Relationship Between Stressful Life Events and Online Deviant Behaviors Among College Students: A Moderated Mediation Model.

With the gradual penetration of the Internet into the study and life of college students, the Internet not only brings convenience to young adults but also becomes a new channel for them to engage in deviant behaviors. This study explores the relationship between stressful life events and college students' online deviant behaviors, as well as the mediating role of negative automatic thoughts and the moderating role of perceived social support. Data is drawn from 448 college students (Mage = 20.10, SDage = 1.74). Results showed that stressful life events were significantly positively correlated with online deviant behaviors, and negative automatic thoughts mediated the relationship between stressful life events and online deviant behaviors. The relationship between stressful life events and online deviant behaviors, as well as that between negative automatic thoughts and online deviant behaviors, were both moderated by perceived social support. This study provides a practical guiding value for effectively preventing and intervening in college students' online deviant behaviors and maintaining the regular order of the online society.

A multi-variable predictive warning model for cervical cancer using clinical and SNPs data.

Introduction: Cervical cancer is the fourth most common cancer among female worldwide. Early detection and intervention are essential. This study aims to construct an early predictive warning model for cervical cancer and precancerous lesions utilizing clinical data and simple nucleotide polymorphisms (SNPs). Methods: Clinical data and germline SNPs were collected from 472 participants. Univariate logistic regression, least absolute shrinkage selection operator (LASSO), and stepwise regression were performed to screen variables. Logistic regression (LR), support vector machine (SVM), random forest (RF), decision tree (DT), extreme gradient boosting(XGBoost) and neural network(NN) were applied to establish models. The receiver operating characteristic (ROC) curve was used to compare the models' efficiencies. The performance of models was validated using decision curve analysis (DCA). Results: The LR model, which included 6 SNPs and 2 clinical variables as independent risk factors for cervical carcinogenesis, was ultimately chosen as the most optimal model. The DCA showed that the LR model had a good clinical application. Discussion: The predictive model effectively foresees cervical cancer risk using clinical and SNP data, aiding in planning timely interventions. It provides a transparent tool for refining clinical decisions in cervical cancer management.

Correlation between genetic alterations and clinicopathological features of papillary thyroid carcinomas.

OBJECTIVE: To investigate the correlations between multigene alterations and clinicopathological features in papillary thyroid carcinoma (PTC) samples. METHODS: In this retrospective study, 111 cytological specimens of thyroid nodules, including 74 PTC samples and 37 benign samples, were analyzed using a 22-gene mutation assay employing next-generation sequencing. Clinicopathological information was retrospectively collected and analyzed. RESULTS: Gene alterations were associated with a higher rate of lymph node metastasis (LNM) and thyroid capsular invasion, a lower rate of coexisting Hashimoto's thyroiditis, the classical PTC subtype, and younger age (<45 years). Among the 22 genes tested, the BRAF mutation rates showed a significant difference between the PTC and benign groups. In the subgroup analysis, younger age (odds ratio = 12.512, 95% confidence interval: 3.126-50.087) was an independent risk factor for LNM. In further analyses, BRAF mutation was significantly associated with LNM in the older subgroup (age ≥ 45 years), suggesting that the BRAF mutation test has greater value for determining PTC prognosis in the older age group. CONCLUSIONS: Our findings will provide a more comprehensive understanding of the relationship between gene mutations and PTC and may contribute to improved PTC management.

Electromagnetic field-mediated chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds regulate the osteoblastic and chondrogenic phenotypes of adipose-derived stem cells to construct osteochondral tissue engineering niche in vitro.

