Responses of Digestive, Antioxidant, Immunological and Metabolic Enzymes in the Intestines and Liver of Largemouth Bass (Micropterus salmoides) under the Biofloc Model.

To investigate the activities of intestinal digestive enzymes, liver antioxidant enzymes, immunological enzymes, and glucometabolic enzymes in largemouth bass (Micropterus salmoides) under the biofloc model, an experiment was conducted in 300-liter glass tanks. The experiment comprised a control group, which was fed a basal diet, and a biofloc group, where glucose was added to maintain a C/N ratio of 15. Each group had three parallel setups, with a stocking density of 20 fish per tank. The experiment ran for 60 days, employing a zero-water exchange aquaculture model. The results showed that at the end of the culture period, there were no significant differences between the initial weight, final weight, WGR, SGR, and SR of the biofloc group and the control group of largemouth bass (p > 0.05), whereas the lower FCR and the higher PER in the biofloc group were significant (p < 0.05); intestinal α-amylase, trypsin, and lipase activities of largemouth bass in the biofloc group were significantly increased by 37.20%, 64.11%, and 51.69%, respectively, compared with the control group (p < 0.05); liver superoxide dismutase and catalase activities, and total antioxidant capacity of largemouth bass in the biofloc group were significantly increased by 49.26%, 46.87%, and 98.94% (p < 0.05), while the malondialdehyde content was significantly reduced by 19.91% (p < 0.05); liver lysozyme, alkaline phosphatase, and acid phosphatase activities of largemouth bass in the biofloc group were significantly increased by 62.66%, 41.22%, and 29.66%, respectively (p < 0.05); liver glucokinase, pyruvate kinase, glucose-6-phosphate kinase, pyruvate kinase, glucose-6-phosphatase, and glycogen synthase activities were significantly increased by 46.29%, 99.33%, 32.54%, and 26.89%, respectively (p < 0.05). The study showed that the biofloc model of culturing largemouth bass can not only enhance digestive enzyme activities, antioxidant capacity, and immune response but can also promote the process of glucose metabolism and reduce feeding costs. This study provides data support for healthy culturing of largemouth bass in future production, provides a theoretical reference for optimizing the biofloc technology culture model, and is crucial for promoting the healthy and green development of aquaculture.

A High-Voltage Cathode Material with Ultralong Cycle Performance for Sodium-Ion Batteries.

Vanadium-based polyanionic materials are promising electrode materials for sodium-ion batteries (SIBs) due to their outstanding advantages such as high voltage, acceptable specific capacity, excellent structural reversibility, good thermal stability, etc. Polyanionic compounds, moreover, can exhibit excellent multiplicity performance as well as good cycling stability after well-designed carbon covering and bulk-phase doping and thus have attracted the attention of multiple researchers in recent years. In this paper, after the modification of carbon capping and bulk-phase nitrogen doping, compared to pristine Na3 V2 (PO4 )3 , the well optimized Na3 V(PO3 )3 N/C possesses improved electromagnetic induction strength and structural stability, therefore exhibits exceptional cycling capability of 96.11% after 500 cycles at 2 C (1 C = 80 mA g-1 ) with an elevated voltage platform of 4 V (vs Na+ /Na). Meanwhile, the designed Na3 V(PO3 )3 N/C possesses an exceptionally low volume change of ≈0.12% during cycling, demonstrating its quasi-zero strain property, ensuring an impressive capacity retention of 70.26% after 10,000 cycles at 2 C. This work provides a facial and cost-effective synthesis method to obtain stable vanadium-based phosphate materials and highlights the enhanced electrochemical properties through the strategy of carbon rapping and bulk-phase nitrogen doping.

Recent advances on low-Co and Co-free high entropy layered oxide cathodes for lithium-ion batteries.

As the price of the precious metal cobalt continues to rise, there is an urgent need for a cobalt-free or low-cobalt electrode material to reduce the cost of lithium-ion batteries, which are widely used commercially, while maintaining their performance as much as possible. With the introduction of the new concept of high entropy (HE) materials into the battery field, low cobalt and cobalt free HE novel lithium-ion batteries have attracted great attention. It possesses important research value to use HE materials to reduce the use of cobalt metal in electrode materials. In this perspective, the comparison between the new cathode materials of low cobalt and cobalt-free HE lithium-ion battery and traditional cathode materials and the latest progress in maintaining structural stability and conductivity are introduced. It is believed that low cobalt and cobalt-free and HE layered oxides can be used to replace the function of cobalt in the cathode materials of lithium-ion batteries. Finally, the future research directions and the synthesis method of HE cathode materials for lithium-ion batteries are also discussed.

