Papers by Author: Ying Jun Wang

Abstract: Computed tomography is used in 13 clinic cases with bone malignant tumor to get 2-dimensional data of diseased area. Reconstruction of 3- dimensional anatomical model, excision range of bone, designing of individual surgical template and bone prosthesis was accomplished preoperatively by computers. Based on computer-assisted-design (CAD) proposal, we cut the tumor accurately, and use allografts bone with personalized prosthesis to reconstruct the bone defect after tumor excision. It is concluded that we can design excision range of bone easily, cut them accurately, reconstruct bone defect of diseased area precisely with the CAD technology.

Abstract: This study was aimed to investigate the effects of acid treatment on the surfacee characteristics ofgrit-blasted titanium alloy (Ti6Al4V). These treatments included (a) Al2O3 blasting, (b) Al2O3 blasting + HF acid etching, (c) Al2O3 blasting + HCl/H2SO4 acid etching, and (d) Al2O3 blasting + HF acid etching + HCl/H2SO4 acid etching. The surface topography and chemical composition of the samples were identified by field-emission scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Roughness of the as-treated samples was obtained from atomic force microscopy (AFM) and profilometry. Wettability of the samples was measured using sessile drop method. The results showed that porous structure on the surface of titanium alloy was prepared by dual acid etching treatment and the surfaces treated with acid had higher roughness and better wettability than the surface treated only by grit-blasting.

Abstract: The bioactivity of HA has been tested by its osteoconduction ability in vivo. Nano HA has higher specific surface area and was presumed to have high bioactivity. In this paper, nano needle HA was synthesized by the microemulsion method. The properties of such nano materials were analyzed by the XRD and TEM. The impact of the nano HA on the expression of two hBMSCs’ genes, inhibitor differentiation 2 and ostopontin, and the ALP activity was researched in this paper.

Abstract: In the present study, an Intelligent Multi-parameter Simulated Evaluation in vitro （IMSE system） was used to study the deposition properties of apatite formation on the surface of biphasic calcium phosphate porous ceramic (BCP) from static and dynamic r-SBF. Results showed that apatite formed on the surface of BCP from static and dynamic r-SBF differed between each other. In static r-SBF, ions were transferred by diffusion, which could not compensate the consuming of calcium ions, and mist apatite layer was formed on the surface of samples. But in the dynamic r-SBF, simulated fluid was adjusted precisely and flowed forcedly, the concentrations of ions were homogeneous; with the compensation of ions, calcium and phosphate were supersaturated, and the free energy of apatite formation was negative, bone-like apatite sheets were formed on the surface of samples.

Abstract: Papers reported that the pH value was rising slowly with the prolonging of soaking time when bioglass was studied into simulated body fluids, and it influenced the formation of apatite layer on the surface of bioglass obviously. An Intelligent Multi-parameter in vitro Simulated Evaluation （IMSE system） was used to study the bio-mineralization properties of 58S bioglass. The deposition of apatite formation on the surface of bioglass (BG) from dynamic r-SBF was studied systemically with IMSE system, which could control and stable such parameters as temperature, fluid rate, ion concentrations and pH value etc. precisely. Results showed that the rate of apatite formation was slowed down when pH value was stabled at about 7.35.

Abstract: The hydroxyapatite (HA) was synthesized by wet mechanochemical method；the effects of surfactant, such as triethanolamine, polyethylene glycol (200000), sodium hexametaphosphate, polyvinylpyrrolidone (K30), on the particle size distribution of as-prepared HA powder were studied. Results were characterized by means of X-ray diffraction (XRD), Scanning electron microscopy (SEM), Laser Scattering Particle Size Distribution Analyzer. The results show that the addition of surfactants eliminated the agglomeration of the powder and the uniform, fine particles (D10=0.1149μm, D50=0.12551μm, D90=0.1481μm) were obtained with the Triethanolamine (6 wt %) and Sodium hexametaphosphate (4 wt %) respectively. Our work demonstrates applicability of the mechanosynthesis for reproducible and low-cost synthesis of uniform, fine HCA powder in large batch-sizes.

Abstract: In order to improve the surface hydrophilicity and the resistance to protein deposition of fluorosilicone acrylate RGP (rigid gas permeable) contact lens, low temperature ammonia plasma treatment was used to modify the lens surface. The changes of surface structures and properties were characterized by contact angle analyzer, X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Effects of exposure time and plasma generating power on surface properties of the RGP contact lens were investigated. The surface contact angle measurements showed a great improvement of hydrophilicity after plasma treatment. XPS analysis indicated that the oxygen content and the nitrogen content increased remarkably after ammonia plasma treatment. Furthermore, the content of the hydrophilic group O-C=O/N-C=O on the surface increased and the content of the hydrophobic group CF2 decreased after plasma treatment. AFM results showed that ammonia plasma could lead to surface etching.

Abstract: Oxygen plasma was employed to treat a fluorosilicone acrylate RGP contact lens material (Boston EO) in order to improve surface hydrophilicity. X-ray photoelectron spectroscopy (XPS) was applied to characterize the surface chemical state. The surface morphology and hydrophilicity were investigated by scanning electron microscope (SEM) and contact angle measurement respectively. The surface contact angle measurement indicated an evident improvement of surface hydrophilicity after plasma treatment. XPS results indicated that the incorporation of oxygen and the transform of -Si-CH3 into hydrophilic -Si-O after plasma treatment were the main reasons for surface hydrophilicity improvement. SEM showed some decrease of surface roughness under moderate plasma condition. But plasma with higher power would etch the material surface.

Abstract: Chitosan membranes were prepared by solvent cast method. In order to increase cell adhesion of the chitosan membranes, oxygen plasma treatment was applied to improve the hydrophilicity of the surface of chitosan membranes. The surface properties were characterized by scanning electron microscopy (SEM), contact angle analyzer, X-ray photoelectron spectroscopy (XPS). The effects of exposure time, plasma generating power, and chamber pressure on water contact angle of the chitosan membranes were investigated. The water contact angle of chitosan membranes decreased from 94.1° to 49.2° after plasma treatment. Which suggested the surfaces became more hydrophilic. XPS analysis showed that the oxygen content and the ratio of O/C increased markedly after oxygen plasma treatment. Furthermore, it was found that C-H bonds were broken with oxygen plasma treatment. C-OH group had been increased after plasma irradiation.

Abstract: Owing to the unique characters of the hybrid scaffold components, a novel biodegradable porous composite scaffold was prepared. The nano hydroxyapatite (HAP) (73~136 nm) was crystallized in situ on the organic polyelectrolyte complex matrix through a biomimetic method. The polyelectrolyte complex composed of chitosan and hyaluronic acid had strong impacts on the formation of the nano HAP and directed in situ crystallization of the nano HAP as template. The in situ nano HAP reduced the interfacial energy and presented nano intensifier to the nano hybrid scaffold. Meanwhile, the scaffold kept high porosity.