Publications by authors named "Hongxu Qi"

We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption.

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We describe the sustained delivery of chondroitinase ABC (ChABC) in the hemisected spinal cord using polypropylene carbonate (PPC) electrospun fibers with chitosan (CS) microspheres as a vehicle. PPC and ChABC-loaded CS microspheres were mixed with acetonitrile, and micron fibers were generated by electrospinning. ChABC release was assessed in vitro with high-performance liquid chromatography (HPLC) and revealed stabilized and prolonged release.

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This study describes the use of poly(propylene carbonate) (PPC) electrospun fibers as vehicle for the sustained delivery of dibutyryl cyclic adenosine monophosphate (dbcAMP) to the hemisected spinal cord. The dbcAMP and PPC were uniformly mixed with acetonitrile; then, electrospinning was used to generate micron fibers. The release of dbcAMP was assessed by ELISA in vitro.

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The delivery of local chemotherapy using polymeric implants is a promising anti-glioma strategy, but a high drug loading rate can lead to a problematic initial burst of drug and subsequent neurotoxicity. In this study, we designed and fabricated a biodegradable implant for the local delivery of combined paclitaxel and temozolomide (TMZ) with low drug loading rates. Paclitaxel-loaded Ca-alginate microparticles were formed using an emulsifying-solvent evaporation process.

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Background: Peripheral nerve regeneration across large gaps is clinically challenging. Scaffold design plays a pivotal role in nerve tissue engineering. Recently, nanofibrous scaffolds have proven a suitable environment for cell attachment and proliferation due to similarities of their physical properties to natural extracellular matrix.

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Objective: Poly (propylene carbonate) (PPC), a newly reported polymer, has good biodegradability and biocompatibility. To explore the feasibility of using electrospinning PPC materials in nerve tissue engineering, and to observe the effect of aligned and random PPC materials on axonal growth of rat dorsal root ganglions (DRGs) in vitro.

Methods: Either aligned or randomly oriented sub-micron scale polymeric fiber was prepared with an electrospinning process.

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To develop effective implants for delivery of 3,4-dihydro-3-methyl-4-oxoimidazo[5,1-d]-as-tetrazine-8-carboxamide (temozolomide; TM) with low initial burst and less neurotoxicity, TM-loaded poly-propylene carbonate (PPC) fiber was fabricated by electrospinning. Some of the fiber sheets were then covered with alginate (ALG). Influences of several preparation parameters on drug delivery behavior were investigated.

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The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells (MSCs) onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated.

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The objective of this study was to fabricate biomatrix/polymer hybrid heart valve leaflet scaffolds using an electrospinning technique and seeded by mesenchymal stem cells. Mesenchymal stem cells were obtained from rats. Porcine aortic heart valve leaflets were decellularized, coated with basic fibroblast growth factor/chitosan/poly-4-hydroxybutyrate using an electrospinning technique, reseeded, and cultured over a time period of 14 days.

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Bone marrow mesenchymal stem cells (MSCs) have demonstrated their pluripotency to differentiate into different cell lineages and may be an alternative cell source for vascular tissue engineering. The objective of this study is to create small diameter vessels by seeding and culture of genetically modified MSCs onto a synthetic polymer scaffold produced by an electrospinning technique. A tubular scaffold (2 mm in diameter) with a microstructure of nonwoven fibers was produced by electrospinning of poly (propylene carbonate) (PPC).

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In this paper, we prepared composite fibers via electrospinning from either W/O or O/W emulsion. SEM images demonstrate the beads-in-string structures in these fibers and proved this technique to be an effective method for microencapsulation. As a practical application, Ca-alginate microspheres, which serve as reservoirs for hydrophilic drugs, were prepared in a reverse emulsion and then incorporated into poly (l-lactic acid) (PLLA) fibers by electrospinning.

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