The field of cellular agriculture has seen huge advances in the development of cultured meat, that is, meat cultivated from animal cells and grown sustainably with no harm to animals and without the substantial resources required by typical farming processes.
David Kaplan, Stern Family Professor of Biomedical Engineering and director of the Tufts University Center for Cellular Agriculture (TUCCA), knows that large-scale production of such meat could have massive benefits for the planet.
“Over time, it’s going to be a complete game changer,” Kaplan said. “We cannot feed the growing population the way we have been with protein-enriched foods unless we do something drastically new and different.”
However, obstacles remain before large-scale production can become a reality. One major challenge has been the development of methods for recreating the texture of a filet or steak, a texture created by muscle fibers, connective tissue, and, importantly, fat. Fat contributes not only to meat’s texture but also to its flavor. Consumer tests with natural beef of varying fat content showed the highest scores for beef containing 36% fat.
Producing cultured fat tissue in sufficient quantities has been a major challenge, however, because as the fat grows into a mass, the cells in the middle become starved of oxygen and nutrients. In nature, blood vessels and capillaries deliver oxygen and nutrients throughout the tissue. Scientists still have no way to replicate that vascular network at large scale in cultivated tissue, so they can only grow muscle or fat to a few millimeters in size.
But Kaplan and his TUCCA research team have had a major breakthrough: They have successfully bulk-produced cultivated fat tissue that has a similar texture and make-up to fat tissue naturally occurring in animals.
To get around the lack of a vascular network, the researchers grew fat cells derived from mice and pigs first in a flat, two-dimensional layer, then harvested those cells and aggregated them into a three-dimensional mass with binders such as alginate (developed from seaweed) and microbial transglutaminase, which are both already used in some commercial foods.
The result offers hope for fully developing the potential of cultivated meat, Kaplan said. “This method of aggregating cultured fat cells with binding agents can be translated to large-scale production of cultured fat tissue in bioreactors, a key obstacle in the development of cultured meat,” he noted. “We continue to look at every aspect of cultured meat production with an eye toward enabling mass production of meat that looks, tastes, and feels like the real thing.”
Kaplan’s revolutionizing of the field of cellular agriculture is one part of an extensive research portfolio. The Kaplan lab focuses on biopolymer engineering to deepen our understanding of structure-function relationships, with emphasis on studies related to self-assembly, biomaterials engineering, and regenerative medicine.
In addition, Kaplan and his team have extensively studied silk-based biomaterials in regenerative medicine, starting from fundamental studies of the biochemistry, molecular biology, and biophysical features of this novel class of fibrous proteins. These studies have led to inquiries into the impact of silk biomaterials on stem cell functions and complex tissue formation.
The result of that work? The emergence of silk as a new option in the degradable polymer field with biocompatibility, new fundamental understanding of control of water to regulate structure and properties, and new tissue-specific outcomes with silk as scaffolding in gel, fiber, film, or sponge formats.