Stacey Le Annie Huynh

1. Tissue engineering Stacey Le Annie Huynh

2. What is it? • Applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve tissue or organ function.[1] • Tissue engineering involves creating medical devices that, once implanted, will replace or enhance tissue function that has been impaired by disease, injury, or age. [2]

3. How is it done? • The cells are harvested from a patient or donor [2] • A scaffold is used as a temporary matrix for the cells to attach to. • Scaffolds are often made of polymers designed to degrade slowly and safely in the body, disappearing as the cells make their renovations • One common scaffold is primarily composed of collagen gel, which is an abundant, tough, fibrous protein that is found in the extracellular matrix of virtually all animals. [3] • The cells divide and migrate along the scaffold, proliferate, synthesize extracellular matrix, & differentiate to form functional tissue. • Design process can involve mechanical engineering, molecular biology, physiology, medicine, polymer chemistry, and nanotechnology [2]

4. Applications • Skin Grafting & Cultured Epidermis • Treating human hair loss • Treating liver, bone, blood vessels, nerves, and pancreas damage. [2] • Regenerating cartilage in a culture dish. • Transplanting cultured corneal epithelium. [4] • Reconstruction in the oral cavity. [5] Cultured Epidermis Corneal Epithelium

5. Skin Grafting • used to permanently replace damaged or missing skin or to provide a temporary wound covering • Importance: skin protects the body from fluid loss, aids in temperature regulation, and helps prevent disease-causing bacteria or viruses from entering the body • Sometimes done as part of elective plastic surgery procedure, but its most extensive use is in the treatment of burns (3rd degree) • Wounds that are left to heal on their own can counteract bacteria • Prevents infection or loss of fluid • 3 types:· Autografts, patches of healthy skin taken from another location on a person’s body; · Allografts, skin from other human sources or skin substitutes; and· Xenografts, grafts made from the skin of other animal species, often pigs. [7]

6. Skin Grafting Procedure • The wound will be measured and cleaned • A pattern of the wound will be traced and then outlined over the donor site • The donor tissue will then be removed with a scalpel • The graft will then be placed on the damaged site; it will be fastened with stitches or staples • A pressure bandage will be applied over the area. A wound VAC may be placed for the first 3-5 days. • 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 underlying tissue. • Within 36 hours, new blood vessels begin to grow • New cells will then grow from the graft to cover the damaged area with new skin [6]

7. Skin Grafting [7]

8. Treating Human Hair Loss • The mechanism where a single hair follicle could be turned into hundreds or thousands of hair follicles. • Still under research for safety, effectiveness, and naturalness. • Process: • Cells are isolated from an organism and grown in the laboratory by keeping the cells bathed in a culture medium and controlling the amount of oxygen and other gases around the cells. • Placed back into balding scalp. • Benefits those suffering from hair loss due to illnesses or diseases such as Alopecia. [8]

9. pictures [9]

10. Regenerating Cartilage • Cartilage tissue does not naturally recover once damaged, making it hard to treat with drugs or other 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]

11. Regenerating Cartilage [4]

12. Ethical Concerns • There are ethical concerns about xenotransplantation which is the transplantation of living cells, tissues or organs from one species to another; the use of animals for tissue or organ generation is a delicate issue for animal activists • the cells that are used such as the allogeneic stem cells that give rise to connective tissue such as blood causes controversy • Allogeneic stem cells are developed from embryonic tissue • People tend to have different views on whether it right to harvest cells from embryonic sources • Debate on whether there is life at conception [10]

13. Practices in other countries Netherlands Specializes in oral tissue engineering Developed a gum tissue that can be used for reconstruction in the oral cavity Autologous (same patient) full thickness May be used to treat gingivitis and treat damaged gums and oral tissue after removing tumors. [5]

14. Practices in other Countries cont. Japan China is currently the leading country in Asia in this area of medical technology, and indeed could become one of the global leaders in the field. Royal Academy of Engineering team observed that the quality of the basic science underpinning Japan’s tissue engineering programs is impressive especially in some of the government owned research institutes.[12] • has now surpassed Canada and Australia to become the world's fifth most prolific contributor to the exploding field that promises repair for ailing organs and tissues. • Blood vessels, bones, cartilage and muscle are being engineered in Chinese labs – a report notes that one top scientist at Shanghai Tissue Engineering Centre created a "famed mouse" with cartilage in the shape of a human ear on its back. [13] • Reasons for advancements: • Regulations were not very strict or enforced [Using discarded fetal cells] • Has been criticized for allowing unproven injections of fetal or embryonic cells that clinics promote as treatments for diseases. • Funding has gone from $5.9(1996) to $44 billion. [11]

15. Video! [14] • link

16. Citations • http://cseserv.engr.scu.edu/NQuinn/ENGR300Winter2001/ResearchProjects/CSu/tissueengineering.htm • http://www.wisegeek.com/contest/what-is-tissue-engineering.htm • http://www.ptei.org/interior.php?pageID=84 • http://www.jpte.co.jp/english/technologies/index.html • http://www.medicalnewstoday.com/articles/137853.php • http://www.surgeryencyclopedia.com/Pa-St/Skin-Grafting.html • http://www.aurorahealthcare.org/yourhealth/healthgate/getcontent.asp?URLhealthgate=%2214862.html%22 • http://www.ishrs.org/articles/hair-follicle-cloning.htm • http://www.aderansresearch.com/ari_ourvision.html • http://jasn.asnjournals.org/cgi/content/full/15/5/1133 • http://www.genengnews.com/news/bnitem.aspx?name=72406702&chid=1&taxid=12 • http://www.innovations-report.de/html/berichte/medizin_gesundheit/bericht-19474.html • http://www.nationalpost.com/news/story.html?id=2416860 • http://dsc.discovery.com/