Guoli Yang

Publications of Guoli Yang

• Bone responses to simvastatin-loaded porous implant surfaces in an ovariectomized model.

  Authors: Guoli Yang, Lina Song, Caihong Guo, Shifang Zhao, Li Liu, Fuming He

  The International journal of oral & maxillofacial implants. 03/2012; 27(2):369-74.

  Purpose: The purpose of this study was to investigate bone responses to simvastatin-loaded porous implant surfaces in an ovariectomized model. Materials and Methods: Roughened implants were dividedPurpose: The purpose of this study was to investigate bone responses to simvastatin-loaded porous implant surfaces in an ovariectomized model. Materials and Methods: Roughened implants were divided into a control group (n = 32), test group 1 (n = 32), and test group 2 (n = 32). Test implants were immersed into 10?7 mol/L (test group 1) or 10?6 mol/L (test group 2) simvastatin solutions for drug adsorption onto implant surfaces. Forty-eight ovariectomized rats randomly received an implant in each tibia. One, 2, 4, and 12 weeks later, the tibiae were retrieved and prepared for histomorphometric evaluation. Bone-to-implant contact and bone area around the implant were determined, and histologic observations were made. Results: New bone formation on test implant surfaces was seen after 1 week, while it was seen on the control implant surface after 2 weeks. There was more bone tissue and bone-to-implant contact along the test implant surfaces than along the control implant surface. The test group 1 and test group 2 implants showed significantly greater bone area and bone-to-implant contact compared to the control implant at all observed time points (P < .05). No differences were found between the two types of test group implants after 1, 2, 4, and 12 weeks (P > .05). Conclusion: Simvastatin-loaded porous implant surfaces have the potential to improve implant osseointegration in an ovariectomized rat model.

• Osteoblast response to puerarin-loaded porous titanium surfaces: An in vitro study.

  Authors: Fan Yang, Rong Zhang, Fuming He, Xiao-Xiang Wang, Shifang Zhao, Guoli Yang

  Journal of biomedical materials research. Part A. 02/2012;

  Recent studies demonstrate puerarin stimulates bone formation, suggesting its potential application in dental implantology field. The aim of this study was to investigate effects of puerarin-loadedRecent studies demonstrate puerarin stimulates bone formation, suggesting its potential application in dental implantology field. The aim of this study was to investigate effects of puerarin-loaded titanium surfaces on the promotion of osteogenesis in preosteoblasts (MC3T3-E1). Puerarin was prepared onto titanium surfaces with varying concentration (10(-9) M, 10(-8) M, 10(-7) M, and 10(-6) M) by biomimetic calcium phosphate deposition process. Surface characteristics were performed by field-emission scanning electron microscope (FSEM), X-ray diffractometer (XRD), and Fourier transform infrared spectroscopy (FTIR). Puerarin concentration in the coatings was performed by High-performance liquid chromatograph (HPLC) analyses. FSEM observation showed puerarin concentration influenced formation of sharp flakes in the coating. The size of flakes decreased with increase of puerarin concentrations. XRD and FTIR examinations demonstrated the puerarin concentration did not affect the chemical compositions of coatings, which composed of octacalcium phosphate (OCP). Puerarin concentration on the surfaces of 10(-8) M group was 10.22 ± 0.32 ng/cm(2) . Puerarin had an increased effect on MC3T3-E1 ALP activities. Significant differences were found in 10(-8) and 10(-7) M groups on day 4, 10(-8) , 10(-7) , and 10(-6) M groups on day 7, and 10(-8) on day 14. In Type I collagen synthesis assay, 10(-9) and 10(-8) M on day 7, 10(-8) on day 14 showed significant differences compared with control group. Furthermore, this stimulatory effect of puerarin was also observed in osteocalcin release assay (p < 0.05, at 10(-8) M and 10(-7) M, maximal at 10(-8) M). These results indicate puerarin-loaded titanium surfaces promote accelerated osteogenic differentiation of preosteoblasts, which has the potential to improve the nature of osseointegration. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.

• Enhanced initial proliferation and differentiation of MC3T3-E1 cells on HF/HNO3 solution treated nanostructural titanium surface.

  Authors: Fuming He, Feng Zhang, Guoli Yang, Xiaoxiang Wang, Shifang Zhao

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 10/2010; 110(4):e13-22.

  The aim of this study was to investigate the effects of nano- or submicro topography and fluoride ion on the biology of osteoblasts. Pure Ti plates were sandblasted, etched with an HCl/H(2)SO(4)The aim of this study was to investigate the effects of nano- or submicro topography and fluoride ion on the biology of osteoblasts. Pure Ti plates were sandblasted, etched with an HCl/H(2)SO(4) solution (control surface) and then etched in a diluted HF/HNO(3) solution (test surface). MC3T3-E1 cells attached, spread, and proliferated on both surfaces. The alkaline phosphatase activity was evidently higher for the test surface than for control surface after 4 and 7 days of cell culture. Real-time PCR showed significant increases in type I collagen and osteocalcin gene expression in osteoblast growth on the test surface after 4 days of culture compared with the control surface. With nanotopography and fluoride, hydrogen ions might improve MC3T3-E1 cell proliferation and differentiation during the early stages of cell culture.