It is critical to explore the effects of electromagnetic field (EMF) on the construction of functional osteochondral tissue, which has shown certain clinical significance for the treatment of osteochondral injury. At present, there are few studies on the effect of the direction of EMF on cells. This study aimed to investigate the effects of EMF coupling on different parameters to control adipose-derived stem cells (ADSCs) proliferation and specific chondrogenic and osteogenic differentiation at 2D level and 3D level. The proliferation and differentiation of EMF-induced ADSCs are jointly regulated by EMF and space structure. In this study, Cs7/Gel3/nHAP scaffolds were prepared with good degradation rate (86.75 ± 4.96 %) and absorb water (1100 %), and the pore size was 195.63 ± 54.72 µm. The bone-derived scaffold with a pore size of 267.17 ± 129.18 µm was obtained and its main component was hydroxyapatite. Cs7/Gel3/nHAP scaffolds and bone-derived scaffolds are suitable as 3D level materials. The optimal EMF intensity was 2 mT for chondrogenic differentiation and proliferation and 1 mT for osteogenic differentiation and proliferation. It is noteworthy that EMF has a negative correlation with ADSCs proliferation in the vertical direction at 2D level, while it has a positive correlation with ADSCs proliferation at 3D level. EMF mediated 3D osteochondral scaffold provide good strategy for osteochondral tissue engineering construction.

The Triterpenoids from Munronia pinnata and Their Anti-Proliferative Effects.

Six new tirucallane-type triterpenoids, named munropenes A-F (1-6), were extracted from the whole plants of Munronia pinnata using a water extraction method. Their chemical structures were determined based on detailed spectroscopic data. The relative configurations of the acyclic structures at C-17 of munropenes A-F (1-6) were established using carbon-proton spin-coupling constants (2,3JC,H) and inter-proton spin-coupling constants (3JH,H). Furthermore, the absolute configurations of munropenes A-F (1-6) were determined through high-performance liquid chromatography (HPLC), single-crystal X-ray diffraction, and electronic circular dichroism (ECD) analyses. The antiproliferative effects of munropenes A-F were evaluated in five tumor cell lines: HCT116, A549, HepG2, MCF7, and MDAMB. Munropenes A, B, D, and F (1, 2, 4, and 6) inhibited proliferation in the HCT116 cell line with IC50 values of 40.90, 19.13, 17.66, and 32.62 µM, respectively.

Study of Finite Element Simulation on the Mechano-Bactericidal Mechanism of Hierarchical Nanostructure Arrays.

Biomimetic nanostructures with bactericidal performance have become the research focus in constructing sterilization surfaces, but the mechano-bactericidal mechanism is still not fully understood, especially for the hierarchical nanostructure arrays with different heights. Herein, the interaction between Escherichia coli cells and nanostructure arrays was simulated by finite element, and the initial rupture points, i.e., critical action sites, of bacterial cells and the effects of nanostructure geometries on the cell rupture speed were analyzed based on the mechano-response of Escherichia coli cells on flat (identical heights) and hierarchical nanostructure arrays. The critical action sites of bacterial cells on nanostructure arrays are all at the three-phase junction zone of cell-liquid-nanostructure, but they are slightly shifted by the height difference ΔH of nanostructures on hierarchical nanopillar (NP)/nanosheet (NS) arrays, where the NP is higher than the NS. When ΔH < 20 nm, the site nears the NS corners, and when ΔH ≥ 20 nm, the site is consistent with that of the NP/NP array, i.e., the site locates at the three-phase junction zone of cell-liquid-high NP. In addition, except for decreasing the NP diameter, the NS thickness/width, or properly increasing the nanostructure spacing, the cell rupture can be accelerated via increasing the ΔH of nanostructures. ΔH = 40 nm is distinguished as the boundary for the effect of nanostructure ΔH on the cell rupture speed. When ΔH < 40 nm, the cell rupture speed rapidly increases as the ΔH increases; when ΔH ≥ 40 nm, the cell rupture speed reaches the maximum value and remains stable. This study provides a new strategy on how to design high-efficiency bactericidal surfaces.

Preparation and Characterization of Polylactic Acid/Nano Hydroxyapatite/Nano Hydroxyapatite/Human Acellular Amniotic Membrane (PLA/nHAp/HAAM) Hybrid Scaffold for Bone Tissue Defect Repair.

