Biomimetic processing of calcium phosphate coating

Most ceramics used in surgical implantation are better tolerated by the bod y environment than other biomaterials, particularly metals. However, the br oader application of ceramics is limited because they are brittle and prone to catastrophic failure. By contrast, naturally produced ceramic organic b iocomposites can possess mechanical properties which make them suitable for use as biomaterials. An example would be the mollusc shell, where an inorg anic phase grows onto a charged and organised organic template. This natura l biomineralization provides a calcium carbonate phase with satisfactory me chanical properties appropriate for surgical implantation. It is reported h ow Langmuir Blodgett films have been used as organic templates for calcium phosphate crystallization. Three different Langmuir Blodgett Films: omega t ricosenoic acid, stearic acid and octadecylamine have been investigated. Th e Langmuir Blodgett Films produced had methyl (CH3) and calcium carboxylate (CaCOO) as functional groups. Atomic force microscopy and scanning electro n microscopy shows that calcium phosphate crystallization occurs in a simil ar manner to natural biomineralization. The calcium carboxylate head group appears to have a physical influence on the morphology and distribution of the calcium phosphate crystals. Under the experimental conditions tested, t he calcium carboxylate functional head group controls calcium phosphate cry stallization by a biomimetic approach. This study strongly suggests that th is approach has the potential for producing high performance ceramics compa rable with those made by mollusc shells. (C) 1998 IPEM. Published by Elsevi er Science Ltd. Ail rights reserved.