Three envelope package for sterile specimens

Abstract

A three-envelope package for preserving tissue specimens or other sterile objects. A sterile tissue sample is sealed within an innermost envelope sterile inside and out. The innermost envelope is sealed within the sterile interior of an intermediate envelope equipped with a peel-back seal for subsequent opening. Both the inside and the outside of the intermediate envelope are sterile. The intermediate envelope is sealed within the sterile interior of an outermost envelope, made of foil or another substance impermeable to a storage medium, such as liquid nitrogen. The outermost envelope provides complete impermeability to liquid nitrogen, eliminating the possibility of nitrogen seepage through the peel-back seal of the intermediate envelope. When the envelope package is removed from storage, the intermediate envelope is removed from the outermost envelope and can be opened in an assumed non-sterile environment, without contaminating the innermost envelope or the tissue specimen therein.

I claim: 
     
       1. A package for storage of a sterile .Iadd.transplantable .Iaddend.specimen in a cryogenic liquid medium, comprising: an outermost envelope having a non-sterile exterior . .impervious to the cryogenic liquid storage medium.!..Iadd., said envelope made from a material that provides an impermeable barrier to liquid nitrogen .Iaddend.and .Iadd.said envelope .Iaddend.having closure means impenetrably sealed against . .the liquid storage medium.!. .Iadd.liquid nitrogen .Iaddend.to define a closed sterile interior,   an intermediate envelope removably received within the outer envelope .Iadd.and .Iaddend.having . .a.!. .Iadd.at least two walls sealed to each other around the periphery thereof to define the .Iaddend.closed . .sterile.!. interior, and   an innermost envelope removably . .received.!. .Iadd.situated .Iaddend.within the interior of the intermediate envelope. ., the intermediate envelope having a sterile exterior and defining a closed sterile interior for containing transplantable tissue so that the impervious.!. .Iadd.comprised of at least two walls sealed to each other around the periphery thereof to define an inner, sterile cavity wherein said .Iaddend.outermost envelope protects against contact by . .the liquid storage medium.!. .Iadd.liquid nitrogen.Iaddend., and the intermediate envelope maintains the sterile exterior of the innermost envelope irrespective of possible contamination occurring to the exterior of the intermediate envelope during removal from the outer envelope, said package being in the cryopreserved state.Iadd.,   wherein the intermediate envelope comprises a peelback opening having a pair of surfaces defining the interior of the intermediate envelope and releasably bonded together along a predetermined course at the periphery of the interior; and the bond of the surfaces being selectively separable by peeling back one such surface relative to the other surface, thereby exposing the sterile interior of the intermediate envelope and the sterile innermost envelope received within, without subjecting the interior of the innermost envelope to possible contamination on the exterior of the intermediate envelope, so that the intermediate envelope is openable without subjecting the innermost envelope to possible contamination on the exterior of the intermediate envelope.Iaddend.. . .2. The envelope package as in claim 1, wherein:   the intermediate envelope comprises a peelback opening having a pair of surfaces defining the interior of the intermediate envelope and releasably bonded together along a predetermined course at the periphery of the interior; and   the bond of the surfaces being selectively separable by peeling back one such surface relative to the other surface, thereby exposing the sterile interior of the intermediate envelope and the sterile innermost envelope received within, without subjecting the interior of the innermost envelope to possible contamination on the exterior of the intermediate envelope,   so that the intermediate envelope is openable without subjecting the innermost envelope to possible contamination on the exterior of the   
     
     
        intermediate envelope..!.3. The package defined in claim 1 wherein the 
     
     
        outermost envelope is comprised of polyimide. 4. The package of claim 1. ., 2.!. or 3 wherein the outermost envelope is a polyimide/fluorinated 
     
     
        ethylene polypropylene laminate. 5. The package of claim 1 wherein the 
     
     
        innermost envelope is comprised of polyimide. 6. The package of claim 1. ., 2.!. or 5 wherein the innermost envelope is a polyimide/fluorinated 
     
     
        ethylene polypropylene laminate. 7. The package of claim 1, . .2,.!. 3 or 5 in combination with a transplantable tissue contained within the 
     
     
        innermost envelope. 8. A method of protecting a tissue sample from damage upon cryopreservation and thawing, and maintaining its suitability for transplant into a patient in need of such treatment, comprising: placing a transplantable tissue sample into a sterile cavity of an innermost envelope in conjunction with a suitable medium;   sealing said innermost envelope;   placing the sealed innermost envelope into the cavity of an intermediate envelope;   sealing the intermediate envelope.Iadd., the intermediate envelope including a peelback seal whereby a pair of surfaces defining the interior of the intermediate envelope are releasably bonded together along a predetermined course at the periphery of the interior; and the bond of the surfaces being selectively separable by peeling back one such surface relative to the other surface, thereby exposing the sterile interior of the intermediate envelope and the sterile innermost envelope received within, without subjecting the interior of the innermost envelope to possible contamination on the exterior of the intermediate envelope.Iaddend.;   placing the sealed intermediate envelope into an outermost envelope.Iadd., said envelope made from a material that provides an impermeable barrier to liquid nitrogen.Iaddend.;   sealing the outermost envelope .Iadd.with a closure means impenetrable by liquid nitrogen.Iaddend.;   maintaining the outermost envelope in a suitable cryogenic freezing medium for a time period and at a temperature effective for cryogenically preserving the tissue contained in the innermost envelope; and   incubating the transplantable tissue to a temperature suitable for   
     
     
        implanting the patient in need of such treatment. 9. A package for storing a transplantable tissue in cryogenic liquid nitrogen comprising: an outermost envelope defining a closed sterile interior and having a non-sterile exterior, the envelope being .Iadd.made from a material that is .Iaddend.impervious to liquid nitrogen and bacteria and .Iadd.said envelope .Iaddend.having a closure means impenetrably sealed against liquid nitrogen and defining a closed sterile interior;   an intermediate envelope impervious to bacteria and removably received within the interior of the outer envelope, and defining a closed sterile interior, and an inner envelope impervious to bacteria, removably received within the interior of the intermediate envelope, having a sterile exterior and defining a closed sterile interior suitable for containing a transplantable tissue,   said outer envelope being useful for protecting the intermediate envelope against contact with liquid nitrogen,   said intermediate envelope maintaining the sterile exterior of the inner envelope irrespective of possible contamination to the exterior of the intermediate envelope during removal from the outer envelope.Iadd., the intermediate envelope including a peelback seal whereby a pair of surfaces defining the interior of the intermediate envelope are releasably bonded together along a predetermined course at the periphery of the interior; and the bond of the surfaces being selectively separable by peeling back one such surface relative to the other surface, thereby exposing the sterile interior of the intermediate envelope and the sterile innermost envelope received within, without subjecting the interior of the innermost envelope to possible contamination on the exterior of the intermediate   
     
     
        envelope.Iaddend.. 10. The package of claim 9 wherein the outermost envelope has an edge which is welded shut for impermeability to liquid nitrogen, so that the outer envelope may be opened by cutting.