Shifang Zhao

Publications of Shifang Zhao

• 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.

• Fabrication and in vitro evaluation of the collagen/hyaluronic acid PEM coating crosslinked with functionalized RGD peptide on titanium.

  Authors: Ying Huang, Qiaojie Luo, Xiaodong Li, Feng Zhang, Shifang Zhao

  Acta biomaterialia. 02/2012; 8(2):866-77.

  Surface modification of titanium (Ti) using biomolecules has attracted much attention recently. In this study, a new strategy has been employed to construct a stable and bioactive coating on Ti. ToSurface modification of titanium (Ti) using biomolecules has attracted much attention recently. In this study, a new strategy has been employed to construct a stable and bioactive coating on Ti. To this end, a derivative of hyaluronic acid (HA), i.e. HA-GRGDSPC-(SH), was synthesized. The disulfide-crosslinked Arg-Gly-Asp (RGD)-containing collagen/hyaluronic acid polyelectrolyte membrane (PEM) coating was then fabricated on Ti through the alternate deposition of collagen and HA-GRGDSPC-(SH) with five assembly cycles and subsequent crosslinking via converting free sulphydryl groups into disulfide linkages (RGD-CHC-Ti group). The assembly processes for PEM coating and the physicochemical properties of the coating were carefully characterized. The stability of PEM coating in phosphate-buffered saline solution could be adjusted by the crosslinking degree, while its degradation behaviors in the presence of glutathione were glutathione concentration dependent. The adhesion and proliferation of MC3T3-E1 cells were significantly enhanced in the RGD-CHC-Ti group. Up-regulated bone specific genes, enhanced alkaline phosphatase activity and osteocalcin production, the increased areas of mineralization were also observed in the RGD-CHC-Ti group. These results indicate that the strategy employed herein may function as an effective way to construct stable, RGD-containing bioactive coatings on Ti.

• Surface modification and its effect on attachment, spreading, and proliferation of human gingival fibroblasts.

  Authors: Feng Zhang, Ying Huang, Xiaodong Li, Shifang Zhao

  The International journal of oral & maxillofacial implants. 11/2011; 26(6):1183-92.

  The purpose of this study was to exploit potential methods of surface modification for improving the seal between the neck portion of a dental implant and the surrounding soft tissue. TitaniumThe purpose of this study was to exploit potential methods of surface modification for improving the seal between the neck portion of a dental implant and the surrounding soft tissue. Titanium surfaces were modified by machining (SM-Ti group); machining and acid etching (AE-Ti group); or machining, acid etching, and depositing 4.5 collagen/hyaluronic acid (col/HA) polyelectrolyte bilayers (CHC-Ti group). These were analyzed using scanning electron microscopy, scanning force microscopy, x-ray photoelectron spectroscopy, contact angle measurement, and quartz crystal microbalance measurement. The degradation behavior of the col/HA multilayer coating was measured. Next, human gingival fibroblasts (HGFs) were cultured on the different surfaces, and cell morphology and spreading were observed using fluorescence microscopy and a shape factor measurement. Cell proliferation was examined by fluorometric quantification of the amount of cellular DNA. Matrix formation of HGFs was determined via enzyme-linked immunosorbent assay. Gene expression was analyzed via reverse transcriptase polymerase chain reaction. Similar surface topology for these three groups was observable on a microscopic scale, and morphologic differences were apparent on the nanoscale. Both acid etching and col/HA deposition improved the hydrophilicity of the titanium surface, in contrast to machining alone. Each col/HA bilayer was about 5 nm thick. The col/HA coating degraded in about a week. Attachment and spreading of HGFs was better on the CHC-Ti surface than on the SM-Ti or AE-Ti surfaces. Moreover, the proliferation and differentiation of HGFs were greatly stimulated when cultured on CHC-Ti. In contrast to two control surfaces (one machined, one machined and acid-etched), col/HA treatment of Ti improved the attachment, spreading, proliferation, and differentiation of HGFs.

• 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.

• A study of properties of "micelle-enhanced" polyelectrolyte capsules: Structure, encapsulation and in vitro release.

  Authors: Xiaodong Li, Tian Lu, Jianxiang Zhang, Jiajie Xu, Qiaoling Hu, Shifang Zhao, Jiacong Shen

  Acta biomaterialia. 03/2009;

  "Micelle-enhanced" polyelectrolyte capsules were fabricated via a layer-by-layer technique, templated on hybrid calcium carbonate particles with built-in polymeric micelles based on"Micelle-enhanced" polyelectrolyte capsules were fabricated via a layer-by-layer technique, templated on hybrid calcium carbonate particles with built-in polymeric micelles based on polystyrene-b-poly(acrylic acid). Due to the presence of a large number of negatively charged micelles inside the polyelectrolyte capsule, which were liberated from templates, the capsule wall was reconstructed and had properties different to those of conventional polyelectrolyte capsules. This type of capsule could selectively entrap positively charged water-soluble substances. The encapsulation efficiency of positively charged substances was dependent on their molecular weight or size. For some positively charged compounds, such as rhodamine B and lysozyme, the concentration in the capsules was orders of magnitude higher than that in the incubation solution. In addition, in vitro release study suggested that the encapsulated compounds could be released through a sustained manner to a certain degree. All these results point to the fact that these capsules might be used as novel delivery systems for some water-soluble compounds.

• A novel system for water soluble protein encapsulation with high efficiency: "micelles enhanced" polyelectrolyte capsules.

