PCL/β-TCP Composite Scaffolds Exhibit Positive Osteogenic Differentiation with Mechanical Stimulation

We investigated the use of Polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) composites with applied mechanical stimulation as scaffold for bone tissue engineering. PCL-based three-dimensional (3D) structures were fabricated in a solvent-free process using a 3D-printing technique. The mass fraction of β-TCP was varied in the range 0–30%, and the structure and compressive modulus of the specimens was characterized. The shape and interconnectivity of the pores was found to be satisfactory, and the compressive modulus of the specimens was comparable with that of human trabecular bone. Human mesenchymal stem cells were seeded on the composites, and various biological evaluations were performed over 9 days. With a mass fraction of β-TCP of 30%, differentiation began earlier; however, the cell proliferation rate was lower. Through the use of mechanical stimulation, however, the proliferation rate recovered, and was comparable with that of the other groups. This stimulation effect was also observed in ECM generation and other biological assays. With mechanical stimulation, expression of osteogenic markers was lower on samples with a β-TCP content of 10 wt% than without β-TCP; however, with mechanical stimulation, the sample with a β-TCP content of 30 wt% exhibited significantly greater expression of those markers than the other samples. We found that mechanical stimulation and the addition of β-TCP interacted closely, and that a mass fraction of β-TCP of 30% was particularly useful as a bone tissue scaffold when accompanied by mechanical stimulation.

Therapeutic Potential of Human Mesenchymal Stem Cells for Treating Ischemic Limb Diseases

Ischemic limb diseases are induced by different obstructions of peripheral arteries. These obstructions result in insufficient nutrient and oxygen supplies to the extremities, thereby leading to severe tissue damage that is in turn related to severe morbidities and mortalities. Mesenchymal stem cells (MSCs) have been isolated from various sources. These cells are multipotent with respect to differentiation and are also characterized by migration, immune suppression, and secretion of paracrine factors. Mesenchymal stem cells have been proposed to have therapeutic potential for the treatment of ischemic limb diseases. In preclinical experiments, injection of single MSCs has been shown to increase angiogenesis and blood flow in ischemic hindlimb animal models; several molecular mechanisms of angiogenesis have also been elucidated. Furthermore, modified strategies have been developed for enhancing angiogenesis and the efficacy of MSCs. These strategies have demonstrated significant effects in pre-clinical studies. In clinical trials, MSCs have shown significant effects in the treatment of ischemic limb diseases. In this review, we focus on the therapeutic properties of human MSCs and the modified methods for enhancing angiogenesis in pre-clinical experiments. We also discuss the clinical applications of MSCs for treating limb ischemia.

Interferon-beta gene engineered human mesenchymal stem cells in the treatment of human prostate cancer xenograft in mouse model / 中华泌尿外科杂志

Objective To investigate the effect of human interferon-beta (IFN-β) gene engineered human mesenchymal stem cells (hMSC) in the treatment of human prostate cancer xenograft in nude mice.Methods An adenovirus vector containing human IFN-β gene was constructed and transfected into hMSC in vitro.IFN-β-expressing mesenchymal stem cells (IFN-β-hMSC) were labeled with 4,6-diamidino-2-phenylindole (DAPI).The human prostate cancer cell line PC-3 were injected into the flank or axillary of severe combined immunodeficiency (SCID) mice subcutaneously to establish human prostate cancer xenograft models.IFN-β-hMSC were injected into the tail vein of mice bearing human prostate cancer xenografts.The tumors,livers,lungs,spleens and kidneys were harvested.Frozen sections and paraffin sections were used to observe the distribution of IFN-β-hMSC in vivo by fluorescence microscope.Mice were divided into seven groups of six animals randomly,IFN-β-hMSC (2 × 106,2 × 105 ) as treatment group,Ad-hMSC,unmodified hMSC,Ad-IFN-β,Recombinant IFN-β,and NS as control group.The weight of the tumor and the survival time of mice were observed to evaluate the experimental efficacies of IFN-β-hMSC in the treatment of prostate cancer. Results IFN-β-hMSC with blue nuclei were distributed extensively in the tumors,but no blue nucleus was seen in the livers,lungs,spleens and kidneys.After treating,the weights of the tumour masses from mice were (1.35 ±0.28) g,(1.43±0.41) g,(3.49 ±0.25)g,(3.58±0.30)g,(3.30 ±0.24) g,(3.32 ±0.25) g,(3.32 ±0.47) g in the IFN-β-hMSC (2 ×106),IFN-β-hMSC (2 ×105),Ad-hMSC,unmodified hMSC,Ad-IFN-β,Recombinant IFN-β,and NS group,the median survival time from mice were 91 d,87 d,57 d,59 d,62 d,61 d,61 d in the IFN-β-hMSC (2 × 106),IFN-β-hMSC (2 × 105),Ad-hMSC,unmodified hMSCs,Ad-IFN-β,Recombinant IFN-β,and NS group,respectively.Injection of IFN-β-MSC can significantly reduce tumor weight and increase animal survival compared with controls ( P ＜ 0.05 ). Conclusion IFN-β-hMSC can migrate to prostate cancer microenviroment in vivo,and injection of IFN-β-MSC can significantly reduce tumor weight and increase animal survival.