Formation of SiO2@C-Ni magnetic nanotubes with excellent performance in 4-nitrophenol reduction.

A facile and rational strategy for immobilizing nickel nanoparticles (Ni NPs) on silica nanotubes (SiO2@C-Ni) was developed via the Stöber method, nickel ion mediated dopamine polymerization and carbonization treatment, coupled with removal of the template of one-dimensional (1D) MnO2 nanowires (NWs). The as-prepared SiO2@C-Ni nanotubes show vast interior space with a large specific surface area and an open channel, which offer a spacious transport channel for molecular diffusion and electron transfer. Consequently, SiO2@C-Ni nanotubes exhibited outstanding catalytic efficiency and excellent stability for 4-nitrophenol (4-NP) reduction. Their superior catalytic activity could be ascribed to the high coverage of Ni NPs and the tubular structure of the obtained SiO2@C-Ni, by which the silica nanotubes enhanced the accessibility of the active sites and increased the mass transfer. This facile and controllable strategy may introduce a new avenue for designing metal NP-supported composites with high dispersion for diverse applications.

Recombinant Virus-like Particles of Human Parvovirus B19 with the Internal Location of VP1 Unique Region Produced by Hansenula polymorpha.

Human parvovirus B19 (HPV B19) is pathogenic to human, which can cause fifth disease, transient aplastic crisis, arthritis, myocarditis, autoimmune disorders, hydrops fetalis, and so on. Currently, no approved vaccines or antiviral drugs are available against HPV B19, and thus the development of effective vaccines is needed. The capsid of HPV B19 is composed of two types of proteins, i.e., the major capsid protein VP2 and the minor protein VP1. Previous experimental studies have shown that the dominant immune responses against HPV B19 are elicited by VP1, especially the unique region on the N-terminus of VP1. It has been found that VP2 alone or VP2 and VP1 together can assemble into virus-like particle (VLP). The VLP structure formed by VP2 has been resolved, however, the location of VP1 in the capsid, especially the location of VP1 unique region with strong immunogenicity, is still not clear. In the present work, using the Hansenula polymorpha expression system developed by our laboratory, two kinds of recombinant HPV B19 VLPs were expressed, i.e., the VLP co-assembled by VP1 and VP2 (VP1/VP2 VLP) and the VLP whose VP1 content was improved (VP1h/VP2 VLP). The expression, purity, and morphology of these two VLPs were characterized, and then their immunogenic properties were investigated and compared with those of the VLP containing VP2 alone (VP2 VLP) previously developed by our group. Furthermore, the location of the VP1 unique region in the VLPs was determined by using the immunogold electron microscopy (IGEM). Our experimental results show that the VP1h/VP2 VLP elicits a stronger neutralization against the HPV B19 than VP2 and VP1/VP2 VLPs, which implies that the increase of VP1 content significantly improves the level of neutralizing antibodies. In addition, the IGEM observations suggest that the unique region of VP1 may be located inside the recombinant VLP. The VLPs recombinantly expressed by our Hansenula polymorpha system may serve as a promising candidate immunogen for HPV B19 vaccine development.

Human Periodontal Ligament Stem Cells Transplanted with Nanohydroxyapatite/Chitosan/Gelatin 3D Porous Scaffolds Promote Jaw Bone Regeneration in Swine.

