Research

  From the research, we know that periodontal disease was proved to be related to many chronic and cardiovascular diseases. Among the pathogenic organisms of periodontal disease, Porphyromonas gingivalis (P. gingivalis) is the most important bacteria that give rise to this bad condition in dogs. To tackle the problem at its roots, we put effort into finding the efficient way to reach the inhibition of Porphyromonas gingivalis first.

   Finally, we chose antimicrobial peptides, LL-37 play the part of bacteria-inhibition. Human cathelicidin-derived LL-37 is a 37-residue cationic, amphipathic α-helical peptide. It is an active component of mammalian innate immunity. LL-37 not only can inhibit P. gingivalis _[1], can also inhibit Escherichia coli itself _[2], preventing DenTeeth from overgrowing after entering the canine mouth.

Design

   Sterilization is the key to periodontal disease. For the wet lab, we first expect the LL-37 could attain the mission. To observe the expression of DenTeeth’s biobrick, the RFP would be inserted behind the LL37. Because DenTeeth would be killed by LL-37 peptide, we added a composite part in the front of the LL-37 producing sequence, preventing engineered bacteria died before entering the mouth.

   As stated before, LL-37 can inhibit E. coli. If the DenTeeth could not exist with LL-37 in a proper proportion, the DenTeeth wouldn't attain the mission of solving the periodontal disease. Therefore, we decided to use the prediction model to predict whether DenTeeth could grow and express under the effect of LL-37. To confirm the feasibility of DenTeeth.

  Only when the temperature is up than 37°C, the LuxR would be expressed (Fig.1 A). At this moment, if the concentration of bacteria is high, the amount of AHL would rise, binding with LuxR. The complex of AHL and LuxR will attach to the Plux (Fig.1 B), activating the expression of LL-37.
To see more details click to design page.arrow_circle_right

  For the dry part, by deriving differential equations based on our assumptions and substituting parameters from published articles, we could analyze the biological parameter of DenTeeth and predict the expression of LL-37.

Build

Cloning Result

  We successfully built DenTeeth with LL-37 .

Model

  Through the modeling build with substituting parameters from published articles, the growth of E. coli and P. gingivalis under the effect of LL-37 would be inhibited significantly. However, the figure also show that E. coli could still live with LL-37. Simply speaking, we successfully test the feasibility of denteeth and find that we can improve the denteeth with both biobrick design and efficiency optimization model.

Learn

  After the engineering of LL-37, we could guarantee LL-37 can secrete out from DenTeeth without cell lysate and inhibit the growth of P. gingivalis. We ensured the process of DenTeeth could work smoothly and the efficiency optimization model could optimize the benefit of DenTeeth.