Bone tissue engineering is a novel and efficient repair method for bone tissue defects, and the key step of the bone tissue engineering repair strategy is to prepare non-toxic, metabolizable, biocompatible, bone-induced tissue engineering scaffolds of suitable mechanical strength. Human acellular amniotic membrane (HAAM) is mainly composed of collagen and mucopolysaccharide; it has a natural three-dimensional structure and no immunogenicity. In this study, a polylactic acid (PLA)/Hydroxyapatite (nHAp)/Human acellular amniotic membrane (HAAM) composite scaffold was prepared and the porosity, water absorption and elastic modulus of the composite scaffold were characterized. After that, the cell-scaffold composite was constructed using newborn Sprague Dawley (SD) rat osteoblasts to characterize the biological properties of the composite. In conclusion, the scaffolds have a composite structure of large and small holes with a large pore diameter of 200 µm and a small pore diameter of 30 µm. After adding HAAM, the contact angle of the composite decreases to 38.7°, and the water absorption reaches 249.7%. The addition of nHAp can improve the scaffold's mechanical strength. The degradation rate of the PLA+nHAp+HAAM group was the highest, reaching 39.48% after 12 weeks. Fluorescence staining showed that the cells were evenly distributed and had good activity on the composite scaffold; the PLA+nHAp+HAAM scaffold has the highest cell viability. The adhesion rate to HAAM was the highest, and the addition of nHAp and HAAM could promote the rapid adhesion of cells to scaffolds. The addition of HAAM and nHAp can significantly promote the secretion of ALP. Therefore, the PLA/nHAp/HAAM composite scaffold can support the adhesion, proliferation and differentiation of osteoblasts in vitro which provide sufficient space for cell proliferation, and is suitable for the formation and development of solid bone tissue.

Sequential gene expression analysis of cervical malignant transformation identifies RFC4 as a novel diagnostic and prognostic biomarker.

BACKGROUND: Cervical squamous cell carcinoma (SCC) is known to arise through increasingly higher-grade squamous intraepithelial lesions (SILs) or cervical intraepithelial neoplasias (CINs). This study aimed to describe sequential molecular changes and identify biomarkers in cervical malignant transformation. METHODS: Multidimensional data from five publicly available microarray and TCGA-CESC datasets were analyzed. Immunohistochemistry was carried out on 354 cervical tissues (42 normal, 62 CIN1, 26 CIN2, 47 CIN3, and 177 SCC) to determine the potential diagnostic and prognostic value of identified biomarkers. RESULTS: We demonstrated that normal epithelium and SILs presented higher molecular homogeneity than SCC. Genes in the region (e.g., 3q, 12q13) with copy number alteration or HPV integration were more likely to lose or gain expression. The IL-17 signaling pathway was enriched throughout disease progression with downregulation of IL17C and decreased Th17 cells at late stage. Furthermore, we identified AURKA, TOP2A, RFC4, and CEP55 as potential causative genes gradually upregulated during the normal-SILs-SCC transition. For detecting high-grade SIL (HSIL), TOP2A and RFC4 showed balanced sensitivity (both 88.2%) and specificity (87.1 and 90.1%), with high AUC (0.88 and 0.89). They had equivalent diagnostic performance alone to the combination of p16INK4a and Ki-67. Meanwhile, increased expression of RFC4 significantly and independently predicted favorable outcomes in multi-institutional cohorts of SCC patients. CONCLUSIONS: Our comprehensive study of gene expression profiling has identified dysregulated genes and biological processes during cervical carcinogenesis. RFC4 is proposed as a novel surrogate biomarker for determining HSIL and HSIL+, and an independent prognostic biomarker for SCC.

Gelatin/sodium alginate hydrogel-coated decellularized porcine coronary artery to construct bilayer tissue engineered blood vessels.

Cardiovascular diseases and vascular trauma can be commonly found in the population. Scholars worldwide hope to develop small-diameter vascular grafts that can replace autologous vessels for clinical use. Decellularized blood vessels can retain the original morphology, structure, and physical properties of blood vessels, which is conducive to cell growth, proliferation, and differentiation. In this study, porcine coronary arteries (PCAs) were decellularized to prepare decellularized porcine coronary artery (DPCA), and bilayer hybrid scaffolds were prepared by coating gelatin and sodium alginate mixed hydrogel of seven different proportions and combined with mouse fibroblasts (L929 cells) to study the construction of tissue engineering vessels in vitro. The obtained bilayer hybrid scaffolds were 3-7 cm in length, 5 mm in external diameter, and 1 mm in average wall thickness. All seven bilayer hybrid scaffolds showed good biocompatibility after cell inoculation. Compared with 2D culture, cells on 3D scaffolds grew relatively slowly in the first 4 days, and the number of cells proliferated rapidly at 7 days. In the same culture days, different concentrations of hydrogel also had an impact on cell proliferation. With the increase of hydrogel content, cells on the 3D scaffold formed cell colonies faster. The results showed that the scaffold had good biocompatibility and could meet the needs of artificial blood vessel construction.

