Paracrine of human adipose-derived mesenchymal stem cells in three-dimensional culture containing functionized self assembling peptide nanofiber hydrogel

Objective To study the paracrine of human adipose-derived mesenchymal stem cells (ADMSCs) in three-dimensional culture containing functionized self assembling peptide nanofiber hydrogel and the influencing factors. Methods ADMSCs were isolated and extracted. Three kinds of peptides (RADAI-16, RGD, KLT) were prepared and functionized self assembling peptide nanofiber hydrogel was made by mixing RADAI-16, RGD and KLT with a volume ratio of 2∶1∶1. Under AFM, the morphology of RADAI-16, RGD, KLT and functionized self assembling peptide nanofiber hydrogel was observed (n=4). ADMSCs were cultured under the three-dimensional condition containing peptide nanofiber hydrogel. ADMSCs were subjected to in situ three-dimensional cultivation for 1 day, then the concentrations of hepatocyte growth factor (HGF, n=3) and vascular endothelial growth factor (VEGF, n=3) were determined in the supernatatn by enzyme linked immunosorbent assay (ELISA). The cells were extracted in peptide nanofiber hydrogel and the expression of heme oxygenase-1 (HO-1, n=3) was detected by Western blotting. The cultured ADMSCs in hypoxic condition and normal circumstance served as controls. Results ADMSCs showed long spindle shape and grew in a whirlpool shape. The diameter of RADAI-16, RGD, KLT and functionized self assembling peptide nanofiber hydrogel was (17.34±1.82), (15.50±1.41), (13.77±1.18) and (20.26±1.25) nm, respectively. The concentration of HGF under three conditions was (47.31±6.75), (247.86±17.59), and (297.25±17.95) ng/L, respectively, and that of VEGF was (218.30±3.03), (267.13±4.27) and (289.14±3.11) ng/L, respectively. Both HGF and VEGF were paracrined more in condition of functionized self assembling peptide nanofiber hydrogel (P=0.000). Western blotting results showed that the expression of HO-1 in the three-dimensional culture group was about 2 times (P=0.000) higher than that in the ordinary culture group, and was 1.2 times higher than that in the hypoxia culture group (P=0.033). Conclusion The three-dimensional culture mediated by the functionized self assembling peptide nanofiber hydrogel can promote the paracrine of ADMSCs, such as HGF and VEGF, and hypoxia is one of the important elements. Key words: Adipose derived Mesenchymal stem cells; Three-dimensional culture; Functionized self assembling peptide nanofiber hydrogel; Paracrine; Hypoxia