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Bone defect is a serious orthopedic disease which has been studied for a long time. Alternative degradable biomaterials are required for bone repairing and regeneration to address the limitation of autogenous bone. β-tricalcium phosphate (β-TCP) is an alternative material with good cytocompatibility and has been used in bone defect treatment. However, whether β-TCP contributes to osteogenesis of bone marrow stem cells (BMSCs) through N6-methyladenosine (m6A) modification remains unknown. To address this issue, we verified the effects of β-TCP on osteogenesis of BMSCs. We also studied the expression of m6A-related enzymes in BMSCs after β-TCP treatment. Furthermore, the m6A level and stability of Runt-related transcription factor 2 (RUNX2) mRNA were investigated after β-TCP treatment. Finally, rat calvarial defect models were performed to detect expression level of osteogenic factors and m6A-related enzymes after the stimulation of three-dimension (3D)-printed β-TCP scaffolds. We found that β-TCP showed good biocompatibility and was osteoinductive. Meanwhile, methyltransferase-like 3 (METTL3) increased, causing the elevation of m6A level of RUNX2, results in stabler RUNX2 mRNA level. At last, based on the animal experiments, we demonstrated that the increase of RUNX2 and METTL3 levels was induced by β-TCP. These findings suggest that METTL3 increases the m6A level of RUNX2 mRNA after β-TCP induction, contributing to its stability, and the results in vivo also confirmed the osteogenic and bone-repair properties of β-TCP.

Tendinopathy is a common disease influencing life quality and tendon function of patients, especially in the elderly and athletes. Inflammation is an important pathologic process of tendinopathy. Hypoxia inducible factor-1 alpha (HIF-1α) participates actively in inflammatory process. However, little is known about the role of HIF-1α in tendinopathy. To address this issue, we verified the expression level of HIF-1α in tendinopathy in vivo and in vitro. Furthermore, the severity of tendinopathy in vivo and in vitro was assessed after HIF-1α inhibition. At the same time, inflammatory signaling cascades were evaluated. The expression level of HIF-1α increased in tendinopathy in vivo and in vitro. The migration and proliferation of tendon cells (TDCs) were reduced after HIF-1α inhibition. In the meantime, HIF-1α inhibition alleviated the severity of tendinopathy and promoted tendon repairing. We also found that HIF-1α inhibition reduced the phosphorylation levels of p65 in NF-κB signaling pathway and the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and Jun N-terminal kinase (JNK) in MAPK signaling pathway. These findings suggest that HIF-1α increases in tendinopathy in vivo and vitro, and HIF-1α inhibition can suppress the severity of tendinopathy by blocking NF-κB and MAPK signaling pathways.

BACKGROUND: The removal of permanent internal fixation devices by secondary surgery could be avoided if these devices were made of degradable magnesium and magnesium alloys. Before such implants can be used clinically, however, the biological effect of magnesium exposure on surrounding bone must be evaluated. Previous studies have focused on bone formation; few have examined the effects of magnesium on the bone quality that affect many biomechanical properties. METHODS: Using bone quality parameters, we analyzed in vivo changes in bone properties and biomechanics after exposure to locally high levels of magnesium. RESULTS: Local bone mineralization was significantly disrupted following exposure to a porous rod of pure magnesium. Normal crystal formation and crystallinity were inhibited and the mineral-to-matrix ratio decreased. These results were consistent with those of in vitro experiments, in which high levels of magnesium inhibited mineral deposition by mesenchymal stem cells (MSCs) but increased alkaline phosphatase (ALP) expression. The same mineralization inhibition was observed around magnesium implants via micro-computerized tomography (micro-CT) and von Kossa staining. Such reduced bone quality around degrading magnesium rods could negatively impact bone biomechanics. CONCLUSIONS: This study showed that exposure to the local high magnesium levels that arise from rapidly degrading magnesium devices may significantly disrupt bone mineralization and negatively impact bone biomechanics.

