Preparation of agarose coated, solid agarose-collagen beads containing secretory cells

Abstract

Biological agents such as secretory cells are encapsulated in a hydrophilic gel made of agarose or collagen-agarose and gelatin sponge-agarose combinations. In a preferred embodiment, semi-solid beads are formed from a suspension containing collagen, agarose and secretory cells such as pancreatic islets, the collagen is polymerized to form solid, agarose-collagen beads and the solid beads are coated with agarose. Coating is preferably by rolling the solid beads in about 5-10% agarose, contacting the rolled beads with mineral oil and washing oil from the beads. Beads containing secretory cells can be transplanted into a mammal to treat a condition caused by impaired secretory cell function.

1. A method for preparing an agarose coated, solid agarose-collagen bead which contains secretory cells, comprising:
 (a) suspending secretory cells in a collagen containing solution,    (b) adding agarose to said solution,    (c) forming a semi-solid bead of said collagen, agarose, and secretory cells,    (d) polymerizing collagen in said semisolid bead to form a solid, agarose-collagen bead containing secretory cells, and    (e) coating said solid, agarose-collagen bead containing secretory cells with agarose.    
     
     
       2. The method of  claim 1 , wherein said secretory cells are contained in pancreatic islets. 
     
     
       3. The method of  claim 2 , wherein said pancreatic islets are human pancreatic islets, bovine pancreatic islets, rat pancreatic islets or porcine pancreatic islets. 
     
     
       4. The method of  claim 3 , wherein said pancreatic islets are human pancreatic islets. 
     
     
       5. The method of  claim 1 , wherein said secretory cells are contained in from about 50,000 to about 700,000 pancreatic islets. 
     
     
       6. An agarose coated, solid agarose-collagen bead containing secretory cells prepared by the process of  claim 1 . 
     
     
       7. The agarose coated, solid agarose-collagen bead of  claim 6 , wherein said secretory cells are contained in pancreatic islets. 
     
     
       8. The agarose coated, solid agarose-collagen bead of  claim 6  wherein said pancreatic islets are human pancreatic islets, bovine pancreatic islets, rat pancreatic islets or porcine pancreatic islets. 
     
     
       9. The agarose coated, solid agarose-collagen bead of  claim 8 , wherein said pancreatic islets are human pancreatic islets. 
     
     
       10. The agarose coated, solid agarose collagen bead of  claim 7 , comprising from about 50,000 to about 700,000 islets. 
     
     
       11. Method for treating a mammal having a condition caused by impaired secretory cell function, comprising:
 transplanting into said mammal a therapeutically effective amount of the agarose coated, solid agarose-collagen bead of  claim 6 .    
     
     
       12. The method of  claim 11 , wherein said condition is insulin dependent diabetes. 
     
     
       13. The method of  claim 12 , wherein said bead contains cells derived from a pancreatic islet. 
     
     
       14. The method of  claim 13 , wherein said pancreatic islet is a human pancreatic islet. 
     
     
       15. The method of  claim 13 , wherein said pancreatic islet is a bovine pancreatic islet. 
     
     
       16. The method of  claim 13 , wherein said pancreatic islet is a porcine pancreatic islet. 
     
     
       17. The method of  claim 11 , wherein said bead is placed in the peritoneal cavity of said mammal. 
     
     
       18. A composition of matter produced by combining a sample of secretory cells selected from the group consisting of pancreatic islets and pancreatic islet cells, gelatin sponge, and a solution containing from  3 %  to  5   %  agarose to form a mixture, treating said mixture to form a bead, and coating said bead with a solution containing from  5   %  to  10   %  agarose.   
     
     
       19. The composition of matter of  claim 18 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islets or pancreatic islet cells. 
     
     
       20. The composition of matter of  claim 18 , wherein said solution combined with the secretory cells and gelatin sponge contains about  5 %  agarose.   
     
     
       21. The composition of matter of  claim 18 , wherein said solution used for coating contains about  5 %  agarose.   
     
     
       22. A method for producing a composition of matter comprising a sample of secretory cells in a bead which comprises agarose, wherein said bead is coated with agarose, comprising:
 ( a )  forming a suspension of secretory cells in an agarose solution,      ( b )  forming a bead from said suspension of secretory cells in agarose solution,      ( c )  coating said bead with a solution containing from  5   %  to  10   %  agarose to form an agarose coated agarose bead,      ( d )  contacting said agarose coated, agarose bead with mineral oil, and      ( e )  washing said agarose coated, agarose bead.     
     
     
       23. The method of  claim 22 , wherein ( c )  comprises coating said bead with agarose by rolling it in said solution containing agarose.   
     
