National Anti-Vivisection Society
National Anti-Vivisection Society - SCIENCE FIRST

A handful of subscribers may have inadvertently received a sneak preview of this week’s Science First, which was distributed ahead of schedule due to a glitch last week. We apologize for any inconvenience, but we want to make sure everyone hears about Karen Samy’s great work.


This week’s Science First highlights the work of Karen Samy, a current recipient of an International Foundation for Ethical Research (IFER) Graduate Fellowship for Alternatives to the Use of Animals in Science.

IFER Graduate Fellowships are awarded annually, through support from the National Anti-Vivisection Society (NAVS), to early career scientists who are developing alternatives to the use of animals in product testing, biomedical research and education.

Karen’s project, which is aimed at developing a three-dimensional cell-based model to mimic the microenvironment of the intestine to perform drug permeability studies, expands upon work conducted by a former IFER fellowship recipient, Erica Schlesinger.

Because most medicines are delivered orally, it is important that a drug’s intestinal absorption be carefully characterized, as this helps researchers understand how suitable the drug is for oral dosing. A number of models are currently used for these tests, including two-dimensional in vitro models and in vivo animal models. Both approaches have limitations that Karen’s work hopes to overcome.

“The existing in vitro standard, the 2-D Transwell model, does not recapitulate the complex in vivo environment of the small intestine,” Karen notes, “which leads to a lack of correlation between permeability measurements from the model and absorption observed in vivo for low permeability compounds.”

And use of animal models has its limitations too. “The use of animals as in vivo models is complicated by differences in intestinal physiology across the different species,” says Karen. “Moreover, there are a lot of ethical as well as cost considerations associated with using animals in drug testing.”

With support from IFER, Karen, under the mentorship of Dr. Tejal Desai at the University of California San Francisco, is creating a human-relevant model mimicking the intestinal microenvironment, which she hopes will overcome limitations of existing models. She designed a permeable tubular scaffold and has successfully cultured human intestinal cells in a continuous monolayer on the inside. She is now in the process of testing multiple drugs to assess their permeability across the scaffold in an effort to see how those permeability values compare to values obtained in vivo.


Once her model is optimized, Karen hopes that pharmaceutical companies will use it to test the intestinal permeability of new drugs in order to predict their in vivo absorption across the gut wall. “This would help limit the use of animals in early drug testing and improve the efficiency of the drug development process,” Karen notes.

Karen strongly believes that as in vitro models improve to better reflect the complexity seen in vivo, reliance on animal models will be lessened. She plans to continue to contribute to this area of research even after completion of her Ph.D., and hopes to develop a complex in vitro system which would link together multiple organ models for use in studies of drug absorption and metabolism.

NAVS is grateful for the contribution that Karen Samy is making toward the development of animal-free drug testing models. We wish her continued success in her efforts to advance science without harming animals.

Please click here to learn more about Karen's project.

Help NAVS and IFER support smarter science—such as Karen's—that advances discovery, innovation and human-relevant solutions without the use of harmful, flawed and costly animal experiments.


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