Background: Repairing complex anatomical load-bearing bone defects is difficult because it requires restoration of load-bearing function, reconstruction of anatomical shape and repair by regenerated bone. We previously developed a Screen–Enrich–Combine(-biomaterials) Circulating System (SECCS) for rapid intraoperative enrichment of autologous bone marrow mesenchymal stem cells (MSCs) to enhance the osteogenic ability of porous bone substitutes. In this study, we prepared a 3D-printed Ti6A14V macroporous frame matching the defect shape to provide early load-bearing support and evaluated the efficacy of filling the frame with SECCS-processed MSCs/beta tricalcium phosphate (β-TCP) for long-term bone growth. Method: Mechanical testing of the cylindrical Ti6Al4V frame identified optimal 3D printing parameters. The lateral part of a goat distal femur was used as the defect model, and a matching electron beam melting technology-prepared (EBM) Ti6Al4V frame was fitted. Three frames filled with nothing, pure porous β-TCP or SECCS-processed MSCs/β-TCP were fixed onto the defect site. Repair efficacy was evaluated by X-ray radiography, computed tomography, histology and histomorphology. Results: In the basic regular hexagon printing unit, the combined side width (w) and inscribed circle diameter (d) determines the printing frame’s mechanical strength. The compressive load was significantly higher for w = 1.9 mm, d = 4.4 mm than for w = 1.7 mm, d = 4.0 mm or w = 2.0 mm, d = 5.0 mm (P < 0.05). The EBM-prepared Ti6Al4V defect-matched frame was well maintained 9 months after implantation. The MSCs successfully adhered to the wall of the porous β-TCP in the SECCS-processed group and had spread fully in the test samples. Each goat in the MSCs/β-TCP–filling group had approximately 31,321.7 ± 22,554.7 MSCs and a larger area of new bone growth inside the frame than the areas in the control and blank groups.Conclusion: Filling the 3D-printed Ti6Al4V large-aperture frame with osteogenic materials achieved biological reconstruction over a larger area of regenerated bone for repair of complex anatomical weight-bearing bone defects under the condition of early frame-supported load bearing. MSCs/β-TCP prepared by SECCS can be used as a filling material for this type of bone defect to obtain more efficacious bone repair.

Two aminosilanes derived from hexamethyldisilazane as chemical vapor deposition (CVD) precursors for SiCxNy and relevant films have been reported and characterized by 1H, 13C, and 29Si NMR as well ...

Background When bone marrow is repeatedly filtered through porous material, the mesenchymal stem cells (MSCs) in the bone marrow can adhere to the outer and inner walls of the carrier material to become enriched locally, and this is a promising method for MSC enrichment. In this process, the enrichment efficiency of MSCs involved in the regulation of the cell ecology of postfiltration composites containing other bone marrow components is affected by many factors. This study compared the enrichment efficiency and characterized the phenotypes of enriched MSCs obtained by the filtration of autologous bone marrow through different porous bone substitutes. Methods Human bone marrow was filtered through representative porous materials, and different factors affecting MSC enrichment efficiency were evaluated. The soluble proteins and MSC phenotypes in the bone marrow before and after filtration were also compared. Results The enrichment efficiency of the MSCs found in gelatin sponges was 96.1% ± 3.4%, which was higher than that of MSCs found in allogeneic bone (72.5% ± 7.6%) and porous β-TCP particles (61.4% ± 5.4%). A filtration frequency of 5–6 and a bone marrow/material volume ratio of 2 achieved the best enrichment efficiency for MSCs. A high-throughput antibody microarray indicated that the soluble proteins were mostly filtered out and remained in the flow through fluid, whereas a small number of proteins were abundantly (> 50%) enriched in the biomaterial. In terms of the phenotypic characteristics of the MSCs, including the cell aspect ratio, osteogenetic fate, specific antigens, gene expression profile, cell cycle stage, and apoptosis rate, no significant changes were found before or after filtration. Conclusion When autologous bone marrow is rapidly filtered through porous bone substitutes, the optimal enrichment efficiency of MSCs can be attained by the rational selection of the type of carrier material, the bone marrow/carrier material volume ratio, and the filtration frequency. The enrichment of bone marrow MSCs occurs during filtration, during which the soluble proteins in the bone marrow are also absorbed to a certain extent. This filtration enrichment technique does not affect the phenotype of the MSCs and thus may provide a safe alternative method for MSC enrichment.

