Papers by Author: Gang Zhou

Abstract: High-purity aluminum oxide is potentially an attractive implante material for total hip joint replacement, because its biocompatibility, excellent wear resistance, high strength and corrosion resistance. The main problem of alumina is relatively low fracture toughness. Thus, this study is the introduction of ZrO2 as second ceramic phase homogeneously dispersed wihtin an alumina matix. Al2O3/ZrO2 nanocomposites disk is prepared by spark plasma sintering (SPS) method at 1500°C and 50MPa, in vacuum for 5min. Then, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the microstucture and phases of this nanocomposite. Moreover, frexual sthrength of the nanocomposites was meausured as well as hardness and fracture toughness. When the content of ZrO2 is up to 15wt%, the fracture toughness value (8.4MPam1/2), and strength (527MPa) are achieved. This Al2O3/ZrO2 nanocomposites may be served as a tatal hip joint replacement.

Abstract: Nano-hydroxyapatite (n-HA)/chitosan (CS)/konjac glucomannan (KGM) composite was prepared by integrating composition and molding. Then, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the physical, chemical and degradable properties of the composite before and after in simulated body fluid (SBF). Moreover, study in vitro test for drug delivery revealed that the amount of released pentoxifylline (1-[5-oxohexyl]-3,7-dimethylxanthine)(PTX) reached a plateau and equaled 80% of the drug loaded in an implant. The newly develop n-HA/CS/KGM composite may serve as a good degradable biomaterial for implantable drug delivery system (IDDS) in bone tissue engineering.

Abstract: Scaffold in bone tissue engineering must have a three-dimensional (3-D) interconnected porous structure acting as a template for bone tissue regeneration, and material fabricating the scaffold must be biocompatible and can provide structural support during bone growth and remodeling at the same time. In this paper, a method of phase separation and particle leaching combined (PS/PL) was used to prepare porous scaffold of nano-hydroxyapatite and polyamide6 (n-HA/PA6) composite. The results show that the scaffold prepared by PS/PL has not only interconnected macropores of 100~300 μm, but also micropores on the walls of macropores, and PS/PL scaffold is more interconnective in compare with phase separation (PS) scaffold. When the porosity of the scaffold is about 79%, its compressive strongth is about 3.27 MPa, that is similar to the human cancellous bone(2~10MPa). Ethanol has some effect on hydrogen bonds, but fabricating method will not change the chemical component of the composite. The porous scaffold is prospect for bone tissue engineering.

Abstract: A unique composite consisted of nano-hydroxyapatite (n-HA), poly (vinyl alcohol) (PVA) and gelatin (Gel), was prepared and characterized by Fourier transform infrared absorption spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and burning test. The homogenicity of the composite was evaluated, and the presence of interior chemical bond was confirmed and discussed. Mechanical strength and water absorption of the prepared composite were investigated, respectively. The results show that n-HA/PVA/Gel composite has good homogeneity, similar mechanical properties to natural cartilage and excellent in vivo biocompatibility.