tissue engineering

the in vitro outside body development of tissues or organ to replace or support the function of defective/injured body parts

serves as temporary/permanent artificial extracellular matrices (ECM) to accomodate cells and support 3d tissue regenerations

scaffolds are materials engineered to contribute to formation of new functional tissues for medical purposes

EXTRACELLULAR MATRICES- a blend of macromolecules (protein) around cells, a non cellular component present in all connective tissues and has a composition specific for each tissue

a 3d network consisting of extracellular macromolecules and minerals such as collagen, enzyme, glycoproteins and hydroxyapatite to provide structral and biochemical support to surrounding cells

cells from a biopsy

monolayer cell culture

expanded cells

culture on a 3d polymeric scaffold

generation of a graft

-wound healing process
-blood clotting
-accidentally cause clot
-chronic inflammatory responses
-biomaterial is persistent source of irritation- chronic inflammatory tissue

the ability of a material to perform with an appropriate host response in a specific application

-act as a template for tissue growth in 3d

-mechanical properties similar to host tissue

interconnected macroporus network for vascularisation, tissue ingrowth, nutrient delivery

bond to the host tissue without formation of scar tissue

resorb at the same rate as the tissue is repaired

influence the genes in the cells of the tissue to enable efficient cell differentiation and proliferation

be easily and cheaply produced- must be easily sterilised

-mechanical stability
-spatial pore orientation and continuity
-sufficient pore volume tissue expansion
-micropores (10-50microm): cell adhesion, diffusion of oxygen, nutrients, waste clearance
-macropores(100microm) : cell infiltration, invasion of blood vessels, building of tissue layers

SYNTHETIC POLYMERS,

THOSE NATURALLY OCCURING IN THE BODY

SYNTHETIC CALCIUM PHOSPHATE

chitosan, algginate
highly hydrated along with desirable mechanical properties

a non biodegradable strong and biocomptaible scaffold material: carbon nanotubes

collagen, elastin, fibrin

fibrin- a non globular protein that is fibrous and involved in the clotting of blood.

polymerized fibrin together with platelets form haemostatic plug or clot over wound site

a major protein component of tissues that require elasticity such as arteries, lungs, bladder, skin, elastic ligaments, cartilage

calcium phosphate based for bone tissue engineering

used for hard component replicating.

porous structures

posess surface properties that support osteoblast adhesion/proliferation

-saves lives
replace inoperative structure with completely living structure

-improve or replace tissues such as skin muscle bone

-improve or replace organs such as heart kidney liver

-engineering tissues can potentially help a person conquer a disease or illness

-tissue engineering may even be able to cure extreme and mild arthritis?

prolonng life

burn victims- regenerate burnt skin

eliminate waiting lists

long term and cost effective advantages that minimise traditional transplantation complications

scaffolds difficult to construct

lots of research and understanding of each organ and tissue

presence of hidden diseases/illness in base tissue

diseases difficult to spot with current technology

many oppose tissue engineering due to their beliefs- defies natural order