In my senior year at CMU, I took the two-semester long Biomedical Engineering Capstone class. The class involved groups working on different projects with applications to biomedical engineering. My group worked on the design of a antibacterial tracheostomy tube.

 

Approximately 2 million people are affected by hospital acquired infections associated with tracheostomies every year only in the US. This project aimed to address hospital-acquired infections due to tracheostomies. Current tracheostomy tubes in the market have a high incidence of causing tracheal infections including bacterial tracheitis, ventilator associated pneumonia and tracheobronchitis due to bacterial biofilms in the tube artificial airway. Using SharkletTM, a micro patterned surface that prevents growth of bacterial biofilm due to its irregular pattern and dimensions, we developed a prototype tracheostomy tube to reduce significantly bacterial infections associated with the tube and prolongate the lifespan of the device.

 

Our project utilized the pattern to reduce the formation of biofilm on tracheostomy tubes. As bacteria establish a biofilm, they send signals that promote increased bacterial growth. The SharkletTM pattern reduces the formation of biofilm by creating an uneven surface at the micro-surface level thus preventing bacteria from communicating with each other. Our final prototype used photolithography to imprint the SharkletTM pattern onto a PDMS film. Sterility tests were performed on the PDMS imprinted material using bleach, ethanol and UV light. Bacterial testing was performed using Streptococcus pyogenes. The SharkletTM pattern was found to significantly reduce the formation of biofilm on the polymer.