Introduction

Stem cells can be divided into three categories:

  • Embryonic Stem Cells
  • Induced Pluripotent Stem Cells
  • Adult Stem Cells

Embryonic Stem Cells are taken from the inner cell mass of a fertilized egg that is five to seven days old. Embryonic Stem Cells have unique cell markers, such as Oct 4, Nanog, Sox 2, SSEA-3, and SSEA-4, which serve as a great advantage. Additionally, they are easy to culture in vitro and have a short doubling time of around 16 hours. More importantly, they have the potential to differentiate into Ectoderm, Mesoderm, and Endoderm. However, there are some significant drawbacks with using Embryonic Stem Cells. Once injected into the patient, the possibility of Teratoma development is present in addition to immune rejection. Induced Pluripotent Stem Cells are not directly from human cells. They are from epidermal cells which are transfected with four genes. They have all the advantages of Embryonic Stem Cells but are very difficult to obtain and will cause Teratoma once injected into the patient. Adult Stem Cells are taken from all kinds of adult tissues. The advantages of Adult Stem Cells are that they will neither cause Teratoma nor immune rejection (autologous). Their disadvantages, however, are that they do not have good cell markers and have difficulty undergoing proliferation and differentiation in vitro. As there seems to be no suitable stem cells to use for therapeutic purposes, the goal of StemBios Technologies, Inc. is to find such cells from humans.

The race for discovery of new stem cells began at the start of the 21st century. In 2002, a paper was published in “Nature” mentioning the findings of stem cells from bone marrow. The size of the cells was around 8 to 10 µm, and its markers were CD13 and SSEA 1. These cells were able to differentiate into Ectoderm, Mesoderm and Endoderm (Nature: 2002, Vol 418, p41). This paper introduced a new idea to discovering pluripotent stem cells from adult tissue. Unfortunately, the ease of obtaining these cells and culture them proved to be a challenge. StemBios began to look for new possibilities of finding the most suitable Pluripotent Stem Cells from adult tissue. Our goal is to find Pluripotent Stem Cells from adult tissue with the following criteria:

  1. a source to easily obtain these cells
  2. good distinguishable markers
  3. easy to purify and activate
  4. easy to culture and expand
  5. easy to induce differentiation
  6. no Teratoma formation in vivo
  7. no ethical issues
  8. no immune-mediated rejection in vivo