignee: University of South Carolina
• Inventors: Goldsmith, Edie C., Gore, C. Michael, Goodwin, Richard L., Yost, Michael J., Terracio, Louis
• Granted Patent: US 7,338,517 B2
• Time in Patent Office: Days
• US Class Current: 435/399
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/33 with parts rotatable relative to each other
• CPC Class Codes: C12M 21/08 for producing artificial tissue or for ex-vivo cultivation of tissue prostheses A61F2/00, grafts A61L27/00
• CPC Class Codes: C12M 25/14 Scaffolds; Matrices in general C12N5/0068

Abstract

A tubular tissue scaffold is described which comprises a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall. The scaffold is capable of directing the morphological pattern of attached and growing cells to form a helical pattern around the tube walls. Additionally, an apparatus for producing such a tubular tissue scaffold is disclosed, the apparatus comprising a biopolymer gel dispersion feed pump that is operably connected to a tube-forming device having an exit port, where the tube-forming device is capable of producing a tube from the gel dispersion while providing an angular shear force across the wall of the tube, and a liquid bath located to receive the tubular tissue scaffold from the tube-forming device. A method for producing the tubular tissue scaffolds is also disclosed. Also, artificial tissue comprising living cells attached to a tubular tissue scaffold as described herein is disclosed. Methods for using the artificial tissue are also disclosed.

Claims

1. A tubular tissue scaffold comprising a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall.

2. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface of the tube is different from the pitch of the helical pattern of the biopolymer fibrils at the outer surface of the tube.

3. The tubular tissue scaffold according to claim 1, wherein the biopolymer is selected from the group consisting of collagen, fibronectin, laminin, elastin, fibrin, proteoglycans, hyaluronan, and combinations thereof.

4. The tubular tissue scaffold according to claim 3, wherein the collagen is selected from the group consisting of type I collagen, type II collagen, type III collagen, type V collagen, type XI collagen, and combinations thereof.

5. The tubular tissue scaffold according to claim 4, wherein the collagen is selected from the group consisting of type I collagen, type III collagen, and combinations thereof.

6. The tubular tissue scaffold according to claim 5, wherein the collagen is type I collagen.

7. The tubular tissue scaffold according to claim 1, wherein the tissue scaffold comprises a tube having an outside diameter, a luminal diameter, and a wall thickness.

8. The tubular tissue scaffold according to claim 7, wherein the outside diameter is between about 0.1 millimeter and about 100 millimeters.

9. The tubular tissue scaffold according to claim 8, wherein the outside diameter is between about 1 millimeter and about 10 millimeters.

10. The tubular tissue scaffold according to claim 7, wherein the wall thickness is between about 0.1 millimeters and about 5 millimeters.

11. The tubular tissue scaffold according to claim 7, wherein the wall thickness is between about 0.1 millimeters and about 1 millimeter.

12. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface is between about 0 degrees and about 89 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface is between about 0 degrees and about 89 degrees, and wherein the pitch of the helical pattern of the fibrils at the luminal surface is different from the pitch of the fibrils at the outer surface.

13. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface is between about 18 degrees and about 62 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface is between about 18 degrees and about 62 degrees.

14. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface is between about 26 degrees and about 60 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface is between about 26 degrees and about 60 degrees.

15. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils changes from a right-hand pitch or a left-hand pitch at the luminal surface to a pitch of the opposite direction at the outside surface of the tube wall.

16. The tubular tissue scaffold according to claim 1, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal wall and the outside wall of the tube are roughly equal in degrees but opposite in direction.

17. The tubular tissue scaffold according to claim 1, wherein the tube wall of the scaffold has pores.

18. The tubular tissue scaffold according to claim 17, wherein the average diameter of the pores is between about 1 micron and about 20 microns.

19. The tubular scaffold according to claim 17, wherein the average diameter of the pores is between about 2 microns and about 10 microns.

20. The tubular tissue scaffold according to claim 1, wherein the luminal surface and the outer surface can support cell attachment and growth.

21. The tubular tissue scaffold according to claim 1, wherein the tissue scaffold directs the morphology of attached cells to align along the helical pattern of the biopolymer fibrils and express a phenotype like that found in vivo.

22. The tubular tissue scaffold according to claim 1, wherein the tube has been split longitudinally and opened into a sheet.

23. The tubular tissue scaffold according to claim 22, wherein the sheet is coated with a layer of biopolymer fibrils, wherein the biopolymer filbrils polymerize and are oriented in the direction in which they are applied.

