ABSTRACT
OBJECTIVE: To assess the role and effect of Wharton's jelly of human umbilical cord oriented scaffold on chondrocytes co-cultured in vitro. METHODS: Chondrocytes from shoulder cartilage of adult New Zealand rabbits were isolated, cultured, amplified, and labelled using fluorescent dye PKH26. Cells were extracted from human umbilical cord tissue using wet-grinding chemical technology to prepare the Wharton's jelly of human umbilical cord oriented scaffold by freeze-drying and cross-linking technology. Second generation of chondrocytes were cultured with Wharton's jelly of human umbilical cord oriented scaffold. Inverted microscope and scanning electron microscope (SEM) were used to observe the cell distribution and adhesion on the scaffold; extracellular matrix secretion of the chondrocytes were observed by toluidine blue and safranin O staining. Cells distribution and proliferation on the scaffold were assessed by fluorescein diacetate-propidium iodide (FDA-PI) and Hoechst33258 staining. The viability of the in vitro cultured and PKH26 fluorescence labelled chondrocytes on the scaffold were assessed via fluorescence microscope. RESULTS: Inverted microscope showed that the cells cultured on the scaffold for 3 days were round or oval shaped and evenly distributed into space of the scaffold. SEM observation showed that large number of cultured cells adhered to the pores between the scaffolds and were round or oval shape, which aggregated, proliferated, and arranged vertically on longitudinally oriented scaffold at 7 days after culture. Histological observation showed that cells distributed and proliferated on the scaffold, and secreted large amount of extracellular matrix at 7 days. Scaffold could guide cell migration and proliferation, and could effectively preserve and promote the secretion of extracellular matrix. Cell viability assessments at 3 days after culture showed most of the adhered cells were living and the viability was more than 90%. PKH26 labelled chondrocytes were seen, which distributed uniformly along the pore of oriented scaffold, and exuberantly proliferated. CONCLUSION: Wharton's jelly of human umbilical cord oriented scaffold favors adhesion, proliferation, and survival of chondrocytes. It possesses a favorable affinity and cell compatibility. Thus, it is an ideal scaffold for cartilage tissue engineering.
