A series of large mesoporous carbons (LMC, 20-50 nm) with hierarchical porosities has been prepared using commercially available CaCO 3 nanoparticles as a template, formaldehyde (PF) resin as carbon precursor, and HCl solution for removing the template. During the carbonization process, the CaCO 3 template decomposes releasing CO 2 which serves as an activating agent to active the carbon materials producing micropores and mesopores as well as enlarging pore sizes. This effect can be named as the ''CO 2 inner-activation effect'', which is proved by comparing the carbon yield, N 2 adsorption/ desorption isotherms, pore-size distribution and textual parameters of carbon materials carbonized at two critical temperatures, namely, 900 C (higher than the pyrolysis temperature of CaCO 3 ) and 650 C (lower than the pyrolysis temperature of CaCO 3 ). Our results show that the LMC samples prepared at different ratios of CaCO 3 to PF have BET surface areas ranging from 503 to 1215 m 2 g À1 , and pore volumes ranging from 1.8 to 9.0 cm 3 g À1 . This one-step carbonization method with a CO 2 inneractivation effect provides a novel route to prepare large mesoporous carbons and hierarchical porous carbon materials.

In this study, for the first time we discovered that the M1/M2 macrophage phenotype ratio is increased in bone marrow of ovariectomized (OVX) osteoporotic C57BL/6 mice. Considering estrogen is the main variable, we assumed that estrogen participated in this alteration. To determine whether and how estrogen contributes to the change of the M1/M2 ratio, we first isolated bone marrow macrophages (BMMs) from mice femur and stimulated the cells with lipopolysaccharide (LPS)/interferon γ (IFN-γ) for M1 polarization and interleukin 4 (IL-4)/IL-13 for M2 polarization. M1 and M2 macrophages were then exposed to RANKL stimulation, we found that M2 macrophage but not M1 macrophage differentiated into functional osteoclast leading to increased M1/M2 ratio. Intriguingly, 17β-estradiol (E2) pretreatment prevented osteoclastogenesis from M2 macrophages. By constructing shRNA lentivirus interfering the expression of different estrogen receptors in M2 macrophages, we found that estrogen protects M2 macrophage from receptor activator of nuclear factor κB ligand (RANKL) stimulation selectively through estrogen receptor α (ERα) and the downstream blockage of NF-κB p65 nuclear translocation. Animal studies showed that ERα selective agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) was able to replicate the therapeutic effects of E2 in treating osteoporotic OVX mice. Together, our findings reveal that estrogen deficiency-mediated M2 macrophage osteoclastogenesis leads to increased M1/M2 ratio in OVX mice. Reducing the M1/M2 ratio is a potential therapeutic target in treating postmenopausal osteoporosis. © 2017 American Society for Bone and Mineral Research.

Insufficient blood perfusion is one of the critical problems that hamper the clinical application of tissue engineering bone (TEB). Current methods for improving blood vessel distribution in TEB mainly rely on delivering exogenous angiogenic factors to promote the proliferation, migration, differentiation, and vessel formation of endothelial cells (ECs) and/or endothelial progenitor cells (EPCs). However, obstacles including limited activity preservation, difficulty in controlled release, and high cost obstructed the practical application of this strategy. In this study, TEB scaffold were modified with cerium oxide nanoparticles (CNPs) and the effects of CNPs existed at the scaffold surface on the growth and paracrine behavior of mesenchymal stem cells (MSCs) were investigated. The CNPs could improve the proliferation and inhibit the apoptosis of MSCs. Meanwhile, the interaction between the cell membrane and the nanoparticle surface could activate the calcium channel of MSCs leading to the rise of intracellular free Ca(2+) level, which subsequently augments the stability of HIF-1α. These chain reactions finally resulted in high expression of angiogenic factor VEGF. The improved paracrine of VEGF could thereby promote the proliferation, differentiation, and tube formation ability of EPCs. Most importantly, in vivo ectopic bone formation experiment demonstrated this method could significantly improve the blood vessel distribution inside of TEB.

Recently, extracellular matrix-based tissue-engineered bone is a promising approach to repairing bone defects, and the seed cells are mostly mesenchymal stem cells. However, bone remodelling is a complex biological process, in which osteoclasts perform bone resorption and osteoblasts dominate bone formation. The interaction and coupling of these two kinds of cells is the key to bone repair. Therefore, the extracellular matrix secreted by the mesenchymal stem cells alone cannot mimic a complex bone regeneration microenvironment, and the addition of extracellular matrix by preosteoclasts may contribute as an effective strategy for bone regeneration. Here, we established the mesenchymal stem cell/preosteoclast extracellular matrix -based tissue-engineered bones and demonstrated that engineered-scaffolds based on mesenchymal stem cell/ preosteoclast extracellular matrix significantly enhanced osteogenesis in a 3 mm rat femur defect model compared with mesenchymal stem cell alone. The bioactive proteins released from the mesenchymal stem cell/ preosteoclast extracellular matrix based tissue-engineered bones also promoted the migration, adhesion, and osteogenic differentiation of mesenchymal stem cells in vitro. As for the mechanisms, the iTRAQ-labeled mass spectrometry was performed, and 608 differentially expressed proteins were found, including the IGFBP5 and CXCL12. Through in vitro studies, we proved that CXCL12 and IGFBP5 proteins, mainly released from the preosteoclasts, contributed to mesenchymal stem cells migration and osteogenic differentiation, respectively. Overall, our research, for the first time, introduce pre-osteoclast into the tissue engineering of bone and optimize the strategy of constructing extracellular matrix–based tissue-engineered bone using different cells to simulate the natural bone regeneration environment, which provides new sight for bone tissue engineering.

