Islet isolation process

Claim 1

A method of recovering intact islets of Langerhans from a pancreas comprising digesting the pancreas with an enzyme preparation effective to break down the exocrine tissue of the pancreas and free intact islets, separating the freed islets from the exocrine tissue of the pancreas and recovering the intact islets in a condition effective to produce insulin.

Claim 2

A method of recovering intact islets of Langerhans from a pancreas comprising digesting the pancreas with an enzyme preparation effective to break down the exocrine tissue of the pancreas and free intact islets, separating the freed islets from the exocrine tissue of the pancreas and recovering the intact islets in a condition effective to produce insulin.

Claim 5

A method according to any one of Claims 1 to 3, wherein the pancreatic tissue is at least partially ruptured during the digestion.

Claim 6

A method according to any one of the preceding Claims, wherein the pancreas is digested for a time effective to loosen the islets from the pancreatic tissue such that on subsequent maceration of the pancreas the majority of islets are sufficiently loosened from the pancreatic tissue that they are freed from the pancreatic tissue in an intact viable condition.

Claim 7

A method according to any of Claims 1 to 5, wherein the pancreas is ductally distended with a mixture of Hank's solution and fetal calf serum during the enzymatic digestion.

Claim 10

A method for isolating the insulin producing tissue from a pancreas, the process comprising: ductally distending the pancreas with a solution containing collagenase and incubating the pancreas in a solution containing collagenase until a satisfactory separation of islets is observed; chopping the macerated pancreas into large fragments and macerating the large fragments; forcing the macerated pancreas through successively smaller screens to filter the pancreas tissue from the freed islets: and purifying the islet material

Claim 11

A method for isolating the insulin producing tissue from a pancreas, the process comprising: ductally distending the pancreas with a solution containing collagenase and incubating the pancreas in a solution containing collagenase until a satisfactory separation of islets is observed; chopping the macerated pancreas into large fragments and macerating the large fragments; forcing the macerated pancreas through successively smaller screens to filter the pancreas tissue from the freed islets: and purifying the islet material

Claim 12

A method of recovering intact islets of Langerhans from pancreas comprising ducally distending an intact pancreas with a mixture of Hank's solution and 10% by volume fetal serum containing 0.2% by weight of an enzyme preparation containing collagenase, and incubating the pancreas to digest the exocrine tissue of the pancreas, monitoring the pancreas at regular intervals during the digestion to determine the point of maximum islet separation,the combination of physical disruption of the distension and the enzymatic digestion being efffective to free viable islets of Langerhans from the pancreatic tissue while retaining the insulin producing properties of the islets, separating the intact islets from the remaining pancreatic tissue and digested product and recovering the intact islets of Langerhans in their insulin producing condition, the recovery being performed by first chopping the digested pancreas and macerating the digested pancreas by mechanical grinding, the grinding being performed under conditions effective to reduce the size of the pancreatic tissue to about the size of an intact islet while retaining the maximum number of islets in their whole, insulin producing condition, and second separating the intact islets from the exocrine tissue of the pancreas by filtration and concentration, the recovered concentrate containing intact islets in a condition effective to produce insulin.

Claim 13

A method of recovering intact islets of Langerhans from pancreas comprising ducally distending an intact pancreas with a mixture of Hank's solution and 10% by volume fetal serum containing 0.2% by weight of an enzyme preparation containing collagenase, and incubating the pancreas to digest the exocrine tissue of the pancreas, monitoring the pancreas at regular intervals during the digestion to determine the point of maximum islet separation,the combination of physical disruption of the distension and the enzymatic digestion being efffective to free viable islets of Langerhans from the pancreatic tissue while retaining the insulin producing properties of the islets, separating the intact islets from the remaining pancreatic tissue and digested product and recovering the intact islets of Langerhans in their insulin producing condition, the recovery being performed by first chopping the digested pancreas and macerating the digested pancreas by mechanical grinding, the grinding being performed under conditions effective to reduce the size of the pancreatic tissue to about the size of an intact islet while retaining the maximum number of islets in their whole, insulin producing condition, and second separating the intact islets from the exocrine tissue of the pancreas by filtration and concentration, the recovered concentrate containing intact islets in a condition effective to produce insulin.

Claim 16

A method according to any one of Claims 1 to 12, wherein a pig pancreas is used and intact pig islets are recovered.

Claim 19

A method according to any one of Claims 1 to 12, wherein a human pancreas is used and the pancreas is digested for between 45 and 90 minutes.

Claim 22

A method according to any of Claims 1 to 18, wherein the pancreas is digested at about 37°C.

Claim 23

A method according to any one of Claims 1 to 19 , wherein the pancreas is distended during the enzymatic digestion.

Claim 24

A method according to any one of the preceding Claims, wherein the enzyme preparation is a mixture of Hank's solution containing about 10% by volume fetal calf serum, the mixture containing about 0.2% by weight of the enzyme preparation.

Claim 25

A method according to any one of the preceding Claims, including partially distending the pancreas, checking for leaks, suturing the leaks closed and fully distending the pancreas for incubation.