Tissue Engineering

1. Tissue Engineering

2. Tissue Engineering • “Application of principles and methods of engineering and life sciences toward fundamental understanding of structure-function relationships in normal and pathological mammalian tissues and the development of biological substitutes to restore, maintain or improve tissue conditions.”

3. Tissue Engineering • In 2007, US Federal R&D agencies have suggested an updated term and definition • Tissue Science and Engineering: the use of physical, chemical, biological and engineering processes to control and direct the aggregate behavior of cells

4. Tissue Engineering • Started in the late 1980s (approved in 1987) • Draft definition by Allan Zelman: “The term ‘tissue engineering’ indicates a new inter-disciplinary initiative which has the goal of growing tissues or organs directly from a single cell taken from an individual.”

5. Tissue Enggineering • Specific list of goals according to Eugene Bell: • 1) providing cellular prostheses or replacement parts for the human body; • 2) providing formed acellular replacement parts capable of inducing regeneration; • 3) providing tissue or organ-like model systems populated with cells for basic research and for many applied uses such as the study of disease states using aberrant cells; • 4) providing vehicles for delivering engineered cells to the organism; and • 5) surfacing non-biological devices.

6. Tissue Engineering • Research fields/subfields • Cell and developmental biology • Cell differentiation, morphogenesis and tissue assembly • Cell-cell and cell-matrix interactions • Growth factors • Cell isolation and selection • Cell culture • Angiogenesis • Stem cells

7. Tissue Engineering • Research fields/subfields • Basic medical and veterinary sciences • anatomy • cytology • physiology and pathophysiology • Transplantation science • Applied immunology – immunosuppression, immunomodulation and immunoisolation • Organ preservation

8. Tissue Engineering • Research fields/subfields • Biomaterials • Natural and synthetic, biodegradable and non-biodegradable polymers • Polymer chemistry • Ceramics • Cell interactions with biomaterials • Controlled release of bioactive molecules • Microencapsulation • Microfabrication techniques

9. Tissue Engineering • Research fields/subfields • Biomaterials (continued) • 3D fabrication techniques • Surface Chemistry • Biophysics and biomechanics • Molecular and cell transport • Micro- and macrocirculatory dynamics • Cell and tissue mechanics

10. Tissue Engineering • Research fields/subfields • Biomedical engineering • Bioreactors • Membranes and filtration • Musculoskeletal joint engineering • Biomedical sensors • Biomedical signal processing, feedback and control • Electrical and mechanical engineering of biohybrid systems • Engineering design and systems analysis • Quantitative tissue characterization • Biosensors and biolectronics

11. Tissue Engineering • Examples • Vascular grafts • Skin grafts • Kidney • Pancreas/Islet cells • Liver • Bone/Cartilage • Either laboratory-based or over-the-counter

12. Tissue Engineering • Drawbacks • Cost • Specificity • Ethical issues • Animal use • Component synthesis (e.g. cells)

13. Regenerative Medicine

14. Regenerative Medicine • Greatly similar to tissue engineering • Overlapping field • “…encompasses some of the knowledge and practice of tissue engineering but also includes ‘self-healing through endogenous recruitment or exogenous delivery of appropriate cells, biomolecules, and supporting stuctures.”

15. Xenotransplantation

16. Xenotransplantation • The transfer of an organ/tissue from one species to another • Humans using organs derived from animals • Low success rate • Excellent source of information for new therapies

17. Xenotransplantation • Drawbacks • Incompatibility • Issues regarding animal use • Cost • Ethics • Risks • Introduction of bacteria and viruses *HIV originated from monkeys