Our RetroNectin^® method is used by various public medical institutions conducting clinical trials in gene therapy as well as in several privately funded clinical trials, and is rapidly becoming the standard for ex vivo gene therapy. As of the end of July 2007, the RetroNectin^® method was being used by 38 public medical institutions, mainly in the U.S., and is licensed out to 4 overseas private corporations.

The birth of RetroNectin^® Takara Bio discovered that a recombinant human fibronectin fragment (RetroNectin^®) dramatically enhanced the efficiency of the gene transduction into hematopoietic stem cells by retrovirus vectors (Nature Medicine, 1996). This big discovery broke the major premise that it is impossible to transduce genes into hematopoietic stem cells.

What is RetroNectin^® ? RetroNectin^® , recombinant human fibronectin fragment, is a protein of ~63 kDa (574 amino acids) containing a central cell-binding domain (type III repeat, 8, 9, 10), a high affinity heparin-binding domain II (type III repeat, 12, 13, 14), and CS1 site within the alternatively spliced III CS region of human fibronectin.

Gene transduction into a cell by RetroNectin^® Cells bind to a VLA-4 ligand, a CS-I site, and a VLA-5 ligand, a cell attachment domain, and virus vectors binds to a heparin binding domain II, which co-locates the cell and the virus vector on RetroNectin®. This process enhances the density of both cells and vectors, and facilitates the gene transduction in the result.

RetroNectin^® of GMP grade is registered for Drug Master File in the U.S., and the gene transduction method using this is a standard of the clinical trial on the gene therapy with retrovirus vector.