The Effects of Graphene on the Biocompatibility of a 3D-Printed Porous Titanium Alloy

3D-printed titanium (Ti) materials have attracted much attention in the field of bone tissue repair. However, the combination strength of traditional alloy materials with bone tissue is lower, and the elastic modulus is higher than that of natural bone tissue, which makes the titanium alloy susceptible to stress shielding phenomena after implantation. Therefore, it is urgent to find better surface modification technology. In this study, the physical and chemical properties, toxicity, and proliferation of adipose stem cells of composite graphene-coated titanium alloy (Gr–Ti) were investigated using 3D-printed titanium alloy as a material model. Physical and chemical property tests confirmed that 3D printing could produce porous titanium alloy materials; the compressive strength and elastic modulus of the titanium alloy scaffolds were 91 ± 3 MPa and 3.1 ± 0.4 GPa, matching the elastic modulus of normal bone tissue. The surface characterization shows that graphene can be coated on titanium alloy by a micro-arc oxidation process, which significantly improves the surface roughness of titanium alloy. The roughness factor (Ra) of the Ti stent was 4.95 ± 1.12 μm, while the Ra of the Gr–Ti stent was 6.37 ± 0.72 μm. After the adipose stem cells were co-cultured with the scaffold for 4 h and 24 h, it was found that the Gr–Ti scaffold could better promote the early cell adhesion. CCK-8 tests showed that the number of ADSCs on the G–Ti scaffold was significantly higher than that on the Ti scaffold (p < 0.01). The relative growth rate (RGR) of ADSCs in Gr–Ti was grade 0–1 (non-toxic). In the in vivo experiment of repairing a critical bone defect of a rabbit mandible, the bone volume fraction in the Gr–Ti group increased to 49.42 ± 3.28%, which was much higher than that in the Ti group (39.76 ± 3.62%) (p < 0.05). In conclusion, the porous graphene–titanium alloy promotes the proliferation and adhesion of adipose stem cells with multidirectional differentiation potential, which has great potential for the application of bone tissue engineering in repairing bone defects in the future.

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Effect of Substrate Elasticity on In Vitro Aging of Human Mesenchymal Stem Cells

MRS Proceedings ◽

10.1557/opl.2012.1678 ◽

2012 ◽

Vol 1498 ◽

pp. 39-45

Author(s):

Courtney E. LeBlon ◽

Caitlin R. Fodor ◽

Tony Zhang ◽

Xiaohui Zhang ◽

Sabrina S. Jedlicka

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Elastic Modulus ◽

Myogenic Differentiation ◽

Human Mesenchymal Stem Cells ◽

Immunofluorescent Staining ◽

Differentiation Potential ◽

Gene And Protein Expression ◽

The Impact

ABSTRACTHuman mesenchymal stem cells (hMSCs) were routinely cultured on tissue-culture polystyrene (TCPS) to investigate the in vitro aging and cell stiffening. hMSCs were also cultured on thermoplastic polyurethane (TPU), which is a biocompatible polymer with an elastic modulus of approximately 12.9MPa, to investigate the impact of substrate elastic modulus on cell stiffening and differentiation potential. Cells were passaged over several generations on each material. At each passage, cells were subjected to osteogenic and myogenic differentiation. Local cell elastic modulus was measured at every passage using atomic force microscopy (AFM) indentation. Gene and protein expression was examined using qRT-PCR and immunofluorescent staining, respectively, for osteogenic and myogenic markers. Results show that the success of myogenic differentiation is highly reliant on the elastic modulus of the undifferentiated cells. The success of osteogenic differentiations is most likely somewhat dependent on the cell elastic modulus, as differentiations were more successful in earlier passages, when cells were softer.

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220 CpG METHYLATION PROFILE OF ADIPOGENIC AND ENDOTHELIAL GENE PROMOTERS IN HUMAN ADIPOSE STEM CELLS SUGGESTS A RESTRICTIVE ENDOTHELIAL DIFFERENTIATION POTENTIAL

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab220 ◽

2007 ◽

Vol 19 (1) ◽

pp. 227

Author(s):

A. C. Boquest ◽

A. Noer ◽

A. L. Sørensen ◽

K. Vekterud ◽

P. Collas

Keyword(s):