Dental-tissue-derived stem cells have been used for tissue engineering owing to their ease of isolation and efficacy in in vitro and in vivo proliferation and differentiation. Nanohydroxyapatite/chitosan/gelatin (nHA/CG) three-dimensional porous scaffolds are promising for bone tissue engineering, especially jaw bone regeneration, because of their structural and functional similarity to natural bone. In our previous study, the efficiency of scaffolds with stem cell complexes in osteogenesis was confirmed in vivo in immunocompromised mice. However, studies on the bone regeneration efficiency of stem cell-seeded nHA/CG scaffolds using large animal jaw bone defect models have not been conducted. This study evaluated the bone regeneration potential of the nHA/CG scaffolds with transplanted human periodontal ligament stem cells (hPDLSCs) in critical-sized jaw bone defects in minipigs. The hPDLSCs isolated from periodontal ligaments of discarded teeth (postorthodontic purposes) were seeded onto the nHA/CG scaffolds. The scaffold was successfully synthesized according to our previous studies. Forty-eight critical-sized jaw bone defects were created in 12 minipigs. The defects were randomly assigned to one of three groups [scaffolds with seeded hPDLSCs (hPDLSCs/nHA/CG), only scaffold (nHA/CG), and a negative control group, ie, no cells and scaffolds implanted into defects] to investigate jaw bone regeneration. The bone regeneration capacities of the three groups were assessed for up to 12 weeks. The results showed that the hPDLSCs adhered well to the nHA/CG scaffold in vitro, and the cell-nHA/CG composites significantly increased new bone formation and generated large bones with normal architectures and vascularization in vivo compared to the nHA/CG and control groups. Immunohistochemistry staining showed that runt-related transcription factor 2 (Runx2) was highly expressed in the bone marrow formed in the hPDLSCs/nHA/CG group. This study provides strong evidence for future clinical applications of the nHA/CG scaffolds transplanted with hPDLSCs to regenerate the bone in large jaw bone defects.

Green synthesis of reusable super-paramagnetic diatomite for aqueous nickel (II) removal.

Adsorption is an effective method for treating wastewater containing nickel due to its minimal equipment requirements and flexible operation. Therefore, an environmental friendly, inexpensive, efficient and recyclable adsorbent is needed. In this work, a reusable dual-functional super-paramagnetic adsorbent was prepared by combining APTES (3-Aminopropyltriethoxysilane) and EDTA (ethylenediaminetetraacetic acid disodium) with magnetic diatomite for the removal of Ni2+. It is named diatomite/CoFe2O4@APTES-EDTA (DECFASEs). The synthetic material was characterized and studied by XRD (X-ray Powder Diffractometer), FTIR (Fourier Transform Infrared Spectrometer), SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), EDS (Energy Dispersive Spectrometer), VSM (Vibrating-Sample Magnetometer), BET (Brunauer-Emmett-Teller) method, Zeta potential analyzer and XPS (X-ray Photoelectron Spectroscopy), respectively. The performance of adsorption Ni2+ by DECFASEs was studied on effect of pH, reaction time and initial concentrations. The adsorption and desorption capacity and recyclability of the adsorbent material were estimated. A adsorption kinetic data had a significant correlation with the pseudo second-order kinetic and also adsorption isotherm data corresponded well with Freundlich adsorption isotherm. The maximum adsorption capacity of the adsorbent material was 19.22 mg/g. The Ni2+ adsorption capacity of DECFASEs decreased slightly from 9.11 to 8.25 mg/g after 4 recycles. The XPS results of DECFASEs before and after Ni2+ uptake showed N and O participated in the complexation of Ni2+ in the adsorption process, which verified the chemical interaction between Ni2+ and DECFASEs. Modified-diatomite is a promising adsorbent for aqueous Ni2+ removal.

Tensile force-induced PDGF-BB/PDGFRß signals in periodontal ligament fibroblasts activate JAK2/STAT3 for orthodontic tooth movement.

Orthodontic force-induced osteogenic differentiation and bone formation at tension side play a pivotal role in orthodontic tooth movement (OTM). Platelet-derived growth factor-BB (PDGF-BB) is a clinically proven growth factor during bone regeneration process with unclear mechanisms. Fibroblasts in periodontal ligament (PDL) are considered to be mechanosensitive under orthodontic force. Thus, we established OTM model to investigate the correlation between PDGF-BB and fibroblasts during bone regeneration at tension side. We confirmed that tensile force stimulated PDL cells to induce osteogenic differentiation via Runx-2, OCN up-regulation, and to accelerate new bone deposition along the periodontium and the alveolar bone interface. Interestingly, PDGF-BB level was remarkably enhanced at tension side during OTM in parallel with up-regulated PDGFRß+/α-SMA+ fibroblasts in PDL by immunohistochemistry. Moreover, orthodontic force-treated primary fibroblasts from PDL were isolated and, cultured in vitro, which showed similar morphology and phenotype with control fibroblasts without OTM treatment. PDGFRß expression was confirmed to be increased in orthodontic force-treated fibroblasts by immunofluorescence and flow cytometry. Bioinformatics analysis identified that PDGF-BB/PDGFRß signals were relevant to the activation of JAK/STAT3 signals. The protein expression of JAK2 and STAT3 was elevated in PDL of tension side. Importantly, in vivo, the treatment of the inhibitors (imatinib and AG490) for PDGFRß and JAK-STAT signals were capable of attenuating the tooth movement. The osteogenic differentiation and bone regeneration in tension side were down-regulated upon the treatment of inhibitors during OTM. Meanwhile, the expressions of PDGFRß, JAK2 and STAT3 were inhibited by imatinib and AG490. Thus, we concluded that tensile force-induced PDGF-BB activated JAK2/STAT3 signals in PDGFRß+ fibroblasts in bone formation during OTM.

