Cedarville Magazine Summer 2018

Norman and Rotello’s research is strictly limited to replacement tissue. “It won’t regrow a limb or reproduce a lot of different types of tissue because it’s just a scaffold with one type of cell growing on it right now,” said Norman. “It’s not really designed for the kind of genetic information inside a cell to be triggered to transcribe genes and send signals that would grow a body part.” Even still, the thought of replacing damaged tissue where the body would have created a scar, deformation, and maybe even impairment, is nothing short of remarkable. SCAFFOLD SCIENCE While the image of a vine slowly engulfing a trellis or the side of a home is easy enough to grasp, recreating that process in the miniature world of cells is tedious and meticulous. For instance, cells won’t grow on just anything. The scaffolds that might be placed in a person’s bone must be like a hothouse for cells, a structure to which they will hold and proliferate. Or to borrow the language of Genesis, Norman and Rotello’s scaffolds must be like tiny Gardens of Eden, where the cells can be fruitful and multiply. What makes a fruitful scaffold? One important factor: stiffness. The scaffolds must be pliable enough to flex under the normal loads that a person would put on that area of bone. But not so pliable the scaffold will easily break down and the growing tissue lost. “Bone varies in stiffness depending on where it’s found in the body and from person to person,” noted mechanical engineering major Jacob Cole ’18, team leader on the project. “We had to find a way to customize the stiffness of the scaffold based on the patient and the location in the body.” “We know that bone cells like a certain amount of stretching to go on,” Norman said. “If you put a bone cell in an area where no load is being applied, it may die because it’s not needed. Bone cells need activity that causes them to thrive. Thriving causes them to actually proliferate.” Imagine the bone cells are like teens checking out a youth group. They want to grow somewhere, but if the “ministry” is stiff and there’s not much happening, they won’t go. The cells want a structure that is flexing, moving, and dynamic, acting like bone even though it isn’t bone. Surface roughness and porosity also play a part in where cells attach. They aren't attracted to a smooth scaffold; they like a roughened surface, similar to how green moss flourishes on a rocky shoreline or microscopic coral attaches to objects to create a reef. “Once they’re stuck, they start to secrete other molecules to multiply and divide," Rotello said. "Some materials you put in the presence of the cells will cause them to quiet down and sort of go to sleep. Great for babies, not so great when trying to create new tissue. But the material Dr. Norman’s lab has generated is conducive to growth. These scaffolds promote cell survival and regenerate tissue.” While Norman and his team are creating the right structures for life to take hold, Rotello and his pharmacy students are responsible for creating the right context. This is the biology of the research — what kind of cells to use, the composition of the solution in the petri dish where the cells will live, whether to stir or not to stir the solution. Once these decisions are made, the cells are introduced to the solution, or media, and everything is placed in an incubator. “Without all of those things, it does not work,” Norman said. “We’re trying to figure out the right combination, and there are a lot of variables.” A STEP UP For both Norman and Rotello, 3D human tissue scaffold research is more than cutting edge, it’s cutting educational. Students are being pushed to think in ways no textbook can duplicate. “This is something they can’t look up,” said Norman. “There’s not a real good example of what they’re doing; they have to think outside the box. Every day, it’s kind of like, ‘Where do we go from here?’” Students who worked on the 3D project with Tim Norman, Professor of Mechanical and Biomedical Engineering, second from left, include (L-R) Daniel Sidle ’18, Stephen Smith ’18, and Jacob Cole ’18. 4 | Cedarville Magazine