Aim: To evaluate the clinical efficacy of mesenchymal stem cell/β-tricalcium phosphate composites (MSC/β-TCP) prepared with a screen-enrich-combine circulating system (SECCS) in patients with depressed tibial plateau fractures. Materials & methods: Bone defects in depressed tibial plateaus were filled with MSC/β-TCP (n = 16) or with β-TCP only (n = 23). Enrichment efficiency and effect of enrichment on cell viability were evaluated. Clinical results were assessed by imaging examination and Lysholm score. Results: SECCS effectively integrated MSCs with β-TCP. At 18 months postimplantation, new bone ratio was significantly higher in patients treated with MSC/β-TCP than in those treated with β-TCP only (p = 0.000). Patients with MSC/β-TCP implants had better functional recovery (p = 0.028). Conclusion: MSC/β-TCP prepared by SECCS were effective in the treatment of bone defects in patients with depressed tibial plateau fractures, promoted bone regeneration and improved joint function recovery.

Bone non-union after fracture, considered a therapeutic challenge for orthopedics, always needs a reversion surgery, including autograft transplantation (AGT). However, adverse events related to autograft harvest cannot be ignored. Our group designed a novel system called the bone marrow stem cell Screen-Enrich-Combine Circulating System (SECCS) by seeding mesenchymal stem cells (MSCs) into β-tricalcium phosphate (β-TCP) during surgery to thereafter rapidly process bioactive bone implantation. In this retrospective case-control study, 30 non-union patients who accepted SECCS therapy and 20 non-union patients who accepted AGT were enrolled. By SECCS therapy, the MSC-enriched β-TCP particles were implanted into the non-union gap. During the enrichment procedure, a significant proportion of MSCs were screened and enriched from bone marrow into porous β-TCP particles, and the cells possessed the capacity for three-line differentiation and were CD90+/CD105+/CD34-/CD45-. Approximately 82.0±10.7% of MSCs were enriched from 60 mL bone marrow without damaging cell viability, and approximately 11,444.0±6,018 MSCs were transplanted per patient. No implant-related infections occurred in any case. After 9 months of follow-up, 27 patients (90%) in the SECCS group acquired clinical union, compared with 18 patients (90%) in the AGT group (clinical union time, P = 0.064), and postoperative radiographic union score at 9 months post-operation was similar between the two groups. In conclusion, the SECCS could concentrate a large proportion of MSCs from bone marrow to acquire enough effective cells for therapy without in vitro cell culture. Bone substitutes processed by SECCS demonstrated encouraging promotion of bone regeneration and showed a satisfactory clinical curative effect for diaphyseal bone non-union, which was non-inferior to AGT.

BACKGROUND: Traditionally, the iliac crest has been the most common harvesting site for autologous bone grafts; however, it has some limitations, including poor bone availability and donor-site morbidity. This study sought to explore the effect of enhanced bone marrow (eBM) in conjunction with three-dimensional (3D)-printed polylactide–hydroxyapatite (PLA-HA) scaffolds in the repair of critical-sized bone defects in a rabbit model. METHODS: First, 3D-printed PLA-HA scaffolds were fabricated and evaluated using micro-computed tomography (µCT) and scanning electron microscopy (SEM). Twenty-seven New Zealand white rabbits were randomly divided into 3 groups (n=9 per group), and the defects were treated using 3D-printed PLA-HA scaffolds (the PLA-HA group) or eBM in conjunction with 3D-printed PLA-HA scaffolds (the PLA-HA/eBM group), or were left untreated (the control group). Radiographic, µCT, and histological analyses were performed to evaluate bone regeneration in the different groups. RESULTS: The 3D-printed PLA-HA scaffolds were cylindrical, and had a mean pore size of 500±47.1 µm and 60%±3.5% porosity. At 4 and 8 weeks, the lane-sandhu X-ray score in the PLA-HA/eBM group was significantly higher than that in the PLA-HA group and the control group (P

A family of 1,1,1,2,2,2-hexaamino-disilanes with the formula (RHN)3Si-Si(NHR)3 (R = nPr, iPr, nBu, iBu, sBu, Cy) as precursors for the CVD growth of silicon-based films has been synthesized and characterized by 1H NMR, 13C NMR, 29Si NMR, EI-HRMS, elemental analysis and X-ray diffraction where necessary. Thermal properties, including stability, volatility, transport behavior and vapor pressure were evaluated by thermogravimetric analysis (TGA) to verify that thermal properties of the precursors can be tuned by small variation of the substituents form secondary amino to primary amino units and to confirm their suitability for the CVD procedure. Finally, deposition was accomplished in a hot wall CVD reactor, which preliminarily verified the ability of these compounds as CVD precursors.

