Proposal for a Logic-Gated Neuro-Diagnostic Platform
What would I like to biomanufacture and why?
I want to biomanufacture a low-cost, point-of-care microfluidic diagnostic chip pre-loaded with freeze-dried biological sensors (split-reporter proteins). The chip tests a single drop of blood plasma to give a clear readout for chronic neurodegenerative diseases like Alzheimer’s or Parkinson’s.My motivation comes from both my personal life and my career direction: Personal Driver: I have close family members and friends who were diagnosed with Multiple Sclerosis (MS) and Parkinson’s disease. They were fortunate enough to get diagnosed early and start treatment, but it constantly leaves me wondering: What happens when a diagnosis comes too late? Professional Focus: As a 4th-year medical student planning to specialize in neurosurgery, I want to focus my work on clinical problems where getting an early, accurate diagnosis directly changes a patient’s outcome.When patients show early symptoms of neurodegeneration, confirming a diagnosis currently requires an expensive battery of tests—including PET/MRI neuroimaging scans, spinal taps, and costly biomarker panels. These machines cost hundreds of thousands of dollars, making definitive testing rare or non-existent in smaller municipal hospitals and developing regions.Worse, simple blood tests for Tau protein fail because of false positives. If someone gets a concussion or has a stroke, dying brain cells dump huge amounts of normal Tau protein into their blood. A standard test measuring “total Tau” will flag a simple concussion as Alzheimer’s. To solve this, my chip uses a biological AND-gate: the sensor only glows if a protein is both misfolded into a toxic shape AND chemically hyperphosphorylated. This filters out background concussion trauma and catches true chronic neurodegeneration.
2. What living system would I use?
I propose using Escherichia coli (E. coli SHuffle maybe) as the primary manufacturing host, deployed via a Cell-Free Protein Synthesis (CFPS) platform.Instead of putting live bacteria onto a diagnostic cartridge , E. coli acts as an upstream protein factory:
We introduce plasmid DNA into E. coli fused to affinity binders targeting pathological Tau.(very excited for the 2nd lecture to learn more about DNA design)
We harvest the E. coli cells, break open their membranes (cell lysis), and extract their active proteinmaking machinery and pre-folded biosensors.(here comes the 3rd lec)
This active cell-free “biological soup” is printed directly into the microchannels of plastic microfluidic chips and freeze-dried (lyophilized).When a patient’s blood plasma sample flows through the chip, it rehydrates the freeze-dried sensors. If pathological Tau is present, the split-reporter halves snap together on the target protein and glow, which a simple $20 handheld electronic reader box can measure.
Now, why SHuffle E. coli instead of standard E. coli?
This is because we’ll most definitely rely on a binder of some sort and since most protein binders rely on disulfide bonds,so we have to provide a meduim that won’t inhibit them.
knowning that a sandard BL21 E. coli will break these bonds because of its cytoplasmic reducing environment. Thus, another strain should be used , with the help of AI I found a paper about SHuffle E. coli strain that will help.
Literature Rationale:
This cell-free approach is grounded in the readings that were assigned by Karim & Jewett (2021), which highlights how decoupling biological machinery from living cell membranes creates stable, cold-chain-independent biosystems. Using E. coli as a high-yield factory also draws on established industrial biomanufacturing principles described by Zhang et al. (2017)
3. How would I use automation?
To be honest, as an absolute beginner to automation, this part felt a bit foggy for me at first, hopefully, in the upcoming 4th lec I get the grasp of it. However, from what I understand so far, automation can cut through a lot of unnecessary manual work, saving both time and money across two key parts of the project:
Automating Repetitive Lab Work During Prototyping :Before we can print working chips, we have to test tons of different combinations of our biosensors, target proteins, and chemical buffers to find the exact right ratio. Doing all this continuous testing by hand in the wet lab means hours of repetitive manual pipetting, which easily leads to human error and wasted reagents.
On the actual diagnostic device, we need to move the patient’s blood plasma sample through the microscopic channels of the chip. If someone tries to push the fluid manually using a handheld syringe, it is very easy to press too hard or unevenly which can easily over-pressurize and damage the fragile plastic chip or create unwanted turbulent fluid flow that messes up the delicate reaction.
Instead, I would use a tiny automated micro-pump controlled by an Arduino. This automates the fluid flow, ensuring the blood plasma moves through the chip at a smooth, continuous, and steady rate without needing risky manual syringe handling.
4. How much would I need to make, and how long would it take?
Well to be honest, I had no idea on this section where would I get relevant information so I relied on AI. The volume of a each microfluidic chip is said to be 10microL , so in order to screen 2000 patients we will need 20mL of cell-free reaction mixture. I’m not sure how much time it will need since I don’t have much experience,but it shouldn’t take more than a day.
5. What don’t I know yet?
1-Affinity Binder Specificity: Can we find or engineer affinity binders (like nanobodies) that bind specifically to hyperphosphorylated residues and misfolded Tau aggregates without picking up background normal Tau monomers?
2-Shelf-Life & Reconstitution Kinetics: How long can the freeze-dried E. coli lysate sit at room temperature before losing its enzymatic activity when rehydrated with plasma?
3-Signal-to-Noise on Low-Cost Hardware: Is a 10microL sample volume big enough to generate a light signal bright enough for a $20 Arduino photodiode sensor to pick up without needing a $50,000 laboratory plate reader?(probably not)
AI used
agent:gemini
prompts:“would a diagnostic test of tau protein be feasible to make for HTBAA course project” because I was afraid I was shooting too high “wouldn’t the standard BL21 E. coli starin inhibit most protein binders that would be used ? because most binders are disulfide bonds dependent, suggest papers that is related to this problem " “how can I calculate how much tests would I need for a meaningful scale” of course I explain the test for it before