Stimuli-responsive bilayer coating to prevent bacterial infection

Hospital acquired infections are a leading cause of death in the US, with about 10% of hospitalized patients developing an infection, a medical cost of $5 billion. Implantable devices are prone to biofilm formations, causing infections in the patient.  Existing medical devices have coatings to promote contact killing of microbes or resistance to adhesion, but the coatings may not be biocompatible or have maximum efficacy.

Researchers in the Composto and Eckmann Labs have developed a novel bilayer system that combats biofilm formation.  The outer layer is a pH-responsive chitosan-based formulation that is resistant to bacterial adhesion, while the inner layer is an anionic poly acrylic acid monolayer grafted directly on to the device. 

The composition of this bilayer brush allows for antibiotic to be loaded and retained. If a biofilm forms, the pH decreases, causing the outer chitosan layer to swell, yielding controlled release of antibiotic.  Because antibiotic release occurs only in when bacterial growth is detected, the patient minimizes exposure to drug. 

• Prevent biofilm formation and eradicate bacterial growth
• Tunable properties allow for control of drug delivery
• Minimize exposure to antibiotic, a critical step in combating antibiotic resistance and growth of superbacteria

• Coating of implantable medical devices, including catheters, shunts, and stents
• Stimuli-responsive drug delivery systems
• Generate multifunctional grafted bilayers