Erratum: LncRNA SNHG16 induced by TFAP2A modulates glycolysis and proliferation of endometrial carcinoma through miR-490-3p/HK2 axis.

[This corrects the article on p. 7137 in vol. 11, PMID: 31814916.].

Appraisal of EUS-guided needle-based confocal laser endomicroscopy in the diagnosis of pancreatic lesions: A single Chinese center experience.

BACKGROUND AND OBJECTIVES: In the recent years, EUS is one of the routine procedures in the diagnosis of pancreatic diseases. EUS-guided needle-based confocal laser endomicroscopy (nCLE) is a novel minimally invasive imaging technique in diagnosis of pancreatic diseases. The pilot researches provided us some preliminary findings and conclusions with small samples, low rate of pathological correspondence. The aim of this current study was to evaluate the diagnostic efficacy of EUS-guided nCLE in solid pancreatic lesions (SPLs) and pancreatic cystic lesions (PCLs) based on large samples. The date was obtained on nCLE imaging findings and high rate of correlation with pathology. MATERIAL AND METHODS: Patients enrolled in the study were underwent EUS-nCLE to achieve the nCLE images and diagnosis. Comparing with the final diagnosis, including surgical histopathological results or cyto-/histopathology through FNA, the efficacy and accuracy of nCLE in diagnosis in solid and cystic pancreatic lesions were evaluated. In other cases, clinical diagnoses were achieved based on the combination with clinical history, image findings and fluid analysis and cytology, by 3 independent committee members strongly agreed with a concordant diagnosis. RESULTS: Totally 172 patients were enrolled into the study. The overall rate of final diagnosis was about 65% while 50% in cystic lesion. The mean sensitivity, specificity, negative predictive value, positive predictive value and accuracy of the nCLE in diagnosis of PDAC is 90.3%, 89.5%, 93.3%, 85.0% and 90.0% respectively. The efficacy and accuracy of pancreatic cystic lesions were very satisfying and some additional nCLE signs were found, including "black aggregates of cells, forming as gland-like structure, surrounding by fibro and vessels" in neuroendocrine tumors (NETs); "black columnar protrusions near vascular area" in the pseudopapillary solid tumor (SPT); macrophage in tuberculosis (TB) and small aggregate of black regular cells maybe corresponds to ovarian-like stroma in mucinous cystadenoma (MCN). In the study, 20 (11.6%) patients suffered complications, including symptomatic (5.2%) and asymptomatic (6.4%). CONCLUSIONS: nCLE observation could improve characterization of indeterminate cysts, or confirm the EUS impression, when cytological confirmation is missing. The technique may deliver information to better guide our clinical decisions.

Green synthesis of reusable multifunctional γ-Fe2O3/bentonite modified by doped TiO2 hollow spherical nanocomposite for removal of BPA.

Eco-friendly treatment of refractory pollutants in wastewater is still full of challenge in catalytic oxidation and adsorption. In this study, based on the concept of green chemistry, sulfur-doped titanium dioxide hollow spheres modified by surfactant loaded on magnetic bentonite (CST/γ-Fe2O3-BT) is synthesized in two steps, and bisphenol A (BPA) was chosen as the representative organic pollutant. These materials were characterized by means of XRD, FTIR, SEM, EDS, TEM, XPS, BET, and VSM techniques. The adsorption and photodegradation behavior of CST/γ-Fe2O3-BT were examined. The Langmuir isotherm exhibited a better fit with a maximum adsorption capacity of 77.36 mg/g. At pH 7, the reaction rate constant (k) of the BPA photocatalytic degradation by product was 0.00104 min-1, and the adsorption equilibrium constant (K) was 0.04034L/mg. In addition, the composite can be recovered from the reaction mixture by applying an external magnetic field due to the existence of the superparamagnetic iron oxide nanoparticles in the construct. The recovered particles retained their catalytic activity which the catalytic activity of the material still reached 91% of the first catalytic experiment after 5 repetitive experiments. Results infer that the material has excellent reusability. Thus, CST/γ-Fe2O3-BT is a significant candidate for the treatment of recalcitrant organic pollutants in wastewater.