• Osseointegration of titanium implants with a roughened surface containing hydride ion in a rabbit model.

  Authors: Zhipeng Cheng, Feng Zhang, Fuming He, Lijuan Zhang, Caihong Guo, Shifang Zhao, Guoli Yang

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 07/2010; 110(1):e5-12.

  The objective of this study was to investigate the effect of hydride ion on bone formation and bone-bonding strength at the early stage of implantation. Implants and plates were treated in 2 ways:The objective of this study was to investigate the effect of hydride ion on bone formation and bone-bonding strength at the early stage of implantation. Implants and plates were treated in 2 ways: test implant (implant surface with hydride ion) and control implant (implant surface without hydride ion). Crystal structure of plate surfaces was analyzed by low angle x-ray diffractometry (XRD). Sixty implants (30 test implants and 30 control implants) were inserted into tibias of 10 rabbits. At 2 and 8 weeks postimplantation, tibias were retrieved and prepared for removal torque tests (RTQ) and histomorphometric evaluation, respectively. TiH(2) diffractions appeared on the XRD pattern of the test surface whereas TiH(2) did not appear on the control surface. The test implants showed 51.28% and 64.63% greater RTQ values than did the control implants at 2 and 8 weeks (P = .010, .011, respectively). Histomorphometric evaluation demonstrated the test implants significantly increased bone-implant contact and peri-implant bone formation at 2 and 8 weeks. These results suggest the presence of hydride ion in the implant surface may improve bone integration with implant surfaces at the early stage of implantation.

• Bone responses to rough titanium implants coated with biomimetic Ca-P in rabbit tibia.

  Authors: Fuming He, Guoli Yang, Xiaoxiang Wang, Shifang Zhao

  Journal of biomedical materials research. Part B, Applied biomaterials. 04/2009;

  A new technique to biomimetic deposition calcium phosphate (BDCaP) coating onto rough titanium substrates has been developed recently. This biomimetic deposition technique seems to be promising. ItA new technique to biomimetic deposition calcium phosphate (BDCaP) coating onto rough titanium substrates has been developed recently. This biomimetic deposition technique seems to be promising. It appears to have some advantages such as an inexpensive and simple set-up, and the possibility to synthesize layers with a defined surface morphology. The aim of this study was to examine the bone responses to BDCaP-coated implants in a rabbit model. Thirty one implants (16 BDCaP and 15 rough) were inserted into both tibia of 15 rabbits. After 2, 4, and 8 weeks following the implantation, the tibias were retrieved and prepared for histological evaluation. After 2 weeks, BDCaP-coated implant showed more bone ingrowth inside threads than the rough implants in medullary region (31.43% vs. 24.38%). Histological and quantitative histomorphometrical measurements demonstrated no more bone ingrowth and bone-implant contact for coated implant as compared with uncoated implant in cortical region at all experiment periods. From the histological viewpoint, the BDCaP coating did not have any positive effect on new bone formation. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009.

• Effect of electrochemically deposited nanohydroxyapatite on bone bonding of sandblasted/dual Acid-etched titanium implant.

  Authors: Fuming He, Guoli Yang, Xiaoxiang Wang, Shifang Zhao

  The International journal of oral & maxillofacial implants. 24(5):790-9.

  Purpose: The aim of this study was to evaluate the effect of an electrochemically deposited nanohydroxyapatite (EDHA) coating on the bone bonding of sandblasted and dual acid-etched titaniumPurpose: The aim of this study was to evaluate the effect of an electrochemically deposited nanohydroxyapatite (EDHA) coating on the bone bonding of sandblasted and dual acid-etched titanium implants. Materials and Methods: One hundred EDHA-coated and uncoated sandblasted/dual acid-etched implants (3 mm in diameter, 10 mm long) were inserted into the femoral condyles of 50 rabbits. The osteotomy sites were enlarged to 3 mm in diameter via a sequence of drills. After 2, 4, 6, 8, and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each implant type. The removed implants were prepared and observed with an electron microscope equipped with an energy dispersive electron probe x-ray microanalyzer. Results: The mean removal torque values for the EDHA-coated implants were 39.6 Ncm at 2 weeks and 40.4 Ncm at 4 weeks; corresponding values for the control implants were 21.1 Ncm and 24.1 Ncm. Removal torque values of the EDHA-coated implants were 87% higher than those of control implants after 2 weeks of healing (P = .015). However, the mean removal torque values for both types of implants were similar after 6, 8, or 12 weeks of healing (no significant differences between the implant surfaces; P > .05). Conclusions: The EDHA nanocrystal coating had a beneficial effect on interfacial shear strength during the early stages of bone healing. Int J Oral Maxillofac Implants 2009;24:790-799.