Methods of Isolation, Expansion and Differentiation of Fetal Stem Cells From Chorionic Villus, Amniotic Fluid, and Placenta and Therapeutic Uses Thereof

Researchers at the Children's Medical Center in Boston, Massachusetts developed US Patent 7968336B2, which is the scientific background for treatments involving fetal stem cells. The claims in this patent indicate these treatments may benefit patients with neurological disabilities. The researchers claim the intellectual rights to the discovery of amniotic fluid, placenta, and chorionic villus as rich sources of fetal stem cells, which could offer treatment options for cerebral palsy.

Abstract Summary

This patent involves fetal stem cells that can differentiate into multiple forms of cells. These fetal stem cells come from amniotic fluid, the placenta, and chorionic villus genetic sampling. Researchers extracted these stem cells through the processes of isolation, expansion, and differentiation. This pattern involves therapeutic uses of these fetal stem cells through manipulation, gene transfection, and other applications.

Terms to Know

The following vocabulary may help clarify this patent and its therapeutic uses.

  • Chorionic villus are a branching outgrowth of the chorion that forms the placenta, along with the maternal tissue.
  • Amniotic fluid is the fluid surrounding an unborn fetus.
  • Stem cells come from an undifferentiated cell of an organism that has the potential to produce an indefinite amount of the same cells. From these stem cells, other types of cells can arise due to the process of differentiation.
  • Placenta is an organ in the uterus of a pregnant woman that feeds, nourishes, and maintains the unborn fetus by transferring nutrients through the umbilical cord.
  • Cell isolation is the process of separating living cells from a block of solid tissue or from suspended cells.
  • Cell expansion is the use of serums, supplements, and other treatments to generate tissue and cell growth.
  • Cell differentiation is the process by which an unspecialized cell becomes specialized in a certain function. This changes a cell's size, metabolic rate, shape, and responsiveness.
  • Pluripotent is a cell that can differentiate into many different cell types.
  • C-kit is a common protein on the surface of cells that binds to a substance called stem cell factor, which invigorates blood cell growth.
  • SSEA is an acronym for Stage-Specific Embryonic Antigen.
Patent Background

Unlike other cells, stem cells have the ability to reproduce, renew themselves, and engage in the process of differentiation. Through differentiation, fetal stem cells can transform into other types of specialized cells. This feature makes them incredibly valuable for cell-based therapeutic treatments, especially for neurodegenerative conditions.

Adult stem cells are not as powerful as younger ones. They can only regenerate a certain amount of times, and have a limited turnover. However, research suggests that embryonic stem cells or fetal stem cells can differentiate at greater rates and have established effects on developmental pathways. Younger stem cells can also retain their pluripotency for a longer period of time than adult stem cells.

Fetal stem cells, which are different from embryonic stem cells, can also differentiate spontaneously into multiple types of tissues, making them vital for therapeutic treatment. In addition, these cells can proliferate and regenerate indefinitely. They can also retain their pluripotent qualities longer than adult stem cells can. This makes the possibilities surrounding fetal stem cell treatments wide-ranging and exciting.

However, transplants for fetal cells are subject to a number of biological and ethical concerns. Scientists can only extract fetal stem cells through a fetus biopsy, aborted embryos, or through umbilical cord blood. Many people find these procedures ethically challenging, and others have religious reasons to decline this treatment. In addition, stem cell treatments require a large quantity of fetal cells to treat a patient effectively.

Patent Claims and Summary

The inventors discovered that chorionic villus, placenta, and amniotic fluid contain large amounts of pluripotent fetal stem cells that researchers could extract for therapeutic treatments. Researchers can isolate these fetal cells without harming human embryos, which helps resolve the ethical dilemma surrounding embryonic stem cell treatment.

Developers directed this patent to these pluripotent fetal stem cells from the three sources, as well as the isolation, differentiation, and expansion techniques to extract them and their potential therapeutic uses. As such, the patent makes claims to a few key scientific concepts.

  1. A composition of isolated human fetal stem cells that are c-kit positive, SSEA3 positive, SSEA1 negative, and/or SSEA4 positive. These cells must be able to grow without a feeder layer, not spontaneously differentiate, and come from the chorionic villus.
  2. An isolated pluripotent human fetal stem sell that is c-kit positive, SSEA3 and/or SSEA4 positive, grows without a feeder layer, does not spontaneously differentiate, and comes from the chorionic villus.
  3. An isolated pluripotent fetal stem cell that is both SSEA3 and SSEA4 positive, c-kit positive, grows without a feeder layer, does not spontaneously differentiate, might be SSEA1 negative, and comes from the chorionic villus.

Researchers can develop several new treatments with the fetal stem cells from this patent, including treatments for diseases that are not associated with the cells. These particular diseases must relate to a lack of an enzyme, hormone, growth factor, or other secreted substance. For example, fetal stem cells may be effective at treating central nervous system disorders such as Alzheimer's, Parkinson's, acute brain injury, cerebral palsy, and other dysfunctions.

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