Stem Cells ◽

Adipogenic Differentiation ◽

Cpg Methylation ◽

Methylation Profile ◽

Adipose Stem Cells ◽

Endothelial Differentiation ◽

Sequencing Analysis ◽

Differentiation Potential ◽

Undifferentiated Cells ◽

Endothelial Lineage

Mesenchymal stem cells (MSCs) have received intense research interest due to their perceived potential application in regenerative medicine; nevertheless, MSCs are primarily restricted to form mesodermal cell types. Adipose stem cells (ASCs) with a CD34+ CD105+ CD45– CD31– immunophenotype can be obtained in an uncultured state with high purity from the stromal vascular fraction of human liposuction material (Boquest et al. 2005 Mol. Biol. Cell 16, 1131–1141). While ASCs differentiate readily into adipocytes, their endothelial lineage commitment has been scarcely reported, and controversy remains regarding ASC contribution to vascularization. To address the epigenetic commitment of ASCs to adipogenic and endothelial lineages, we carried out a bisulfite sequencing analysis of CpG methylation in the promoters of adipogenic (LEP, PPARG2, FABP4, LPL), endothelial (CD31, CD144), and myogenic (MYOG) genes in freshly isolated and in clonal ASC cultures in relation to gene expression and differentiation potential. Uncultured ASCs display mosaic hypomethylation of adipogenic promoters, in contrast to MYOG, CD31, or CD144 which are methylated (Noer et al. 2006 Mol. Biol. Cell 17, in press). Nevertheless, CpG methylation does not reflect transcriptional status of these genes in undifferentiated cells. Culture and adipogenic differentiation of ASCs maintains the hypomethylated profile of adipogenic promoters and the hypermethylation of non-adipogenic promoters. Endothelial stimulation of ASCs in methylcellulose elicits tubule-like networks, up-regulation of CD31 and CD144, and restrictive induction of a CD31+ CD144+ immunophenotype. Discrete and lineage-specific changes in CpG methylation in the CD31 and CD144 promoters take place but no global demethylation that marks endothelial cells occurs. Promoters not involved in endothelial differentiation retain a methylation profile characteristic of undifferentiated cells. Hypermethylation of CD31 and CD144 suggests a restricted commitment of ASCs to the endothelial lineage. This contrasts with hypomethylation of adipogenic promoters which reflects a propensity toward adipogenic differentiation. Despite the up-regulation of lineage-specific transcripts, overall maintenance of promoter methylation after adipogenic, osteogenic, and endothelial differentiation suggests the maintenance of an epigenetic signature characteristic of undifferentiated cells. Analysis of CpG methylation at lineage-specific promoters should provide a robust assessment of epigenetic commitment of stem cells to a specific lineage.

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Chondrogenesis of Infrapatellar Fat Pad Derived Adipose Stem Cells in 3D Printed Chitosan Scaffold

PLoS ONE ◽

10.1371/journal.pone.0099410 ◽

2014 ◽

Vol 9 (6) ◽

pp. e99410 ◽

Cited By ~ 65

Author(s):

Ken Ye ◽

Raed Felimban ◽

Kathy Traianedes ◽

Simon E. Moulton ◽

Gordon G. Wallace ◽

...

Keyword(s):

Stem Cells ◽

Adipose Stem Cells ◽

Infrapatellar Fat Pad ◽

Fat Pad ◽

Chitosan Scaffold ◽

3D Printed

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Three-dimensional Printed Polylactic Acid and Hydroxyapatite Composite Scaffold with Urine-derived Stem Cells Treatment for Bone Defects

10.21203/rs.3.rs-996295/v1 ◽

2021 ◽

Author(s):