The title compounds of the type R-C(=NiPr) (-N′ iPrSiMe3) (with R = Me or nBu) as potential chemical vapor deposition (CVD) precursors have been synthesized and characterized by 1H, 13C, and 29Si NMR spectroscopy as well as by EI-MS and elemental analysis where necessary. Thermal properties, including stability, volatility, transport behavior, and vapor pressure, were evaluated by thermogravimetric analysis to confirm that they are suitable for the CVD procedure. Deposition was accomplished in a hot wall CVD reactor system, which qualitatively verified the ability of these compounds as CVD precursors.

Background Efficacious bone substitute is essential for the treatment of a critical size bone defect. Currently, the bone substitutes commonly used in clinical practice lack osteogenic capacity and the therapeutic efficacy is not ideal. Herein, a novel stem cell screen-enrich-combine(−biomaterials) circulating system (SECCS) was introduced to provide the substitutes with osteogenic ability. The stem cell screening, enrichment, and recombination with substitutes could be integrated during the surgical operation. Using SECCS, the bioactive mesenchymal stem cells (MSCs) and porous β-tricalcium phosphate (β-TCP) composites (MSCs/β-TCP) were rapidly prepared for critical size bone defect repair and validated in goat models of critical size tibia defects. Methods Twelve goats with right hind limb tibia defects of 30 mm were randomly divided into two groups: six (the experimental group) were treated with MSCs/β-TCP prepared by SECCS and the other six goats (the control group) were treated with pure porous β-TCP. The repair effect was assessed by x-ray, computed tomography (CT), micro-CT, histology and histomorphology 6 months after the operation. In addition, the enrichment efficacy of MSCs and the characteristics of the MSCs/β-TCP prepared by SECCS were evaluated. Results The SECCS could compound about 81.3 ± 3.0% of the MSCs in bone marrow to the porous β-TCP without affecting the cell viability. The average number of MSCs for retransplantation was 27,655.0 ± 5011.6 for each goat from the experimental group. In vitro, satisfactory biocompatibility of the MSCs/β-TCP was performed, with the MSCs spreading adequately, proliferating actively, and retaining the osteogenic potential. In vivo, the defect repair by MSCs/β-TCP with good medullary cavity recanalization and cortical remodeling was significantly superior to that of pure porous β-TCP. Conclusions The MSCs/β-TCP prepared through SECCS demonstrated significant therapeutic efficacy in goat models of critical size bone defect. This provides a novel therapeutic strategy for critical size bone defects caused by severe injury, infection, and bone tumor resection with a high profile of safety, effectiveness, simplicity, and ease.

Silicon(IV) amide Si(c-C5H9NH)4 (1), was synthesized and characterized by 1H, 13C, and 29Si NMR spectroscopy, EI-MS, elemental analysis, and X-ray diffraction. Its thermal stability and volatility were also investigated. The as-grown film, which was characterized by SEM, AFM, XRD and XPS, was deposited using 1 as single precursor through a low-pressure chemical vapor deposition (LPCVD) process at a temperature as low as 600 °C. The results demonstrated that silicon(IV) amides can be promising single-precursor for deposition of low-temperature SiC films.

Three chlorine-containing aminodisilanes of the type Cl(RR′N)2Si–Si(NRR′)2Cl (with R = alkyl and R′ = H or R) as potential chemical vapor deposition (CVD) precursors for silicon nitride (SiNx) films have been synthesized and characterized by X-ray diffraction; 1H, 13C, and 29Si NMR spectroscopy; and elemental analysis. They were obtained in high yields by the reactions of hexachlorodisilane (Si2Cl6) with excess liquid amines in diethyl ether through a general single-step procedure. Their thermal properties including stability, volatility, transport behavior, and vapor pressure were evaluated by thermogravimetric analysis (TGA) to confirm that they are suitable for the CVD procedure. The deposition of SiNx films was accomplished with a hot-wall CVD reactor system, which preliminarily verified the suitability of these compounds as CVD precursors.

Reduction of tertiary phosphine oxides and sulfides into the corresponding phosphines with amine-assisted aluminum hydrides has been studied. The method is characterized by mild conditions, short reaction time, high efficiency, and expanded substrate scope. The new method is an alternative to the currently used methods of reducing phosphine oxides or recycling phosphines engaged in organic reactions.

