ABSTRACT
More than 15 million people each year suffer from diseases such as osteoarthritis and chondrosarcoma, which damage cartilage and severely affect the quality of their daily life (Martin and Bucklwater, 2002). Cartilage is an avascular, alymphatic, aneural connective tissue present in different parts of the body. Depending on the location, its function and composition varies. Mechanically, cartilage is stiff but not hard as bone. The cartilage lines the bone
CONTENTS
5.1 Introduction .......................................................................................................................... 93 5.2 History of Biological Scaffolds ........................................................................................... 94 5.3 Characteristics of a Scaffold ............................................................................................... 95
5.3.1 3D Porous Structure with Interconnected Pores ................................................. 95 5.3.2 Mechanical Properties Similar to Native Cartilage ............................................ 95 5.3.3 Biocompatible, Bioresorbable, and Biodegradable .............................................. 96 5.3.4 Surface Properties of the Scaffold ......................................................................... 96
5.4 Polymeric Scaffolds for Cartilage Tissue Engineering ................................................... 96 5.4.1 Natural Polymers as Scaffolds ............................................................................... 97
5.4.1.1 Collagen ...................................................................................................... 97 5.4.1.2 Chitosan...................................................................................................... 97 5.4.1.3 Fibrin ........................................................................................................... 97 5.4.1.4 Agarose ....................................................................................................... 98 5.4.1.5 Alginate ...................................................................................................... 98 5.4.1.6 Hyaluronan ................................................................................................ 98
5.4.2 Synthetic Polymers as Scaffolds for Cartilage Tissue Engineering ..................99 5.4.2.1 Polycaprolactone ........................................................................................99 5.4.2.2 PLGA ...........................................................................................................99 5.4.2.3 Polyglycolic Acid .......................................................................................99 5.4.2.4 Polyvinyl Alcohol .................................................................................... 100
5.5 Biomimetic Scaffolds for Cartilage Tissue Engineering .............................................. 100 5.5.1 Physical Modications .......................................................................................... 100 5.5.2 Chemical Modications ........................................................................................ 101 5.5.3 Biological Modications........................................................................................ 101
5.6 Recent Advancements ....................................................................................................... 102 References ..................................................................................................................................... 103
surface at the joints, protecting the bone from wear and tear. Hence, cartilage should have enough mechanical strength to resist the compression and tear. The extracellular matrix (ECM) components of the cartilage are responsible for imparting its functional properties. The collagen bers impart tensile strength and the glycosaminoglycan is responsible for the resilience to resist the compression. In native cartilage, the chondrocytes are dispersed in a very specialized ECM made of dense brillary network of collagen type-II and negatively charged glycosaminoglycan. The cells are responsible for the maintenance of the ECM by secreting the ECM components in response to the signals stored in the matrix.