24. The tubular tissue scaffold according to claim 1, wherein the tubular tissue scaffold is treated with UV radiation.

25. The tubular tissue scaffold according to claim 24, wherein the UV radiation comprises a wavelength that is from about 250 to about 280 nm and an energy density of from about 100 to about 1000 μ

w/cm².

26. The tubular tissue scaffold according to claim 1, wherein the tubular tissue scaffold has a burst pressure of at least about 100 mm Hg.

28. An apparatus for producing a tubular tissue scaffold having aligned biopolymer fibrils, the apparatus comprising a biopolymer gel dispersion feed pump that is operably connected to a tube-forming device having an exit port, where the tube-forming device is capable of producing a tube from the gel dispersion while providing an angular shear force across the wall of the tube, and a liquid bath located to receive the tubular tissue scaffold from the tube-forming device.

27. The tubular tissue scaffold according to claim 28, wherein the tubular tissue scaffold has a burst pressure of at least about 250 mm Hg.

29. The apparatus according to claim 28, wherein the apparatus further comprises a gas source that is interconnected to provide for the addition of gas to the luminal space of the tubular tissue scaffold exiting the tube-forming device, and a controlled atmosphere chamber enclosing the exit port of the tube-forming device and the bath.

30. The apparatus according to claim 28, wherein the tube-forming device is a rotating cone extruder having an annular-shaped exit port, wherein the annular exit port is interconnected with the gas source to provide for the addition of gas to the luminal space of a tubular tissue scaffold exiting the extruder.

31. The apparatus according to claim 30, wherein the rotating cone extruder is a counter-rotating cone extruder.

32. The apparatus according to claim 30, wherein the annular-shaped exit port has an outside diameter and an inside diameter the difference between which defines the width of the annular space.

33. The apparatus according to claim 30, wherein the outside diameter of the annular-shaped exit port is between about 1 mm and about 50 mm, and the width of the annular space is between about 0.1 mm and about 5 mm.

34. The apparatus according to claim 31, wherein the counter-rotating cone extruder comprises an external rotating member having a cone-shaped cavity therethrough and an internal rotating cone which fits within the cone-shaped cavity of the external rotating member, and wherein the external rotating member and the internal rotating cone terminate near the apex of the cones to form an annular-shaped exit port.

35. The apparatus according to claim 34, wherein the external rotating member and the internal rotating cone are operably connected to one or more drive motors that can spin the external rotating member and the internal rotating cone about a common axis but in opposite directions.

36. The apparatus according to claim 35, wherein the external rotating member and the internal rotating cone are operably connected to the same drive motor.

37. The apparatus according to claim 35, wherein the one or more drive motors can be adjusted to vary the speed at which the external rotating member and the internal rotating cone rotate.

38. The apparatus according to claim 35, wherein the rotational speed of the external rotating member and the internal rotating cone can be varied between about 1 rpm and 1800 rpm.

39. The apparatus according to claim 28, wherein the biopolymer feed pump can be adjusted to vary the rate at which biopolymer is fed to the tube-forming device.

40. The apparatus according to claim 28, wherein the liquid bath is located below the extruder exit port, whereby tubular tissue scaffold exiting the extruder falls into the bath by force of gravity.

41. The apparatus according to claim 40, wherein the surface of the liquid bath is located a defined distance below the extruder exit port.

42. The apparatus according to claim 41, wherein the defined distance is between about 0.25 centimeter and about 60 centimeters.

43. The apparatus according to claim 29, wherein the gas source can provide a mixture of air and ammonia.

44. The apparatus according to claim 43, wherein the mixture of air and ammonia is about a 50:

50 mixture by volume.

45. The apparatus according to claim 28, wherein the controlled atmosphere chamber is filled with a gas mixture comprising air and ammonia.

46. The apparatus according to claim 45, wherein the gas mixture comprises a mixture of about 50:

50 air and ammonia by volume.

47. The apparatus according to claim 28, wherein the liquid bath comprises water having sufficient ammonia absorbed therein to bring the pH of the water to between about 9 and 11.

48. A method of producing a tubular tissue scaffold, the method comprising:

providing a gel dispersion comprising a biopolymer;

feeding the gel dispersion to a tube-forming device that is capable of producing a tube from the gel dispersion while providing a radial shear force across the wall of the tube and having a gas channel connecting a gas source with the luminal space of the tubular tissue scaffold as it exits the tube-forming device;

forming the gel dispersion into a tube; and

causing the gel dispersion to solidify, thereby forming a tubular tissue scaffold comprising a tube wall having biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube and where the pitch of the helical pattern changes with the radial position in the tube wall.