Polymer binder plays a pivotal role in electrochemical performance of high-capacity silicon (Si) anode that usually suffers from severe capacity fading due to enormous substantial volume change of Si during cycling. In an effort to find efficient polymer binder that could mitigate such capacity fading, alginate-carboxymethyl chitosan (Alg-C-chitosan) composite polymer was investigated as a low-cost watersoluble binder for silicon anodes in lithium-ion batteries. The electrostatic interaction between carboxylate (-COO -) of Alg and protonated amines (-NH 3 ? ) of C-chitosan forms a selfhealing porous scaffold structure. Synergistic effect on the enhanced porous scaffold structure and self-healing electrostatic interaction of Alg-C-chitosan binder effectively can tolerate the tremendous volume change of Si and maintain an integrated electrode structure during cycling process. The Si nanopowder electrodes with Alg-C-chitosan composite binder exhibit an excellent cycling stability, with a capacity of 750 mAhÁg -1 remaining after 100th cycling. In addition, an extraordinary areal capacity of 3.76 mAhÁcm -2 is achieved for Si-based anodes with Alg-C-chitosan binder.

Period1 (PER1) is an important core clock gene, which regulates normal cell proliferations and physiological rhythms of human beings. Recent studies have showed aberrant expressions and altered rhythms of PER1 were highly correlated to the carcinogenesis and development of malignant tumors. However, there is no study on the correlation of aberrant expressions and altered rhythms of PER1 with the growth, proliferation and metastasis of buccal squamous cell carcinoma (BSCC). In this study, PER1 and MMP-2 expression in the cancerous and adjacent noncancerous tissues of 38 patients with BSCC and its correlations with patients' clinical pathologic characteristics were investigated. A mouse model of BSCC was also established and mice were sacrificed at 4 different time points in a period of 24 hours. Xenografted tumor weight, proliferation index (PI), and mitotic index (MI) of tumors in the 4 time groups were detected. Results showed that PER1 expression was significantly down-regulated in cancerous tissues of patients with BSCC (P<0.05). PER1 expression was significantly down-regulated in patients of T3∼T4 staging and those with lymph node metastasis compared to that of T1∼T2 staging and those without lymph node metastasis (P<0.05), respectively. PER1 mRNA expression, MI and tumor weight had significant differences among the 4 time groups, which PI all confirmed to circadian rhythms. MI, PI, MMP-2 mRNA and tumor weight had negative correlation with PER1 mRNA expression. Peak value of PER1 mRNA expression and trough values of MI, PI and tumor weight all appeared in middle activity phase, whereas trough value of PER1 mRNA expression and peak values of MI, PI and tumor weight all occurred in middle rest phase. Our study suggested that aberrant expression of PER1 had significant correlation with the growth, proliferation and metastasis of BSCC and it might act as an anti-oncogene.

Dihydroartemisinin (DHA) is a widely used antimalarial drug isolated from the plant Artemisia annua. Recent studies suggested that DHA has antitumor effects utilizing its reactive oxygen species (ROS) yielding mechanism. Here, we reported that DHA is inhibitory on lipopolysaccharide (LPS)-induced osteoclast (OC) differentiation, fusion and bone-resorption activity in vitro. Intracellular ROS detection revealed that DHA could remarkably increase ROS accumulation during LPS-induced osteoclastogenesis. Moreover, cell apoptosis was also increased by DHA treatment. We found that DHA-activated caspase-3 increased Bax/Bcl-2 ratio during LPS-induced osteoclastogenesis. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria into the cytosol were observed, indicating that ROS-mediated mitochondrial dysfunction is crucial in DHA-induced apoptosis during LPS-induced osteoclastogenesis. In vivo study showed that DHA treatment decreased OC number, prevents bone loss, rescues bone microarchitecture and restores bone strength in LPS-induced bone-loss mouse model. Together, our findings indicate that DHA is protective against LPS-induced bone loss through apoptosis induction of osteoclasts via ROS accumulation and the mitochondria-dependent apoptosis pathway. Therefore, DHA may be considered as a new therapeutic candidate for treating inflammatory bone loss.

Bone defects/fractures are common in older people suffering from osteoporosis. Traditional hydroxyapatite (HA) materials for osteoporotic bone repair face many challenges, including limited bone formation and aseptic loosening of orthopedic implants. In this study, a new multifunctional HA is synthesized by spontaneous assembly of alendronate (AL) and FeO onto HA nanocrystals for osteoporotic bone regeneration. The chemical coordination of AL and FeO with HA does not induce lattice deformation, resulting in a functionalized HA (Func-HA) with proper magnetic property and controlled release manner. The Func-HA nanocrystals have been encapsulated in polymer substrates to further investigate their osteogenic capability. In vitro and in vivo evaluations reveal that both AL and FeO, especially the combination of two functional groups on HA, can inhibit osteoclastic activity and promote osteoblast proliferation and differentiation, as well as enhance implant osseointegration and accelerate bone remodeling under osteoporotic condition. The as-developed Func-HA with coordinating antiresorptive ability, magnetic property, and osteoconductivity might be a desirable biomaterial for osteoporotic bone defect/fracture treatment.