Revista nº 813

Ibáñez Cortés M, et al. | Artificial oral mucosa Actual Med. 2021; 106(813): 177- 187 183 CONNECTIVE TISSUE AND SUBMUCOSA Connective tissue is rich in fibrillar and non fibrillar components. The main fibrillar component is the collagen type I, III and VI that has been widely used for connective tisssue characterization by immunohistochemistry techniques. Likewise, the non fibrillar components such as decorin and tenascin have been also identified by immunohistochemistry. CD90 positive expression has been linked to the mesenchymal origin of fibroblasts, the main cellular component of the connective and submucosa tissue (15,29,31) (Table 3). The use of histochemistry tecniques in native human oral mucosa characterization have included trichrome of Masson and picrosirius stainings for the detection of collagen I. In addition, periodic acid- Schiff staining confirms the presence of glycoproteins as tenascin and fibronectin. For the detection of proteoglycans, alcian blue staining was used accompained by the detection of other proteoglycans such as syndecan and decorin. Trimeric collagen III fiber called reticulin is visualizated by the use of Gomori’s technique. Finally, elastic fibers formed by elastin and fibrilin are confirmed by the Verhoeff staining (5,11,19,20,30,32) (Table 4). Additionally, connective and submucosa tissues are immunohistochemically recognized by the use of endothelial markers as CD31 due to the presence of blood vessels and capillaries (5,12,29) (Table 3) and histochemically identified by the use of Oil Red O staining which colours the adipose tissue found in some types of submucosa (5,12,33) (Table 4). Several research groups have developed different types of artificial oral mucosa (Table 5) using several epithelial, basement membrane, connective and submucosa tissue markers. However, in some cases morphological classification of artificial oral mucosa substitutes are rare mentionated or remain unclear. According to this, the analysis of the cytokeratin expression profile will be a helpful tool to classify the type of oral mucosa substitute and to match the proper substitute to recipient zone developing a tailored artificial oral mucosa substitutes. In this regard, immunohistochemical methods for the classification of oral mucosa should include Mas Pic PAS AB Gom Ver ORO Bibliography Basement membrane Basal lamina + (5, 11, 30) Reticular lamina + (19, 30) Connective tissue Papillary layer + + + (5, 11, 19, 20, 30, 32) Reticular layer + + + + + + (5, 11, 19, 20, 30, 32) Submucosa + + + (5, 12, 33) Table 4. Histochemical characterization of the basement membrane, the connective tissue and the submucosa. +: possitive staining. Mas: Masson staining for collagen I. Pic: picrosirius staining for collagen I. PAS: periodic acid–Schiff staining for glycoproteins as integrins, laminins, entactin, fibronectin and tenascin. AB: alcian blue staining for proteoglycans as hialuronic acid, heparin sulphate, syndecan and decorin. Gom: Gomori’s technique for reticulin formed by trimeric collagen III. Ver: Verhoeff staining for elastic fibers formed by elastin and fibrilin. ORO: Oil Red O staining for neutral lipids. HISTOLOGICAL STUDIES OF ARTIFICIAL ORAL MUCOSA DEVELOPED BY TISSUE ENGINEERING