49. The method according to claim 48, wherein the method comprises:

providing a gel dispersion comprising a biopolymer;

feeding the gel dispersion to a counter-rotating cone extruder having an annular-shaped exit port and having a gas channel connecting a gas source with the center of the annular-shaped exit port and opening into the luminal space of the tubular tissue scaffold as it exits the extruder;

extruding the gel dispersion to form a tube; and

causing the gel dispersion to solidify, thereby forming a tubular tissue scaffold comprising a biopolymer having fibrils in the tube wall that are aligned in a helical pattern around the longitudinal axis of the tube and where the pitch of the helical pattern on the luminal surface of the tube is different from the pitch of the helical pattern on the outside surface of the tube.

50. The method according to claim 49, wherein the biopolymer comprises collagen, fibronectin, laminin, elastin, fibrin, proteoglycans, hyaluronan, or combinations thereof.

51. The method according to claim 50, wherein the biopolymer comprises collagen.

52. The method according to claim 51, wherein the biopolymer comprises type 1 collagen.

53. The method according to claim 52, wherein the gel dispersion of collagen is prepared by a method comprising:

removing the hair from the hide of a bovine;

washing the hide sequentially in water, water containing NaHCO₃ and surfactant, and water;

contacting the hide with an aqueous solution containing NaHCO₃, Ca(OH)₂ and NaHS;

washing the hide in water;

treating the hide with an aqueous solution of Ca(OH)₂;

rinsing the hide with water and trimming the hide of any remaining skin tissue and fat;

placing the hide in an aqueous NaCl solution and adding hydrochloric acid solution until the pH is stable between about 6.0 and 8.0;

washing the hide in water;

placing the hide in an aqueous solution of acetic acid with or without pepsin;

mixing and allowing the hide to swell;

placing the swollen hide in a mill and processing into a gel dispersion;

filtering the gel dispersion to remove undissolved particles;

centrifuging the gel dispersion to remove small undissolved particles;

adding NaCl to the gel dispersion in an amount sufficient to precipitate collagen from the gel dispersion;

filtering the collagen precipitate and resuspending it in deionized water;

adding NaOH to bring the pH of the collagen dispersion to a pH between about 6 and about 8;

dialyzing the collagen dispersion against phosphate buffered saline solution;

resuspending the collagen in deionized water;

centrifuging the collagen dispersion to concentrate solid collagen gel as a pellet; and

resuspending the pellet in aqueous HCl.

54. The method according to claim 51, wherein the gel dispersion of collagen is prepared by a method comprising:

removing the hair from the hide of a freshly killed bovine;

washing the hide sequentially in water, water containing 0.2% NaHCO₃ and 0.02% surfactant, percent by weight, and water;

contacting the hide with an aqueous solution containing 0.6% NaHCO₃, 2% Ca(OH)₂ and 4.3% NaHS, percent by weight, for a period of from about 0.1 hrs to about 10 hrs;

washing the hide in three changes of deionized water;

treating the hide with an aqueous solution of 2% Ca(OH)₂, percent by weight, for a period of from about 1 to about 24 hours;

rinsing the hide with water and trimming the hide of any remaining skin tissue and fat;

placing the hide in an aqueous 2M NaCl solution and adding hydrochloric acid solution until the pH is stable between about 6.8 and 7.0;

washing the hide in three changes of deionized water;

placing the hide in an aqueous solution of 0.5 N acetic acid with or without pepsin added to give a 1;

100 weight ration based on wet hide weight;

mixing for a period of from about 1 to about 24 hours and allowing the hide to swell;

placing the swollen hide in a high-shear mill with ice and processing into a gel dispersion;

filtering the gel dispersion to remove undissolved particles;

centrifuging the gel dispersion to remove small undissolved particles;

adding NaCl to the gel dispersion in an amount sufficient to give a 2 M concentration, which will cause the precipitation of collagen from the gel dispersion;

filtering the collagen precipitate and resuspending it in deionized water;

adding NaOH to bring the pH of the collagen dispersion to pH 7.2;

dialyzing the collagen dispersion against phosphate buffered saline solution for a period of from about 1 to about 24 hours;

resuspending the collagen in three changes of deionized water over a period of about 24 hours;

centrifuging the collagen dispersion to concentrate solid collagen gel as a pellet; and

resuspending the pellet in 0.012 N HCl to a final collagen concentration of about 20 mg/ml.

