452nd Hospital of Chinese PLA


452nd Hospital of Chinese PLA

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Liu Q.F.,University of Miami | Liu Q.F.,Chengdu Medical College | Yang Z.,University of Miami | Li J.C.,Chengdu Medical College | And 4 more authors.
Neurology Psychiatry and Brain Research | Year: 2012

The mechanism of action of nuclear factor-kappa B (NF-κB)'s has been widely studied in nervous system damage and disease since 2000. NF-κB is widely present in eukaryotic cells, and inactive NF-κB is present in the cytoplasm. Activated NF-κB transfers into the nucleus and induces expression of several target genes. Through the action of different downstream effectors, NF-κB plays a bi-directional interactive role in central nervous system damage, as well as learning and memory. While NF-κB can induce pro-inflammation factor release and exacerbate brain injury, it can also exert protective effects on neurons in central nervous system diseases and injuries by upregulating endothelial nitric oxide synthase (eNOS), Mn-superoxide dismutase (Mn-SOD), B-cell lymphoma/leukaemia-2 (Bcl-2), and inhibitors of apoptosis protein (IAPs). Moreover, NF-κB is required for spatial learning and memory and passive avoidance training. However, a decrease in NF-κB activity in the hippocampal dentate gyrus is necessary for active avoidance training. This paper reviews NF-κB's bi-directional interactive role in these processes.© 2012 Elsevier GmbH. All rights reserved.

Guo L.-Y.,Southwest Jiaotong University | Zhang J.-W.,Southwest Jiaotong University | Zhao J.,Southwest Jiaotong University | Wang J.-X.,Southwest Jiaotong University | And 2 more authors.
Wuji Cailiao Xuebao/Journal of Inorganic Materials | Year: 2011

The pore interconnectivity is a key factor for the application of porous bioceramics as bone tissue engineering scaffolds. Packed wax spheres were treated with dimethyl benzene and acted as the porogen for the preparation of porous ceramic scaffolds, in order to increase the inter-sphere connectivity. The morphology, porosity, shrinkage, and the compressive strength of the obtained ceramic scaffolds were analyzed. The cell compatibility of the scaffolds was evaluated with Sprague-Dawley (SD) osteoblasts. The results showed that the pore interconnectivity and volumetric porosity were significantly increased by the dimethyl benzene treatment. Scaffolds with different porosities had similar shrinkage. Osteoblasts migrated deeply into the center of the porous ceramic scaffold through the interconnected pores and got normal activity. Porous scaffolds with better interpore connectivity could provid more space for the proliferation of osteoblasts.

Zhang Y.,Chongqing Medical University | Li L.,Chongqing Medical University | Zhu J.,Chongqing Medical University | Kuang H.,452nd Hospital of Chinese PLA | And 4 more authors.
Biomaterials | Year: 2012

The cell-extracellular matrix (ECM) interaction has been employed to direct tissue-specific cellular responses and tailor biomaterial development. Given the important roles of integrin-fibronectin interactions and homophilic cadherin responses, we postulated that the recreation of the biological function of ECM in a recombinant fibronectin/cadherin chimera (rFN/CDH) at the nanoscale may properly address the integration impediment at the interface. This study aimed to investigate the feasibility and validity of an rFN/CDH bio-inspired ceramic surface generated via layer-by-layer (LbL) self-assembly to induce osteogenesis. The successful fabrication of a multilayered structure of BCP/. LbL/[Chi-rFN/CDH] and excellent physico-chemical properties were confirmed by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, contact angle, and scanning electron microscopy. Sustained release was observed during degradation, and the multilayered construct also displayed a significantly enhanced ability to guide bMSC adhesion, proliferation, and osteogenic differentiation. A mechanistic exploration revealed that the interaction of rFN/CDH with integrin α5β1/αvβ3 may be a regulatory pivot. These results demonstrate the hybrid potential of bioceramics coated with biofunctional rFN/CDH multilayers in osteoconductive and osteoinducive potency. This study therefore presents a basis for fabricating potential bio-functionalised ceramic-based substitutions for preclinical and clinical application to bone defects and reconstruction. © 2012 Elsevier Ltd.

