Abstract
Bioactive ceramics are now clinically used as artificial bones because they can make direct bonding to bone after implantation in bony defects. However, there are some limitations in their application due to the more brittleness and lower fractured toughness of the ceramics than those of bone. Since bone consists of hydroxyapatite and collagen, composites consisting of bone-like apatite and organic polymer is an important candidate for production of novel artificial bones. This paper reviews some of approaches to fabricate such a composite through the biomineralization-guided concept utilizing a simulated body fluid (SBF) that mimics human extracellular fluid. To deposite bone-like apatite on the organic polymer in SBF, functional groups on the polymer surface is an important parameter to induce heterogeneous nucleation of hydroxyapatite as well as increase in the degree of supersaturation with respect to hydroxyapatite through release of such ions as Ca2+. Arrangement of the functional groups on the substrates is also effective on nucleation of hydroxyapatite in addition to the kinds of the functional groups implying carboxyl groups. These molecular design brings novel biomaterials for bone substitutes with much compatibility to living bone.
