ULTRASTRUCTURAL ANALYSIS OF EXTRACELLULAR MATRIX FROM DECELLULARIZED CANINE MASTOCYTOMA

Background Canine cutaneous mast cell tumor is a neoplasm, caused by the abnormal proliferation of mast cells, which are physiologically responsible for the immune, inflammatory and allergic systems. Due to the unpredictable behavior of this neoplasm, associated with the incidences of metastasis and recurrences, studies on the extracellular matrix (ECM) become relevant. However, literature on this information is still scarce. Then, the objective of this work is to evaluate the decellularized extracellular matrix canine mastocytoma and to study ultrastructural aspects using different decellularization protocols. Methods The mastocytoma tissue was immersed in two different detergents, 0.5% sodium dodecyl sulfate (SDS) or 1% Triton X-100, under stirring at 120 rpm for 24 hours at room temperature. Afterwards, Scanning Electron Microscopy was performed as an ultrastructural analysis of the native and decellularized mastocytoma matrices. It was possible to verify the molecules in the ECM that can be compared with the histological degrees already established and correlate with aspects of tumor progression using histological techniques. Results The cell-free appearance of the decellularized matrices under macroscopic analysis and Scanning Electron Microscopy were the same, when used non-ionic 1% Triton X-100 or ionic 0.5% SDS detergents in the decellularization processes. Histological analyses using Hematoxylin and Eosin, Gomori Trichrome and Picrosirius Red staining were carried out in the native and decellularized matrices allowing to analyze the presence/absence of cells, the preservation of collagen fibers, and other structures. The integrity of the matrix was better preserved when non-ionic Triton X-100 detergent was used in the process. Conclusion Both detergents proved to be effective in the decellularization process of canine mastocytoma MEC, however, its integrity was better preserved in the protocol using non-ionic 1% Triton X-100 detergent. Keywords cancer, dogs, histology, collagen, biomaterial Financial support CAPES, CNPq, FAPESP