Massachusetts Institute of Technology Technolog Harvard Medical School Schoo Brigham and Women s Hospital VA Boston Healthcare System 2 79J 3 96J 20 441 HST522J BIOMATERIALS TISSUE INTERACTIONS BIOMATERIALS T l ffor U Tools Understanding d di the h M Molecular l l C Cellular ll l and Physiological Bases of the Tissue Response to Implants p M Spector Spector Ph D BIOMATERIALS TISSUE INTERACTIONS Tissue Biomaterial Cell Matrix Structure comprising cells of the same type Solid surface CELL MATRIX INTERACTIONS In Tissue Tissu Cell Extracellular Matrix In Tissue Engineering Scaffolds Cell Biomaterial Scaffold CONCEPTS FOR UNDERSTANDING BIOMATERIALS TISSUE INTERACTIONS Control Volume Unit Cell Processes Types of Tissues Tissue Tissue Formation and Remodeling In Vitro W Wound dH Healing li In I Vi Vivo Articular Cartilage Extracellular Extracellular Matrix Cell Figures by MIT OpenCourseWare 4 mm 10 m Chondrocytes P2 Canine in a Type I Collagen GAG Scaffold 40min Courtesy Elsevier Inc http www sciencedirect com Used with permission 2 1 3 Control Volume 4 B Kinner 5 Zaleskas J M et al Contractile forces generated by articular chondrocytes in collagen glycosaminoglycan matrices Biomaterials 25 no 7 8 2004 1299 1308 6 UNIT CELL PROCESSES Concept of a Control Volume around a Cell Soluble Regulator A Cell Matrix Cell Matrix Product Soluble Regulator Regulator B Regulator Product Control Volume UNIT CELL PROCESSES Concept of a Control Volume around a Cell Soluble Regulator Autocrine factor Cell Matrix Cell Matrix Product Soluble Regulator Regulator Regulator Product Control Volume Another Cell Circulation Paracrine Endocrine UNIT CELL PROCESSES Concept of a Control Volume around a Cell Soluble Mechanical Regulator Loading Strain Subject 2 785 A Cell Cell Matrix Matrix Product Soluble Regulator Regulator B Regulator Product Control Volume CONCEPTS FOR UNDERSTANDING BIOMATERIALS TISSUE INTERACTIONS Control Volume Unit Cell Processes Types of Tissues Tissue Tissue Formation and Remodeling In Vitro W Wound dH Healing li In I Vi Vivo UNIT CELL PROCESSES Mitosis Migration Synthesis C Contraction i Endocytosis Exocytosis UNIT CELL PROCESSES Mitosis Migration Synthesis C Contraction i Endocytosis Exocytosis UNIT CELL PROCESSES Mitosis Migration Synthesis C Contraction i Endocytosis Exocytosis Apoptosis Differentiation COLLAGEN GAG MATRICES MODEL BIOMATERIALS ANALOGS OF EXTRACELLULAR MATRIX Investigation of cell interactions UCPs in vitro Type I bovine and porcine Type T II porcine i Chondroitin 6 sulfate 1mm Freeze dried Dehydrothermally cross cross linked linked Additional cross linking See IV Yannas et al PNAS 1989 500 m CELL MATRIX INTERACTIONS WITH COLLAGEN GAG MATRICES IN VITRO Can provide insights into interrelationships among cell processes How do mitosis and synthesis interrelate How do mitosis and synthesis relate to contraction How does migration relate to contraction Can provide insights into cell behavior in vivo Can provide insights into scaffold composition and structure for improved p p performance in regenerative medicine Chondrocytes Passage 2 Canine in a Type I Collagen GAG Collagen GAG Matrix Live cell imaging for a period of 5 hours J Cheng CELL MATRIX INTERACTIONS Mitosis Migration S th i Synthesis Contraction Chondrocyte P2 Canine in a Type I Collagen GAG Matrix Mitosis Photo removed due to copyright restrictions J Cheng Effects of Cross Linking on Chondrocyte Proliferation DNA Content in Collagen GAG Matrices 60 Mean SEM DN NA ug g 50 DHT UV GTA EDAC 40 30 20 Inc cross cross linking 10 0 00 10 10 Day 20 20 30 30 CR Lee et al Biomat 2001 22 3145 CELL MATRIX INTERACTIONS Mitosis Migration Synthesis Contraction Fibroblasts Migrate Away from Soft Substrates NIH 3T3 cells are plated on polyacrylamide substrates with a transition in flexibility The soft side is marked with fluorescent beads to the left Cells turn to avoid the soft substrate as they approach the boundary from the stiff side by retracting the leading lamellipodium that crossed the boundary Courtesy of Yu Li Wang Used with permission C M Lo et al Biophys J 79 144 2000 Fibroblasts Migrate Toward Stiff Substrates NIH 3T3 cells are plated on polyacrylamide substrates with a transition in flexibility The soft side is marked with fluorescent beads to the left Cells turn toward and enter the stiff side as they approach the boundary from the soft side by expanding protrusions toward the boundary into a leading lamellipodium Courtesy of Yu Li Wang Used with permission C M Lo et al Biophys J 79 144 2000 Fibroblasts Migrate Toward Stretching Forces NIH 3T3 cells are plated on polyacrylamide substrates Pulling forces are exerted by inserting a blunted needle in the substrate near the trailing end of the cell and dragging the needle away from the cell Cells switch the direction of migration by expanding secondary protrusions toward the needle into a leading lamellipodium Courtesy of Elsevier Inc http www sciencedirect com Used with permission C M Lo et al Biophys J 79 144 2000 Fibroblasts Migrate Away from Compressing Forces NIH 3T3 cells are plated on polyacrylamide substrates Pushing forces are exerted by inserting a blunted needle in the substrate near the leading edge of an approaching cell and moving the needle toward the cell Cells switch the direction of migration by retracting the leading lamellipodium Courtesy of Elsevier Inc http www sciencedirect com Used with permission C M Lo et al Biophys J 79 144 2000 Migration of Epithelial Cells In Vitro in a Wound Healing Assay 100 m 2001 L C Santy and J E Casanova License CC BY NC SA Published by The Rockefeller Published Rockefeller University University Press Press http dx doi org 10 1083 jcb 200104019 Monolayers were wounded by scraping LC Santy J Cell Biol 154 599 2001 Chondrocytes P2 Canine in a Type I CollagenGAG Matrix Migration and Contraction 40min J Zaleskas et al Biomat 25 1299 2004 2 1 3 4 5 B Kinner 6 Courtesy Elsevier Inc http www sciencedirect com Used with permission Diagram removed due to copyright restrictions Fig 2 in Fi i MMad dri i Kid KidneyIInt 41 1992 1992 562 562 Schematic of the modulation of microvascular endothelial cell phenotype during angiogenesis Madri Kidney Int 41 562 1992 CELL MATRIX INTERACTIONS Mitosis Migration Synthesis Contraction nmol h hour hour g DNA Effects of Cross Linking on Chondrocyte Biosynthesis in Collagen GAG Matrices 01 0 15 Protein Synthesis p Proline Incorporation DHT UV GTA EDC 0 1 0 03 0 02 0 05 0 01 0 0 2 7 15 Day 29