Low-temperature additive manufacturing (AM) holds promise for fabrication of three-dimensional (3D) scaffolds containing bioactive molecules and/or drugs. Due to the strict technical limitations of current approaches, few materials are suitable for printing at low temperature. Here, a low-temperature robocasting method was employed to print biomimic 3D scaffolds for bone regeneration using a routine collagen-hydroxyapatite (CHA) composite material, which is too viscous to be printed via normal 3D printing methods at low temperature. The CHA scaffolds had excellent 3D structure and maintained most raw material properties after printing. Compared to nonprinted scaffolds, printed scaffolds promoted bone marrow stromal cell proliferation and improved osteogenic outcome in vitro. In a rabbit femoral condyle defect model, the interconnecting pores within the printed scaffolds facilitated cell penetration and mineralization before the scaffolds degraded and enhanced repair, compared to nonprinted CHA scaffolds. Additionally, the optimal printing parameters for 3D CHA scaffolds were investigated; 600-μm-diameter rods were optimal in terms of moderate mechanical strength and better repair outcome in vivo. This low-temperature robocasting method could enable a variety of bioactive molecules to be incorporated into printed CHA materials and provides a method of bioprinting biomaterials without compromising their natural properties.
We report the synthesis of uniform triangular gold nanoplates by a modified seeded growth method. The concentration of cetyltrimethylammonium bromide (CTAB) in the growth solution and the time interval between multiple steps of growth were important factors which determined the formation of uniform triangular Au nanoplates. In addition, by further isotropic overgrowth, the thickness of triangular Au nanoplates can be finely tuned within a wide range of 10-80 nm, which at present remains a challenge using conventional seeded growth.
Mn doping-induced structural and magnetic transformations in the antiferroelectric phase of the Bi1−xNdxFeO3 perovskites J. Appl. Phys. 112, 064105 (2012) Neutron diffraction study of stability and phase transitions in Cu-Sn-In alloys as alternative Pb-free solders J. Appl. Phys. 112, 053520 (2012) Communication: From graphite to diamond: Reaction pathways of the phase transition J. Chem. Phys. 137, 101101 (2012) Structural study in highly compressed BiFeO3 epitaxial thin films on YAlO3 A lead-free ceramic with the composition ͑K 0.55 Na 0.45 ͒ 0.965 Li 0.035 Nb 0.80 Ta 0.20 O 3 was found having an outstanding piezoelectric performance. It possesses high piezoelectric properties of d 33 a͒ Electronic mail: zhangjialiang@sdu.edu.cn. APPLIED PHYSICS LETTERS 95, 022909 ͑2009͒
Recent studies show that biomaterials are capable of regulating immune responses to induce a favorable osteogenic microenvironment and promote osteogenesis and angiogenesis. In this study, we investigated the effects of zinc silicate/nanohydroxyapatite/collagen (ZS/HA/Col) scaffolds on bone regeneration and angiogenesis and explored the related mechanism. We demonstrate that 10ZS/HA/Col scaffolds significantly enhanced bone regeneration and angiogenesis in vivo compared with HA/Col scaffolds. ZS/HA/Col scaffolds increased tartrate-resistant acid phosphatase (TRAP)-positive cells, nestin-positive bone marrow stromal cells (BMSCs) and CD31-positive neovessels, and expression of osteogenesis (Bmp-2 and Osterix) and angiogenesis-related (Vegf-α and Cd31) genes increased in nascent bone. ZS/HA/Col scaffolds with 10 wt % ZS activated the p38 signaling pathway in monocytes. The monocytes subsequently differentiated into TRAP+ cells and expressed higher levels of the cytokines SDF-1, TGF-β1, VEGF-α, and PDGF-BB, which recruited BMSCs and endothelial cells (ECs) to the defect areas. Blocking the p38 pathway in monocytes reduced TRAP+ differentiation and cytokine secretion and resulted in a decrease in BMSC and EC homing and angiogenesis. Overall, these findings demonstrate that 10ZS/HA/Col scaffolds modulate monocytes and, thereby, create a favorable osteogenic microenvironment that promotes BMSC migration and differentiation and vessel formation by activating the p38 signaling pathway.
Gut microbiota dysbiosis is closely associated with primary hepatocellular carcinoma (HCC). Recent studies have evaluated the early diagnosis of primary HCC through analysis of gut microbiota dysbiosis. However, the relationship between the degree of dysbiosis and the prognosis of primary HCC remains unclear. Because primary HCC is accompanied by dysbiosis and dysbiosis usually increases the circulatory concentrations of endotoxin and other harmful bacterial substances, which further increases liver damage, we hypothesized that level of dysbiosis associated with primary HCC increases with the stage of cancer progression. To test this hypothesis, we introduced a more integrated index referred to as the degree of dysbiosis ( D dys ); and we investigated D dys of the gut microbiota with the development of primary HCC through high-throughput sequencing of 16S rRNA gene amplicons. Our results showed that compared with healthy individuals, patients with primary HCC showed increased pro-inflammatory bacteria in their fecal microbiota. The D dys increased significantly in patients with primary HCC compared with that in healthy controls. Moreover, there was a tendency for the D dys to increase with the development of primary HCC, although no significant difference was detected between different stages of primary HCC. Our findings provide important insights into the use of gut microbiota analysis during the treatment of primary HCC.
