Modeling the Human Placenta in Vitro
Senior Students: Li Ying Wang, Lunan Shao, Orysya Stus, Sana Hussain
Project Advisors: Dr. Prashant Mali, Dr. Mana M. Parast
Group 15, Spring 2016
The in Vitro Model
To make an in vitro model we used a bioprinter and a 6-well plate. First, we printed a 1mm thick layer of collagen embeded with mesenchymal stem cells (MSCs). Since we used a 6-well plate the diameter of this layer is 6mm.
Next we bioprinted a layer of gelatin in the shape of a vessel and incubated the entire strucutre at 20⁰C.
Then we bioprinted a second layer of collagen embeded with MSCs over the gelatin and incubated the construct at 37⁰C in order to melt the gelatin. We removed this melted gelatin by pumping media containing human umbilical vein endothelial cells (HUVECs) through our model and push the gelatin out.
As a result from melting and removing the geltain we obtained an endothelial lined vessel as indicated by the hole in our model. Then, we bioprinted a layer of matrigel (an extracellular matrix) over the collagen and MSCs so that when we added cells on top of it, those cells would better adhere to our model.
Over the matrigel, we added a layer of JEG3 trophoblast stem cells with the intent that they would form a monolayer on top of our model.
For our complete model, we expect the JEG3 trophoblast stem cells to invade downward into our model towards the artifical vessel and interact with the enthothelial cells as the chorionic villi do in an actual human placenta.
These are real images of our 6-well plate construct where our model is in the middle two wells. The top image should the plate right after the model had been bioprinted and the clear solution was removed so that the pink solution shown in the bottom image could be added. This pink solution is media containing the JEG3 trophoblast stem cells and was added so that the cells could adhere to our model as a monlayer as discussed above.
While this is not aesthetically similar to a human placenta, the goal of the project was to create a model that physically works and is structurally similar to that of an actual placenta. Thus, the function and structure of our model is most important.