Abstract: Compositions and methods for delivery of mRNA agents to subjects are provided in which the mRNA agents are encapsulated in exosomes prepared from human stem cells or progenitor cells, such as human mesenchymal stem cells, human embryonic stem cells or human cardiac progenitor cells. The compositions and methods can be used for delivery of mRNA agents encoding therapeutics, such as enzymes (e.g., metabolic enzymes), cytokines, growth factors, antigens, antibodies or immunomodulatory agents, by administering the compositions to the subject. Methods of preparing compositions comprising exosomes encapsulating mRNA agents are also provided.

Abstract: The present invention provides methods for isolating human cardiac ventricular progenitor cells (HVPs), wherein cultures of day 5-7 cardiac progenitor cells are negatively selected for one or more first markers expressed on human pluripotent stem cells, such as TRA-1-60, to thereby isolate HVPs. The methods can further include positive selection for expression of a second marker selected from the group consisting of JAG1, FZD4, LIFR, FGFR3 and TNFSF9. Large populations, including clonal populations, of isolated HVPs that are first marker negative/second marker positive are also provided. Methods of in vivo use of the HVPs for cardiac repair or to improve cardiac function are also provided. Methods of using the HVPs for cardiac toxicity screening of test compounds are also provided.

Abstract: The present invention provides methods for isolating human cardiac ventricular progenitor cells (HVPs), wherein cultures of day 5-7 cardiac progenitor cells are negatively selected for one or more first markers expressed on human pluripotent stem cells, such as TRA-1-60, to thereby isolate HVPs. The methods can further include positive selection for expression of a second marker selected from the group consisting of JAG1, FZD4, LIFR, FGFR3 and TNFSF9. Large populations, including clonal populations, of isolated HVPs that are first marker negative/second marker positive are also provided. Methods of in vivo use of the HVPs for cardiac repair or to improve cardiac function are also provided. Methods of using the HVPs for cardiac toxicity screening of test compounds are also provided.

Abstract: The present invention provides methods for isolating human cardiac ventricular progenitor cells (HVPs), wherein cultures of day 5-7 cardiac progenitor cells are negatively selected for one or more first markers expressed on human pluripotent stem cells, such as TRA-1-60, to thereby isolate HVPs. The methods can further include positive selection for expression of a second marker selected from the group consisting of JAG1, FZD4, LIFR, FGFR3 and TNFSF9. Large populations, including clonal populations, of isolated HVPs that are first marker negative/second marker positive are also provided. Methods of in vivo use of the HVPs for cardiac repair or to improve cardiac function are also provided. Methods of using the HVPs for cardiac toxicity screening of test compounds are also provided.

Abstract: The present invention provides methods for isolating human cardiac ventricular progenitor cells (HVPs), wherein cultures of day 5-7 cardiac progenitor cells are negatively selected for one or more first markers expressed on human pluripotent stem cells, such as TRA-1-60, to thereby isolate HVPs. The methods can further include positive selection for expression of a second marker selected from the group consisting of JAG1, FZD4, LIFR, FGFR3 and TNFSF9. Large populations, including clonal populations, of isolated HVPs that are first marker negative/second marker positive are also provided. Methods of in vivo use of the HVPs for cardiac repair or to improve cardiac function are also provided. Methods of using the HVPs for cardiac toxicity screening of test compounds are also provided.