Development of a micro‐plastination protocol for morphological research

Abstract

IntroductionUltrathin‐sheet plastination technique has been used to study microscopic details in anatomy. The aim of this study was to develop an ultra‐thin sheet plastination protocol in an induced model of osteoarthritis in rat humeral joint.Material and methodRat humeral joints, with osteoatrhitis, were used for this research. Sixteen weeks after osteoatrhitis induction, the animals were euthanized and injected with red epoxy resin through toracic aortha. Humeral joints and surrounded tissue were fixed in 10 % formalin. Samples were submitted to the plastination technique. The first step was dehydration during ten days, with acetone (100 %) at −25 °C. Later, for degreased, samples were inmerse in methylene chloride at room temperature during one week. Forced impregnation, the most important step in plastination, was peformed inside a stove with vacuum chamber. The plastinated blocks were cutted with a low speed band saw, with a diamond saw blade. Slices were placed in curing chambers to achieve polymerization and final transparentation.ResultsWe obtained slices of humeral joint of 230 μm thick, in which articular cartilage characteristic osteoarthritis morphological changes, including neovascularization, were observed.DiscussionUltra‐thin sheet Plastination is generally not used as a methodology for the identification of morphological changes caused by pathologies. However, we have applied this technique to identify the changes caused by osteoarthritis in the humeral joint of rats, as tjhe invasion of blood vessels in subchondral bone.ConclusionUltra‐thin sheet plastination technique was a methodology that can be used for the identification, measurement and comparison of morphological modifications caused by various pathologies, including osteoarthritis.