Week 1 HW: Final Project Ideas

HTBAA Homework #1: Final Project Idea

1. What would I like to biomanufacture and why?

I would like to biomanufacture a functional 3D model of the human urinary bladder to study neurogenic bladder dysfunction.

The model would reproduce key components of bladder tissue and allow us to study how engineered tissue responds to filling, distension, and stimulation.

I am interested in this because neurogenic bladder can affect people with spina bifida, and managing it can require long-term catheterization. Rather than trying to manufacture a replacement organ immediately, I want to create a controllable experimental system to investigate how bladder function could be improved.

This project is also personally meaningful to me because someone in my family has spina bifida. Seeing their experience has shown me how congenital conditions can create challenges from childhood into adulthood.

The goal is therefore not simply to make tissue that looks like a bladder, but to build a working model that can be tested, measured, and used to investigate bladder function. Tissue engineering has already been explored for urinary bladder reconstruction and functional tissue models, although important challenges remain (Adamowicz et al., 2017; Horst et al., 2013).

2. What living system would I use?

I would use a mammalian cell culture system with human bladder cells.

The initial model would contain:

  • Human urothelial cells, forming the inner bladder barrier.
  • Human bladder smooth muscle cells, responsible for bladder contractions.
  • A 3D biocompatible scaffold or hydrogel to organize the cells into tissue.

The cells would be cultured under controlled conditions that encourage attachment, proliferation, organization, and maturation.

The resulting construct would be a 3D engineered bladder tissue model, not a complete artificial organ.

After maturation, the tissue could be tested through controlled stretching and electrical stimulation while measuring pressure and contractile responses.

A neural component could be added later to study neuromuscular communication more closely. At this stage, I assume that suitable human cells and a biocompatible scaffold are available, but the cell source, cell ratios, scaffold composition, and culture conditions would still need to be optimized experimentally.

Previous studies show that scaffold design and cell environment can strongly affect bladder tissue engineering outcomes (Adamowicz et al., 2017; Sivaraman et al., 2015).

3. How would I use automation?

I would connect the tissue culture system to an automated liquid-handling and bioreactor platform, ideally connected to a Cloud Lab or another programmable laboratory automation system.

Automation could be used for:

  1. Dispensing cells and scaffold materials.
  2. Changing culture media.
  3. Maintaining multiple tissue constructs in parallel.
  4. Applying controlled mechanical stretching and electrical stimulation.
  5. Recording pressure and contractile responses.
  6. Imaging the constructs to monitor tissue shape and health.
  7. Analyzing the results and selecting conditions for the next experiment.

The goal would be to create a repeated experimental cycle:

Build → Culture → Stimulate → Measure → Analyze → Optimize → Repeat

This would allow different tissue compositions, culture conditions, and stimulation settings to be tested systematically while reducing manual work.

4. How much would I need to make, and how long would it take?

Because this is a research model rather than a therapeutic product, I would define meaningful scale as enough constructs to compare several conditions with biological replicates.

First experimental campaign

  • Experimental conditions: 6
  • Biological replicates: 4 per condition
  • Total constructs: 24
  • Initial culture time: ~6 weeks
  • Prototype goal: compare tissue and stimulation conditions

I am not yet specifying an exact cell number or construct volume because these would depend on the final scaffold design and cell source.

The main time constraint would probably be tissue maturation, rather than the automated handling steps. Previous bladder tissue engineering work has used culture periods of several weeks. For example, Gabouev et al. (2003) constructed bladder wall tissue using primary porcine cells and maintained the constructs in a three-dimensional rotating bioreactor for six weeks.

Therefore, I would initially estimate about six weeks of culture for a mature prototype, while recognizing that the actual time would have to be determined experimentally.

Scaling

Once the prototype is reliable, I could increase output by adding identical culture modules.

For example:

1 module → 24 constructs 4 modules → ~96 constructs

This is only a scaling estimate. The larger system would still need to be tested to make sure that tissue quality and function remain consistent when more constructs are cultured simultaneously.

5. What don’t I know yet?

  1. Can we make tissue that functions properly?

The cells need to do more than survive and organize. The tissue should be able to:

  • tolerate controlled stretching,
  • maintain appropriate pressure during filling,
  • contract and relax,
  • and recover between stimulation cycles.

I need to determine which combination of cells, scaffold, and culture conditions produces these properties (Horst et al., 2013).

  1. What stimulation conditions work best?

I need to determine the electrical stimulation strength, frequency, duration, and timing that produce a consistent response without damaging or excessively stressing the tissue.

I also need to determine whether electrical stimulation alone is sufficient or whether a future model will need a neural component.

  1. How should bladder function be measured?

Stronger contractions alone do not necessarily mean better bladder function.

The model should consider both storage and emptying, including:

  • pressure during filling,
  • tissue flexibility,
  • contraction strength,
  • relaxation,
  • recovery between cycles,
  • and overall tissue health.

The combination of measurements that best represents functional bladder performance is still an open question.

AI Use

I used ChatGPT (OpenAI) to help organize and refine my initial project idea and to check that the proposal addressed the homework questions.

The core project idea and initial draft were my own. I used ChatGPT for language refinement, organization, and citation placement.

Prompts included:

  • “Pulir el contenido que acabo de escribir para que responda punto por punto al enunciado, añadir referencias/citas y preparar el bloque Markdown completo listo para copiar y pegar en ese editor.”
  • “Mantener mi nivel de inglés para que no parezca artificialmente académico.”

I reviewed the generated suggestions and adapted the final text to reflect my own project idea and understanding.

References

Adamowicz, J., Pokrywczynska, M., Van Breda, S. V., Kloskowski, T., & Drewa, T. (2017). Concise review: Tissue engineering of urinary bladder; We still have a long way to go? Stem Cells Translational Medicine, 6(11), 2033–2043. https://doi.org/10.1002/sctm.17-0101

Gabouev, A. I., Schultheiss, D., Mertsching, H., Köppe, M., Schlote, N., Wefer, J., Jonas, U., & Stief, C. G. (2003). In vitro construction of urinary bladder wall using porcine primary cells reseeded on acellularized bladder matrix and small intestinal submucosa. International Journal of Artificial Organs, 26(10), 935–942. https://doi.org/10.1177/039139880302601011

Horst, M., Madduri, S., Gobet, R., Sulser, T., Milleret, V., Hall, H., Atala, A., & Eberli, D. (2013). Engineering functional bladder tissues. Journal of Tissue Engineering and Regenerative Medicine, 7(7), 515–522. https://doi.org/10.1002/term.547

Sivaraman, S., Ostendorff, R., Fleishman, B., & Nagatomi, J. (2015). Tetronic®-based composite hydrogel scaffolds seeded with rat-bladder smooth muscle cells for urinary bladder tissue engineering applications. Journal of Biomaterials Science, Polymer Edition, 26(3), 196–210. https://doi.org/10.1080/09205063.2014.989482