LncRNA SNHG16 induced by TFAP2A modulates glycolysis and proliferation of endometrial carcinoma through miR-490-3p/HK2 axis.

Increasing evidence indicates the important roles of long noncoding RNA (lncRNA) in the endometrial carcinoma (ECa). Here, we identified the roles of SNHG16 in the ECa proliferation and glycolysis, and revealed the underlying mechanism. Results presented that SNHG16 expression was increased in the ECa tissue and cells, and the ectopic SNHG16 overexpression was closely correlated with the poor survival rate and recurrence free survival of ECa. As regarding the upstream, transcription factor TFAP2A bound with the promotor region of SNHG16 and activated its transcription. In functional experiments, SNHG16 knockdown suppressed the proliferation, glycolysis and tumor growth of ECa cells. In mechanical experiments, SNHG16 upregulated HK2, the target gene of miR-490-3p, by competitively sponging miR-490-3p and then promoted endometrial carcinoma proliferation and glycolysis. In conclusion, this finding illustrates the vital role of SNHG16 via the TFAP2A/SNHG16/miR-490-3p/HK2 axis in the ECa proliferation and glycolysis, providing an interesting insight for the ECa tumorigenesis.

Synthesis of amino-functionalized bentonite/CoFe2O4@MnO2 magnetic recoverable nanoparticles for aqueous Cd2+ removal.

Magnetic nano-composite materials have been attracting considerable attention due to their unique properties and versatile applications. In this study, a novel magnetic amino-functionalized conjugate adsorbent, named as bentonite/CoFe2O4@MnO2-NH2 (BCFMNs), was synthesized by combining APTES and MnO2 with magnetic bentonite. XRD, FT-IR, SEM, EDS, TEM, and VSM techniques were used to characterize its structure and magnetic properties. Results were in indicative of productive synthesis, well-defined architecture and satisfactory magnetism. BET examinations illustrated 84.97m2/g of specific surface area, 0.15cm3/g of pore volume and 7.02nm average pore size. The effect parameters such as adsorbent dosage, contact time, initial concentration and ion selectivity and recycling were evaluated and optimized systematically. Also, the metal concentrations were measured by ICP-MS spectrometer. The feasibility of the BCFMNs for removal of Cd2+ from aqueous solution was also evaluated by adsorption experiments with the maximal adsorption efficiency for Cd2+ up to 98.88%. Cd2+ adsorption could be interpreted by the Langmuir adsorption isotherm and the maximum adsorption capacity was 115.79mg/g. The results revealed that the adsorbent still had higher selectivity of Cd2+ removal even in the presence of high concentration coexisting cations. The as-prepared magnetic conjugate adsorbent could be recycled by taking advantage of its magnetic properties. The distinctive structure of BCFMNs and its excellent adsorption performance of cadmium reflects its prospective application in water treatment.

The Effects of Platelet-Derived Growth Factor-BB on Human Dental Pulp Stem Cells Mediated Dentin-Pulp Complex Regeneration.