     
       24. The method of  claim 22 , wherein said secretory cells comprise pancreatic islets or pancreatic islet cells. 
     
     
       25. The method of  claim 24 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islets or pancreatic islet cells. 
     
     
       26. The method of  claim 22 , comprising coating said bead with a solution containing  5 %  agarose.   
     
     
       27. The method of  claim 22 , comprising forming a suspension of secretory cells and a  0 . 5 %  to  5 . 0   %  solution of agarose.   
     
     
       28. The method of  claim 27 , wherein said secretory cells comprise pancreatic islets or pancreatic islet cells. 
     
     
       29. The method of  claim 27 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islets or pancreatic islet cells. 
     
     
       30. The method of  claim 28 , wherein said solution comprises about  1 %  agarose.   
     
     
       31. The method of  claim 28 , wherein said solution comprises about  5 %  agarose.   
     
     
       32. A method for treating a subject having a condition caused by impaired function of secretory cells, comprising transplanting an amount of the composition of matter produced by  claim 22  to said subject, in an amount sufficient to alleviate said condition. 
     
     
       33. The method of  claim 32 , wherein said condition is insulin dependent diabetes and said secretory cells comprise pancreatic cells or pancreatic islets. 
     
     
       34. The method of  claim 33 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islet cells or pancreatic islets. 
     
     
       35. The method of  claim 32 , comprising transplanting said composition of matter to the intraperitoneal cavity of said subject. 
     
     
       36. A method for producing a composition of matter comprising a sample of secretory cells in a bead which comprises agarose and collagen, and is coated with a coating of agarose, comprising:
 ( a )  forming a suspension of said secretory cells in a solution containing collagen,      ( b )  adding a mixture of agarose to the suspension of step  ( a )  to form secretory cells suspended in agarose and collagen,      ( c )  forming a collagen - agarose semi - solid bead from the suspension of  ( b ),    ( d )  polymerizing collagen contained in the semi - solid bead of  ( c ) , to form a collagen - agarose bead having secretory cells entrapped therein,      ( e )  coating said bead with a solution containing  5   %  to  10   %  agarose to form an agarose coated, agarose collagen bead,      ( f )  contacting said agarose coated, agarose collagen bead with mineral oil, and      ( g )  washing said agarose coated, agarose collagen bead.     
     
     
       37. The method of  claim 36 , wherein said secretory cells comprise pancreatic islet cells or pancreatic islets. 
     
     
       38. The method of  claim 37 , wherein said pancreatic islet cells or pancreatic islets are human, bovine or porcine pancreatic islets or pancreatic islet cells. 
     
     
       39. A method for treating a subject having a condition caused by impaired functioning of secretory cells, comprising transplanting an amount of the composition of matter produced by the process of  claim 36  sufficient to alleviate said condition to said subject. 
     
     
       40. The method of  claim 39 , wherein said condition is diabetes and said secretory cells comprise pancreatic islet cells to pancreatic islets. 
     
     
       41. A method for producing a composition of matter comprising a sample of secretory cells entrapped in a bead, whereas said bead comprises agarose and gelatin sponge, and is coated with a coating of agarose, comprising:
 ( a )  suspending secretory cells on gelatin sponge,      ( b )  adding agarose to said suspended secretory cells and gelatin sponge,      ( c )  forming a bead of the suspended secretory cells, gelatin sponge, and agarose of  ( b ) , and      ( d )  coating said bead with a solution containing from  5   %  to  10   %  agarose.     
     
     
       42. The method of  claim 41 , wherein said secretory cells comprise pancreatic islets or pancreatic islet cells. 
     
     
       43. The method of  claim 42 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islets or pancreatic islet cells. 
     
     
       44. The method of  claim 41 , wherein the agarose of ( b )  is added in a  3   % - 5   %  solution.   
     
     
       45. The method of  claim 44 , wherein said solution is a  5 %  agarose solution.   
     
     
       46. The method of  claim 41 , comprising coating said bead with a  5 %  agarose solution.   
     
     
       47. A method for treating a subject having a condition caused by impaired functioning of secretory cells, comprising transplanting an amount of the composition of matter produced by  claim 41  sufficient to alleviate said condition. 
     
     
       48. The method of  claim 47 , wherein said condition is insulin dependent diabetes and said secretory cells comprise pancreatic islets or pancreatic islet cells. 
     
     
       49. The method of  claim 48 , wherein said pancreatic islets or pancreatic islet cells are human, bovine, or porcine pancreatic islets or pancreatic islet cells. 
     
     
       50. The method of  claim 47 , comprising transplanting said composition of matter to the intraperitoneal cavity of said subject.