Cell based biologics Flashcards
What do we mean by cell therapy? Where can we get them from?
The clinical use of cells to replace or repair damaged or defective tissues of the body.
- Cells can be removed from one part of the body and used elsewhere in the body
- Cells can be removed from a donor source
- Cells can be expanded in vitro (ex vivo)
What does ATMP stand for?
What are some examples of them?
advanced therapy medicinal products
- gene therapy medicinal products
- somatic therapy medicinal product
- tissue engineered products
A tissue engineered product means a product that:
- contains or consists of engineered cells or tissues, and
- is presented of having properties for human administration in order to repair or replace a human tissue
- a tissue engineered product may contain cells or tissues from human origin, animal origin, or both.
- Cells may be viable or non-viable. They may also contain additional substances such as cellular products, biomolecules, biomaterials, chemical substances, scaffolds or matrices.
There are three sources for somatic cell therapy. (all cells are living cells). What do these three sources mean?:
- autologous
- allogenic
- xenogenic
- from the patient themselves
- from another human being
- from an animal
What is reconstruction?
The ability to rebuild missing tissues/ organs e.g grafting/ tissue engineering
What is regeneration?
The ability to create an environment to allow the body to rebuild itself e.g. cells, growth factors, supply of templates
Name some soft tissues
Heart Skin Cornea Pancreas Blood vessels Neuronal tissue
Name some hard tissues
Bone
Cartilage
- Stem cells are not themselves _______ differentiated.
- When they divide, each daughter cell has a choice:
- They can divide without _____; they usually express an enzyme ______ that prevents _______ ________. Therefore they do not ______ (stop dividing)
- terminally
- either remain as a stem cell or embark on a course that commits to terminal differentiation
- limit
- telomerase
- telomere shortening
- senesce
The ______ the stem cell potency, the more cell types it can give rise to and the _____ differentiation the cell is considered to be
higher
less
single cell embryo = ________ stem cell
totipotent
5-7 day embryo = _______ stem cells
pluripotent
Adult stem cells = ________ stem cells
multipotent
Early development (embryogenesis) is characterised by the rapid
proliferation of embryonic cells, which then differentiate to form the specialised cells of adult tissues and organs
In general, there are epithelial tissues deriving from all of the embryological germ lines. These are:
- ectoderm (e.g. epidermis)
- endoderm (e.g lining of GI tract)
- mesoderm (e.g inner linings of blood cavities)
Where are some places where adult stem cells are found?
- bone marrow stromal cells (mesenchymal)
- haemotopoietic stem cells
- epidermal skin cells
- gut epithelial stem cells
- neural steam (–> go on to form neurones, astrocytes etc)
READ AND TRY REMEMBER
- Intestinal epithelial stem cells replace the intestinal epithelium every few days.
- They migrate upwards from the crypt of the bowel lining.
- They have limited potency i.e. they are destined to become absorptive epithelial cells, goblet cells or microendocrine cells.
Ethics, Legal and Social issues:
- Current UK legislation allows the use of spare embryos from fertility clinics to be used in stem cell research until _____ after creation
- It is ___ currently permissible to create new embryos purely for research purposes
- Therapeutic cloning (i.e. the fusion of an adult somatic and an egg cell) to create ES cells ____ permissible
- 14 days
- not
- is
Skin epithelial stem cells are_____ stem cells, basally located, slow cycling cells with ____ proliferative potential
unipotent
high
What region of the cornea contains a reservoir of slow cycling, corneal epithelial ‘stem’-cells
Limbal
READ THIS SUMMARY
- Both embryonic and adult stem cells have potential uses for cell therapy and tissue engineering.
- Adult stem cells are difficult to isolate and have limited potency.
- Embryonic stem cells can potentially be differentiated into any cell type, however establishing the growth factor regime required to do that is difficult and there are legal and ethical implications.
- Applications range from the use of cells for tissue regeneration (e.g. skin, corneal, neuronal, hepatic, cardiac etc) to the engineering of whole organs in the laboratory.
