The processing and characterization of animal-derived bone to yield materials with biomedical applications - Part 1: Modifiable porous implants from bovine condyle cancellous bone and characterization of bone materials as a function of processing

A study on the development of a process to form materials suitable for biom edical xenograft implants from bovine cancellous bone is presented. Bone cu bes cut from the condyle portion of bovine femurs sourced from abattoir was te were subjected to a defatting and subsequent deproteination procedure to produce shape-modifiable materials in which the biocompatible mineral calc ium hydroxycarbonate apatite component was preserved in the original osseou s architecture of the bovine bone. Optimum defatting was achieved by (1) th awing of the precut bone cubes in water, (2) pressure cooking at 15 psi in water, (3) soaking in 0.1 mol l(-1) NaOH followed by a thorough rinse under running water, (4) microwave heating of the bone cubes in water, (5) reflu xing in methyl acetate and finally (6) removal of internal liquid from the cubes by shaking and then air drying. Subsequent deproteination of the defa tted bone cubes was optimally achieved by (1) soaking in 5% sodium hypochlo rite solution at ambient temperature using ultrasonication, (2) thorough ri nsing of the cubes in water followed by drying. The final product is a defa tted/deproteinated, bleached material that can be molded into various shape s for implant use in the body. The bone specimens were characterized by a s uite of analytical techniques (i.e. infrared, P-31 and C-13 solid magic-ang le spinning (MAS) nuclear magnetic resonance (NMR), X-ray photoelectron spe ctroscopies, atomic absorption (AA) spectrometry, inductively coupled plasm a (ICP) spectrometry, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM)) in order to follow compositional changes during the various stages of processing. In general, bovine condyles proved to be the best source of xenograft materials with condyles from other animal spe cies (i.e. deer, sheep and ostrich) being too small to constitute a utiliza ble source of cancellous bone. This study shows how value can be added to a hitherto underutilized abattoir by-product by using simple processing tech niques. (C) 2000 Kluwer Academic Publishers.