BIOCERAMIC SCAFFOLD—BONE TISSUE ENGINEERING - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 84

4.1 Introduction
Tissue engineering was defined by Langer and Vacanti 1 as an inter-
disciplinary field that applies the principles of engineering and
life sciences toward the development of biological substitutes that
restore, maintain, or improve tissue function. It can also be defined
as the use of a combination of cells, engineering materials, and
suitable biochemical factors to improve or replace biological func-
tions in an effort to effect the advancement of medicine. The total
market for the regeneration and repair of tissues and organs was
estimated to be $25 billion worldwide 2 in 2001. As per a recent
market forecast the worldwide market and emerging technolo-
gies for tissue engineering and regenerative medicine products will
exceed $118 billion in 2013. 3 Although transplantation of organs
has become an established and successful method of therapy, the
severe scarcity of donor organs and immune rejection have become
a major limitation and have stimulated the tissue engineering field.
Two different approaches were being employed in assisted self-
assembly of cells. In the first approach, donor cells and growth fac-
tors were seeded in vitro into a biodegradable scaffold. After the
required period for cell growth and multiplication, the scaffold was
surgicallyimplantedintothebodyforthegenerationofhealthynew
tissue. In the second approach the scaffold was implanted into the
damaged area along with the cells and the growth factors to stimu-
latetissueregeneration.Scaffoldingarchitectureplaysanimportant
role in these three-dimensional (3D) matrix supports composed of
cells and an extracellular matrix similar to natural tissue organiza-
tion. Mimicking the natural tissue organization contributes signifi-
cantly to the biological function of the tissue-engineered material.
Enormous advances have been made in the field of materials sci-
encewiththeadventofnanotechnology.Bonetissueengineeringisa
specific area in nanotechnology where the development of nanos-
tructured biomaterials may be able to replace hard and soft skele-
tal tissue and biocompatible materials for tissue genesis. Other
relatedareasincludecreationofnanoporousbiocapsulesforcellular
therapy. Tissue engineering stands to benefit most from nanotech-
nology because of the growing ability to fabricate complex nanos-
tructured materials. This chapter reviews some of the important