Episomal reprogramming with chemicals

Abstract

Methods and composition of induction of pluripotent stem cells are disclosed. For example, in certain aspects methods for generating essentially vector-free induced pluripotent stem cells with cell signaling regulators are described. Furthermore, certain aspects of the invention provide novel compositions comprising induced pluripotent stem cells essentially free of exogenous retroviral vector elements in the presence of a medium comprising signaling inhibitors. In certain aspects, feeder-free episomal reprogramming methods may be provided.

1 .- 33 . (canceled) 
     
     
         34 . A composition comprising a population of induced pluripotent stem (iPS) cells essentially free of exogenous genetic elements and a medium comprising externally added glycogen synthase kinase 3 (GSK-3) inhibitor and at least one other externally added chemical inhibitor selected from the group consisting of mitogen-activated protein kinase kinase (MEK) inhibitor and transforming growth factor beta (TGF-β) receptor inhibitor. 
     
     
         35 . The composition of  claim 34 , wherein the medium is chemically defined. 
     
     
         36 . The composition of  claim 34 , further comprising a matrix component. 
     
     
         37 . The composition of  claim 36 , wherein the matrix component comprises Matrigel™. 
     
     
         38 . The composition of  claim 34 , wherein the medium further comprises externally added LIF. 
     
     
         39 . The composition of  claim 34 , wherein the medium further comprises externally added HA-100. 
     
     
         40 . The composition of  claim 34 , wherein the medium further comprises externally added FGF.