55. The method according to claim 49, further comprising feeding a gas from the gas source to the luminal space of the tubular tissue scaffold as it exits the extruder.

56. The method according to claim 55, wherein the gas comprises a mixture of air and ammonia gas.

57. The method according to claim 56, wherein the mixture of air and ammonia is about a 50:

50 mixture by volume.

58. The method according to claim 55, wherein the outside surface of the tubular tissue scaffold is contacted with a mixture of air and ammonia gas as it exits the extruder.

59. The method according to claim 58, wherein the tubular tissue scaffold exiting the extruder falls into a liquid bath located to receive the tubular tissue scaffold from the extruder.

60. The method according to claim 59, wherein the liquid bath is located a defined distance beneath the exit port of the extruder.

61. The method according to claim 60, wherein the liquid bath is a aqueous ammonia bath at a pH of about 10.

62. The method according to claim 60, wherein the biopolymer gel dispersion is fed to the extruder at a defined feed rate, and the defined feed rate and the defined distance are selected so that the gel dispersion solidifies to form a tubular tissue scaffold comprising a biopolymer having fibrils in the tube wall that are aligned in a helical pattern around the longitudinal axis of the tube and where the pitch of the helical pattern on the luminal surface of the tube is different from the pitch of the helical pattern on the outside surface of the tube.

63. The method according to claim 62, wherein the outside diameter of the annular-shaped exit port is about 5 mm and the width of the annular space is about 0.5 mm, and wherein the defined feed rate is sufficient to provide a tube extrusion rate of about 150 cm/min. and the defined distance is between about 10 cm and about 20 cm.

64. The method according to claim 60, where the tubular tissue scaffold remains in the bath for about 15 min.

65. The method according to claim 50, wherein the step of causing the gel to solidify includes immersing the tube in an aqueous solution containing 0.3% sodium bicarbonate, percent by weight.

66. The method according to claim 50, further comprising sterilizing the tubular tissue scaffold with gamma or UV radiation.

67. The method according to claim 50, wherein the counter-rotating cone extruder comprises an external rotating member having a cone-shaped cavity therethrough and an internal rotating cone which fits within the cone-shaped cavity of the external rotating member, and wherein the external rotating member is driven to rotate in one direction at a speed of from about 1 to about 1800 rpm and the internal rotating cone is driven to rotate in the opposite direction at a speed of from about 1 to about 1800 rpm.

68. The method according to claim 67, wherein the external rotating member is driven to rotate in one direction at a speed of from about 150 to about 900 rpm and the internal rotating cone is driven to rotate in the opposite direction at a speed of from about 150 to about 900 rpm.

69. Artificial tissue comprising living cells attached to a tubular tissue scaffold comprising a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall.

70. Artificial tissue according to claim 79, wherein the biopolymer is selected from the group consisting of collagen, fibronectin, laminin, elastin, fibrin, proteoglycans, hyaluronan, and combinations thereof.

71. Artificial tissue according to claim 80, wherein the collagen is selected from the group consisting of type I collagen, type II collagen, type III collagen, type V collagen, type XI collagen, and combinations thereof.

72. Artificial tissue according to claim 71, wherein the collagen is type I collagen.

73. Artificial tissue according to claim 69, wherein the tissue scaffold comprises a tube having an outside diameter, a luminal diameter, and a wall thickness.

74. Artificial tissue according to claim 73, wherein the outside diameter of the tubular tissue scaffold is between about 0.1 millimeter and about 100 millimeters.

75. Artificial tissue according to claim 73, wherein the outside diameter of the tubular tissue scaffold is between about 1 millimeters and about 10 millimeters.

76. Artificial tissue according to claim 73, wherein the wall thickness of the tubular tissue scaffold is between about 0.1 millimeters and about 3 millimeters.

77. Artificial tissue according to claim 73, wherein the wall thickness of the tubular tissue scaffold is between about 0.5 millimeters and about 1 millimeter.

78. Artificial tissue according to claim 69, wherein the pitch of the helical pattern of the biopolymer fibrils of the tubular tissue scaffold at the luminal surface is between about 0 degrees and about 89 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface is between about 0 degrees and about 89 degrees, and wherein the pitch of the helical pattern of the fibrils at the luminal surface is different from the pitch of the fibrils at the outer surface.

