不同支架材料构建组织工程化口腔黏膜的比较

Comparison of Tissue-Engineered Oral Mucosa with Different Scaffolds

目的比较3种不同支架材料——聚羟基乙酸（PGA）、胶原膜和脱细胞真皮基质材料（Alloderm）在构建组织工程化口腔黏膜方面的特点。方法体外培养、扩增人口腔黏膜上皮细胞和成纤维细胞（OFC）。呈对数生长期的OFC接种至PGA支架上培养7d后，将口腔黏膜上皮细胞分别与PGA-OFC、胶原膜和Alloderm复合，液面下培养4～7d后，进行气-液界面培养7d。光镜、电镜下进行组织形态学及超微结构观察。倍果以PGA为支架构建的组织工程化口腔黏膜，含类似上皮层和固有层，但细胞层次不清；胶原膜上可见口腔黏膜上皮细胞黏附生长，并形成复层上皮样组织，但无成熟的桥粒及基底膜样结构；以Alloderm作为支架材料的构建物，出现正常上皮形态，含半桥粒及细胞指状突起等超微结构。倍论PGA、胶原膜和Alloderm支架材料都能构建出含上皮层和固有层的口腔黏膜样组织；胶原膜由于降解速度和不易操作等特点，而不适宜作为组织工程化口腔黏膜支架材料；Alloderm作为支架的构建物更接近于人类正常口腔黏膜。

Objective To develop and compare tissue-engineered oral mucosa with scaffolds of polyglycolic acid （PGA）, collagen membrane and human cadaveric dermis （Alloderm） ex vivo. Methods Oral keratinocytes （OKCs） and fihrohlasts were isolated, cultured and proliferated. Tissue-engineered oral mucosa were reconstructed by seeding human oral fihrohlast （OFC） onto PGA cultured for 7 days, and seeding human OKCs on PGA-OFC, collagen membrane and Alloderm, respectively. They were cultured for 4 -7 days submerged and then for another 7 days at air-liquid interface. Samples of the composites were taken for histological examination at day 7 and day 14 since OKCs were seeded. Results Multi-layer epithelia without hemidesmosome and basal membrane were ohserved in composites of PGA showing ill-defined cell layers. OKCs could adhere and proliferate onto collagen membrane forming multi-layer epithelia, with no mature hemidesmosome and basal membrane. That of Alloderm showed normal epithelial structures, with hemidesmosome, basal membrane and cell pseudopod in lamina propria. Conclusion Tissue-engineered oral mucosa could he reconstructed with the scaffolds of PGA, collagen membrane and Alloderm. Collagen membrane is easy to degenerate and seems to be unsuitable for tissue-engineered oral mucosa. However, the composites with Alloderm resemble normal human oral mucosa better.