Dentin-pulp complex regeneration is a promising alternative treatment for the irreversible pulpitis caused by tooth trauma or dental caries. This process mainly relies on the recruitment of endogenous or the transplanted dental pulp stem cells (DPSCs) to guide dentin-pulp tissue formation. Platelet-derived growth factor (PDGF), a well-known potent mitogenic, angiogenic, and chemoattractive agent, has been widely used in tissue regeneration. However, the mechanisms underlying the therapeutic effects of PDGF on dentin-pulp complex regeneration are still unclear. In this study, we tested the effect of PDGF-BB on dentin-pulp tissue regeneration by establishing PDGF-BB gene-modified human dental pulp stem cells (hDPSCs) using a lentivirus. Our results showed that PDGF-BB can significantly enhance hDPSC proliferation and odontoblastic differentiation. Furthermore, PDGF-BB and vascular endothelial growth factor (VEGF) secreted by hDPSCs enhanced angiogenesis. The chemoattractive effect of PDGF-BB on hDPSCs was also confirmed using a Transwell chemotactic migration model. We further determined that PDGF-BB facilitates hDPSCs migration via the activation of the phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway. In vivo, CM-DiI-labeled hDPSCs were injected subcutaneously into mice, and our results showed that more labeled cells were recruited to the sites implanted with calcium phosphate cement scaffolds containing PDGF-BB gene-modified hDPSCs. Finally, the tissue-engineered complexes were implanted subcutaneously in mice for 12 weeks, the Lenti-PDGF group generated more dentin-like mineralized tissue which showed positive staining for the DSPP protein, similar to tooth dentin tissue, and was surrounded by highly vascularized dental pulp-like connective tissue. Taken together, our data demonstrated that the PDGF-BB possesses a powerful function in prompting stem cell-based dentin-pulp tissue regeneration. Stem Cells Translational Medicine 2017;6:2126-2134.

Dalbergioidin (DAL) protects MC3T3-E1 osteoblastic cells against H2O2-induced cell damage through activation of the PI3K/AKT/SMAD1 pathway.

Reactive oxygen species (ROS) is a pivotal pathogenic factor in the development of osteoporosis. Dalbergioidin (DAL) can be isolated from Uraria crinite, an edible herb used as a natural food for childhood skeletal dysplasia. Recent research has implicated DAL as having an antiosteoporosis effect, although the mechanism of this is unclear. We used an effective oxidative stress model, induced by hydrogen peroxide (H2O2) in osteoblastic MC3T3-E1 cells, to investigate the protective effects of DAL in osteoporosis and the underlying molecular mechanisms. The results indicated that treatment with DAL maintained redox balance, reduced MC3T3-E1 cell apoptosis, improved alkaline phosphatase activity, and elevated the osteogenic-related protein expression of Runx2, Osterix, and BMP2 against oxidative damage induced by H2O2. The potential molecular mechanism involved in the protective effect of DAL against H2O2-induced cell death in MC3T3-E1 cells may lie in the activation of the PI3K/AKT/SMAD1 cell signal pathway. Taken together, the results indicated that the potential protective effects of DAL against osteoporosis were linked to a reduction in oxidative damage, suggesting that DAL may be useful in bone metabolism diseases, particularly osteoporosis.

Geographical and seasonal patterns of geosmin and 2-methylisoborneol in environmental water in jiangsu province of china.

This study was conducted to obtain the basic data of two common odorants-geosmin and 2-methylisoborneol (GSM and 2-MIB)-in environmental water. More specifically, the headspace solid-phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS) was applied to determine the levels of GSM and 2-MIB in water samples, and the samples were collected depending on water sources, conventional treatment processes, and seasons. The significant difference was shown for the 2-MIB levels of source water (P < 0.05), the concentrations of GSM and 2-MIB decreased significantly as treatment process of tap water moved forward (P < 0.0001), and the significant differences for the levels of GSM and 2-MIB were observed among three sampling periods (P < 0.01). The levels of GSM and 2-MIB in all water samples were lower than 10 ng L(-1), the odor threshold concentration (OTC), and the conventional treatment process plays a significant role in removing odorants in tap water.

Vacuum extraction enhances rhPDGF-BB immobilization on nanotubes to improve implant osseointegration in ovariectomized rats.

Nanotube morphology has been previously applied to improve osseointegration in osteoporosis, but the osteogenic capability of the technique requires further improvements. This study aimed to investigate the effects of vacuum extraction on the loading of rhPDGF-BB on nanotube arrays as well as its effects on the osseointegration of ovariectomized (OVX) rats. More rhPDGF-BB protein particles aggregated on the nanotube surface and into the nanotube after vacuum extraction for 10 min. The immobilized protein could be slowly released for at least 14 days and still kept its biological activity. In vitro, the immobilized rhPDGF-BB enhanced cell adhesion, proliferation and osteogenic differentiation. In vivo, more rhPDGF-BB immobilized on the nanotube surface also promoted the osseointegration. These results suggest that the enhanced immobilization of rhPDGF-BB on nanotube arrays can potentially be used in the future as an implant surface modification strategy in dental and orthopedic applications in osteoporotic patients. FROM THE CLINICAL EDITOR: This study presents convincing evidence that enhanced immobilization of recombinant human PDGF-BB protein particles on nanotubes lead to improved osteogenic differentiation in an experimental system. When used as a surface modification strategy for dental or orthopedic implants, this method was able to promote osseointegration even in an osteoporotic animal model, raising the likelihood for potential future clinical applications.

rhPDGF-BB via ERK pathway osteogenesis and adipogenesis balancing in ADSCs for critical-sized calvarial defect repair.