79. Artificial tissue according to claim 69, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface of the tubular tissue scaffold is between about 18 degrees and about 62 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface of the tubular tissue scaffold is between about 18 degrees and about 62 degrees.

80. Artificial tissue according to claim 69, wherein the pitch of the helical pattern of the biopolymer fibrils at the luminal surface of the tubular tissue scaffold is between about 26 degrees and about 60 degrees and the pitch of the helical pattern of the biopolymer fibrils at the outer surface of the tubular tissue scaffold is between about 26 degrees and about 60 degrees.

81. Artificial tissue according to claim 69, wherein the pitch of the helical pattern of the biopolymer fibrils of the tubular tissue scaffold changes from a right-hand pitch or a left-hand pitch at the luminal surface to a pitch of the opposite direction at the outside surface of the tube wall.

82. Artificial tissue according to claim 69, wherein the pitch of the helical pattern of the biopolymer fibrils of the tubular tissue scaffold at the luminal wall and the outside wall of the tube are roughly equal in degrees but opposite in direction.

83. Artificial tissue according to claim 69, wherein the tube wall of the scaffold has pores.

84. Artificial tissue according to claim 83, wherein the number average diameter of the pores is between about 1 micron and about 20 microns.

85. Artificial tissue according to claim 69, wherein the living cells are introduced to the luminal and outer surfaces of the tubular tissue scaffold.

86. Artificial tissue according to claim 69, wherein the living cells align along the helical pattern of the biopolymer fibrils.

87. Artificial tissue according to claim 69, wherein the living cells are selected from the group consisting of myocyte precursor cells, cardiac myocytes, skeletal myocytes, satellite cells, fibroblasts, cardiac fibroblasts, chondrocytes, osteoblasts, endothelial cells, epithelial cells, embryonic stem cells, hematopoetic stem cells, neuronal cells, mesenchymal stem cells, anchorage-dependent cell precursors, and combinations thereof.

88. Artificial tissue according to claim 69, wherein the living cells establish intercellular and extracellular connections.

89. Artificial tissue according to claim 69, wherein the living cells are contractile.

90. Artificial tissue according to claim 89, wherein the contractile cells are cardiac myocytes.

91. Artificial tissue according to claim 90, wherein the cardiac myocytes contract synchronously along the helical pattern of the biopolymer, resulting in a wringing action of the tubular tissue scaffold.

92. Artificial tissue according to claim 69, wherein the living cells are attached to two or more tubular tissue scaffolds.

93. Artificial tissue according to claim 92, wherein the tubular tissue scaffolds are in the form of concentric tubes.

94. Artificial tissue according to claim 92, wherein the living cells attached to individual tubular tissue scaffolds are of different cell types.

95. Artificial tissue according to claim 69, wherein the tubular artificial tissue has been split longitudinally and opened into a sheet.

96. Artificial tissue according to claim 69, wherein the tubular tissue scaffold is treated with a growth factor prior to attaching the living cells to the tissue scaffold.

97. Artificial tissue according to claim 96, wherein the growth factor is selected from the group consisting of vascular endothelial growth factor, epidermal growth factor, fibroblast growth factor, erythropoietin, hematopoietic cell growth factor, platelet-derived growth factor, nerve growth factor, transforming growth factor α

, bone morphogenic protein, transforming growth factor β

, and combinations thereof.

98. Artificial tissue according to claim 96, wherein the growth factor is selected from the group consisting of vascular endothelial growth factor, platelet-derived growth factor, nerve growth factor, and combinations thereof.

99. Artificial tissue according to claim 96, wherein the tubular tissue scaffold is treated with UV radiation prior to being treated with the growth factor.

100. Artificial tissue according to claim 99, wherein the UV radiation comprises a wavelength of 254 nm and an energy density of 500 μ

w/cm².

101. A method for preconditioning a tubular artificial tissue scaffold comprising seeding a tubular artificial tissue scaffold having aligned biofibrils with living cells and culturing the cells in the presence of media containing at least one growth factor and under conditions where the tubular artificial tissue scaffold is subjected to stretch and pressure pulse of controlled frequency and amplitude.

102. A preconditioned artificial tissue comprising living cells that are attached to a tubular artificial tissue scaffold having aligned biofibrils, wherein the cells have been cultured in the presence of media containing at least one growth factor and under conditions where the tubular artificial tissue scaffold is subjected to stretch and pressure pulse of controlled frequency and amplitude.

