Therapeutic encapsulated embryonic stem cells and mesenchymal stromal cells

Abstract

This application discloses alginate microencapsulation-mediated differentiation of embryonic stem cells and use of the stem cell differentiation method for the development of effective treatment of various diseases and disorders. The microencapsulation of embryonic stem (ES) cells results in decreased cell aggregation and enhanced neural lineage differentiation through incorporating the soluble inducer retinoic acid (RA) into the permeable microcapsule system. This application also discloses a micro-encapsulation system for immobilizing mesenchymal stromal cells (MSCs) while sustaining the molecular communication. Thus, the invention provides the use of encapsulated mesenchymal stromal cells in the cellular transplantation therapies. Moreover, the invention provides methods for delivery of encapsulated MSCs into the central nervous system and therapies derived therefrom, such as, the treatment of spinal cord injury (SCI) and other inflammatory conditions.

1 . A method for inducing differentiation of stem cells into desired lineage cells, comprising: (a) encapsulating the stem cells within an alginate polyelectrolyte microenvironment; (b) culturing the encapsulated stem cells in a differentiation cell media; and (c) allowing the encapsulated stem cells to differentiate into the desired lineage cells or end stage cells optionally in the presence of an inducer capable of inhibiting cell aggregation. 
     
     
         2 . The method of  claim 1 , wherein said encapsulating comprises: (i) dissolving an alginic acid salt in a medium to form an alginate solution; (ii) optionally filtering the alginate solution through a filter; (iii) adding to the alginate solution an aliquot of stem cell suspension to form a cell-alginate mixture; (iv) generating alginate beads using an electrostatic bead generator; (v) allowing the alginate beads to polymerize; and (vi) suspending the beads in a solution comprising a polyelectrolyte. 
     
     
         3 . The method of  claim 2 , wherein said culturing comprises: (i) removing the polyelectrolyte solution; (ii) washing the beads; (iii) suspending the washed beads in a differentiation media, wherein said differentiation media optionally comprises an inducer; and (iv) optionally replacing the differentiation media periodically. 
     
     
         4 . The method of  claim 3 , wherein said polyelectrolyte is poly-L-lysine, and said inducer is retinoic acid. 
     
     
         5 . The method of  claim 1 , wherein the stem cells are embryonic stem cells (ES cells), and the desired lineage is neural lineage. 
     
     
         6 . The method of  claim 5 , wherein the inducer is retinoic acid (RA). 
     
     
         7 . The method of  claim 1 , further comprising augmenting the differentiation process by supplementing the cell culture with a specific differentiation pathway regulator. 
     
     
         8 . The method of  claim 7 , wherein said supplementing comprising adding the regulator into the differentiation media at a differentiation acceleration stage. 
     
     
         9 . The method of  claim 7 , wherein said specific differentiation pathway regulator is a PPAR agonist. 
     
     
         10 . The method of  claim 1 , wherein said stem cells are mesenchymal stromal cells (MSCs), and said desired end stage cells are cartilage or chondrocyte cells. 
     
     
         11 . An isolated cell population comprising a single-cell suspension of stem cells encapsulated within an alginate polyelectrolyte microenvironment, wherein the encapsulated ES cells are capable of differentiating within said microenvironment into desired lineage or end stage cells. 
     
     
         12 . The isolated cell population of  claim 11 , wherein the single-cell suspension further comprises an inducer, the stem cells are embryonic stem cells (ES cells), and the desired cell lineage is neural lineage. 
     
     
         13 . The isolated cell population of  claim 12 , wherein the inducer is retinoic acid, and the neural lineage cells have a reduced level of cell-cell aggregation in comparison with an isolated cell population in the absence of the alginate polyelectrolyte microenvironment and/or the inducer. 
     
     
         14 . The isolated cell population of  claim 11 , wherein the stem cells are mesenchymal stromal cells (MSCs), and the desired cell lineage is cartilage or chondrocyte cell lineage. 
     
     
         15 . A micro-encapsulation system comprising an alginate polyelectrolyte, wherein the system is capable of immobilizing mesenchymal stromal cells (MSCs) within an alginate microenvironment while sustaining molecular communication, wherein the encapsulated MSCs are capable of differentiating within said alginate microenvironment into desired end stage cells, and wherein said alginate microenvironment is capable of sustaining the MSC viability for a pre-determined amount of time. 
     
     
         16 . The micro-encapsulation system of  claim 15 , wherein the alginate polyelectrolyte has a concentration in the range from about 1.7% (w/v) to about 2.5% (w/v). 
     
     
         17 . The micro-encapsulation system of  claim 15 , wherein the alginate polyelectrolyte has a concentration of about 2.2% (w/v). 
     
     
         18 . The micro-encapsulation system of  claim 15 , wherein the alginate polyelectrolyte is poly-L-lysine. 
     
     
         19 . A method for promoting tissue repair or regeneration, or for treating spinal cord injury (SCI) or other inflammatory diseases or conditions in a subject, comprising administering to the subject an effective dose of MSCs encapsulated within an alginate polyelectrolyte microenvironment, wherein the encapsulated MSCs are capable of differentiating within said microenvironment into desired end stage cells. 
     
     
         20 . The method of  claim 19 , wherein the spinal cord injury is characterized by an inflammatory condition in a spinal cord site of contusion, and the method comprises delivering an effective dose of alginate encapsulated MSCs directly into cerebrospinal fluid of the spinal cord at the cauda equina.