Physical stimulation and scaffold composition efficiently support osteogenic differentiation of mesenchymal stem cells.

BACKGROUND: Despite significant achievements in the field of tissue engineering, simplification and improvement of the existing protocols are of great importance. The use of complex differentiation media, due to the presence of multiple factors, may have some undesired effects on cell health and functions. Thus, minimizing the number of involved factors, while maintaining the differentiation efficiency, provides less costly and controllable conditions. Adipose-derived Mesenchymal stem cells (ASCs), the adult stem cells present in adipose tissue, can be a suitable source of stem cells due to abundant and ease of access. The aim of this study is to optimize the osteogenic differentiation of ASCs by chemical composition of scaffold, in the first step, and then by electromagnetic treatments. METHODS: ASCs were cultured on PVA/PES scaffold and tissue culture polystyrene surfaces (TCPS) and osteogenic differentiation was performed with either osteogenic medium, or electromagnetic field or both. The impact of each treatment on ASCs growth and proliferation was measured by MTT assay. Changes in gene expression levels of osteogenic-specific markers including ALP and RUNX2 were determined by Real Time PCR. Furthermore, alkaline phosphatase activity and calcium deposition were measured. RESULTS: The MTT assay showed the significant effects on cell growth and respiration in scaffold-seeded ASCs treated with electromagnetic field, compared to control TCPS plate. Also, the electromagnetic treatment, increased alkaline phosphatase activity and calcium deposition. Finally, Real Time PCR showed higher expression of ALP and RUNX2 genes in electromagnetic field groups compared to control groups. CONCLUSION: It can be concluded that PVA/PES scaffold used in this study improved the osteogenic capacity of ASCs. Moreover, the osteogenic potential of ASCs seeded on PVA/PES scaffold could be augmented by electromagnetic field without any chemical stimulation.

Enhancement of osteogenic differentiation of adipose-derived stem cells by PRP modified nanofibrous scaffold.

Recent developments in bone tissue engineering have paved the way for more efficient and cost-effective strategies. Additionally, utilization of autologous sources has been considered very desirable and is increasingly growing. Recently, activated platelet rich plasma (PRP) has been widely used in the field of bone tissue engineering, since it harbours a huge number of growth factors that can enhance osteogenesis and bone regeneration. In the present study, the osteogenic effects of PRP coated nanofibrous PES/PVA scaffolds on adipose-derived mesenchymal stem cells have been investigated. Common osteogenic markers were assayed by real time PCR. Alkaline phosphate activity, calcium deposition and Alizarin red staining assays were performed as well. The results revealed that the highest osteogenic differentiation occurred when cells were cultured on PRP coated PES/PVA scaffolds. Interestingly, direct application of PRP to culture media had no additive effects on osteogenesis of cells cultured on PRP coated PES/PVA scaffolds or those receiving typical osteogenic factors. The highest osteogenic effects were achieved by the simplest and most cost-effective method, i.e. merely by using PRP coated scaffolds. PRP coated PES/PVA scaffolds can maximally induce osteogenesis with no need for extrinsic factors. The major contribution of this paper to the current researches on bone regeneration is to suggest an easy, cost-effective approach to enhance osteogenesis via PRP coated scaffolds, with no additional external growth factors.