Article published - Jun
5, 2006
BIOTECH/BIOMED: Sausalito's Xgene advances human tissue
Biotech startup has found applications in research, cosmetics
industry testing
BY Loralee Stevens
STAFF REPORTER
SAUSALITO – Five scientists in this southern Marin town are quietly
advancing the biotechnology of growing human tissue.
Their work, following discoveries made at Stanford University School of
Medicine, has enormous potential to regenerate skin – and potentially
other parts of the body – from tissue-destroying diseases and severe
burns.
Led by former Stanford faculty member Warren Hoeffler, Ph.D, Xgene
Corporation has patented a method of growing both the inner and outer
layers of tissue that cover the human frame and organs.
"The interaction between the epidermal and mesenchymal layers is
vital to the functionality of each part of the body, so the living cells
are instructed to interact in similar ways at different locations,"
said Dr. Hoeffler. "The skin lining of the mouth, the digestive
track and even the veins are made up of those two layers."
Xgene is already providing the tissue layers to several large research
organizations, biotechnology companies and cosmetic firms, which in
Europe are facing a ban on animal testing.
"Most cosmetic companies are aware of us. We work for them on a
contract basis, customizing the material to their particular
needs," he said.
Human tissue has been grown before, but always in a single layer, the
cells demonstrating a single functionality. What Dr. Hoeffler and his
colleagues at Stanford discovered is that a slurry of cells, made from
churning together both inner and outer layers, will separate on its own
into tiers that comprise a particular part of the body.
"This spontaneous cell sorting and cell typing means that all the
different linings of the body can be grown. It could change the
dermatology industry significantly," he said.
All pharmaceuticals, skin products, clothing, absorbent material and
food products must be tested extensively to determine their effect on
the part of the body they come in contact with, whether outer skin or
inner linings.
They must be tested for toxicity, the time and quantity necessary for
optimum effectiveness, long-term reactions and many other aspects of
interaction, either to satisfy the FDA and other regulatory bodies, or
simply to commercialize and market a product successfully.
Most of this testing is done on animals, which is increasingly
out-of-favor.
The European Union has voted to ban animal testing starting in 2009.
That ban encountered particular resistance from the cosmetics industry.
The European cosmetics industry generates close to $40 billion annually.
"The advantage to testing on complex layers of human skin are
obvious," said Dr. Hoeffler.
Although Xgene has generated several million dollars in sales, it spends
the revenue just as quickly on further research. So far the company has
stayed away from the venture capital community.
"We wanted to incubate our technology to maturity before being
pushed to profitability," Dr. Hoeffler said.
May benefit from stem-cell program
He and his team have received grants from the National Institutes of
Health, and may be indirectly on the receiving end of some of the $3
billion California has slated to spend on stem cell research.
That's because Xgene has just formed an agreement with Alameda-based
Advanced Cell Technology, a stem cell company that recently relocated to
California. Advanced Cell President Michael West, Ph.D, collaborated
with Dr. Hoeffler at Stanford.
"We have the ability to reproduce the stem cells, and Xgene can
build the skin," said Dr. West. "The collaboration has the
potential of growing human skin that can regenerate itself, something
that only embryonic stem cells can do. The implications for healing of
reducing scarring are huge.
"Also, there's the potential to grow tissue that would be closer to
human skin than any ever made before, and far less likely to be rejected
in the case of grafting,"
According to Michael Schuppenhauer, Ph.D, former senior editor of
Biocentury and currently a consultant to Bay Area cities on the biotech
industry, Xgene has overcome the technical challenge of growing both
skin layers together, but faces a regulatory challenge.
"Whenever you apply foreign cell material to patients, the FDA
wants many, many assurances that cancer or other damaging cells won't go
along. It's a major hindrance to skin grafting technologies."
Dr. Hoeffler admits his research has been met with a certain amount of
skepticism.
"Our insistence on regenerating complex tissues from cell slurries
has been confusing to the non-scientific community, but then advances
are often met with skepticism. 'Why to we need another source of light,'
people asked Edison. 'Candles and gas lamps already do a great job.'
"Innovation begins in the dark, and ultimately some positive
discoveries may come to light," he said.
