PatentGO-A blog on University technology

United States Patent Application 20070026518:
Controlling stem cell destiny with tunable matrices.

Focus of the Patent:

The technology is essentially a biochemically defined scaffold that allows controlled and directed growth of specific types of stem cells. These cells can be used for various therapeutic purposes in regenerative medicine as well as investigative models to understand molecular signaling events.

Limited Technical Details:

At the core of the technology is a scaffold referred to as a semi-interpenetrating polymer network (SIPN). This comprises of a mesh of cross-linked polymers. Entangled in the mesh are linear polymers attached to specific ligands which contain the bioactive component that promotes stem cell growth, proliferation, self-renewal and differentiated function.
One tested application has been using peptide ligands containing the amino acid sequence Arg-Gly-Asp (RGD) present in many extracellular matrix proteins, which are responsible for the signaling that produces the earlier mentioned cellular responses. Scaffolds engineered to contain these ligands have been demonstrated to precisely control neural stem cells growth and development into neurons and other types of cells in vitro. The patent claims are however wide enough to include a variety of biological ligands containing many different active amino acid sequences to produce varied effects as well as an entire range of different stem cells.

Applications and Market Potential:

The primary market that this patent focuses on is regenerative medicine which is increasingly being developed to address diseases as diverse and widespread as diabetes, cardiac failure and stroke and the mostly untapped global market potential for tissue engineering and regenerative medicine products is projected to grow at a 16.2% compound annual rate approaching $3.2 billion by 2013. Regenerative medicine needs reliable and specific sources of stem cells to engineer tissue implants. A biochemically defined matrix that can be manipulated to specifically direct and regulate self-renewal and differentiation of a heterogeneous collection of harvested stem cells can greatly benefit the bioprocess of stem cell expansion used for tissue regeneration. An immediate application of this patent is the stem cell subset involving regeneration of neural tissue and the treatment of spinal-cord injury, stroke, multiple sclerosis, Alzheimer’s disease and Parkinson’s disease. StemCells Inc., Geron Corporation and ReNeuron are some of the companies that are on the way to marketing therapies using neural stem cells. But the patent covers a variety of stem cells and biological ligands and the range of applications can be broadened in future.
Another area where this scaffold can be marketed is the stem cell research sector. A chemically defined and characterized matrix, free of animal products allows for an in vitro cell culture system that can be used to study of the basic processes and signaling events responsible for the stem cell behaviors that result in regeneration.

Past History of Inventors:

Kevin E. Healy has founded several companies to develop materials for applications in biotechnology and regenerative medicine and has authored or co-authored more than 200 published articles, abstracts, or book chapters which emphasize the relationship between materials and the tissues they contact. He is a named inventor on numerous issued United States and international patents relating to biomaterials. He is currently a Professor in the Departments of Bioengineering and Materials Science and Engineering at the University of California at Berkeley.
David Schaffer is a Professor at UC Berkeley and Krishanu Saha is a Postdoctoral Fellow at Whitehead Institute.

In our opinion:

In studying this patent application a couple of things stand out. The demand for stem cell technology and its potential impact on regenerative medicine is large. Patented stem cell technologies have been the genesis of several successful commercial enterprises such as Osiris, Geron, Vistagen and StemCells inc. Additionally, every major pharmaceutical company has an active stem cell program. Pfizer announced in November of 2008 that it would invest in regenerative medicine and that its research would include both adult and embryonic stem cell projects. Stem cells products are being commercially developed for diseases such as type 1 diabetes, acute spinal cord injury and inflammatory bowel disease and are being pursued for such forward applications as, heart injury, and osteoarthritis in academia and in partnership with biotechnology companies, thereby allowing for a fast growing market.
However what any stem cell needs is a place to grow and direct their development, like children need a good home. This technology is an important “infrastructure” invention that can direct the maturation of resident stem cells into regenerative therapeutics. The SIPN scaffold is similar to other patented technologies in that it precisely controls the geometry of the of the fibers and the presentation of chosen ligands, and in that way it can create molecular contexts that are relevant to human disease states. However the inventor Kevin Healy points out that what makes it unique is being able to independently tune the mechanical properties of the cross network and the biological properties of the ligands on the linear chains allowing for more control of the cellular behavior. The defined and precise nature of the matrix also sets it apart from commonly used materials such as Matrigel which are complex and tend to vary from batch to batch. Additionally the fact that this technology is amenable to combination with other approaches such as micro-patterning opens up more complex design possibilities and arrangements to better mimic the environments found in the human body and potentially leads to more effective stem cell therapies.