Tissue engineering Flashcards
What is tissue engineering?
Repair, regeneration or replacement of damaged or diseased tissues to their original state and function.
Engineered to replace the original tissue.
What is the procedure for tissue engineering?
Making cell cultures using scaffolds:
1. Human stem cells from patients
2. Cell proliferation/differentiation
3. Attachment to scaffold
4. Laying down of extracellular matrix to give a bio-composite
5. Implantation
Why do we use degradable material for scaffolds?
Instead of using existing tissue, we grow our own tissue. This allows for biomaterials scaffolds, growing cells in the scaffold to become tissue, and using cells from the patient to avoid rejection.
Why is lactic acid produced?
During extensive exercise, it hurts because it is an acid.
What are athymic mice?
Mice missing thymus or majority of immune system, hence when cells are put in there is minimum rejection.
What are polylactic and polyglycolic acid?
Esters which can degrade in water. The degradation products are glycolic acid and lactic acid respectively, both occurring naturally in the body.
Polyglycolide is widely used for degradable sutures.
What is degradation by hydrolysis?
Water penetrates in the material and starts breaking bonds.
What is the Vacanti mouse?
A nude mouse with an ear on its back.
What are the sources of cells used in tissue engineering?
- Mature [non-stem] cells from patient (nullipotent)
- Adult stem cells from patient: bone marrow/marrow stroma - Mesenchymal stem cells (multipotent)
- Umbilical cord blood stem cells (hematopoietic stem cells) (multipotent)
- Embryonic stem (ES) cells (pluripotent)
- Induced pluripotent stem cells.
What are the advantages and disadvantages of adult cells?
Advantages: Often easily obtained from patient, no need for immuno-suppression.
Disadvantages: Poor growth, difficult to get enough cells, tendency to turn into different, unwanted cell types.
