Specific Safety Concerns

Chassis Organisms

Our chassis is HEK293 cell line, from Homo sapiens. It is a very safe type of cell line wildly used in cell research.

Laboratory Safety

During the experiment, we regularly isolate exosomes from the culture medium of HEK293 cells. Then the exosomes are added to the culture medium of various types of cell lines such as A549, Neuro2A, C2C12 and MCF-7, after which we inject the exosomes into C57BL/6J mice that are commonly used in animal experiments. All of these cell lines are nontoxic and commonly used in scientific research. Our operations are strictly held in biosafety cabinets, and the animal experiments are under the control of our instructor. The ethical board of Nanjing University has approved the experimental procedure.

During the seven months of experiment, we choose to use safe gene segments and reagents. All other reagents such as morphine are under strict control of the instructor. In our project, we use a peptide of tpep-lamp 2b fusion protein. Although sounds horrible, the part we use is actually a small sequence of a peptide, which holds none original biological activity and is therefore harmless to human.

Generally, our project design has little chance to harm human bodies.

Training and Enforcement

All team members participate in lab work and learn biosafety rules in our lab, such as how to use the equipment (e.g., biosafety cabinet). The team members also learn how to deal with the laboratory waste such as cell culture medium and sharp objects. Before entering laboratory, the team members systematically learn how to protect themselves if there is any accident such as gas leaking. During experiments we normally wear rubber gloves and lab coats for protection, and sterilize materials and wastes if necessary. Regarding animal experiments, the chosen team members all have received specific training before experiments and conduct experiments with the help of technicians in our lab.

Future Implications

Currently we engineer siRNA-loaded exosomes to treat obesity in animal model. In the future, we expect to isolate fat from patients with adiposity, which can be engineered as cell factory to produce exosomes. Moreover, the exosomes can be engineered to express a tpep-lamp 2b fusion protein (specifically identify and target fat cells) on the exosomal membrane surface and filled with siRNA of the BCL2. We firstly test the drug’s efficiency and safety in little animals such as mice. Only when the exosomes are guaranteed to be safe and ideally effective can we perform next step experiments in larger animals such as dogs. The further experiments will be performed in primates to ensure its safety. If accomplished, we can expect to realize it on human beings.