Tissue Bioreactor by Karen Chen, Rachel Mosher, Dustin Gardner, Richard Bamberg Client: Susan Thibeault Advisor: Brenda Ogle (March 9, 2007)

Outline  Problem Statement  Background  Summary PDS  Design Alternatives and Matrix  Future Work  Conclusion

Problem Statement  Improve Current Design: No contact between vibrating strips Inconsistent distribution of vibration Tecoflex is a porous substrate  “More accurately simulate human vocal folds”  Research: growth of vocal fold fibroblasts

Background – Vocal Folds  2 mucous membranes  Extracellular matrix  Cartilage  Horizontally stretched across larynx  Vibration ranging Hz  Modulate airflow from lungs during phonation

Background – Vocal folds

Background - Bioreactor  Supports/mimics a biological system  Similar to vocal fold environment  Cell culturing/seeded Tecoflex strips  Vibration  Closed system  Fluid provides nutrition

Client Requirements  Concerted bar vibration (0-400Hz frequency)  Contact between strips during vibration  Cartilaginous structures around strips  Easy to sterilize with disposable parts  Tecoflex substrate alternative  Target Cost $5,000

Bioreactor Specifications  Culture vocal fold fibroblasts for research  Research fibroblast reactions to stimuli (vibrations)  Environment monitored by software interface  Manual replacement and sterilization of components  Size: Slightly larger than T-75 flask.  Weight: Function of bioreactor unaffected

Operating Environment and Considerations  Effective simulation of vocal fold environment  Uniform vibrations to cell-seeded strips  Temperature range: Incubator (37°C)  Pressure: Negligible, ΔP = ½ psi  Corrosion: Fluids retained in T-flask only

Bioreactor Lifespan  Long shelf life  Vibration motor (actuator) is life-limiting  T-flask properly sealed and disposable  T-flask disposed after use (several weeks)  Periodic cleaning of mechanical components  Minor sterilization of some components

Project Objectives  Improve previous design for research  Only one prototype will be constructed  Simultaneous use of multiple bioreactors  Research purposes (several dozen nationwide)  Original bioreactor was $15,000  No intent to patent design

Design Alternatives  Double-sided vibration, angled strips  Double-sided vibration, parallel strips  Single-sided vibration, angled strips  Single-sided vibration, parallel strips

Single-Sided Vibration Pros  Easier to fabricate  Less expensive Cons  May not provide even vibratory distribution

Parallel Strips Pros  Strips make contact across entire length  Easier to implement than angled strips Cons  Adjustable angled strips more realistic

Design Matrix Cost Effectiveness (1- 10) Frequency Distribution (1-30) Realistic Imitation of Environment (1-20) Feasibility / Practicality of Design (1-30) Client Contentedness (1- 10) Total (100) Two-sided Vibration V-shape Strips Two-sided Vibration Parallel Strips One-sided Vibration V-shape Strips One-sided Vibration Parallel Strips

Future Work  Order custom parts  Fabricate parts ourselves  Put prototype together  Testing and Analysis

Conclusion  Bioreactor has many complicated components  Research vocal folds and drug therapy  Proper vibratory stimulus essential  Single-sided vibration of parallel strips  Parts need ordering and fabrication

Credits