| ObjectTo ascertain an effective and mild method for the defatting of bovine bone in order to produce a new-type bone substitutes.MethodThe fats in bovine cancellous bone were drawn out by petroleum ether using a Soxhlet extractor, chloroform /methanol with the help of a vibratory unit and supercritical CO2 fluid combined with normal hexane. Extracts were collected and weighed respectively, their chemical constituents and relative content were determined by Gas Chromatography-Mass Spectrometry(GC-MS), afterwards the three degreasing methods above mentioned were evaluated by One-way Analysis Of Variance(One-way ANOVA). Both fresh bovine cancellous bone strips and degreased ones were observed by the general histological section, HE stain and optical microscope inspect. ResultsThere was a significant difference in fats extraction ratio between different defatting methods(P<0.05). Petroleum ether extraction using a Soxhlet extractor cleared fats most thoroughly in a mild manner, but the volume of the extractor was limited, let alone a small quantity of bone cost large amounts of organic solvents. Defatting by chloroform/methanol with a vibratory unit had the lowest efficiency and the biggest toxicity therefore it should be disused. Both the extraction rate and operating conditions of supercritical CO2 fluid combined with normal hexane were acceptable, moreover, it required a little time. According to the GC-MS, there were no apparent disparities in terms of chemical constituents but a slightly dissimilarity upon component contents among those defatting methods. Tissue sections of defatted bovine cancellous bone strips showed that there were a few cell remnants in the core sites of bone trabecula.ConclusionPetroleum ether extraction using a Soxhlet extractor is the most effective and convenient method, and it can be used for mass production with a slightly modification of the apparatus. Supercritical CO2 fluid extraction is the most promising method and deserving of research. Anyway, a further treatment is imperative to remove cell debris after defatting for the purpose of fabricating a more biocompatible bone substitutes. |
