This experiment was done to test the efficiency of transdermal patches in delivering lantibiotics through the surface of a membrane by diffusion. We accomplished this by simulating cell layers of human skin. Using .22 and .45 µm (micron) filters as “patches,” we coated each with a different combination of materials. The materials used were Collagen, Ampicillin, Nisin, horse blood, and E. coli. Placing the patches on agar plates, which were seeded with Pediococcus a Gram positive bacteria (bacteria with thicker cell walls), we identified the patch that had best drug delivery by looking at how many bacteria around the patch were killed. This area of clearing is called a zone.
Transdermal patches have gained popularity in delivering drugs like birth control, nicotine, nitroglycerin. This method of treatment is more advantageous because of the fact that the delivery process is painless and easier to use. The purpose of our experiment was to test the efficiency of transdermal patches in the delivering of lantibiotics through the surface of a membrane. In doing so, we find which patch works the best in transporting lantibiotics.
These are the patches with the largest zones from each day of testing. The data shows that 0.10 M Collagen and 0.01 M Ampicillin work well. 0.10 M Nisin also works. The E. coli that was not resistant to Ampicillin (Day 2) worked better than the E. coli that was (Day 3). .45 micron filters are the best.
This graph displays our results from a single plate of patches coated with ampicillin-resistant E. coli.The comparison of ampicillin and nisin differs from that found in other plates.
After having experimented with different combinations of solutions to coat the patches, we have discovered that our early hypothesis was incorrect. We thought that the Ampicillin was going to spread furthest in the agar plates because it is a smaller molecule than Nisin. Nisin proved to be less effective at killing all the surrounding bacteria. However, it spread further lengthwise. We also found that .45 µm filters allowed the lantibiotics to diffuse more efficiently, since they have larger pores.
To improve our experiment in the future, things we could do would be to try to find more precise ways to model the layers of skin, to allow more time for data collection, and to develop a better method for measuring the strength of the drugs coated on the patches.
We would like to thank Iva Jovanovic for being our mentor for this project and being here to help us with and explaining the different concepts involved in this process. Also, Drs. Michelle Bothwell and Joe Mcguire for generously allowing us to use their lab, Dr. Skip Rochefort for giving us incredible guidance and support. Last but not least, we’d like to thank all the people at SESEY who have made this such a great experience for us! Thanks much,
Miranda Fix and Michelle Zhao