Reed Courtney R, Han Li, Andrady Anthony, Caballero Montserrat, Jack Megan C, Collins James B, Saba Salim C, Loboa Elizabeth G, Cairns Bruce A, van Aalst John A
Division of Plastic Surgery, University of North Carolina, Chapel Hill, NC 27599-7195, USA.
Ann Plast Surg. 2009 May;62(5):505-12. doi: 10.1097/SAP.0b013e31818e48bf.
Tissue engineering has largely focused on single tissue-type reconstruction (such as bone); however, the basic unit of healing in any clinically relevant scenario is a compound tissue type (such as bone, periosteum, and skin). Nanofibers are submicron fibrils that mimic the extracellular matrix, promoting cellular adhesion, proliferation, and migration. Stem cell manipulation on nanofiber scaffolds holds significant promise for future tissue engineering. This work represents our initial efforts to create the building blocks for composite tissue reflecting the basic unit of healing. Polycaprolactone (PCL) nanofibers were electrospun using standard techniques. Human foreskin fibroblasts, murine keratinocytes, and periosteal cells (4-mm punch biopsy) harvested from children undergoing palate repair were grown in appropriate media on PCL nanofibers. Human fat-derived mesenchymal stem cells were osteoinduced on PCL nanofibers. Cell growth was assessed with fluorescent viability staining; cocultured cells were differentiated using antibodies to fibroblast- and keratinocyte-specific surface markers. Osteoinduction was assessed with Alizarin red S. PCL nanofiber scaffolds supported robust growth of fibroblasts, keratinocytes, and periosteal cells. Cocultured periosteal cells (with fibroblasts) and keratinocytes showed improved longevity of the keratinocytes, though growth of these cell types was randomly distributed throughout the scaffold. Robust osteoinduction was noted on PCL nanofibers. Composite tissue engineering using PCL nanofiber scaffolds is possible, though the major obstacles to the trilaminar construct are maintaining an appropriate interface between the tissue types and neovascularization of the composite structure.
组织工程学主要聚焦于单一组织类型的重建（如骨骼）；然而，在任何临床相关情形下，愈合的基本单位都是复合组织类型（如骨骼、骨膜和皮肤）。纳米纤维是模仿细胞外基质的亚微米级原纤维，可促进细胞黏附、增殖和迁移。在纳米纤维支架上对干细胞进行操控，对未来的组织工程学而言具有重大前景。这项工作代表了我们为创建反映愈合基本单位的复合组织构建模块所做的初步努力。采用标准技术静电纺丝制备聚己内酯（PCL）纳米纤维。从接受腭裂修复手术的儿童身上采集人包皮成纤维细胞、小鼠角质形成细胞和骨膜细胞（4毫米冲孔活检样本），并在合适的培养基中培养于PCL纳米纤维上。在PCL纳米纤维上对人脂肪来源的间充质干细胞进行成骨诱导。通过荧光活力染色评估细胞生长情况；使用针对成纤维细胞和角质形成细胞特异性表面标志物的抗体对共培养细胞进行分化。用茜素红S评估成骨诱导情况。PCL纳米纤维支架支持成纤维细胞、角质形成细胞和骨膜细胞的强劲生长。共培养的骨膜细胞（与成纤维细胞一起）和角质形成细胞显示角质形成细胞的寿命有所延长，不过这些细胞类型的生长在整个支架中呈随机分布。在PCL纳米纤维上观察到强劲的成骨诱导现象。使用PCL纳米纤维支架进行复合组织工程是可行的，不过对于三层结构而言，主要障碍在于维持组织类型之间的适当界面以及复合结构的新生血管形成。