Validation of the mechano-bactericidal mechanism of nanostructured surfaces with finite element simulation.

The mechano-bactericidal property of nanostructured surfaces has become the focus of intensive research toward the development of a new generation of antibacterial surfaces, especially in the current era of spreading antibiotic resistance. However, the mechanisms underlying nanostructured surfaces mechanically damaging bacteria remain unclear, which ultimately limits translational potential toward real-world applications. Using finite element simulation technique, we developed the three-dimensional thin wall with turgor pressure finite element model (3D-TWTP-FEM) of bacterial cell and verified the reliability of this model by the AFM indentation experiment simulation of the cell, and the cell model is able to simulate suspended bacterial cell and the process of cell adhering to the flat and nanopillar surfaces. Since bacterial cells suffer greater stress and deformation on the nanopillar surfaces, a two-stage model of the elastic and creep deformation stage of the cells on the nanostructured surfaces was developed. The calculations show that the location of the maximum stress/strain on the cells adhered to the nanopillar surfaces is at the liquid-cell-nanopillar three phase contact line. The computational results confirmed the ability of nanostructured surfaces to mechanically lyse bacteria and gave the effect of nanopillar geometry on the efficiency and speed of bacterial cell rupture. This study provides fundamental physical insights into how nanopillar surfaces can serve as effective and fast mechanical antimicrobial materials.

Low-Temperature Hydrothermal Synthesis of Novel 3D Hybrid Nanostructures on Titanium Surface with Mechano-bactericidal Performance.

Titanium is extensively employed in modern medicines as orthopedic and dental implants, but implant failures frequently occur because of bacterial infections. Herein, three types of 3D nanostructured titanium surfaces with nanowire clusters (NWC), nanowire/sheet clusters (NW/SC) and nanosheet clusters (NSC), were fabricated using the low-temperature hydrothermal synthesis under normal pressure, and assessed for the sterilization against two common human pathogens. The results show that the NWC and NSC surfaces merely display good bactericidal activity against Escherichia coli, whereas the NW/SC surface represents optimal bactericidal efficiency against both Escherichia coli (98.6 ± 1.23%) and Staphylococcus aureus (69.82 ± 2.79%). That is attributed to the hybrid geometric nanostructure of NW/SC, i.e., the pyramidal structures of ∼23 nm in tip diameter formed with tall clustered wires, and the sharper sheets of ∼8 nm in thickness in-between these nanopyramids. This nanostructure displays a unique mechano-bactericidal performance via the synergistic effect of capturing the bacteria cells and penetrating the cell membrane. This study proves that the low-temperature hydrothermal synthesized hybrid mechano-bactericidal titanium surfaces provide a promising solution for the construction of bactericidal biomedical implants.

Mechanism Study of Bacteria Killed on Nanostructures.

It is important to study the bactericidal mechanism with nanostructures for the design and preparation of high-efficiency sterilization materials. In this paper, the interfacial energy gradient between cells and nanopillars is proposed to be the driving force to promote cells to migrate into nanostructures and get killed. The expressions of interfacial energy and its gradient were first established, then the deformation of cells pressured by nanostructures was calculated. The results show that the interfacial energy gradient or the pressure on cells is influenced by nanopillar parameters substantially. The smaller the nanopillar diameter and the larger the pitch, the greater the pressure on cells. Only high enough nanocolumns can ensure sufficient cell creep deformation and become punctured. Furthermore, a cell volume and its adhesion morphology also influence the interaction between cells and nanostructures. The smaller the cell volume, the greater the pressure on it. And the larger the contact angle of adhered cells, the greater the pressure on the cells by nanopillars. Besides, the wettability of substrate material also influences the interaction between cells and nanopillars. It can be concluded that the model is reasonable and reliable since its calculation results are in good accordance with the experimental measurements.

