NARRATOR: This year in the United States, nearly 70,000
people will be diagnosed with brain tumors. Of those, nearly
12,000 will be diagnosed with glioblastoma multiforme.
DR. MARK DEWHIRST: The problem is that virtually all the
patients die. So it's a death note if you have it.
NARRATOR: Glioblastoma multiforme is a particularly
deadly brain cancer. It kills more than half its victims
within one year, more than 90% within three years.
DR. STEFAN BOSSMANN: If you want to beat cancer and
especially gliomas, you cannot dangle your feet in the water
and say, "In principle, we can do this." We are in for
making a difference.
NARRATOR: As a professor of chemistry, Stefan Bossmann may
be an unlikely cancer researcher, as is his Kansas
State colleague Deryl Troyer, an expert in veterinary medicine,
but together, these two are blazing a trail to better the
odds of surviving glioblastoma.
DR. STEFAN BOSSMANN: Classic chemotherapy delivers about 1%
of the drug to the tumor and classic nanotherapy, about 10%.
So obviously, that's not enough.
NARRATOR: Bossmann and Troyer are developing a new cell-based
therapy that could deliver more than 50% of prescribed
anti-cancer drugs to brain tumors. Their method attempts
to solve one of brain cancer treatment's biggest challenges:
getting enough anti-cancer medicine past the blood-brain
barrier, a protective network of blood vessels and cells that
filters foreign substances from flowing to the brain. The
problem is the barrier also filters anti-cancer drugs,
causing medications meant to be beneficial to instead harm
otherwise healthy cells, but Bossmann and Troyer's plan
uses a kind of Trojan horse to slip medications across the
blood-brain barrier.
DR. DERYL TROYER: So the idea that we are pursuing is to use
cells as cargo ships to ferry therapeutic drugs so that they
go only to tumors and don't cause a lot of the side effects
that therapy often causes.
NARRATOR: Their cargo ship of choice? The patient's own white
blood cells. They move across the blood-brain barrier and
target tumors as a natural function of the immune system.
DR. DERYL TROYER: The idea is that cells can respond to
signals coming from the tumor, travel to the tumor, and then
migrate actively into the interior of the tumor.
NARRATOR: But for white blood cells to be effective cargo
ships, they have to carry the anti-cancer drugs placed within
them safely and that's where Bossmann and Troyer's research
comes in. Funded by a grant from the National Science
Foundation, they're using material science to develop a
new class of drug-carrying containers. They're called
protease activatable polymer-caged liposomes that
travel inside white blood cells.
DR. STEFAN BOSSMANN: So the major problem is to get a drug
which is really toxic to the tumor cell and not to
any other cells.
NARRATOR: Liposomes are artificial bubbles inside a cell
that can be used to carry medicine. Bossmann and Troyer
are developing self-assembling cages that wrap around
these artificial bubbles and keep them safely
contained during transport.
DR. DERYL TROYER: The cage that surrounds these liposomes is
designed so that it can only be released when the cell tells it
to open. When the cell reaches the tumor, then the cell
activates enzymes or we can make the cell activate enzymes that
will open the cage and release the drug.
DR. STEFAN BOSSMANN: So this is a typical materials problem and
material science will be able to make a lot of anti-cancer drugs
very effective, which are not currently used because they are
too toxic when you inject them in the patient's bloodstream.
NARRATOR: The team has successfully developed test
liposomes and used breast cancer in mice to prove tumors are
capable of attracting large numbers of white blood cells.
Bossmann and Troyer anticipate human clinical trials in the
next few years.
DR. MARK DEWHIRST: Brain tumors are extremely difficult to cure
and there are many kinds of innovative therapies that have
gone into the trash can. So if they can get adequate amount of
drug in there to prolong somebody's life, that's a
win-win in a brain tumor patient.
NARRATOR: The goal is for these advanced liposome cages to help
brain cancer patients live longer and in the face of an
otherwise bleak prognosis, give patients and their
doctors a glimmer of hope.
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