Citizens for
Alternatives to Animal Research and Experimentation (CAARE)
January 2017
Droplet-based microfluidic technology can also be applied to creating other types of human microtissues to study a range of diseases. It is yet one more technology for creating sophisticated human tissues that can bring about the end to animal experiments.
Twenty-first century science has been forever transformed by
organs-on-chips, but the technology has only just begun to be tapped for its
full potential.
Last month the National Institute of Biomedical Imaging and Engineering
announced that scientists have created a “liver-in-a drop.” Utilizing
advances in microfluidics, a team of researchers led by Professor David A.
Weitz at Harvard University has developed a droplet that contains two
essential types of liver cells – hepatocytes and fibroblasts – that can be
used for drug testing.
Approximately 95 percent of all drugs that show promise in development fail
when tested in human clinical trials, largely due to ineffective animal
tests. Almost weekly the media reports on drugs that show great promise in
studies with rats, mice or monkeys, only to fail when used in humans.
Dr. Weitz and his team have created a microfluidic device that generates thousands of droplets, each with the capacity to mimic liver function, hence the term “liver-in-a-drop.” Each droplet consists of a variety of cells in a 3D core-shell that function as artificial human tissue.
The past five years have seen the rapid development of organs-on-chips, in which bioengineering techniques use cultured live human cells to manufacture miniature devices that can mimic the structure and function of real human tissue and organs.
Much research has focused on the liver-on–a-chip because of the essential
role the liver plays in drug metabolism.
Yet liver chips are complicated to make, and according to Dr. Weitz, they
may lack uniformity and are difficult to modify. Using the droplet-based
microfluidic technique, up to one thousand droplets per second can be
generated, allowing huge numbers of drugs to be screened at varying
combination and doses.
Each droplet functions like a mini experiment, and a single milliliter of
fluid allows scientists to perform a million trials!
The liver in a drop is not expected to replace organ chips but will
complement them by streamlining productivity and enabling high throughput
screening of vast numbers of drugs.
“Currently, it is very time-consuming and expensive to develop new drugs,”
explains Dr. Weitz. “One reason is that many drugs fail in clinical trials
after animal studies, simply because animals are very different from humans.
One promising means of solving this problem is to replace animal experiments
with artificial human tissues that can be used to directly screen a drug.”
Droplet-based microfluidic technology can also be applied to creating other
types of human microtissues to study a range of diseases.
It is yet one more technology for creating sophisticated human tissues that
can bring about the end to animal experiments.
Citizens for Alternatives to Animal Research (CAARE), is a 501(c)(3) non-profit organization, established to highlight and promote research without animals.
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