Tissue Engineering By: Cassie Kuchta & Tim Rohman

 There are approximately 500,000 surgical procedures performed every year in the U.S. which require bone substitutes.  Currently available bone substitutes, including autografts, allografts, and synthetic materials, are the most implanted materials second only to transfused blood products. Rapid Fabrication of Engineered Bone

Autograft A graft, or portion of living tissue, taken from one part of the body and placed in another site on the same individual. A graft, or portion of living tissue, taken from one part of the body and placed in another site on the same individual.

Allograft Grafts between two or more individuals allogenic (genetically different although belonging to or obtained from the same species) at one or more loci. Grafts between two or more individuals allogenic (genetically different although belonging to or obtained from the same species) at one or more loci.

A bone graft is a piece of bone transplanted to another part of the skeleton where it is needed to improve function or strengthen the structure of the area. A bone graft is a piece of bone transplanted to another part of the skeleton where it is needed to improve function or strengthen the structure of the area. Sometimes a bone graft is taken from a cadaver, but usually it is harvested from the patient for which it will be used. Sometimes a bone graft is taken from a cadaver, but usually it is harvested from the patient for which it will be used. Bone grafts are typically harvested from the patient's iliac crest (top of the hip bone), ribs, or fibula in the lower leg. Bone grafts are typically harvested from the patient's iliac crest (top of the hip bone), ribs, or fibula in the lower leg. This can be quite painful and the complication rate can be high. Approximately 40% of spine fusion patients complain of pain at the harvest site for as long as five years after surgery. This can be quite painful and the complication rate can be high. Approximately 40% of spine fusion patients complain of pain at the harvest site for as long as five years after surgery.

 when people with liver failure can be cured with implanted "neo-organs" made of liver cells and plastic fibers  when insulin-dependent diabetics will not have to take frequent insulin injections because they have semi-synthetic replacement pancreases  when kidney dialysis machines are obsolete because anyone with damaged kidneys can be outfitted with new ones grown from their very own cells. Sound like science fiction? Imagine a day… …this day might not be as far away as you think…..

What is tissue engineering?  a multidisciplinary/interdisciplinary field that applies the principles of biology and engineering to develop tissue substitutes to restore, maintain, or improve the function of diseased or damaged human tissues.  one of the goals of tissue engineering is to develop methods to construct organs in the laboratory that can subsequently be used in medical applications.

(1) start building material (e.g., extracellular matrix, biodegradable polymer), (2) shape it as needed (3) seed it with living cells (4) bathe it with growth factors (5) cells multiply & fill up the scaffold & grow into three-dimensional tissue (6) implanted in the body (7) cells recreate their intended tissue functions (8) blood vessels attach themselves to the new tissue (9) the scaffold dissolves (10) the newly grown tissue eventually blends in with its surroundings Process for Tissue Engineering

Tissue engineers use two methods to engineer tissues: First scenario:  tissue engineer injects or places a given molecule, such as a growth factor, into a wound or an organ that requires regeneration  these molecules cause the patient's own cells to migrate into the wound site  after migration the cells turn into the right type of cell and regenerate the tissue

Second scenario:  more ambitious procedure  patient receives cells - either his or her own or those of a donor - that have been harvested previously and incorporated into three-dimensional scaffolds of biodegradable polymers, such as those used to make dissolvable sutures  the entire structure of cells and scaffolding is transplanted into the wound site  the cells replicate, reorganize and form new tissue  at the same time, the artificial polymers break down, leaving only a completely natural final product in the body - a neo- organ  the creation of neo-organs applies the basic knowledge gained in biology over the past few decades to the problems of tissue and organ reconstruction, just as advances in materials science make possible entirely new types of architectural design

Why We Need Tissue Engineering fewer livers available for transplant than there are patients waiting for new livers fewer livers available for transplant than there are patients waiting for new livers a strategy for construction of the organ must be developed a strategy for construction of the organ must be developed tissue engineering holds the promise of producing better organs for transplant tissue engineering holds the promise of producing better organs for transplant using tissue engineering techniques and gene therapy it may be possible to correct many otherwise incurable genetic defects using tissue engineering techniques and gene therapy it may be possible to correct many otherwise incurable genetic defects

 artificial tissues can revolutionize health care by providing a supply of soft and hard connective tissues on demand  Other applications include replacement of lost skin; replacement or repair of defective or damaged bones, cartilage, connective tissue, or intervertebral discs; replacement of worn and poorly functioning tissues (i.e. aged muscles or corneas); replacement of damaged blood vessels; and restoration of cells that produce critical enzymes, hormones, and other metabolites.

Benefits  reduced costs w/ use of less expensive treatments  dramatic improvements in treatment outcomes  improved quality of life for patients

Works Cited