BME 350 Lecture 4

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BME 350 Lecture 4
2015-02-24 20:48:34
BME 350
BME 350
BME 350
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  1. What is a heart in the simplest terms
    It is a pump that performs mechanical work.
  2. What was the first artificial heart
    First artificial heart (Jarvik-7)
  3. What is the first self contained total artificial heart?
    • AbioCor
    • Powered by a rechargable battery, rather than an external device
  4. What is the Berlin Heart
    • EXCOR Pediatric VAD.
    • Children with congenital heart defects waiting for a heart, they are given this device. This device sits outside of the body. The range of sizes make it appealing for pediatric situations, can keep upgrading sizes as child grows until they receive a transplant.
  5. What does VAD stand for? what are some examples?
    • Ventricular Assist Device
    • HeartMate 2
    • DuraHeart
  6. What are the challenges and limitations of VADs?
    • Durability
    • Host response/biocompatibility
    • External power supply
    • Therefore, these offer temporary solutions as bridge to transplant.
  7. Describe cardiac muscle:
    • Highly organized tissue.
    • Parallel alignment of myocytes.
    • Very sensitive to hypoxia.
    • Highly vascularized.
  8. How to avascular tissues become nourished?
    Passive diffusion
  9. What does the feeder layer do in embryonic stem cell cultures?
    Feeder layers secrete a morphagen
  10. Name a morphagen
    VEGF - vascular endothelial growth factor
  11. What causes cells normally to differentiate?
  12. What is the significance of morphogen gradients?
    • Diffusing patterns of reacting chemical can form steady-state heterogeneous spatial patterns.
    • This phenomenon could be a biological mechanism of pattern formation.
  13. Talk about the development of cells with growth factors.
    • During development groups of inducing cells called organizing centers secrete graded growth factor signals.  The concentration gradient of a morphogen can induce multiple cell differentiation choices.
  14. What is the conclusion relative to growth factors and morphogen gradients?
    • Conclusion; a morphogen  gradient can be generated by a source of growth factor (such as BMP) or by a localized source of inhibitor (such as Chordin).  Both mechanisms are used.
    • This is how organizing centers work in embryonic induction.
  15. What is a way to create morphogen gradients?
    Microfluidics - microchannel network
  16. What is the method of Soft Lithogrophy?

    This is good for rapid prototyping. Have some design concept on a computer that you can use to imprint your design onto a silicone waver. In this case, pour a soft polymer onto this wafer, like silicone. this silicone rubber will capture the geometry and you use it to imprint that geometry into other things.
  17. Describe the process of rapid prototyping:
  18. Name a cheap polymer:
    why is it desirable?
    • PDMS
    • Low cost
    • Easy fabrication
    • Elastomeric/Soft
    • Moldable
    • Surface Chemistry
    • Bonding
    • Biocompatible
  19. Describe the micropatterning approach:
  20. Name an application of microscale technologies:
    Controlling cell shape
  21. Describe a purpose of the 3-channel inlet device
    Set up gradients to look at cells in blood stream response to bacterial loading. Looking at the fluorescence, you can see the phenomena of no convection mixing. see the laminar flow. Over a distance, you could see the simple diffusion.
  22. Diffusible gradients of soluble morphgens may be very important to..
    direct cells to a desired phenotype
  23. what is a critical consideration for any regenerative therapy?
    Diffusion of morphogens and small molecules (e.e.o2) from blood vessels into a tissue
  24. What is a common, recurring, biomedical design problem that you must be able to model and understand?
    Diffusion of drugs from a device into the tissue