Plastination with low viscosity silicone: strategy for less tissue retraction
Name: YURI FAVALESSA MONTEIRO
Type: MSc dissertation
Publication date: 15/12/2020
Advisor:
Name |
Role |
|---|---|
| ATHELSON STEFANON BITTENCOURT | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ATHELSON STEFANON BITTENCOURT | Advisor * |
| LUCAS CUNHA DIAS DE REZENDE | Internal Examiner * |
Summary: Plastination is an anatomical technique for preserving biological tissues, whose principle is the replacement of body fluids with a curable polymer. The main polymers used in the technique are epoxy, polyester and silicone, with silicone being the most used worldwide due to its versatility and greater range of use. The inputs are usually acquired via import, so the acquisition of alternative polymers of national acquisition would facilitate the diffusion of plastination. In addition, there are no studies in the literature that evaluate the use of low viscosity silicones in plastination, using tissue retraction as a parameter. With this, the idea of evaluating the nationally acquired silicone Polisil® Poliplast 1 (P1) and the imported silicone (reference) Biodur S10 emerges, investigating its chemical and rheological properties and how much to use in plastination. For chemical and rheological characterization, mass spectrometry, infrared spectroscopy and rheometry were used, in order to characterize the functional groups, molecular mass, study of flow and deformation of polymeric materials and viscosity. And to evaluate the use of these silicones in the technique, the tissue retraction of different tissues caused in the forced impregnation stage was investigated. The human tissues used were cardiac, pulmonary, splenic, renal, hepatic, muscular and bone. For this, a male human corpse sliced in 13-15 mm thick cuts was used, having as parameter the before and after plastination with the different silicones. It followed the standard slicing plastination protocol: dehydration, forced impregnation and curing. Half of the cuts obtained were plastinated with silicone P1 (group P1) and the other half with S10 (group S10). The results found in the infrared, mass spectrometry and rheometry tests showed that the structural formula of the silicone molecules is identical, compatible with the polydimethylsiloxane (PDMS) and presented a strong indication that the P1 silicone has less molar mass compared to S10, due to its lower viscosity, greater presence of silanol groups and distribution of m/z of the fragments obtained in EM. All tissues and anatomical segments analyzed in this study showed less or equal retraction when compared to the control group (S10) plastination with silicone P1. From this, it is concluded that the lower viscosity silicone promotes less tissue retraction, making it a viable alternative to the reference.
Keywords: plastination; viscosity; silicone; shrinkage.
