As engineers and scientists, we have the responsibility to ensure that our technical work is conducted in a safe environment and that the final product is safe for real life applications.
Northwestern iGEM 2016 took the matter of safety very seriously throughout our project, considering ethics, social justice, public safety, security, and potential accidents at each step in the design and execution.
Safe Project Design
During the iterative process of developing our project, we received feedback from professors in the chemical engineering department, experts in the field of antibiotic resistance, and a current medical student with a background in research.
Many issues arise when considering downstream applications of packaging genome editing proteins in bacterial vesicles for a therapeutic device.
One of the first considerations is the significant risk of an adverse immune response to a therapeutic formed from bacterial membranes. Fortunately, research has shown that the surface of OMVs can be modified with a wide range of proteins, including a membrane protein that cloaks vesicles from mammalian immune systems 1. Along with modified OMV membranes, specified use of OMV packaged Cas9 for topical applications would minimize the risk of complicating immune response.
The unintentional delivery of other naturally occurring and potentially toxic periplasmic proteins offers another safety consideration. Previous OMV experiments have not shown this to be a problem yet, but it is a consideration for downstream applications.
Off target effects are always an issue when working with genome editing proteins. The implications of off target effects in this setting is a concern as unintended DNA cleavage could lead to killing healthy bacteria; however, using OMVs offers safety in the fact that Cas9 will not be delivered to mammalian cells and the possibility for specific targeting using modified membrane proteins. The delivery of whole protein is also safer than viral delivery because it is more transient and is not incorporated in the host cell genome, minimizing off target risks 2. Effective design of RNA guides will also minimize off-target issues.
Real World Applications
Our product is designed to be used by professionals with medical training in a hospital setting. It focuses on addressing antibacterial resistance in developed countries, with the potential to expand to applications in developing countries with proper production, storage, and transportation conditions.
Safe Laboratory Practice:
Our lab was a certified Biological Safety Level 1 laboratory handling non-pathogenic organisms with minimal risk to lab personnel and the environment. Before beginning work in our lab in the basement of the campus science and technology building, each member of our team underwent preliminary laboratory safety training through Northwestern’s Office of Research Safety (ORS).
Our lab followed standard microbiological practices and standard chemical safety procedure, including proper handling, storing, and disposal of acids, flammables, sharps, and biohazards, as well as the use of PPE when doing wet lab work. Laboratory safety procedures were demonstrated at the start of experimentation by our graduate student advisors.