Two aminosilanes derived from hexamethyldisilazane as chemical vapor deposition (CVD) precursors for SiCxNy and relevant films have been reported and characterized by 1H, 13C, and 29Si NMR as well as by EI-MS and elemental analysis, where necessary. Thermal stability, transport behavior and vapor pressures were evaluated by simultaneous thermal analyses (STA). Chemical vapor deposition was accomplished in a hot wall CVD reactor system to further demonstrate the ability of these compounds as CVD precursors. Most importantly, characterization (XPS) of the as-grown films proved that the composition of the films can be controlled by the molecular structure of the precursors. The result suggests future strategy for the design of CVD precursors for SiCxNy and related films.

A family of silicon(IV) compounds, where the Si centers of trimethylsilyl (–SiMe3) are linked with 2-alkyl-aminopyridine ligands, has been synthesized by reaction of the corresponding lithium salt of these ligands and SiMe3Cl in a general procedure. They were characterized by 1H NMR, 13C NMR, 29Si NMR, EI-MS and elemental analysis where necessary. Thereinto, 29Si NMR and the synthesis of 2-N,N-bis(trimethylsilyl)aminopyridine were achieved for the confirmation of their coordination structures. Significantly, the evaluation of these silicon compounds containing 2-aminopyridinates as CVD precursors was discussed for the first time. Thermal stability, transport behavior and vapour pressures were assessed by simultaneous thermal analyses (STA). Chemical vapor deposition was accomplished in a hot wall CVD reactor system to qualitatively demonstrate the ability of them as CVD precursors.

The title compounds of the type (Me3Si)2N–C(N′R)(–N′′RSiMe3) (with R = iPr or Cy) as potential CVD precursors have been synthesized and characterized by X-ray diffraction, 1H NMR, 13C NMR, 29Si NMR and elemental analysis where necessary. Among these characterizations, solid-/liquid-state 29Si NMR were accomplished to study their behavior in the solid and solution. Thermal properties including stability, volatility, transport behavior and vapour pressure were evaluated by thermogravimetric analysis (TGA) to confirm that they are suitable for the CVD procedure. Deposition was accomplished in a hot wall CVD reactor system, which preliminarily verified the ability of these compounds as CVD precursors.

A family of silicon (IV) compounds containing N,N’-symmetrically alkyl substituted 1,3-diketimine ligands as chemical vapor deposition (CVD) precursors for silicon-based films has been reported and characterized by 1H, 13C, and 29Si NMR, EI-MS and elemental analysis where necessary. The compounds were synthesized by reaction of corresponding lithium salt of the diketimine ligands and SiMe3Cl according to a general procedure. Theoretical simulation was performed io order to understand their structures. Thermal stability, transport behavior and vapor pressures were evaluated by simultaneous thermal analyses (STA). Chemical vapor deposition was accomplished in a hot wall CVD reactor system to further demonstrate the ability of these compounds as CVD precursors. Characterization (SEM and XPS) of the as-grown films proved that the family indeed possesses the potential to fabricate silicon-based films with compact and uniform structure.

Objectives: This work aims to investigate the expression of miRNA-186 in patients with colorectal cancer tissues, blood and feces and its roles in regulating the infiltration and invasion in colorectal cancer. Methods: Totally 39 patients with surgical resection were included from August 2012 to February 2015 in Jilin Province People’s Hospital as the Colorectal Neuroendocrine tumor (CNET). Peripheral blood, stool, and resected tumor tissues with adjacent normal of each patient was collected. In the same period, the blood and stool from 25 patients with hemorrhoids or other non-neoplastic diseases were collected and these samples used as clinical control group. MiR-186 expression and PTTG1 (pituitary tumor-transforming 1) expression were detected by quantitative Real-Time PCR (qRT-PCR). The PTTG1 protein expression in tumor samples were detected by Western Blot, while its expression in blood and stool were detected by Elisa. Results: Compared with the control group, the expression of PTTG1 mRNA and protein was significantly up-regulated in tumor samples, blood, and stool of patients with CNET, while the expression of miR-186 was down-regulated (P < 0.05). Conclusion: PTTG1 expression was significantly up-regulated in patients with CNET, which was induced by the down-regulated miR-186. MiR-186 may participate in the regulation of infiltration and invasion in CNET patients through targeting PTTG1 expression.