Development of an Effective Scalable Enantioselective Synthesis of the HIV-1 Entry Inhibitor BNM-III-170 as the Bis-Trifluoroacetate Salt.

We report here the development and optimization of a process synthesis for the HIV-1 entry inhibitor BNM-III-170 bis-TFA salt (1). The synthesis features a dynamic-kinetic resolution (DKR) to establish the initial stereogenicity. By taking advantage of significant sequence modifications of our first generation synthesis, inconjunction with the low solubility of late-stage intermediates, the overall efficiency of the synthesis has been significantly improved, now to proceed in an overall yield of 9.64% for the 16-steps, requiring only a single chromatographic separation.

Total Synthesis of (-)-Nodulisporic Acids D, C, and B: Evolution of a Unified Synthetic Strategy.

A unified synthetic strategy leading to the total synthesis of (-)-nodulisporic acids D, C, and B is described. Key synthetic transformations include a nickel-chromium-mediated cyclization, an aromatic ring functionalization employing a novel copper-promoted alkylation, a palladium-catalyzed cross-coupling cascade/indole ring construction, and a palladium-mediated regio- and diastereoselective allylic substitution/cyclization reaction, the latter to construct ring D.

[The anti-inflammatory effects of idazoxan on inflammatory mediator release in endotoxin-challenged mice in vivo and activated macrophages in vitro].

Objective: To study the anti-inflammatory effects of idazoxan (IDA) on endotoxin lipopolysaccharide (LPS) challenged mice in vivo and activated macrophages in vitro, and explore its potential molecular mechanisms. Methods: To do the experiments in vivo,30 adult male C57BL/6 mice were randomly divided into control group, model group, and low,medium and high doses IDA groups (IDA-L,IDA-M, and IDA-H groups),n =6 in each group. The inflammatory model was reproduced by intraperitoneal injection of LPS 10 mg/kg, and the control group was injected with the same amount of normal saline. The IDA groups received LPS (10 mg/kg) and IDA 0.3,1.0 and 3.0 mg/kg, respectively. The blood samples of mice in each group were collected at 6 hours after the reproduction of the model .For the in vitro experiments, primary peritoneal macrophages were collected from 20 adult male C57BL/6 mouse cells and they were divided into control group, LPS group (10 mg/L) and LPS+IDA-L,IDA-M,IDA-H groups (10 mg/L LPS + 5,25,100 µmol/L IDA, respectively).Cell culture supernatants were collected at 24 hours after the reproduction of the model. Detection methods: enzyme linked immunosorbent assay (ELISA) was used to determine the levels of serum tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),monocyte chemotactic protein-1 (MCP-1) and nitric oxide (NO).Western Blot was used to determine the effect of IDA on the expression levels of nuclear factor-κB (NF-κB) in macrophages. Results: ① For the in vivo experiment, the serum levels of TNF-α and IL-6 were significantly elevated in the model group as compared with those in the control group [TNF-o (ng/L):403.96 ± 40.98 vs.17.50 ± 8.68;IL-6 (ng/L):61 400.31 ± 7 826.61 vs.2 436.30 ± 448.89;both P ＜ 0.01].IDA treatment could inhibit the elevation of inflammatory cytokines in a dose-dependent manner, with the most significant decrease in LPS+IDA-H group [TNF-α (ng/L):170.09 ± 28.53 vs.403.96 ± 40.98,IL-6 (ng/L):16 570.81 ± 1 083.65 vs.61 400.31± 7 826.61;both P ＜ 0.01].② For the in vitro experiment, the levels of TNF-α,IL-6,MCP-1,and NO secreted by LPS-stimulated macrophages were distinctly higher in the LPS group than those in the control group [TNF-α (ng/L):7 259.14 ± 320.70 vs.28.50±27.08,IL-6 (ng/L):14809.60±5852.73 vs.1 113.47±465.53,MCP-1 (ng/L):20847.37± 1 788.33 vs.447.37± 395.69,NO (µmol/L):1 900.00 ± 144.31 vs.603.03 ± 102.18;all P ＜ 0.01]. However, IDA intervention could lower the secretion of TNF-α,IL-6,MCP-1 and NO in a dose-dependent manner, with the most notable decrease in the LPS+IDA-H group [TNF-α (ng/L):784.40±281.90 vs.7259.14±320.70,IL-6 (ng/L):1 802.96± 1 534.18 vs.14 809.60± 5 852.73,MCP-1 (ng/L):2005.26± 1 534.28 vs.20847.37 ± 1 788.33,NO (µ mol/L):654.54± 150.21 vs.1 900.00 ± 144.31;all P ＜ 0.05].In addition, IDA at the concentration of 100 µmol/L could promote the translocation of NF-κBp65 in macrophages into the nucleus 15 minutes early and lead to increased NF-κBp65 expression (gray value:18.70 ± 2.29 vs.1.09 ± 0.36,P ＜ 0.05),hut significantly reduce the expression levels of NF-κBp50 in the nucleus at 45 minutes after treatment (gray value:1.99 ± 0.14 vs.2.94 ± 0.54,P ＜ 0.05). Conclusions: IDA could significantly reduce inflammation of mice challenged with LPS and inhibit inflammatory cytokines and mediators secreted by macrophage in a dose-dependent manner. High concentration of IDA (100 µmol/L) exhibited the greatest anti-inflammatory effects. The anti-inflammatory effect of IDA may be worked through NF-κB signaling pathway.

