Lecture-12SS - Host Reactions to Biomaterials Slide Set 12...

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Unformatted text preview: Host Reactions to Biomaterials Slide Set 12 Slide Dr. Anthony Brennan University of Florida Tel: 352.392.6281 Email: [email protected] EMA 6580 Science of Biomaterials University of Florida Copyright Protected EMA 1 Lecture Slide Set 12 – Host Reactions to Biomaterials and Their Evaluation to • Learning Objectives 12: – Generally there are three levels of Generally interaction, i.e., systemic, local and device “associated” complications “associated” – Inflammation is an immune system Inflammation response to a foreign body and localized tissue changes associated with implantation/contact with biomaterial implantation/contact – The immune system responds both The innately and adaptively to foreign body innately EMA 6580 Science of Biomaterials University of Florida Copyright Protected 2 Section 1 – Lecture Slide Set 12 HOST REACTIONS HOST EMA 6580 Science of Biomaterials University of Florida Copyright Protected 3 The Inflammatory Response – Koch’s/Mitchell’s Postulates Koch’s/ • Infectious (antigen specific) agent Infectious (antigen recoverable from pathologic lesion of human host human • Agent (transplanted from exp host) Agent induces pathologic lesion in second host host • Agent (cells) recoverable from the Agent (cells) pathologic lesion of animal pathologic EMA 6580 Science of Biomaterials University of Florida Copyright Protected 4 Biomaterial-Tissue Interactions Biomaterial-Tissue Chemical Mechanical Physical Electrical Thermal Isolation EMA 6580 Science of Biomaterials University of Florida Copyright Protected 5 Bioresponses to Materials Bioresponses • Outcomes – Systemic Effects – Thromboembolic Thromboembolic Complications Complications – Turmogenesis – Infection • Initial – Injury at implantation Injury site site – Blood-material Blood-material reactions reactions – Inflammation • Acute • Chronic – Granulation tissue – Immune Response • Foreign body Foreign responses (macronuclear giant cells) cells) – Fibrosis/Encapsulation EMA 6580 Science of Biomaterials University of Florida Copyright Protected 6 Bio-inflammation Components Bio-inflammation • Blood cells – Erythrocytes – Neutrophils (PMNs, Neutrophils Polymorphonuclear leukocytes) leukocytes) – Monocytes – Eosinophils – Lymphocytes – Plasma cells – Basophils – Platelets • Connective tissue Connective cells cells – – – Mast cells Fibroblasts Lymphocytes • Extracellular – – – – – Collagen Elastin Proteoglycan Fibronectin Laminin EMA 6580 Science of Biomaterials University of Florida Copyright Protected 7 Kinetics of Bioresponse Kinetics Neovascularization Foreign Body Giant Cells Fibroblas Fibrosis EMA 6580 Science of Biomaterials University of Florida Copyright Protected 8 Cell Derived Mediators Cell Mediators Vascoactive Agents Examples Histamines, serotonin, Endothelial Derived Relaxing Factor, etc Plasma Proteases Kinin System Bradykinin Complement System C3a, C5a, C3b, C5b-C9 Coagulation/Fibrinolytic system Fibrin Leukotrienes LTB4 Lysosomal proteases Collagenase, elastase Oxygen derived free radicals Peroxide, superoxides Platelet Activating factors Cell membrane lipids Cytokines Interleukin 1, tumor necrosis factor Growth Factors Platelet derived, fibroblast, transforming and epithelial growth factors EMA 6580 Science of Biomaterials University of Florida Copyright Protected 9 Section 2– Lecture Slide Set 12 INFLAMMATORY RESPONSE INFLAMMATORY EMA 6580 Science of Biomaterials University of Florida Copyright Protected 10 Injury Driven Inflammation Th2, IL-4, IL-13 EMA 6580 Science of Biomaterials University of Florida Copyright Protected EMA 11 Graft Infection Correlates with Neointimal Hyperplasia Neointimal EMA 6580 Science of Biomaterials University of Florida Copyright Protected 12 Neointimal Hyperplasia – Luminal narrowing –ePTFE grafts narrowing EMA 6580 Science of Biomaterials University of Florida Copyright Protected 13 Granulation – mechanism for tissuegenesis tissuegenesis EMA 6580 Science of Biomaterials University of Florida Copyright Protected 14 Transverse section of graft – 4mos post implantation 4mos EMA 6580 Science of Biomaterials University of Florida Copyright Protected 15 Summary Summary • Tissue-material interactions involve Tissue-material cellular mechanisms that induce changes in both tissue and materials changes • Complications associated with Complications biomaterial implants extend to infections and other clinical challenges. challenges. • Infections demonstrated to correlate Infections with neointimal hyperplasia of grafts. with EMA 6580 Science of Biomaterials University of Florida Copyright Protected 16 Additional References • • • References on Web including: http://www.ncbi.nlm.nih.gov/books/bv.fcgi? Papers 31, 32 and 33 on site EMA 6580 Science of Biomaterials University of Florida Copyright Protected EMA 17 ...
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This note was uploaded on 07/25/2011 for the course EMA 6580 taught by Professor Staff during the Spring '08 term at University of Florida.

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