Stacey LeStacey Le

Annie Huynh Annie Huynh

What is it?What is it?

Applies the principles of engineering and Applies the principles of engineering and life sciences toward the development of life sciences toward the development of biological substitutes that restore, maintain biological substitutes that restore, maintain or improve tissue or organ function.or improve tissue or organ function. [1]

Tissue engineering involves creating Tissue engineering involves creating medical devices that, once implanted, will medical devices that, once implanted, will replace or enhance tissue function that replace or enhance tissue function that has been impaired by disease, injury, or has been impaired by disease, injury, or age. age. [2][2]

How is it done?How is it done? The cells are harvested from a patient or donor The cells are harvested from a patient or donor

[2][2]

A scaffold is used as a temporary matrix for the A scaffold is used as a temporary matrix for the cells to attach to.cells to attach to.

Scaffolds are often made of polymers Scaffolds are often made of polymers designed to degrade slowly and safely in designed to degrade slowly and safely in the body, disappearing as the cells make the body, disappearing as the cells make their renovationstheir renovations

One common scaffold is primarily One common scaffold is primarily composed of collagen gel, which is an composed of collagen gel, which is an abundant, tough, fibrous protein that is abundant, tough, fibrous protein that is found in the extracellular matrix of virtually found in the extracellular matrix of virtually all animals. all animals. [3][3]

The cells divide and migrate along the scaffold, The cells divide and migrate along the scaffold, proliferate, synthesize extracellular matrix, & proliferate, synthesize extracellular matrix, & differentiate to form functional tissue. differentiate to form functional tissue.

Design process can involve mechanical Design process can involve mechanical engineering, molecular biology, physiology, engineering, molecular biology, physiology, medicine, polymer chemistry, and medicine, polymer chemistry, and nanotechnology nanotechnology [2][2]

Applications Applications Skin Grafting & Cultured EpidermisSkin Grafting & Cultured Epidermis Treating human hair lossTreating human hair loss Treating liver, bone, blood vessels, Treating liver, bone, blood vessels,

nerves, and pancreas damage. nerves, and pancreas damage. [2][2]

Regenerating cartilage in a culture Regenerating cartilage in a culture dish.dish.

Transplanting cultured corneal Transplanting cultured corneal epithelium. epithelium. [4][4]

Reconstruction in the oral cavity. Reconstruction in the oral cavity. [5][5]

Cultured Epidermis

Corneal Epithelium

Skin GraftingSkin Grafting used to permanently replace damaged or missing skin or to provide used to permanently replace damaged or missing skin or to provide

a temporary wound coveringa temporary wound covering Importance: skin protects the body from fluid loss, aids in Importance: skin protects the body from fluid loss, aids in

temperature regulation, and helps prevent disease-causing temperature regulation, and helps prevent disease-causing bacteria or viruses from entering the bodybacteria or viruses from entering the body

Sometimes done as part of elective plastic surgery procedure, but Sometimes done as part of elective plastic surgery procedure, but its most extensive use is in the treatment of burns (3its most extensive use is in the treatment of burns (3rdrd degree) degree)

Wounds that are left to heal on their own can counteract bacteriaWounds that are left to heal on their own can counteract bacteria Prevents infection or loss of fluid Prevents infection or loss of fluid

3 types:3 types:· Autografts, patches of healthy skin taken from another location on · Autografts, patches of healthy skin taken from another location on a person’s body; a person’s body; · Allografts, skin from other human sources or skin substitutes; and· Allografts, skin from other human sources or skin substitutes; and· Xenografts, grafts made from the skin of other animal species, · Xenografts, grafts made from the skin of other animal species, often pigs. often pigs. [7][7]

Skin Grafting ProcedureSkin Grafting Procedure The wound will be measured and cleanedThe wound will be measured and cleaned A pattern of the wound will be traced and then outlined over the donor A pattern of the wound will be traced and then outlined over the donor

sitesite The donor tissue will then be removed with a scalpelThe donor tissue will then be removed with a scalpel The graft will then be placed on the damaged site; it will be fastened The graft will then be placed on the damaged site; it will be fastened

with stitches or stapleswith stitches or staples A pressure bandage will be applied over the area. A wound VAC may A pressure bandage will be applied over the area. A wound VAC may

be placed for the first 3-5 days. be placed for the first 3-5 days. This is a device that has a suction and is used to control drainage This is a device that has a suction and is used to control drainage Initially, the graft will survive on oxygen and nutrients from the Initially, the graft will survive on oxygen and nutrients from the

underlying tissue.underlying tissue. Within 36 hours, new blood vessels begin to growWithin 36 hours, new blood vessels begin to grow New cells will then grow from the graft to cover the damaged area New cells will then grow from the graft to cover the damaged area

with new skin with new skin [6][6]

Skin GraftingSkin Grafting[7][7]

Treating Human Hair LossTreating Human Hair Loss The mechanism where a single hair follicle could The mechanism where a single hair follicle could

be turned into hundreds or thousands of hair be turned into hundreds or thousands of hair follicles.follicles.

Still under research for safety, effectiveness, Still under research for safety, effectiveness, and naturalness. and naturalness.

Process:Process: Cells are isolated from an organism and grown in the Cells are isolated from an organism and grown in the

laboratory by keeping the cells bathed in a culture laboratory by keeping the cells bathed in a culture medium and controlling the amount of oxygen and medium and controlling the amount of oxygen and other gases around the cells.other gases around the cells.