Thermo-responsive poly(N-isopropylacrylamide)-grafted hollow fiber membranes for osteoblasts culture and non-invasive harvest.

Hollow fiber membrane (HFM) culture system is one of the most important bioreactors for the large-scale culture and expansion of therapeutic cells. However, enzymatic and mechanical treatments are traditionally applied to harvest the expanded cells from HFMs, which inevitably causes harm to the cells. In this study, thermo-responsive cellulose acetate HFMs for cell culture and non-invasive harvest were prepared for the first time via free radical polymerization in the presence of cerium (IV). ATR-FTIR and elemental analysis results indicated that the poly(N-isopropylacrylamide) (PNIPAAm) was covalently grafted on HFMs successfully. Dynamic contact angle measurements at different temperatures revealed that the magnitude of volume phase transition was decreased with increasing grafted amount of PNIPAAm. And the amount of serum protein adsorbed on HFMs surface also displayed the same pattern. Meanwhile osteoblasts adhered and spread well on the surface of PNIPAAm-grafted HFMs at 37 °C. And Calcein-AM/PI staining, AB assay, ALP activity and OCN protein expression level all showed that PNIPAAm-grafted HFMs had good cell compatibility. After incubation at 20 °C for 120 min, the adhering cells on PNIPAAm-grafted HFMs turned to be round and detached after being gently pipetted. These results suggest that thermo-responsive HFMs are attractive cell culture substrates which enable cell culture, expansion and the recovery without proteolytic enzyme treatment for the application in tissue engineering and regenerative medicine.

Differentiation of reprogrammed human adipose mesenchymal stem cells toward neural cells with defined transcription factors.

Somatic cell reprogramming may become a powerful approach to generate specific human cell types for cell-fate determination studies and potential transplantation therapies of neurological diseases. Here we report a reprogramming methodology with which human adipose stem cells (hADSCs) can be differentiated into neural cells. After being reprogrammed with polycistronic plasmid carrying defined factor OCT3/4, SOX2, KLF4 and c-MYC, and further treated with neural induce medium, the hADSCs switched to differentiate toward neural cell lineages. The generated cells had normal karyotypes and exogenous vector sequences were not inserted in the genomes. Therefore, this cell lineage conversion methodology bypasses the risk of mutation and gene instability, and provides a novel strategy to obtain patient-specific neural cells for basic research and therapeutic application.

[Stimulation of sphingosine-1-phosphate on cardiomyogenic differentiation of mesenchymal stem cells].

