In her Brown University laboratory, Edith
Mathiowitz makes tiny particles coated in polymers. These
microcapsules, some as small as the point of a pin, can carry
medicines, genes, paints, pesticides – any molecule that
needs protection or controlled release.
Mathiowitz developed her technique as a drug delivery system,
but her microcapsules are now being put to a very different use
– to make ink for the first durable but removable tattoo.
Under a new intellectual property licensing agreement signed by Brown
University and Freedom-2 Holdings Inc., the company has the right to
make and sell their ink based on research Freedom-2 has funded in the
Mathiowitz lab.
With Freedom-2 funding, Mathiowitz and her team have made
microencapsulated beads filled with dyes. These beads are mixed with a
solution to make Freedom-2 tattoo inks. The inks are safer than
conventional products, free of heavy metals and other toxins. The inks
can also be easily removed. A single laser treatment breaks the polymer
beads, allowing the body to naturally expel the dye trapped inside.
Currently, it takes about six or seven laser treatments to remove a
tattoo using traditional inks.
“It’s terrific that my technology has such
a cool consumer application,” Mathiowitz said. “My
microencapsulation technique has other potential uses, particularly for
making new medicines. Any fragile, bioactive molecule –
proteins, hormones, DNA – can be coated so that it can be
safely delivered to where it is needed in the body and still do its job
once it gets there. There are enormous possibilities for drug delivery
with this technology.”
Microencapsulation, or suspending particles in biodegradable
coatings, is widely used in manufacturing. The process is used to make
products such as aspirin, plant food, stain remover, and cake mix.
It’s even used to make scratch-and-sniff perfume
advertisements found in magazines: Scratch the treated paper and
microbeads burst to release the scent.
Mathiowitz, a Brown professor of medical science and
engineering, is known in the field for coming up with innovative
coatings for molecules. The trick, she says, is understanding the
substance that you’re trying to protect. Knowing how a
particular solid, liquid or gas behaves when exposed to heat, light,
water or enzymes is critical to developing the correct coating method
that will properly protect a substance until it can be released.
Microencapsulation requires a smorgasbord of scientific
knowledge. Expertise in physics, physiology, biology and pharmacology
is needed to do the work. Most of all, the work demands expertise in
chemistry – and the Mathiowitz lab reveals its chemistry
roots. The room is filled with beakers and vats bubbling with solvents,
polymers and dyes used to make Freedom-2 inks.
“Microencapsulation is a real science,”
she said, “and a real art.”
It can also be big business. Microcapsules can be made to
carry vaccines or human growth factors that can help the body
regenerate bone, nerves or cartilage. Microcapsules can also carry
controlled release drugs. Of the top 200 best-selling drugs in 2004, 11
compounds used oral controlled or extended release technologies and
comprised sales of about $9 billion.
In 1997, Mathiowitz founded Spherics Inc., a pharmaceutical
company that now makes drugs to treat nervous system disorders,
gastrointestinal diseases and cancer.
“Encapsulation is a wonderful tool that can be used
to benefit human health,” Mathiowitz said.
“We’re just beginning to see the
possibilities.”
Posted 17th July 2007
