Osteogenic Differentiation Of rMSCs Research Articles

Stereocomplexation Reinforced High Strength Poly(L-lactide)/Nanohydroxyapatite Composites for Potential Bone Repair Applications.

Composite materials composed of polylactide (PLA) and nano-hydroxyapatite (n-HA) have been recognized as excellent candidate material in bone repai The difference in hydrophilicity/hydrophobicity and poor interfacial compatibility between n-HA filler and PLA matrix leads to non-uniform dispersion of n-HA in PLA matrix and consequent poor reinforcement effect. In this study, an HA/PLA nanocomposite was designed based on the surface modification of n-HA with poly(D-lactide) (PDLA), which not only can improve the dispersion of n-HA in the poly(L-lactide) (PLLA) matrix but also could form a stereocomplex crystal with the matrix PLLA at the interface and ultimately lead to greatly enhanced mechanical performance The n-HA/PLA composites were characterized by means of scanning electron microscopy, Fourier transform infrared spectroscopy, X-Ray diffraction, thermal gravity analysis, differential scanning calorimetry, and a mechanical test; in vitro cytotoxicity of the composite material as well as its efficacy in inducing osteogenic differentiation of rat bone marrow stromal cells (rMSCs) were also evaluated. Compared with those of neat PLLA, the tensile strength, Young’s modulus, interfacial shear strength, elongation at break and crystallinity of the composites increased by 34%, 53%, 26%, 70%, and 17%, respectively. The adhesion and proliferation as well as the osteogenic differentiation of rMSCs on HA/PLA composites were clearly evidenced. Therefore, the HA/PLA composites have great potential for bone repai.

Preparation and Characterization of Coaxial Electrospinning rhBMP2-Loaded Nanofiber Membranes

DEX and rhBMP2-loaded core-shell nanofiber membranes were synthesized by electrospinning method in one step. Zein/PLLA, Zein-DEX/PLLA, Zein/PLLA-rhBMP2, and Zein-DEX/PLLA-rhBMP2 were fabricated; and morphology, hydrophilicity, mechanics properties, in vitro drug release behavior, cell proliferation, and osteogenic differentiation were investigated. The results showed that the dual-release system containing rhBMP2 and DEX prepared by electrospinning had rough surface, constant drug release behavior, and could also significantly promote cell proliferation and osteogenic differentiation of RMSCs, indicating that the scaffolds we fabricated might be suitable for bone tissue engineering.

Tenascin-C mimetic Peptide nanofibers direct stem cell differentiation to osteogenic lineage.

Extracellular matrix contains various signals for cell surface receptors that regulate cell fate through modulation of cellular activities such as proliferation and differentiation. Cues from extracellular matrix components can be used for development of new materials to control the stem cell fate. In this study, we achieved control of stem cell fate toward osteogenic commitment by using a single extracellular matrix element despite the contradictory effect of mechanical stiffness. For this purpose, we mimicked bone extracellular matrix by incorporating functional sequence of fibronectin type III domain from native tenascin-C on self-assembled peptide nanofibers. When rat mesenchymal stem cells (rMSCs) were cultured on these peptide nanofibers, alkaline phosphatase (ALP) activity and alizarin red staining indicated osteogenic differentiation even in the absence of osteogenic supplements. Moreover, expression levels of osteogenic marker genes were significantly enhanced revealed by quantitative real-time polymerase chain reaction (qRT-PCR), which showed the remarkable bioactive role of this nanofiber system on osteogenic differentiation. Overall, these results showed that tenascin-C mimetic peptides significantly enhanced the attachment, proliferation, and osteogenic differentiation of rMSCs even in the absence of any external bioactive factors and regardless of the suitable stiff mechanical properties normally required for osteogenic differentiation. Thus, these peptide nanofibers provide a promising new platform for bone regeneration.

A Comparative Study on Morphochemical Properties and Osteogenic Cell Differentiation within Bone Graft and Coral Graft Culture Systems

The objective of this study was to compare the morphological and chemical composition of bone graft (BG) and coral graft (CG) as well as their osteogenic differentiation potential using rabbit mesenchymal stem cells (rMSCs) in vitro. SEM analysis of BG and CG revealed that the pores in these grafts were interconnected, and their micro-CT confirmed pore sizes in the range of 107-315 µm and 103-514 µm with a total porosity of 92% and 94%, respectively. EDS analysis indicated that the level of calcium in CG was relatively higher than that in BG. FTIR of BG and CG confirmed the presence of functional groups corresponding to carbonyl, aromatic, alkyl, and alkane groups. XRD results revealed that the phase content of the inorganic layer comprised highly crystalline form of calcium carbonate and carbon. Atomic force microscopy analysis showed CG had better surface roughness compared to BG. In addition, significantly higher levels of osteogenic differentiation markers, namely, alkaline phosphatase (ALP), Osteocalcin (OC) levels, and Osteonectin and Runx2, Integrin gene expression were detected in the CG cultures, when compared with those in the BG cultures. In conclusion, our results demonstrate that the osteogenic differentiation of rMSCs is relatively superior in coral graft than in bone graft culture system.