  Authors: Xiaodong Li, Xiaohui Li, Jianxiang Zhang, Shifang Zhao, Jiacong Shen

  Journal of biomedical materials research. Part A. 07/2008; 85(3):768-76.

  Novel "micelles enhanced" polyelectrolyte (PE) capsules based on functional templates of hybrid calcium carbonate were fabricated. Evidences suggested that the structure of capsule wall was differentNovel "micelles enhanced" polyelectrolyte (PE) capsules based on functional templates of hybrid calcium carbonate were fabricated. Evidences suggested that the structure of capsule wall was different from that of conventional PE capsules, and the wall permeability of these PE capsules changed significantly. Lysozyme, a positively charged protein in neutral solution, was studied as a model protein to be encapsulated into the "micelles enhanced" PE capsules. Confocal laser scanning microscope was used to observe the entrapping process in real time, while UV-Vis spectroscope and scanning force microscope measurements suggested the high efficiency of encapsulation. In addition, the fluorescence recovery after photobleaching technique was employed to determine the existence form of deposited molecules. Further studies showed even negatively charged water-soluble peptides or proteins can be encapsulated into these hybrid capsules by modulating the pH value in bulk solution under its isoelectronic point as well.

• [Fast formation of biomimetic apatite coatings on pure porous titanium implant's surface]

  Authors: Fuming He, Li Lin, Shifang Zhao, Shanshan Zhao, Song Chen, Xiaoxiang Wang

  Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi. 09/2007; 24(4):806-11.

  The aim of this study was to elaborate a dense, strong and thin calcium-phosphate coating on commercial porous pure titanium implant surface in the light of a fast biomimetic procedure. After beingThe aim of this study was to elaborate a dense, strong and thin calcium-phosphate coating on commercial porous pure titanium implant surface in the light of a fast biomimetic procedure. After being polished, sandblasted, cleaned and treated with the mixture of HF and HNO3, the titanium plates were divided into two groups, namely group A and group B. The specimens of group A were free from any treatment. The specimens of group B were treated with the mixture of 48% H2SO4 and 18% HCl. All specimens soaked in SBF-A solution for 1d. Then the specimens were immersed in the SBF-B solution for 2 d. A thin calcium-phosphate coating was deposited on all the specimens of the two groups, the surface consisted of well-formed crystals, which were proved to be the mixture of hydroxycarbonated apatite (HCA) and octacalcium phosphate (OCP); the coating's Ca/P rate was 1.51. A thin carbonated calcium-phosphate coating was deposited on porous pure titanium by the use of the fast biomimetic procedure.

• [A study on the repair of bone defects with deproteinized bone surrounded by titanium mesh and osteoblasts]

  Authors: Qingguo Zhang, Shifang Zhao, Wenbin Chen, Jinglong Huang, Chenglin Chu, Yuepu Pu

  Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi. 05/2005; 22(2):254-7.

  To investigate the ability of composite graft of osteobalsts and deproteinized bone-titanium mesh (DPB-TM) scaffold to repair cranial bone defect. 30 rabbits were randomly divided into 3 groups. TheTo investigate the ability of composite graft of osteobalsts and deproteinized bone-titanium mesh (DPB-TM) scaffold to repair cranial bone defect. 30 rabbits were randomly divided into 3 groups. The passage 3 fetal rabbit osteoblasts were seeded into porous DPB-TM scaffolds at the density of 5 x 10(6) ml(-1) as the experimental group. The same defects were respectively reconstructed by DPB-TM or osteoblasts as the control groups. After 12 weeks, the result was evaluated by three-dimensional computed tomographic scanning, gross inspection, scanning electron microscopy, histological examination and mechanics test, respectively. In the experimental group, bone trabecula was observed to pass the defect and interface was mixed. No demarcation between the region of the bone defect and the normal bone was observed. There was plenty of new bone on the scaffold. Part of the scaffold was absorbed. In view of mechanics, the intensity of artificial bone (18.93+/-1.12 MPa) was higher than that of normal bone (16.96+/-1.60 MPa) (P<0.05). In the control groups, only fibrous tissue was observed in the defect region, there was no new bone formation. The tissue engineering bone constructed by osteoblasts and DPB-TM scaffold can be applied to the repair of bone defect.

• Clinical application and histological observation of pedicled buccal fat pad grafting.

  Authors: Lijie Fan, Guanfu Chen, Shifang Zhao, Ji'an Hu

  Chinese medical journal. 11/2002; 115(10):1556-9.

  OBJECTIVE: To introduce the applied anatomy of pedicled buccal fat pad (BFP) graft and a series of histological changes in the healing process of BFP as an uncovered pedicled graft. METHODS: TheOBJECTIVE: To introduce the applied anatomy of pedicled buccal fat pad (BFP) graft and a series of histological changes in the healing process of BFP as an uncovered pedicled graft. METHODS: The healing processes of BFP are demonstrated via uncovered pedicled grafts on rabbits in histological examination. Uncovered buccal fat pads were used to repair soft tissue defects in rabbit oral cavities. RESULTS: The uncovered buccal fat pads showed complete epithelialization of their oral surfaces at 6 to 8 weeks after surgery and were slowly replaced by fibrous tissue. CONCLUSIONS: Advantages of the pedicled buccal fat pad graft include an anatomic region that is consistent and easy to excise. The operation can be performed in one incision, affecting neither appearance nor function of the area. Use of the buccal fat pad provides a good reconstruction of soft tissue defects in the mouth.

• 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.