Effects of Bisphosphonates on the Proliferation and the Alkaline Phosphatase Activity of Human Bone Marrow Derived Mesenchymal Stem Cells

Effect of RGD peptide coating of implant titanium surface on human mesenchymal stem cell response / 대한치과보철학회지

PURPOSE: The aim of this in vitro study was to estimate surface characteristic after peptide coating and investigate biological response of human mesenchymal stem cell to anodized titanium discs coated with RGD peptide by physical adhesion and chemical fixation. MATERIALS AND METHODS: Fluorescence isothiocyanate (FITC) modified RGD-peptide was coated on the anodized titanium discs (diameter 12 mm, height 3 mm) using two methods. One was physical adhesion method and the other was chemical fixation method. Physical adhesion was performed by dip and dry procedure, chemical fixation was performed by covalent bond via silanization. In this study, human mesenchymal stem cell was used for experiments. The experiments consisted of surface characteristic evaluation after peptide coating, analysis about cell adhesion, proliferation, differentiation, and mineralization. Obtained data are statistically treated using Kruskal-Wallis test and Bonferroni test was performed as post hoc test (P=.05). RESULTS: The evaluation of FE-SEM images revealed no diffenrence at micro-surfaces between each groups. Total coating dose was higher at physical adhesion experimental group than at chemical fixation experimental group. In cell adhesion and proliferation, RGD peptide coating did not show a statistical significance compared with control group (P>.05). In cell differentiation and mineralization, physical adhesion method displayed significantly increased levels compared with control group and chemical fixation method (P<.05). CONCLUSION: RGD peptide coating seems to enhance osseointegration by effects on the response of human mesenchymal stem cell. Especially physical adhesion method showed more effective than chemical fixation method on response of human mesenchymal stem cell.

Effect of enamel matrix derivative (EMD, Emdogain(R)) on the differentiation of cultured human periodontal ligament cells and mesenchymal stem cells

Pleiotrophin effects on binding and subsequent osteogenesis of human mesenchymal stem cells

Comparison of Phenotypic Characterization between "Alginate Bead" and "Pellet" Culture Systems as Chondrogenic Differentiation Models for Human Mesenchymal Stem Cells

Chondrogenesis involves the recruitment of mesenchymal cells to differentiate into chondroblasts, and also the cells must synthesize a cartilage-specific extracellular matrix. There were two representative culture systems that promoted the chondrogenic differentiation of human mesenchymal stem cells. These systems were adaptations of the "pellet" culture system, which was originally described as a method for preventing the phenotypic modulation of chondrocytes, and the "alginate bead" culture system, which was used to maintain encapsulated cells at their differentiated phenotype over time, and also it was used to maintain the cells' proteoglycan synthesis at a rate similar to that of primary chondrocytes. We performed test on the differences of phenotypic characterization with the two methods of differentiating human mesenchymal stem cells into chondrocytes. The typical gene for articular cartilage, collagen type II, was more strongly expressed in the "alginate bead" system than in the "pellet" culture system, in addition, specific gene for hypertrophic cartilage, collagen type X, was more rapidly expressed in the "pellet" system than in "alginate bead" culture system. Therefore, the "alginate bead" culture system is a more phenotypical, practical and appropriate system to differentiate human mesenchymal stem cells into articular chondrocytes than the "pellet" culture system.