Placed back into balding scalp. Placed back into balding scalp. Benefits those suffering from hair loss due to Benefits those suffering from hair loss due to

illnesses or diseases such as Alopecia. illnesses or diseases such as Alopecia. [8][8]

picturespictures [9][9]

Regenerating CartilageRegenerating Cartilage

Cartilage tissue does not naturally recover once Cartilage tissue does not naturally recover once damaged, making it hard to treat with drugs or damaged, making it hard to treat with drugs or other therapiesother therapies.

Process: An orthopedic surgeon extracts a small

amount of cartilage from the area. It is cultured after being mixed with

atelocollagen gel.• Culture period: (4 weeks) the cartilage cells

proliferate and begins to look like the original. [4][4]

Regenerating CartilageRegenerating Cartilage[4][4]

Ethical ConcernsEthical Concerns There are ethical concerns about There are ethical concerns about

xenotransplantation which is the xenotransplantation which is the transplantation of living cells, tissues or transplantation of living cells, tissues or organs from one species to another; the use of organs from one species to another; the use of animals for tissue or organ generation is a animals for tissue or organ generation is a delicate issue for animal activistsdelicate issue for animal activists

the cells that are used such as the allogeneic the cells that are used such as the allogeneic stem cells that give rise to connective tissue stem cells that give rise to connective tissue such as blood causes controversy such as blood causes controversy

Allogeneic stem cells are developed from Allogeneic stem cells are developed from embryonic tissueembryonic tissue

• People tend to have different views on People tend to have different views on whether it right to harvest cells from whether it right to harvest cells from embryonic sources embryonic sources

Debate on whether there is life at Debate on whether there is life at conceptionconception [10][10]

Practices in other countries Practices in other countries NetherlandsNetherlands

Specializes in oral tissue engineeringSpecializes in oral tissue engineering• Developed a gum tissue that can be used Developed a gum tissue that can be used

for reconstruction in the oral cavityfor reconstruction in the oral cavity• Autologous (same patient) full thicknessAutologous (same patient) full thickness

May be used to treat gingivitisMay be used to treat gingivitisand treat damaged gums and and treat damaged gums and oral tissue after removing tumors. oral tissue after removing tumors. [5][5]

Practices in other Countries Practices in other Countries cont.cont.

JapanJapan is currently the leading country in Asia is currently the leading country in Asia

in this area of medical technology, and in this area of medical technology, and indeed could become one of the global indeed could become one of the global leaders in the field.leaders in the field.

Royal Academy of Engineering team Royal Academy of Engineering team observed that the quality of the basic observed that the quality of the basic science underpinning Japan’s tissue science underpinning Japan’s tissue engineering programs is impressive engineering programs is impressive especially in some of the government especially in some of the government owned research institutes.owned research institutes.[[1212]]

ChinaChina has now surpassed Canada and Australia to has now surpassed Canada and Australia to

become the world's fifth most prolific contributor become the world's fifth most prolific contributor to the exploding field that promises repair for to the exploding field that promises repair for ailing organs and tissues.ailing organs and tissues.

Blood vessels, bones, cartilage and muscle are Blood vessels, bones, cartilage and muscle are being engineered in Chinese labs – a report being engineered in Chinese labs – a report notes that one top scientist at Shanghai Tissue notes that one top scientist at Shanghai Tissue Engineering Centre created a "famed mouse" Engineering Centre created a "famed mouse" with cartilage in the shape of a human ear on its with cartilage in the shape of a human ear on its back. back. [13][13]

Reasons for advancements:Reasons for advancements: Regulations were not very strict or enforced Regulations were not very strict or enforced

[Using discarded fetal cells] [Using discarded fetal cells] Has been criticized for allowing unproven Has been criticized for allowing unproven

injections of fetal or embryonic cells that injections of fetal or embryonic cells that clinics promote as treatments for diseases.clinics promote as treatments for diseases.

Funding has gone from $5.9(1996) to $44 Funding has gone from $5.9(1996) to $44 billion. billion. [[11]11]

Video!

link

[14]

Citations1. http://cseserv.engr.scu.edu/NQuinn/ENGR300Winter2001/ResearchProje

cts/CSu/tissueengineering.htm

2. http://www.wisegeek.com/contest/what-is-tissue-engineering.htm3. http://www.ptei.org/interior.php?pageID=84 4. http://www.jpte.co.jp/english/technologies/index.html 5. http://www.medicalnewstoday.com/articles/137853.php 6. http://www.surgeryencyclopedia.com/Pa-St/Skin-Grafting.html7. http://www.aurorahealthcare.org/yourhealth/healthgate/getcontent.asp?U

RLhealthgate=%2214862.html%22

8. http://www.ishrs.org/articles/hair-follicle-cloning.htm9. http://www.aderansresearch.com/ari_ourvision.html 10. http://jasn.asnjournals.org/cgi/content/full/15/5/113311. http://www.genengnews.com/news/bnitem.aspx?name

=72406702&chid=1&taxid=12 12. http://www.innovations-report.de/html/berichte/medizin_gesundheit/berich

t-19474.html13. http://www.nationalpost.com/news/story.html?id=241686014. http://dsc.discovery.com/