Methods of manufacture of immunocompatible chorionic membrane products

Abstract

Provided herein is a placental product comprising an immunocompatible chorionic membrane. Such placental products can be cryopreserved and contain viable therapeutic cells after thawing. The placental product of the present invention is useful in treating a patient with a tissue injury (e.g. wound or burn) by applying the placental product to the injury. Similar application is useful with ligament and tendon repair and for engraftment procedures such as bone engraftment.

1 - 33 . (canceled) 
     
     
         34 . A method of manufacturing a placental product comprising the steps of:
 a. obtaining a placenta;   b. selectively depleting the chorionic membrane of a substantial portion of one or more types of immunogenic cells, wherein
 i. the one or more types of immunogenic cells comprise trophoblasts, functional CD14+ macrophages, or both trophoblasts and functional CD14+ macrophage; and 
 ii. the step of selective depletion does not comprise killing or removing substantially all native therapeutic cells; and 
   c. cryopreserving the chorionic membrane in a cryopreservation medium.   
     
     
         35 . The method of  claim 34 , wherein the selective depletion step further comprises removing substantially all vascularized tissue or vascularized tissue-derived immunogenic cells from the placenta, or the chorionic membrane. 
     
     
         36 . The method of  claim 34 , wherein the selective depletion step comprises treating the placenta with a protease and removing a layer comprising the trophoblasts, and optionally, wherein the protease is dispase. 
     
     
         37 . The method of  claim 34 , wherein the selective depletion step comprises any of scraping the trophoblasts from the chorionic membrane, blunt dissection of the trophoblast layer from the chorionic membrane, and removal of the trophoblast layer without removing the basement membrane from the chorionic membrane. 
     
     
         38 . The method of  claim 34 , wherein the selective depletion of the functional CD14+ macrophages comprises selectively killing or inactivating the functional CD14+ macrophages. 
     
     
         39 . The method of  claim 38 , wherein the selective depletion of the functional CD14+ macrophages comprises refrigerating the placenta in the cryopreservation medium for a period of time before the step of cryopreservation. 
     
     
         40 . The method of  claim 34 , wherein the cryopreservation medium comprises a cell-permeating cryopreservative, a non-cell-permeating cryopreservative, or a combination thereof. 
     
     
         41 . The method of  claim 39 , wherein the cryopreservation medium comprises a cell-permeating cryopreservative comprising DMSO in amount of about 2% to about 20%. 
     
     
         42 . The method of  claim 40 , wherein the period of time is about 10 min to about 120 min. 
     
     
         43 . The method of  claim 41 , wherein the refrigerating comprises incubating the placenta for the period of time at a temperature of about 2° to about 8° C. 
     
     
         44 . The method of  claim 43 , wherein the step of cryopreserving comprises reducing the temperature at a rate of less than about 5° C./min. 
     
     
         45 . The method  claim 34 , wherein the selective depletion of functional CD14+ macrophages comprises treating the placenta with at least one of an anti-TNF-α antibody or IL-10. 
     
     
         46 . The method of  claim 34 , comprising the step of removing substantially all vascularized tissue or vascularized tissue-derived immunogenic cells from the placenta or the chorionic membrane by lysing red blood cells, removing blood clots from the placenta or a combination thereof. 
     
     
         47 . The method of  claim 46 , wherein said removing substantially all vascularized tissue or vascularized tissue-derived immunogenic cells comprises treating the placenta with an anticoagulant. 
     
     
         48 . The method of  claim 34 , further comprising the step of removing the amniotic membrane from the placenta. 
     
     
         49 . The method of  claim 48 , wherein at least about 15.9% of the amniotic epithelial cells are retained in the placental product. 
     
     
         50 . The method of  claim 34 , wherein the selective depletion step further comprises:
 a. removing substantially all vascularized tissue or vascularized tissue-derived immunogenic cells from the placenta, or the chorionic membrane;   b. treating the placenta with a protease;   c. removing a layer comprising the trophoblasts by any of scraping the trophoblasts from the chorionic membrane, blunt dissection of the trophoblast layer from the chorionic membrane, and removal of the trophoblast layer without removing the basement membrane from the chorionic membrane; and   d. selectively killing or inactivating the functional CD14+ macrophages.   
     
     
         51 . A method of treating a tissue injury comprising administering a placental product of produced by the method of  claim 34  to the tissue injury of a subject.