Project Description

Custom control of gene expression is a powerful tool for research, therapeutics and industry

The development of experimental methods to control gene expression have allowed significant advancements in our understanding of many fundamental biological research areas. These include gene function, epigenetics, developmental biology, neuroscience and behavioural science. Beyond basic research, the applications of custom control of gene expression have been established in an expansive range of real-world areas, most prominently in the fields of medicine, agriculture and biotechnology. Key examples of these include:

• Gene Therapy (Liu et al.,2024): Treatment for medical conditions, including the use of Zolgensma® to treat over 3,700 patients with spinal muscular dystrophy as of March 2024.
• Genetically Modified Crops: 94% of all soybeans planted in 2020 were GMO, modified to increase herbicide tolerance and yield.
• Production of Biofuels: Using genetically modified bacteria and algae to overexpress biosynthesis of lipids, increasing biodiesel yield by transesterification.

However, current methods of gene expression control have significant limitations

For example, optogenetics is an increasingly popular method of gene expression modulation which uses light to regulate gene expression. One implementation uses light sensitive ion channels (such as channelrhodopsins) on cell surfaces of engineered cell lines which are stimulated to open by specific wavelengths. Optogenetics has already been shown to be a powerful technology for neuroscience, biomanufacturing, cardiac research and therapeutic applications. However it is held back by a major obstacle: its inability to penetrate opaque materials. This prevents it from being capable of effective remote gene regulation, severely limiting its use in systems like organoids and requiring invasive surgery to be performed for use in neuroscience research (Lee et al,2020). To solve this problem and provide a new way to regulate gene expression spatially, we aimed to develop a new technology which can act as an alternative.

Magnogenetics: a novel method for spatiotemporal control of gene expression

Magnetogenetics involves applying magnetic fields to cells in order to modulate gene expression (Del Sol-Fernández et al, 2022). This methodology has not yet been extensively developed, presenting an exciting opportunity for our research to make significant progress. Furthermore, this area of research holds great potential in both laboratory and real-world applications, from use as a research tool to therapeutic applications.

Magnetogenetics is possible because when magnetic fields are applied to cells , this can be transduced into cellular signalling cascades in a number of ways: heating magnetic nanoparticles around the cells causing thermal signalling, applying forces to magnetic nanoparticles bound to cell membrane proteins or by native proteins which undergo a conformational change. Each of these target cellular signals can be triggered via a different magnetic field strength and oscillation frequency.

We aimed to develop magnet induced AND gates

Magnetic fields penetrate tissues with no attenuation, thus overcoming a major limitation of light based control. However, applying stimuli remotely makes spatial targeting using conventional methods impossible and instead bulk activation is achieved. We wanted to solve this problem.

Our plan was to develop several electromagnets to separately target specific regions of cells (planes). We would then use genetic AND gates so that only the intersection of these regions was activated. This system would provide valuable spatial precision in gene expression control. This is only possible if the target magneto-responsive pathways are receptive to different magnetic field types (oscillation frequencies) so that only a single pathway is activated in each region. The steps involved in activating gene expression are as follows:

1. Magnetic fields applied in different orientations, of differing oscillation frequency and/or strength.
2. Stimulation of mechanosensitive channel proteins in cells, or vibration of magnetic nanoparticles embedded in the cell surface membrane or free-floating in the cytosol.
3. Subsequent movement of ions through channels, or heat production to stimulate heat-sensitive transcription factors.
4. Resultant cell signalling cascades.
5. Each cascade will produce half of a transcription factor dimer, so gene expression will only be affected where both magnetic fields, and thus both cell signalling cascades, are active.

We worked towards this goal in two parts. First, we have attempted to characterise chosen cellular magneto-responsive pathways. Second, we have produced a standard hardware system for spatial targeting magnetogenetics to reduce the barriers to entering research in this area.

We chose E. coli and S. cerevisiae as our model systems since they act as representatives of both prokaryotes and eukaryotes and are standard enough that we could reasonably work with them both over the 3 month period of wet lab time that we had available. With these as a proof of concept, future applications could feasibly use the same parts and achieve similar activation of pathways, moving into more complicated organisms.

Guided by the requirement for localised heating within specific regions of cells, we developed a system for the spatially precise control of magnetic nanoparticles and magnetosensitive proteins called MagentaBox. This hardware provides an all in one system for control and sensing of magnetosensitive colonies and tissues under 35mm diameter. It is fitted with fluorescent imaging, thermal imaging and colour imaging, all connected to a user-friendly interface.

Throughout our design and building process, we maintained a focus on making our hardware accessible, both in terms of cost and user experience. The Magentabox's open source design and cost of only £324.80 ($430.80 USD) allows any interested research team to try it out at low risk. We also trialled MagentaBOX with advisors, researchers and hobbyists, in order to incorporate their feedback into our final design. Furthermore, to accompany our hardware we have written both a build guide and a user guide. We hope that our careful documentation of our development process and hardware success will aid future teams with similar hardware.

Through our work on Integrated Human Practices, we explored applications in various areas of fundamental research and real-world contexts. We carefully considered the feasibility and responsibility of our ideas, using our key values and stakeholder discussions to guide us. Our interviews with academics, doctors and industry professionals left us feeling optimistic about the positive impact which Magenta technology could have on the world.

The most feasible and exciting of our ideas were:

1. Controlling the production and distribution of morphogens in organoid development
2. Enabling the use of CAR T-cell therapy to treat solid tumours
3. Treating the recurrence of glioblastomas from resection borders