103. A method of treatment comprising implanting in the body of a subject artificial tissue comprising living cells attached to a tubular tissue scaffold comprising a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall.

104. The method according to claim 103, wherein the biopolymer is selected from the group consisting of collagen, fibronectin, laminin, elastin, fibrin, proteoglycans, hyaluronan, and combinations thereof.

105. The method according to claim 104, wherein the collagen is selected from the group consisting of type I collagen, type II collagen, type III collagen, type V collagen, type XI collagen, and combinations thereof.

106. The method according to claim 103, wherein the living cells are introduced to the luminal and outer surfaces of the substrate.

107. The method according to claim 103, wherein the living cells align along the helical pattern of the biopolymer fibrils.

108. The method according to claim 103, wherein the living cells are selected from the group consisting of myocyte precursor cells, cardiac myocytes, skeletal myocytes, satellite cells, fibroblasts, cardiac fibroblasts, chondrocytes, osteoblasts, endothelial cells, epithelial cells, embryonic stem cells, hematopoetic stem cells, neuronal cells, mesenchymal stem cells, anchorage-dependent cell precursors, and combinations thereof.

109. The method according to claim 108, wherein the living cells originate from the subject receiving treatment.

110. The method according to claim 103, wherein the living cells are cultured in vitro for a period of time necessary for the cells to degrade the original scaffold biopolymer and regenerate a matrix of secreted extracellular matrix proteins.

111. The method according to claim 103, wherein the living cells establish intercellular and extracellular connections.

112. The method according to claim 111, wherein the living cells are contractile.

113. The method according to claim 112, wherein the contractile cells are cardiac myocytes.

114. The method according to claim 113, wherein the cardiac myocytes contract synchronously along the helical pattern of the biopolymer fibrils to pump fluid through the lumen of the tubular tissue scaffold.

115. The method according to claim 112, wherein the contractile cardiac myocyte-containing artificial tissue is preconditioned by the application of mechanical stress before being implanted in the subject.

116. The method according to claim 103, wherein treatment is for an injury, disease, or disorder selected from the group consisting of congestive heart failure, dilated cardiomyopathy, hypertrophic cardiomyopathy, infiltrative cardiomyopathy, ischemic heart disease, heart attack, heart failure, coronary artery disease, atherosclerosis, hypertension, chronic renal disease, cerebrovascular disease, carotid artery disease, and peripheral vascular disease.

117. The method according to claim 112, wherein the rate of contraction is controlled by a pacing device.

118. The method according to claim 103, wherein the tubular artificial tissue is used to repair or replace a tube-shaped organ.

119. The method according to claim 118, wherein the tube-shaped organ is selected from the group consisting of blood vessels, coronary arteries, renal arteries, ureters, fallopian tubes, and nerve fiber conduits.

120. The method according to claim 103, wherein the tubular tissue scaffold is split longitudinally and opened into a sheet prior to attaching living cells to the tissue scaffold.

121. The method according to claim 120, wherein the sheet is coated with a layer of biopolymer fibrils, wherein the biopolymer filbrils polymerize and are oriented in the direction in which they are applied.

122. The method according to claim 121, wherein the living cells are selected from the group consisting of myocyte precursor cells, cardiac myocytes, skeletal myocytes, satellite cells, fibroblasts, cardiac fibroblasts, chondrocytes, osteoblasts, endothelial cells, epithelial cells, embryonic stem cells, hematopoetic stem cells, neuronal cells, mesenchymal stem cells, anchorage-dependent cell precursors, and combinations thereof.

123. The method according to claim 122, wherein the living cells are selected from the group consisting of myocyte precursor cells, cardiac myocoytes, skeletal myocytes, satellite cells, fibroblasts, and combinations thereof.

124. The method according to claim 122, wherein the living cells originate from the subject receiving treatment.

125. The method according to claim 120, wherein treatment is for hernia, heart attack, congenital heart defects, skin burns, organ damage, and muscle damage.

126. A method of identifying the effects of a pharmaceutical composition on cell function comprising administering said pharmaceutical composition in vitro to artificial tissue comprising living cells attached to a tubular tissue scaffold comprising a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall.

127. The method according to claim 126, wherein the living cells are contractile cardiac myocytes.

128. The method according to claim 127, further comprising determining the effects of the pharmaceutical composition on the living cells.

129. The method according to claim 126, wherein the tubular artificial tissue has been split longitudinally and opened into a sheet.