Comparison of osteogenic differentiation potential of induced pluripotent stem cells on 2D and 3D polyvinylidene fluoride scaffolds.

In recent decades, tissue engineering has been the most contributor for introducing 2D and 3D biocompatible osteoinductive scaffolds as bone implants. Polyvinylidene fluoride (PVDF), due to the unique mechanical strength and piezoelectric properties, can be a good choice for making a bone bioimplant. In the present study, PVDF nanofibers and film were fabricated as 3D and 2D scaffolds, and then, osteogenic differentiation potential of the human induced pluripotent stem cells (iPSCs) was investigated when grown on the scaffolds by evaluating the common osteogenic markers in comparison with tissue culture plate. Biocompatibility of the fabricated scaffolds was confirmed qualitatively and quantitatively by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and scanning electron microscopy assays. Human iPSCs cultured on PVDF nanofibers showed a significantly higher alkaline phosphate activity and calcium content compared with the iPSCs cultured on PVDF film. Osteogenic-related genes and proteins were also expressed in the iPSCs seeded on PVDF nanofibers significantly higher than iPSCs seeded on PVDF film, when investigated by real-time reverse transcription polymerase chain reaction and western blot analysis, respectively. According to the results, the PVDF nanofibrous scaffold showed a greater osteoinductive property compared with the PVDF film and due to the material similarity of the scaffolds, it could be concluded that the 3D structure could lead to better bone differentiation. Taken together, the obtained results demonstrated that human iPSC-seeded PVDF nanofibrous scaffold could be considered as a promising candidate for use in bone tissue engineering applications.

Bladder smooth muscle cell differentiation of the human induced pluripotent stem cells on electrospun Poly(lactide-co-glycolide) nanofibrous structure.

Smooth muscle cell (SMC) regeneration plays an important role in retrieving the bladder-wall functionality and it can be achieved by a proper cell-co-polymer constructed by tissue engineering. Human induced pluripotent stem cells (iPSCs), which can be specifically prepared for the patient, was considered as cells in this study, and Poly(lactide-co-glycolide) (PLGA) as a most interesting polymer in biomedical applications was applied to the scaffold fabrication by electrospinning. After scaffold characterization, SMC differentiation potential of the human iPSCs was investigated while cultured on the PLGA nanofibrous scaffold by evaluation of the SMC related important gene and protein markers. Alpha-smooth muscle actin (ASMA), Smooth muscle 22 alpha (SM-22a) as two early SMC markers were significantly up regulated either two and three weeks after differentiation induction in human iPSCs cultured on PLGA compared to those cells cultured on the tissue culture polystyrene (TCPS). But Calponin-1, Caldesmon1 and myosin heavy chain (MHC) expression differences in human iPSCs cultured on PLGA and TCPS were significant only three weeks after differentiation induction based on its lately expression in the differentiation process. ASMA and MHC proteins were also considered for evaluation by immunocytochemistry on differentiated iPSCs whereas results showed higher expression of these proteins in stem cells grown on PLGA compared to the TCPS. According to the results, human iPSCs demonstrated a great SMC differentiation potential when grown on PLGA and it could be considered as a promising cell-co-polymer for use in bladder tissue engineering.

In vitro osteogenic differentiation potential of the human induced pluripotent stem cells augments when grown on Graphene oxide-modified nanofibers.

Due to the several limitations that surgeons are faced during bone tissue implantation there are daily increases in introducing new cell-co-polymer composites for use in bone tissue engineering approaches. In this study tried to develop a suitable nanostructured bio-composite for enhancing osteogenic differentiation of the human induced pluripotent stem cells (iPSCs). Polyvinylidene fluoride-Graphene oxide (PVDF-GO) nanofibers was fabricated by electrospinning and then characterized using scanning electron microscope, tensile and viability assays. After that osteogenic differentiation of the iPSCs was investigated in three groups, including PVDF, PVDF-GO and tissue culture plate as a control group. Alkaline phosphatase activity and calcium content of the iPSCs cultured on PVDF-GO were significantly higher than those cultured on other groups. In addition, Runx2, osteocalcin and osteonectin genes were up regulated in iPSCs cultured on PVDF-GO significantly higher than those cells cultured on PVDF and control. Finally, osteocalcin and osteopontin proteins expression evaluated and the results confirmed higher osteoinductivity of the PVDF-GO nanofibers in comparison with the PVDF nanofibers. According to the results, it was demonstrated that PVDF-GO nanofibers have a great osteoinductive potential and taking together iPSCs-PVDF-GO nanofibrous construct can be an appropriate bio-implant to use for bone tissue engineering applications.