Medium for growing human embryonic stem cells

Patent Number: 7,455,983

One of the issues of embryonic stem cell therapeutics development is the relative lack of methods for expanding them without inducing their differentiation.  Various methodologies are known in the art, for example use of different feeder layers or speciality media.   

The current patent is very interesting.  It covers a method of finding suitable culture conditions to expand ES cells.

Specifically, the one issued claim in the patent is:

 "A method of evaluating a media for culturing human embryonic stem (hES) cells in vitro to determine if they proliferate without differentiating, comprising culturing hES cells on an extracellular matrix and in a medium comprising: an isotonic buffer; a protein nutrient, comprising serum, serum replacement, albumin, or essential and non-essential amino acids; lipids, fatty acids, or cholesterol, either as artificial additives or as the HDL or LDL extract of serum; added fibroblast growth factor at a concentration of 40 ng/mL; and added Flt-3 ligand at a concentration of 15 ng/ml; and culturing hES cells in the medium through at least four passages; and determining if the hES cells cultured in the medium have differentiated."

This is a great example of how to leverage existing know-how into IP.  In our opinion one of the reasons this patent was issued was because culture conditions were already set up by Geron that maintained ES viability, the unknown variable was the additive being tested.

View this patent on the USPTO website.