Overview

    Aiming to design a novel therapy for depression and expecting to develop further commercial application, we consider safety a crucial point and comply strictly to the command of security throughout our work. For more details, please visit our safety form.

Safe and Secure Project Design

1.Safe chassis:

     The engineered bacteria used in our final product is Bifidobacterium longum, which is one kind of safe probiotic that inhabits originally in human intestine and some particular strain has been proved to have antidepressant effects [1]. In the experimental stage, Escherichia coli DH5-α and BL21 were used for clone and Bacillus subtilis was used in function tests, all of which are on the White List.

2.Moderate health supplement:

    We chose S-adenosyl methionine (SAMe) as the effective constituent produced to alleviate depression. SAMe is a natural antidepressant with low side effects [2], and it has been proven to have almost equal efficacy as other common antidepressants [3].

3.Kill switches:

     With the aim of actively controlling the engineered bacteria, we set up parallel kill switch including an AHL-based switch and a temperature-controlled switch, both with Holin, a bacterial toxin, downstream. With the former switch, the patients can stop the process of drug-delivery by intaking one kind of harmless AHL to prevent the disordered delivery caused by overlong work from affecting health. The other will work once bacteria’s surrounding temperature is below 36 degrees Celsius, which means the engineered bacteria have left the gut. Obliviously, this module can effectively prevent bacteria from leaking into the environment.

4.Oscillator:

    The oscillator consists of modules of λcI, TetR and LacI. These three proteins can repress expression of one another to achieve oscillation and regulate the secretion of SAMe to guarantee its concentration in blood is kept at a harmless but effective level.

Safe and Secure Laboratory Work

Rules learning & Laboratory safety:

    Each of us has undergone regular laboratory safety training from the college and has got special reminder of safety from our team. We conducted our experiments in the Level 1 scientific training laboratory equipped with a clean bench and a fume hood, which worked well and was safe enough for our assays. Personal protection and garbage classification were also implemented to protect wet-lab members, downstream handlers and the environment. All our operations were under the supervision of the teachers in charge.

Safe and Secure Transfers

Get biobricks:

    Our materials of experiments are from iGEM, bio-tech companies and our Pis’s lab. We got those carefully in compliance with relevant regulations even though they are not harmful to human.

Reference

[1] Dinyadarshini J.; Sivakumar T.; Vengadesh L. Exploring the Role and Potential of Probiotics in the Field of Mental Health: Major Depressive Disorder. Nutrients 2021, 13, 1728.
[2] Sharma A, Gerbarg P, Bottiglieri T, Massoumi L, Carpenter LL, Lavretsky H, Muskin PR, Brown RP, Mischoulon D; as Work Group of the American Psychiatric Association Council on Research. S-Adenosylmethionine (SAMe) for Neuropsychiatric Disorders: A Clinician-Oriented Review of Research. J Clin Psychiatry. 2017 Jun;78(6):e656-e667. doi: 10.4088/JCP.16r11113. PMID: 28682528; PMCID: PMC5501081.
[3] Nguyen M, Gregan A. S-adenosylmethionine and depression. Aust Fam Physician. 2002 Apr;31(4):339-43. PMID: 12043126.