Three-Dimensional Nanofiber Scaffolds for Regenerative Medicine

Abstract

Tissue engineering is an interdisciplinary technology of the basic concept of bioscience and biotechnology. It is aiming to make tissues that can replace or regenerate diseased tissues and organs after understanding of correlation between the structure and function of normal biological tissues. The regenerated tissues made in such way are improving, reviving, restoring, or substituting the functions of human body as well as maintaining the functions after transplanted into human body.1 The three elements of tissue engineering for regenerating the biological tissues are cell, growth factor, and scaffold. When the number of cells has been reduced due to some troubles of cell proliferation in the damaged tissue, cell can regenerate the damaged area by insertion of external cells, and the growth factor controls the growth and differentiation of cells. Scaffold is used to assist the growth and proliferation of cells. Scaffold helps cells growing and functioning in normal condition. If scaffold does not play its role properly, the replace or regenerate diseased tissues and organs must not success. Recent researches, therefore, have been focused on the development of scaffold that is influencing the proliferation and differentiation of cells. Scaffold must have, particularly, the similar form of extracellular matrix that supports cells, which should have the following characteristics.1,2 (1) Scaffold must connect tissue and blood vessel with each other by the appropriate size pores. (2) Scaffold must be able to adjust the biodegradability and bioabsorbability. (3) Scaffold must have the chemical surface where cells can achieve adherence, differentiation, and proliferation. (4) Scaffold must not induce other reverse functions or side effects. (5) Scaffold must be formed in various shapes and sizes, and it must be easy for the penetration or manipulation of various materials inside the scaffold. Nanofiber is getting noticed the most intensively among the scaffolds with above characteristics (Fig.1).3 Nanofiber is expected to overcome the limitation of conventional materials. So, it will be adopted in the new field with lots of advantages of high surface area per unit volume, high porosity, numerous fibers in the unit area, micro space created between fibers, and its flexibility. Nanofiber can be produced through phase separation, self-assembly method, electrospinning method, etc. Nanofiber can be used in various biomedical application such as high-functional filter and wound healing material, reinforced fiber of composite biomaterials, and scaffold for tissue engineering. Among them, the nanofiber as a scaffold for