Educational content about tissue enginering

1. Tissue Engineering
P.Samuel, Ph.D
Assistant Professor of Biotechnology,
ANJA College, Sivakasi

2. What is Tissue engineering?
• Tissue engineering is the use of a combination
of cells, engineering and materials methods, and
suitable biochemical and physicochemical factors to
improve or replace biological tissues.
• The term regenerative medicine is often used
synonymously with tissue engineering, although
those involved in regenerative medicine place more
emphasis on the use of stem cells or progenitor
cells to produce tissues.
• Langer and Vacanti were the first to state the
definition for tissue engineering.

3. Steps in regenerative medicine

4. • According to Langer and Vacanti, tissue engineering
can be defined as this is an interdisciplinary field
based on the principles of engineering and life
sciences to produce biological substitutes to restore
the function of damaged organ.
• Scientific advances in biomaterials, stem
cells, growth and differentiation factors,
and biomimetic environments have created unique
opportunities to fabricate tissues in the laboratory
from combinations of engineered extracellular
matrices ("scaffolds"), cells, and biologically active
molecules.

5. Cells are the building blocks
• Tissue engineering uses living cells as
engineering materials.
• Ex: living fibroblasts in skin replacement or
repair and cartilage repaired with
living chondrocytes.
• While scientist were involved in a project on
extending telomeres (1998) discovered
immortalized cell lines.

6. Extraction of Cells
Blood is the source of cells
usually centrifugation or apheresis.
In the case when cells are extracted From solid tissues
tissue is minced, and then digested with
the enzymes trypsin or collagenase to remove
the extracellular matrix
After that, the cells are free floating, and extracted
using centrifugation or apheresis

7. Types of cells
• Autologous cells: Cells are harvested from the
individual itself. Under some circumstances like
genetic diseases and burns the cells are not
available.
• Recently there has been a trend towards the use
of mesenchymal stem cells from bone
marrow and fat. These cells can differentiate into a
variety of tissue types, including bone, cartilage, fat,
and nerve.

8. • Allogeneic cells come from the body of a
donor of the same species.
• Xenogenic cells are these isolated from
individuals of another species particularly
animal cells are use for construction of cardio
vascular implants.
• Syngenic or isogenic cells are isolated from
genetically identical organisms, such as twins,
clones, or highly inbred research animal
models.
• Primary cells are from an organism.
• Secondary cells are from a cell bank.

9. Scaffold
• Scaffold is a support that allow
the seeded cells to interact and
establish in to a new organ. It
functions like ECM. The scaffold
material should be
Biocompatible and
Biodegradable.
• Materials: Collagen, Polyester,
Polyglycolic acid and
Polycaprolactone.
Carbon nanotubes as
scaffolds

11. Synthesis of scaffold
• Nanofibre self assembly
• Textile technologies
• Solvent casting and
particulate leaching
• Gas foaming
• Emulsification – freeze
drying
• Thermally induced phase
separation
• Electrospinning

12. Bioreactor for tissue engineering
• The Bioreactors used for 3D cell
cultures are small plastic cylindrical
chambers.
• The bioreactor
uses bioactive synthetic materials
such as polyethylene
terephthalate membranes to
surround the spheroid cells. They
are easy to open and close, so that
cell spheroids can be removed for
testing, yet the chamber is able to
maintain 100% humidity throughout.
• MC2 Biotek has developed a
bioreactor known as
ProtoTissue] that uses gas
exchange to maintain high oxygen
levels

13. Applications of Tissue engineering