Xiang Zhang ◽

Jialei Chen ◽

Hongren Wang ◽

Xin Duan ◽

Feng Gao

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Bone Tissue Engineering ◽

Bone Tissue ◽

Polylactic Acid ◽

Composite Scaffold ◽

Bone Defects ◽

Skull Defect ◽

Defect Area ◽

3D Printed

Abstract BACKGROUND: Bone defects still pose various challenges in osteology. As one of the treatment options for bone defects, bone tissue engineering requires biomaterials with good biocompatibility and seed cells with good differentiation capacity. This study aimed to fabricate a 3D-printed polylactic acid and hydroxyapatite (PLA/HA) composite scaffold with urine-derived stem cells (USCs) to study its therapeutic effect in a model of skull defect in rats.METHODS: USCs, isolated and extracted from the urine of healthy adult males, were inoculated onto a 3D-printed PLA/HA composite scaffold and a PLA scaffold. Skull defect model rats were randomly divided into three groups (control, PLA, and PLA/HA). Twelve weeks after implanting scaffolds containing USCs into rats with a skull defect, the therapeutic efficacy was evaluated by real-time PCR, micro-CT, histology, and immunohistochemistry.RESULTS: The 3D-printed PLA/HA composite scaffold had good mechanical properties and porosity. The adhesion and proliferation of USCs on scaffolds also demonstrated excellent biocompatibility. PLA and PLA/HA containing USCs promoted bone regeneration in the defect area, supported by the general observation and CT images at 12 weeks after treatment, with coverage of 74.6%±1.9% and 96.7%±1.6%, respectively. Immunohistochemical staining showed a progressive process of new bone formation on PLA/HA scaffolds containing USCs at the defect site compared to that in PLA and control groups.CONCLUSION: The 3D-printed PLA/HA composite scaffold with USCs was successfully applied to the skull defect in rats. Under the linkage of the scaffold, the proliferation, differentiation, and osteogenesis expression of USCs were promoted near the bone defect area. These findings demonstrated broad application prospects of PLA/HA scaffolds with USCs in bone tissue engineering.

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DNA methylation profile of different clones of human adipose stem cells does not allow to predict their differentiation potential

Journal of Histotechnology ◽

10.1080/01478885.2019.1655962 ◽

2019 ◽

Vol 42 (4) ◽

pp. 183-192 ◽

Cited By ~ 1

Author(s):

Beatriz Vera-Pérez ◽

María I Arribas ◽

Nestor Vicente-Salar ◽

Juan A Reig ◽

Enrique Roche

Keyword(s):

Dna Methylation ◽

Stem Cells ◽

Methylation Profile ◽

Adipose Stem Cells ◽

Differentiation Potential ◽

Dna Methylation Profile ◽

Human Adipose Stem Cells

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3D-printed Porous Titanium Alloy Cages Versus PEEK Cages in Patients With Osteoporosis

Case Medical Research ◽

10.31525/ct1-nct04086784 ◽

2019 ◽

Author(s):

Keyword(s):

Titanium Alloy ◽

Porous Titanium ◽

3D Printed

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Increased COUP-TFII Expression Mediates the Differentiation Imbalance of Bone Marrow-Derived Mesenchymal Stem Cells in Femoral Head Osteonecrosis

BioMed Research International ◽

10.1155/2019/9262430 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Sheng-Hao Wang ◽

Guo-Hau Gou ◽

Chia-Chun Wu ◽

Hsain-Chung Shen ◽

Leou-Chyr Lin ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Femoral Head ◽

Bone Tissue ◽

Mesenchymal Cells ◽

Control Group ◽

Differentiation Potential ◽

Femoral Head Osteonecrosis ◽

Neck Fracture

Objective. Bone marrow-derived mesenchymal stem cells (BMSCs) have multilineage differentiation potential, which allows them to progress to osteogenesis, adipogenesis, and chondrogenesis. An imbalance of differentiation between osteogenesis and adipogenesis will result in pathologic conditions inside the bone. This type of imbalance is also one of the pathological findings in osteonecrosis of the femoral head (ONFH). Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) was previously reported to mediate the differentiation of mesenchymal stem cells. This study investigated the expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, and COUP-TFII in the femoral head tissue harvested from ONFH patients, and characterized the effect of COUP-TFII on the differentiation of primary BMSCs. Methods. Thirty patients with ONFH were recruited and separated into 3 groups: the trauma-, steroid- and alcohol-induced ONFH groups (10 patients each). Bone specimens were harvested from patients who underwent hip arthroplasty, and another 10 specimens were harvested from femoral neck fracture patients as the control group. Expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, C/EBP-α, and COUP-TFII was analyzed by Western blotting. Primary bone marrow mesenchymal cells were harvested from ONFH cells treated with COUP-TFII RNA interference to evaluate the effect of COUP-TFII on MSCs. Results. ONFH patients had significantly increased expression of the adipogenesis regulator PPARγ and C/EBP-α and decreased expression of the osteogenesis regulator osteocalcin. ONFH bone tissue also revealed higher COUP-TFII expression. Immunohistochemical staining displayed strong COUP-TFII immunoreactivity adjacent to osteonecrotic trabecular bone. Increased COUP-TFII expression in the bone tissue correlated with increased PPARγ and decreased osteocalcin expression. Knockdown of COUP-TFII with siRNA in BMSCs reduced adipogenesis and increased osteogenesis in mesenchymal cells. Conclusion. Increased COUP-TFII expression mediates the imbalance of BMSC differentiation and progression to ONFH in patients. This study might reveal a new target in the treatment of ONFH.

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