Peng Q.,Southwest Jiaotong University | Jiang F.,Southwest Jiaotong University | Huang P.,Southwest Jiaotong University | Huang P.,452nd Hospital of Chinese PLA | And 5 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2010

A novel scaffold with large dimension of 3-4 cm in length and 1-1.5 cm in diameter was designed and fabricated for engineering large bone tissue in vivo. The scaffold was constructed by filling hydroxyapatite (HA) spherules into a porous HA tube. The HA spherules were prepared by chitin sol emulsification in oil and gelation in situ, and their sizes can be controlled by parameters such as stirring rate and oil temperature. Accumulation of the HA spherules formed the interconnected pores in the scaffold, and the porosity and microstructure of the scaffold can be controlled by varying the size and miroporous structure of the HA spherules. Porous HA tube coated with a thin layer of poly(L-lactic acid) (PLA) held the HA spherules together and provided the initial strength of scaffolds. HA spherules can be easily compounded with biological substance, such as comminuted bone granules, before being filled into the HA tubes. A pilot study is underway to use the hybrid scaffolds at different sites such as muscle, peritoneum, and bone side. © 2009 Wiley Periodicals, Inc.

Zhang C.,452nd Hospital of Chinese PLA | Huang P.,452nd Hospital of Chinese PLA | Weng J.,Southwest Jiaotong University | Zhi W.,Southwest Jiaotong University | And 5 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2012

Porous hydroxyapatite (HA) ceramic cylinder tubes coated with polylactic acid on the exposed surfaces were implanted in four nonskeletal sites (omentum, peritoneum, vastus lateralis, and side of femur). Six months postoperatively, proper amount of Chinese ink was injected to dye the implanting areas. Decalcified and nondecalcified sections were observed under inverted microscope. The results showed that the soft tissues around the HA cylinder tubes in peritoneum, vastus lateralis, and side of femur groups appeared visible black. Some small blacked vascular architectures were also discernible. However in omentum group, only small number of blacked vessels existed. Histological observations indicated that vascularization and ossification occurred in peritoneum, vastus lateralis, and side of femur groups. In omentum group, there was no any sign of vascularization and ossification. A conclusion could be made in this study that excepting bones and muscles, parietal peritoneum could serve as a potential spot for culturing histoengineering hydroxyapatite (HA)-polylactic acid (PLA) ceramic bone substitutes. © 2012 WILEY PERIODICALS, INC.

Zhi W.,Southwest Jiaotong University | Zhang C.,452nd Hospital of Chinese PLA | Duan K.,Southwest Jiaotong University | Li X.,Southwest Jiaotong University | And 7 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2014

In vivo engineering of bone autografts using bioceramic scaffolds with appropriate porous structures is a potential approach to prepare autologous bone grafts for the repair of critical-sized bone defects. This study investigated the evolutionary process of osteogenesis, angiogenesis, and compressive strength of bioceramic scaffolds implanted in two non-osseous sites of dogs: the abdominal cavity and the dorsal muscle. Hydroxyapatite (HA) sphere-accumulated scaffolds with controlled porous structures were prepared and placed in the two sites for up to 6 months. Analyses of retrieved scaffolds found that osteogenesis and angiogenesis were faster in scaffolds implanted in dorsal muscles compared with those placed in abdominal cavities. The abdominal cavity, however, can accommodate larger bone grafts with designed shape. Analyses of scaffolds implanted in abdominal cavities [an environment of a low mesenchymal stem cell (MSC) density] further demonstrated that angiogenesis play critical roles during osteogenesis in the scaffolds, presumably by supplying progenitor cells and/or MSCs as seed cells. This study also examined the relationship between the volume of bone grafts and the physiological environment of in vivo bioreactor. These results provide basic information for the selection of appropriate implanting sites and culture time required to engineer autologous bone grafts for the clinical bone defect repair. Based on these positive results, a pilot study has applied the grafts constructed in canine abdominal cavity to repair segmental bone defect in load-bearing sites (limbs). © 2013 Wiley Periodicals, Inc.

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