Encapsulated cell indicator system

Abstract

The invention features an encapsulated cell indicator system that includes (a) indicator cells having a signal-responsive element operably linked to a reporter gene; (b) encapsulating material; and (c) a permeable membrane. In this encapsulated cell indicator system, the indicator cells are encapsulated in the encapsulated material and the encapsulated material and the indicator cells are surrounded by the permeable membrane.

1 . An encapsulated cell indicator system comprising:
 (a) indicator cells comprising a signal-responsive element operably linked to a reporter gene;   (b) encapsulating material; and   (c) a permeable membrane,   
       wherein said indicator cells are encapsulated in said encapsulating material and said encapsulating material and said indicator cells are contained within said permeable membrane. 
     
     
         2 . The encapsulated cell indicator system of  claim 1 , wherein said indicator cells comprise embryonic stem cells or bone marrow stem cells. 
     
     
         3 . The encapsulated cell indicator system of  claim 1 , wherein said indicator cells comprise human cells. 
     
     
         4 . The encapsulated cell indicator system of  claim 1 , wherein said indicator cells comprise mouse cells or pig cells. 
     
     
         5 . The encapsulated cell indicator system of  claim 1 , wherein said reporter gene encodes β-galactosidase, green fluorescent protein, or luciferase. 
     
     
         6 . The encapsulated cell indicator system of  claim 1 , wherein said encapsulating material comprises alginate, collagen, gelatin, chitosan, polylactic acid, polyglycolic acid, or polylactide/glycolide copolymer. 
     
     
         7 . The encapsulated cell indicator system of  claim 1 , wherein said permeable membrane comprises polyethylene terephthalate membrane, nylon mesh, porous nylon membrane, or porous polytetrafluoroethylene (PTFE/Teflon). 
     
     
         8 . A method of determining the differentiation state of cells in culture, said method comprising the steps of:
 (a) providing a population of cells and an encapsulated cell indicator system, said encapsulated cell indicator system comprising:
 (i) indicator cells comprising a signal-responsive element operably linked to a reporter gene; 
 (ii) encapsulating material; and 
 (iii) a permeable membrane, wherein said indicator cells are encapsulated in said encapsulating material and said encapsulating material and said indicator cells are contained within said permeable membrane, wherein the expression of said reporter gene correlates with the differentiation state of said population of cells; and 
   (b) measuring the expression of said reporter gene while said cells are contained within said permeable membrane using a method that does not result in substantial loss of viability of said population of cells, wherein said expression level of said reporter gene is indicative of the state of differentiation of said population of cells.   
     
     
         9 . The method of  claim 8 , wherein said indicator cells comprise embryonic stem cells or bone marrow stem cells. 
     
     
         10 . The method of  claim 8 , wherein said indicator cells comprise human cells. 
     
     
         11 . The method of  claim 8 , wherein said indicator cells comprise mouse cells or pig cells. 
     
     
         12 . The method of  claim 8 , wherein said reporter gene encodes β-galactosidase, green fluorescent protein, or luciferase. 
     
     
         13 . The method of  claim 8 , wherein said encapsulating material comprises alginate, collagen, gelatin, chitosan, polylactic acid, polyglycolic acid, or polylactide/glycolide copolymer. 
     
     
         14 . The method of  claim 8 , wherein said permeable membrane comprises polyethylene terephthalate membrane, nylon mesh, porous nylon membrane, or porous polytetrafluoroethylene (PTFE/Teflon). 
     
     
         15 . A method of preparing bone marrow stem cells for transplantation into cardiac tissue of a patient, said method comprising the steps of:
 (a) providing a population of bone marrow stem cells from said patient and an encapsulated cell indicator system, said encapsulated cell indicator system comprising:
 (i) indicator cells comprising a signal-responsive element operably linked to a reporter gene; 
 (ii) encapsulating material; and 
 (iii) a permeable membrane, wherein said indicator cells are encapsulated in said encapsulating material and said encapsulating material and said indicator cells are contained within said permeable membrane, wherein the expression of said reporter gene correlates with the differentiation state of said bone marrow stem cells; 
   (b) culturing said population of bone marrow stem cells and said encapsulated cell indicator system under conditions that induce said bone marrow stem cells to differentiate as cardiac cells;   (c) measuring the expression of said reporter gene while said cells are contained within said permeable membrane using a method that does not result in substantial loss of viability of said population of cells; and   (d) collecting said bone marrow stem cells when the expression of said reporter gene indicates that at least some of said bone marrow stem cells have been induced to differentiate as cardiac cells.   
     
     
         16 . The method of  claim 15 , wherein said permeable membrane is transparent or semitransparent.