BackgroundCirculating tumor cells (CTCs) have been actively studied for their functions in hepatocellular carcinoma (HCC) recurrence. However, the relationship between circulating tumor cells subtypes and hepatocellular carcinoma recurrence is still unclear.MethodsCTCs were collected from the peripheral blood of 62 postoperative HCC patients. The CTCs were isolated with a filtration-based method. Multiplex fluorescence in situ hybridization was used to characterize the CTCs based on mRNA expression levels of epithelial and mesenchymal markers.ResultsOf the 62 HCC patients, 26 were diagnosed with early recurrence (ER) and 36 did not experience recurrence. Comparison between the recurrence group and the non-recurrence group showed the total number of CTCs, mesenchymal CTCs, and mixed CTCs in the recurrence group was significantly higher than in the non-recurrence group. Receiver operator characteristic (ROC) curve analysis was performed to define the positive cutoff values as follows: total number of CTCs ≥ 4, mesenchymal CTCs ≥ 1, and mixed CTCs ≥ 3. Analysis showed that portal vein tumor thrombus (hazard ratio [HR] = 2.905, P = 0.023) and mesenchymal CTC positivity (HR = 3.453, P = 0.007) were independent risk factors for ER. The correlation between the presence of mesenchymal CTCs and time to recurrence was further examined, and the results showed significantly shortened postoperative disease-free survival in patients positive for mesenchymal CTCs (P < 0.001).ConclusionsHCC patients with positive peripheral mesenchymal CTCs have a more serious risk of ER, which could be a potential biomarker in HCC prognosis monitoring.
Homeostatic pressure-driven compaction is a ubiquitous mechanical force in multicellular organisms and is proposed to be important in the maintenance of multicellular tissue integrity and function. Previous cell-free biochemical models have demonstrated that there are cross-talks between compaction forces and tissue structural functions, such as cell-cell adhesion. However, its involvement in physiological tissue function has yet to be directly demonstrated. Here, we use the bile canaliculus (BC) as a physiological example of a multicellular functional structure in the liver, and employ a novel 3D microfluidic hepatocyte culture system to provide an unprecedented opportunity to experimentally modulate the compaction states of primary hepatocyte aggregates in a 3D physiological-mimicking environment. Mechanical compaction alters the physical attributes of the hepatocyte aggregates, including cell shape, cell packing density and cell-cell contact area, but does not impair the hepatocytes' remodeling and functional capabilities. Characterization of structural and functional polarity shows that BC formation in compact hepatocyte aggregates is accelerated to as early as 12 hours post-seeding; whereas non-compact control requires 48 hours for functional BC formation. Further dynamic immunofluorescence imaging and gene expression profiling reveal that compaction accelerated BC formation is accompanied by changes in actin cytoskeleton remodeling dynamics and transcriptional levels of hepatic nuclear factor 4α and Annexin A2. Our report not only provides a novel strategy of modeling BC formation for in vitro hepatology research, but also shows a first instance that homeostatic pressure-driven compaction force is directly coupled to the higher-order multicellular functions.
Background and Purpose-Perihematomal edema contributes to secondary brain injury in intracerebral hemorrhage (ICH). Increase of matrix metalloproteinases (MMPs) and growth factors is considerably involved in blood-brain barrier disruption and neuronal cell death in ICH models. We therefore hypothesized that increased levels of these molecular markers are associated with perihematomal edema and clinical outcome in ICH patients. Methods-Fifty-nine patients with spontaneous ICH admitted within 24 hours of symptom onset were prospectively investigated. Noncontrast CT was performed on admission for diagnosis of ICH and quantification of initial hematoma volume. MRI was performed on day 3 to evaluate perihematomal edema. Concentrations of MMP-3, MMP-9, as well as vascular endothelial growth factor and angiopoietin-1 on admission were determined by enzyme-linked immunosorbent assays. Clinical outcome was assessed by modified Rankin Scale at 90 days. Results-Increased MMP-3 levels were independently associated with perihematomal edema volume (P<0.05). Cytotoxic edema surrounding the hematoma was seen in 36 (61%) cases on 3-day MRI. Cytotoxic edema did not correlate with the level of any of the biomarkers studied. Levels of MMP-3 ≥12.4 ng/mL and MMP-9 ≥192.4 ng/mL but not vascular endothelial growth factor and angiopoietin-1 predicted poor clinical outcome at 90 days (modified Rankin Scale >3) independent of stroke severity and hematoma volume at baseline (odds ratio, 25.3, P=0.035; odds ratio, 68.9, P=0.023; respectively). Conclusions-MMPs 3 and 9 seem to be significantly involved in secondary brain injury and outcome after primary ICH in humans, and thus should be further evaluated as targets for therapeutic strategies in this devastating disorder. (Stroke. 2013;44:658-663.)
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