Platelet‐rich plasma‐derived growth factors promote osteogenic differentiation of rat muscle satellite cells: in vitro and in vivo studies

PRP (platelet-rich plasma)-derived growth factors are a new application of tissue engineering and a developing area for researchers and clinicians. We have assessed the effects of PRP-derived growth factors on the proliferation and osteogenic differentiation of rMSCs (rat muscle satellite cells), and constructed a novel tissue engineering bone composed of PRP-derived growth factors and rMSCs. PRP were created by a freeze-thaw process. rMSCs were isolated from rat masticatory muscle using serial platings technique. Wst-1 assay, SEM (scanning electron microscopy), ALP (alkaline phosphatase) activity, total protein concentration, AR (Alizarin red S) staining, calcium analyses and RT-PCR (reverse transcription-PCR) of osteogenic-related genes were used to assess the effect of PRP-derived growth factors on proliferation and osteogenic differentiation of cultured rMSCs on scaffolds. The different composite scaffolds were implanted to the subcutaneous spaces of nude mice. H&E (haematoxylin and eosin) and Masson's trichrome staining were used to examine the ectopic bone formation. In vitro, we found that PRP-derived growth factors showed excellent cell compatibility and significantly enhanced cell proliferation over serum and control groups at 48 and 72 h. SEM, ALP activity, AR staining, calcium analyses and RT-PCR showed that PRP-derived growth factors significantly increased cells osteogenic differentiation when compared with other groups. In vivo examination showed that more fibrous tissue capsule and bone with lamellar structures appeared in PRP-derived growth factors groups. These results suggest that the PRP-derived growth factors significantly promote rMSCs proliferation, osteogenic differentiation compared with serum and scaffolds alone, and may be suitable for stem cell growth factors delivery and bone tissue engineering.

L-type calcium channels play a crucial role in the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

L-type voltage-dependent Ca2+ channels (VDCCL) play an important role in the maintenance of intracellular calcium homeostasis, and influence multiple cellular processes. They have been confirmed to contribute to the functional activities of osteoblasts. Recently, VDCCL expression was reported in mesenchymal stem cells (MSCs), but the role of VDCCL in MSCs is still undetermined. The aim of this study was to determine whether VDCCL may be regarded as a new regulator in the proliferation and osteogenic differentiation of rat MSC (rMSCs). In this study, we examined functional Ca2+ currents (ICa) and mRNA expression of VDCCL in rMSCs, and then suppressed VDCCL using nifedipine (Nif), a VDCCL blocker, to investigate its role in rMSCs. The proliferation and osteogenic differentiation of MSCs were analyzed by MTT, flow cytometry, alkaline phosphatase (ALP), Alizarin Red S staining, RT-PCR, and real-time PCR assays. We found that Nif exerts antiproliferative and apoptosis-inducing effects on rMSCs. ALP activity and mineralized nodules were significantly decreased after Nif treatment. Moreover, the mRNA levels of the osteogenic markers, osteocalcin (OCN), bone sialoprotein (BSP), and runt-related transcription factor 2 (Runx2), were also down-regulated. In addition, we transfected α1C-siRNA into the cells to further confirm the role of VDCCL in rMSCs, and a similar effect on osteogenesis was found. These results suggest that VDCCL plays a crucial role in the proliferation and osteogenic differentiation of rMSCs.

Curcumin increases rat mesenchymal stem cell osteoblast differentiation but inhibits adipocyte differentiation

Background:Curcumin is a phenolic natural product isolated from the rhizome of Curcuma longa (turmeric) and has effects on bone health and fat formation. The bone marrow mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into osteoblasts and adipocytes. Osteoblast differentiation of MSCs can be a result of upregulation of heme oxygenase (HO)-1 expression. Curcumin can potently induce HO-1 expression.Objective:The present study describes the effects of curcumin on rat MSC (rMSCs) differentiation into osteoblasts and adipocytes.Materials and Methods:Rat bone marrow MSCs were isolated and treated with or without curcumin. Osteoblast differentiation was confirmed and determined by alkaline phosphatase (ALP) activity, mineralized nodule formation, the expression of Runx2 (runt-related transcription factor 2) and osteocalcin. Adipocyte differentiation was determined by Oil red O staining and the expression of peroxisome proliferator-activated receptor-γ 2 (PPARγ2) and CCAAT/enhancer-binding protein (C/EBP) α.Results:Curcumin increased ALP activity and osteoblast-specific mRNA expression of Runx2 and osteocalcin when rMSCs were cultured in osteogenic medium. In contrast, curcumin decreased adipocyte differentiation and inhibited adipocyte-specific mRNA expression of PPARγ2 and C/EBPα when rMSCs were cultured in adipogenic medium. HO-1 expression was increased during osteogenic differentiation of rMSCs.Conclusions:These findings demonstrate that curcumin can promote osteogenic differentiation of rMSCs and inhibit adipocyte formation. The effect of curcumin on osteogenic differentiation of rMSCs is correlated with HO-1 expression.