Massachusetts Institute of Technology VE RII! TAS Harvard medical school Brigham and Womens/Massachusetts General Hosp VA Boston Healthcare System 279J396J/BE441/HST522J BIOMATERIALS FOR JOINT REGENERATION-II M. Spector, Ph D and I.v. Yannas, Ph. D
Massachusetts In Massachusetts Institute of Technology stitute of Technology Harvard Medical School Harvard Medical School Brigham and Wo Brigham and Women’s/Massachusetts General Hosp. men’s/Massachusetts General Hosp. VA Boston Healthcare System VA Boston Healthcare System 2.79J/3.96J/BE.441/HST522J 2.79J/3.96J/BE.441/HST522J BIOMATERIALS FOR JOINT BIOMATERIALS FOR JOINT REGENERATION REGENERATION-II M. Spector, Ph.D. and I.V. Yannas, Ph.D. M. Spector, Ph.D. and I.V. Yannas, Ph.D
TISSUES COMPRISING JOINTS Permanent Regeneration Prosthesis Scaffold Bone Yes Yes Articular cartilage 0 Yes* Meniscus 0 Yes x Ligaments No Yes i Synovium No No s In the process of being developed
TISSUES COMPRISING JOINTS TISSUES COMPRISING JOINTS Permanent Permanent Regeneration Regeneration Prosthesis Prosthesis Scaffold Scaffold Bone Yes Yes Articular cartilage Articular cartilage No Yes* Meniscus Meniscus No Yes* Ligaments Ligaments No Yes* Synovium Synovium No No * In the process of being developed * In the process of being developed
INTRAARTICULAR JOINT TISSUES What are the unique characteristics of the ioint environmen Why dont these tissues heal? How are such diverse functions met by only one structural protein- collagen
INTRAARTICULAR JOINT TISSUES INTRAARTICULAR JOINT TISSUES • What are the unique characteristics of What are the unique characteristics of the joint environment? the joint environment? • Why don’t these tissues heal? Why don’t these tissues heal? • How are such diverse functions met by How are such diverse functions met by only one structural protein only one structural protein - collagen? collagen?
INTRAARTICULAR ENVIRONMENT Synovial fluid High mechanical loads Low vascularity
INTRAARTICULAR INTRAARTICULAR ENVIRONMENT ENVIRONMENT • Synovial fluid Synovial fluid • High mechanical loads High mechanical loads • Low vascularity Low vascularity
JOINT TISSUES Limitations to Healing Absence of a fibrin clot Absent or low vascularity Dissolution of clot in synovial fluid Cell migration restricted by matrix ° Low cell density Low mitotic activit Mechanical loading disrupts reparative tissue
JOINT TISSUES JOINT TISSUES Limitations to Healing Limitations to Healing • Absence of a fibrin clot Absence of a fibrin clot –Absent or low vascularity Absent or low vascularity –Dissolution of clot in synovial Dissolution of clot in synovial fluid • Cell migration restricted by matrix Cell migration restricted by matrix • Low cell density Low cell density • Low mitotic activity Low mitotic activity • Mechanical loading disrupts Mechanical loading disrupts reparative tissue reparative tissue