2. 79J/3.96J/BEH 441J/HST522J Biomaterials-Tissue Interactions CONTENTS Introduction Chapter 1. Irreversible Healing of Extracellular Matrix Chapter 2. Cell-Matrix Interactions Chapter 3. Synthesis of Tissues and Organs TEXT: I.V. Yannas. Tissue and Organ regeneration in Adults. New York: Springer, 2001
2.79J/3.96J/BEH.441J/HST522J Biomaterials-Tissue Interactions CONTENTS Introduction. Chapter 1. Irreversible Healing of Extracellular Matrix. Chapter 2. Cell-Matrix Interactions. Chapter 3. Synthesis of Tissues and Organs. TEXT: I. V. Yannas. Tissue and Organ Regeneration in Adults. New York: Springer, 2001. 1
Introduction How are biomaterials used? Brief survey from organs to cells
Introduction. How are biomaterials used? Brief survey: from organs to cells. 2
How are biomaterials used? Today's brief survey: from organ to cell outline of survey 1. Five Therapies for the Missing Organ Examples of permanent implants Examples of regenerated organs 2. Tissue and organ regeneration viewed asas processes of chemical synthesis 3. What is the mechanism of organ regeneration? 4. Cell-matrix interactions 5. The unit cell process
How are biomaterials used? Today’s brief survey: from organ to cell outline of survey 1. Five Therapies for the Missing Organ Examples of permanent implants Examples of regenerated organs 2. Tissue and organ regeneration viewed as as processes of chemical synthesis. 3. What is the mechanism of organ regeneration? 4. Cell-matrix interactions. 5. The unit cell process. 3
Five Therapies for the Missing organ 1. Transplantation( e.g., kidney transplant, heart transplant, liver transplant) 2. Autografting(e. g, heart bypass, skin grafting) 3. Permanent implants(e. g, hip prosthesis, pacemaker, breast implant) 4. In vitro synthesis(e.g, epidermis) 5. In vivo synthesis or regeneration(e.g, skin, nerves, conjunctiva). Remarks: Biomaterials are used in therapies #3, 4 and 5. tissue engineering includes therapies #4 and 5
Five Therapies for the Missing Organ 1. Transplantation (e.g., kidney transplant, heart transplant, liver transplant) 2. Autografting (e.g., heart bypass, skin grafting). 3. Permanent implants (e.g., hip prosthesis, pacemaker, breast implant) 4. In vitro synthesis (e.g., epidermis) 5. In vivo synthesis or regeneration (e.g., skin, nerves, conjunctiva). Remarks: Biomaterials are used in therapies #3, 4 and 5. Tissue engineering includes therapies #4 and 5. 4
Therapy #3: Example of permanent implant Pelvis Socket or cup Cement Stem Detail Femur Another example of permanent implant Abiocor M Implantable Replacement Heart (http://www.abiocor.com
Therapy # 3 : Example of permanent implant Another example of permanent implant AbioCor™ Implantable Replacement Heart (http://www.abiocor.com) 5
Two cases of massively burnt patients 1. Six-year-old boy burned massively was treated in upper abdomen with own skin(meshed autograft and in lower abdomen with template. 2. Middle-aged man burned in industrial fire, lost skin in right side of face was treated with template
Two cases of massively burnt patients 1. Six-year-old boy burned massively was treated in upper abdomen with own skin (meshed autograft) and in lower abdomen with template. 2. Middle-aged man burned in industrial fire, lost skin in right side of face was treated with template. 6
Example of poor nerve regeneration undegraded template inside nerve chamber Image removed due to copyright considerations Example of good nerve regeneration template inside nerve chamber degraded optimally Image removed due to copyright considerations
Example of poor nerve regeneration undegraded template inside nerve chamber Image removed due to copyright considerations. Image removed due to copyright considerations. Example of good nerve regeneration template inside nerve chamber degraded optimally Image removed due to copyright considerations. Image removed due to copyright considerations. 7
2. Tissue and Organ Regeneration viewed asas processes of chemical synthesis Ammonia synthesis(F Haber) T P 3H2+ 2 →2NH 3 Reactants→ Products NOTE: stoichiometry of chemical equation expresses conservation of mass( Lavoisier)
Ammonia synthesis (F. Haber) 3H 2 + N 2 2NH 3 reactor reactants products NOTE: stoichiometry of chemical equation expresses conservation of mass (Lavoisier) T, P Reactants → Products 2. Tissue and Organ Regeneration viewed as as processes of chemical synthesis. 8
Apply chemical symbolism and terminology to organ regeneration EXample of"reaction diagram" Kc+DRT→ EBM.RR.D Reactants: cells, regulators, matrices Reactors: in vitro cell culture; in vivo(anatomical site) Products: either scar or regenerated tissue(or intermediate cases)
Apply chemical symbolism and terminology to organ regeneration • Example of “reaction diagram”: KC + DRT → E•BM•RR•D • Reactants: cells, regulators, matrices • Reactors: in vitro cell culture; in vivo (anatomical site) • Products: either scar or regenerated tissue (or intermediate cases) 9
3. What is the mechanism of organ regeneration? 1. Data: There is an antagonistic relation between contraction of a wounded site and regeneration at that site 2. Theory of induced regeneration: Blocking of contraction process leads to regeneration. 3. Contraction is mediated by cell-matrix interactions. Templates block these interactions 10
3. What is the mechanism of organ regeneration? 1. Data: There is an antagonistic relation between contraction of a wounded site and regeneration at that site. 2. Theory of induced regeneration: Blocking of contraction process leads to regeneration. 3. Contraction is mediated by cell-matrix interactions. Templates block these interactions. 10