Mother Nature has provided the lizard with a unique ability to
regrow body tissue that is damaged or torn ― if its tail is
pulled off, it grows right back. She has not been quite so generous
with human beings. But we might be able to come close, thanks to
new research from Tel Aviv University.
Prof. Meital Zilberman of TAU's Department of Biomedical
Engineering has developed a new biologically active "scaffold" made
from soluble fibers, which may help humans replace lost or missing
bone. With more research, she says, it could also serve as the
basic technology for regenerating other types of human tissues,
including muscle, arteries, and skin.
"The bioactive agents that spur bone and tissue to regenerate
are available to us. The problem is that no technology has been
able to effectively deliver them to the tissue surrounding that
missing bone," says Prof. Zilberman. Her artificial and flexible
scaffolding connects tissues together as it releases
growth-stimulating drugs to the place where new bone or tissue is
needed ― like the scaffolding that surrounds an existing
building when additions to that building are made.
Scientific peer-reviewed research on this scaffold fiber has
appeared in a number of journals, including Acta
Biomaterialia, and is currently being licensed through Ramot,
TAU's technology transfer company.
Active implants
The invention, which does not yet have a name, could be used to
restore missing bone in a limb lost in an accident, or repair
receded jawbones necessary to secure dental implants, says Prof.
Zilberman. The scaffold can be shaped so the bone will grow into
the proper form. After a period of time, the fibers can be
programmed to dissolve, leaving no trace.
Her technology also has potential uses in cosmetic surgery.
Instead of silicon implants to square the chin or raise cheekbones,
the technology can be used to "grow your own" cheekbones or puffy
lips. But Prof. Zilberman says it's far too early to think of such
uses. She first started her work in biomaterials at the UT
Southwestern Medical Center at Dallas, Texas, and currently is
concentrating on various medical applications. One of them intends
to make dental implants more effective. She envisions applying the
invention to organ tissue regeneration in the future.
A question of structure
"Our material is very special," Prof. Zilberman explains. "The
fibers not only support body parts like bones and arteries. They're
also specially developed to release drugs and proteins in a
controlled manner. Our special 3-D matrix can hold together drugs
that are particularly vulnerable to breaking down easily. The
matrix gives the body shape and form, coaxing it to re-grow and
strengthen missing parts," she says.
Until now in vitro results on bone have been good, and some
basic unpublished results from animal models have shown excellent
promise for bone regeneration, says Prof. Zilberman. "It sounds
simple, but it's not. It's quite difficult to develop a process for
scaffold formation for bone growth. It's a delicate balance to
apply only mild conditions that will not destroy the activity of
the growth factor molecules."
Currently Prof. Zilberman has developed both a fibrous
artificial scaffold and an organic scaffold which forms a film. The
technology could also be applied to peripheral nerve regeneration.
"Our fibers provide all the advantages that clinicians in tissue
regeneration are calling for," says Prof. Zilberman. "Being thin,
they're ideal when delicate scaffolds are called for. But they can
also be the basic building blocks of bones and tissues when bigger
structures are needed."
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