1 / 25

Tissue Engineering & Materials Processing

Tissue Engineering & Materials Processing. Replacements Parts. Features of Soft Tissues. Multi-cellular Three-dimensional structures Multi-functional Takes cues from the environment Blend in with surroundings. Tissue Engineering.

abrahama
Télécharger la présentation

Tissue Engineering & Materials Processing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Tissue Engineering & Materials Processing

  2. Replacements Parts

  3. Features of Soft Tissues • Multi-cellular • Three-dimensional structures • Multi-functional • Takes cues from the environment • Blend in with surroundings

  4. Tissue Engineering Applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function.

  5. Engineered Heart Patches and Blood Vessels

  6. Engineered Skin

  7. Tissue Scaffold Approach:

  8. Scaffold Fabrication Methods

  9. Solvent Casting (I) • Procedure:Polymer is dissolved in a suitable solvent;Poured into a mold and frozen; • Solvent is then removed, leaving the polymer set in the desired shape.Polymer concentration: 10-30% • AdvantagesEase of fabrication, without the need of specialized equipment; Simple; Inexpensive; Room Temperature, no effect on degradation behavior. • LimitationsLimited to simple shapes -can be stacked; Possible retention of toxic solvent within scaffold/ Can be overcome by allowing scaffold fully dry and using vacuum to further remove.Use solvent can denature proteins and other incorporated molecules.

  10. Solvent Casting (II) • Flat Structures • Tubular Conduits

  11. 1-5000 rpm Vacuum Spin casting/coating(A sub-type of solvent casting) • Form Ultrathin films (<5mm). Polymer concentration 5-20%. • Non-stick, smooth surfaces (Glass coverslips; silicon wafers) • Rotation speedAccelerationSpinning timeSolution viscositySolution density Centrifugal forces Thickness of Film

  12. Leaching (I)—Particle Leaching Porogen(>70%): Salt, Sugar, Wax….. Polymer solution Sieved Particles (Porogen) Well mixed solution Pour into Mold Solvent Evaporation Immerse into solvent for particles

  13. Leaching (II)—Ball Leaching (Hexane)

  14. Leaching (III)—Fiber Leaching

  15. Gas Foaming • Route 1: • Foam forming agent: Ammonium Bicarbonate; • Vacuum dry or immerse in water. • Route 2: • High pressure CO2 for long time • Rapid decrease to atmospheric pressure

  16. Emulsification/Freeze-drying (I) • Polymer is dissolved in solvent, nonsolvent is added to form an emulsion, mixed well • Mixture is cast into mold • Quench using liquid nitrogen/low temperature • Freeze-dried (Removal both solvent and non-solvent)

  17. Emulsification/Freeze-drying (II) • Quenching condition (temperature) • Polymer concentration; • Solvent/Non-solvent ratio Liqiud Nitrogen, 1% Polymer(PLGA) 87/13 solvent(Dioxane)/nonsolvent(Water) -15 oC, 1% Polymer(PLGA) 87/13 solvent(Dioxane)/nonsolvent(Water) Liqiud Nitrogen, 10% Polymer(PLGA) 87/13 solvent(Dioxane)/nonsolvent(Water) -15 oC, 10% Polymer(PLGA) 87/13 solvent(Dioxane)/nonsolvent(Water) -40 oC, 10% Polymer(PLGA) 87/13 solvent(Dioxane)/nonsolvent(Water) -15 oC, 10% Polymer(PLGA) 90/10 solvent(Dioxane)/nonsolvent(Water) Liqiud Nitrogen, 10% Polymer(PLGA) 90/10 solvent(Dioxane)/nonsolvent(Water) -40 oC, 10% Polymer(PLGA) 90/10 solvent(Dioxane)/nonsolvent(Water)

  18. Melt Spinning

  19. Polymer Solution Power Supply Fibers Electrospinning

  20. Fiber Bonding (I) • Welding by Melt (High temperature) • Spray using polymer solution: Thin spray and thick spray. (Toxic solvent removal) Before fiber bonding and after fiber bonding

  21. Fiber Bonding (II) Tubular scaffold fabrication by thick spraying fiber bonding

  22. Braid Techniques

  23. 3-D printing: Wafer Stacking System

  24. Scaffold Assembly System (I)

More Related