Adipose-derived stem cells (ADSCs) with the capacity of differentiating into osteo-like cells have been widely investigated for bone tissue engineering as a novel seed cell source. Recombinant human platelet-derived growth factor (rhPDGF-BB) is a clinically proven growth factor with the potential of promoting cell proliferation and osteogenic differentiation during the bone regeneration process. In this study, we investigated the effects of rhPDGF-BB on the proliferation and osteogenic and adipogenic differentiation of rat ADSCs and explored whether the extracellular signal-related kinase (ERK) signaling pathway might be involved. We found that rhPDGF-BB significantly enhanced ADSCs proliferation and osteogenic differentiation, as detected by MTT, real-time polymerase chain reaction (PCR), ALP activity assays, and calcium deposition in vitro, in concert with ERK pathway activation. In contrast, the adipogenesis of ADSCs, as detected by real-time PCR and Oil Red O staining, was suppressed in the presence of rhPDGF-BB. Furthermore, with the supplement of the ERK inhibitor PD98059, cell proliferation and osteogenesis were reduced; as expected, adipogenesis was enhanced. Subsequently, for the first time, we evaluated the effect of ADSCs associated with rhPDGF-BB on bone regeneration in a critical-sized rat calvarial defect model with silk scaffold as a carrier. Micro-computed tomography and histological analyses exhibited dramatically more new bone formation and trabecular number in the Silk/PDGF/ADSC group. These data indicated that rhPDGF-BB promoted cell proliferation and osteogenic differentiation and suppressed adipogenic differentiation in vitro via ERK pathway and that ADSCs associated with rhPDGF-BB could be a promising tissue-engineered construct for craniofacial bone regeneration in vivo.

[Repair of calvarial defect using a tissue-engineered bone with simvastatin-loaded ß-tricalcium phosphate scaffold and adipose derived stem cells in rabbits].

PURPOSE: The osteogenic-angiogenic differentiation effects of simvastatin (Sim) were explored on adipose tissue-derived stem cells (ASCs). A tissue-engineered bone with simvastatin loaded ß-tricalcium phosphate (ß-TCP) scaffold and ASCs was constructed to repair the calvarial defect in rabbits. METHODS: ASCs were obtained from the groin of rabbits. After 14 days of osteogenic inducing culture, sufficient cells were expanded for the following experiments. Cell counting was conducted to ASCs in osteogenic inducing medium containing 0, 0.01, 0.1 and 1 µmol/L simvastatin. Concentrations of 0.05 and 0.1 µmol/L simvastatin were administrated to ASCs for real-time PCR of angiogenesis-osteogenesis related genes like RUNX2, OPN, OCN, and VEGF on day 1, 7. ALP staining was performed on day 7, Alizarin red staining for calcium deposits was carried out on day 14. Bilateral critical-sized defects were created on 12 New Zealand rabbits. Four groups of tissue-engineered bone were randomly allocated to them. Group A: ß-tricalcium phosphate (ß-TCP) (n=6); group B: ß-TCP/Cell (n=6); group C: ß-TCP/Sim (n=6); group D: ß-TCP/Cell/Sim (n=6). Specimens were decalcified and stained by HE 8 weeks after operation. The data was statistically analyzed using SPSS 17.0 software package. RESULTS: The use of simvastatin with the concentration of 0.05 µmol/L enhanced the expression of angiogenic-osteogenic related genes like RUNX2, OPN, OCN, and VEGF. ALP activity and von Kossa were significantly stronger in osteogenic inducing medium containing 0.05 µmol/L simvastatin. The new bone formation area of ß-TCP/Cell/Sim group at 8-week after implantation was significantly larger than the other groups. CONCLUSIONS: 0.05 µmol/L simvastatin enhances the angiogenic-osteogenic differentiation of ASCs. Simvastatin loaded ß-TCP scaffold and ASCs successfully repair the calvarial defect in rabbits. These results indicate a promising future in application of simvastatin for bone regeneration.