Antimicrobial Nanoparticles

According to the WHO, infections remain some of the most common causes of death worldwide.  The CDC reports that sepsis (the body’s overwhelming and life-threatening response to infection) is the 9th leading cause of disease related deaths worldwide and costs US hospitals over $20 billion each year.  Hardly anyone reading this will not have experienced or cared for a loved one with a serious bacterial illness.

The first antibiotic, penicillin, was discovered in 1928.  Since then we have seen a tremendous improvement in global health and longevity.  While the statistics described above sound grim, they pale in comparison to the pre-antibiotic era.  Unfortunately, emerging antimicrobial resistance is becoming one of the greatest threats to global human health and has the potential to plunge us back to this era.  The bacteria we have kept at bay for the last 75 years are becoming resistant to the few weapons we have against them.  As more and more pathogenic bacteria develop resistance to multiple classes of antibiotics, previously treatable illnesses will become lethal. 

Despite the severity of the problem and repeated calls to action, there have been no new classes of antibiotics for nearly 40 years.  Unfortunately, high throughput screening of novel chemicals libraries for antibacterial function have failed to produce acceptable candidate molecules for one reason or another.  That well has dried up.  The time for a bold paradigm shift in antimicrobial pharmaceuticals is now. 

In the VanEpps Lab we will look beyond typical organic chemical substrates to inorganic nanomaterials as novel antimicrobials.  Nanotechnology is successfully providing a new path to manipulate the chemistry and structure of surfaces to modify bacterial growth and behavior.  In collaboration with faculty in Chemical Engineering we have been exploring zinc oxide nanoparticles with shape-dependent biomimetic enzyme inhibitory properties as a novel mechanism against methicillin resistant Staphylococcus aureus (a.k.a. MRSA).  In addition, working with colleagues in Chemical and Mechanical Engineering we have recently developed and characterized graphene based quantum dots that target amyloid fibers which provide staphylococcal biofilms protection from chemical and mechanical debridement.  Other materials being evaluated include gold nanoparticles, starch loaded with copper nanoparticles, and iron sulfide nanoparticles.   

Background:  Zinc oxide nanoparticles clustered within a bacterial cell