To study the effect of sphingosine-1-phosphate (S1P) on the cardiomyogenic differentiation of human umbilical cord mesenchymal stem cells (UC-MSCs) and human adipose-derived mesenchymal stem cells (AD-MSCs), we seeded the cells in the culture plates and used cardiomyocyte culture medium (CMCM) combining with different concentration of S1P to induce UC-MSCs and AD-MSCs in vitro for 7, 14 and 28 days. Cardiomyogenic differentiations were identified through immunofluorescence staining, and the results were observed with fluorescence microscopy and confocal microscopy. The effects of S1P and CMCM on cell activity were evaluated by the methyl thiazolyl tetrazolium assay. The functional characteristic similar to cardiomyocytes was evaluated through detecting calcium transient. Our results showed that cardiomyogenic differentiation of UC-MSCs or AD-MSCs were enhanced with S1P concentration increasing, but cell activities declined. Results showed that the suitable differentiation time was 14 days, and the optimal concentration of S1P was 0.5 micromol/L. When working together with CMCM, S1P could promote the differentiation of UC-MSCs or AD-MSCs into functional cardiomyocytes, giving rise to specific electrophysiological properties (the calcium transient). Taken together, our results suggested that S1P could promote the differentiation of UC-MSCs or AD-MSCs into functional cardiomyocytes when being cultured in CMCM.

Induced pluripotent stem cells generated from human adipose-derived stem cells using a non-viral polycistronic plasmid in feeder-free conditions.

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells by ectopic expression of defined transcription factors (TFs). However, the optimal cell type and the easy reprogramming approaches that minimize genetic aberrations of parent cells must be considered before generating the iPSCs. This paper reports a method to generate iPSCs from adult human adipose-derived stem cells (hADSCs) without the use of a feeder layer, by ectopic expression of the defined transcription factors OCT4, SOX2, KLF4 and C-MYC using a polycistronic plasmid. The results, based on the expression of pluripotent marker, demonstrated that the iPSCs have the characteristics similar to those of embryonic stem cells (ESCs). The iPSCs differentiated into three embryonic germ layers both in vitro by embryoid body generation and in vivo by teratoma formation after being injected into immunodeficient mice. More importantly, the plasmid DNA does not integrate into the genome of human iPSCs as revealed by Southern blotting experiments. Karyotypic analysis also demonstrated that the reprogramming of hADSCs by the defined factors did not induce chromosomal abnormalities. Therefore, this technology provides a platform for studying the biology of iPSCs without viral vectors, and can hopefully overcome immune rejection and ethical concerns, which are the two important barriers of ESC applications.

Three-dimensional fabrication of engineered bone with human bio-derived bone scaffolds in a rotating wall vessel bioreactor.

Bone tissue engineering has emerged as a promising strategy in the effort to regenerate and repair diseased or damaged bone. The bioreactor, within which engineered bone tissue is cultured, plays a key role in the development of engineered bone graphs. In this work, the potentials of the rotating wall vessel bioreactor (RWVB) and the human bio-derived bone scaffolds (BDBS) for 3D bone culture are evaluated. The osteoblasts isolated from the cranium of neonatal Sprague-Dawley (SD) rat of 3 days old were expanded firstly with microcarrier suspension culture in a RWVB. After the assessment of the biological functions of the expanded cells by histomorphometry, the cells were seeded at 2 x 10(6) and 1 x 10(6) cells/mL, respectively, onto the 3D human BDBS and cultured for 3 weeks in the RWVB. The cells metabolism and nutrient concentration were monitored in the whole culture processes. The structure of the harvested bone tissues was observed with optical microscope and scanning electron microscope (SEM). The biological properties of the engineered bone were detected by alkaline phosphatase (ALP) expression and alizarin red staining to visualize the newly formed bone. Acridine orange/ethidium bromide (AO/EB) double fluorescence staining was used to analyze the cell activity. For a comparative study, cell seeded constructs were also cultured in static conditions. The results indicate that the bone grafts cultured in RWVB with two different seeded cell densities grew well, and the cell number expanded in RWVB was five times as that in T-flask and spinner flask. There were significantly more collagen fibers mineralized nodules and new osteoid tissue formed than those in T-flask and spinner flask. It also demonstrated that with the stress stimulation inside the fluid in the RWVB, the ALP expression could be increased; the formation of mineralized nodules can be accelerated.