Design, synthesis and biological evaluation of CDC20 inhibitors for treatment of triple-negative breast cancer.

The involvement of CDC20 in promoting tumor growth in different types of human cancers and it disturbs the process of cell division and impedes tumor proliferation. In this work, a novel of Apcin derivatives targeting CDC20 were designed and synthesized to evaluate for their biological activities. The inhibitory effect on the proliferation of four human tumor cell lines (MCF-7, MDA-MB-231, MDA-MB-468 and A549) was observed. Among them, compound E1 exhibited the strongest inhibitory effect on the proliferation of MDA-MB-231 cells with an IC50 value of 1.43 µM, which was significantly superior to that of Apcin. Further biological studies demonstrated that compound E1 inhibited cancer cell migration and colony formation. Furthermore, compound E1 specifically targeted CDC20 and exhibited a higher binding affinity to CDC20 compared to that of Apcin, thereby inducing cell cycle arrest in the G2/M phase of cancer cells. Moreover, it has been observed that compound E1 induces autophagy in cancer cells. In 4T1 Xenograft Models compound E1 exhibited the potential antitumor activity without obvious toxicity. These findings suggest that E1 could be regarded as a CDC20 inhibitor deserved further investigation.

Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces.

OBJECTIVE: The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite (Zn-HA) coating, applied by an electrochemical process, on implant osseointegraton in a rabbit model. METHODS: A Zn-HA coating or an HA coating was deposited using an electrochemical process. Surface morphology was examined using field-emission scanning electron microscopy. The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). A total of 78 implants were inserted into femurs and tibias of rabbits. After two, four, and eight weeks, femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque (RTQ) tests. RESULTS: Rod-like HA crystals appeared on both implant surfaces. The dimensions of the Zn-HA crystals seemed to be smaller than those of HA. XRD patterns showed that the peaks of both coatings matched well with standard HA patterns. FTIR spectra showed that both coatings consisted of HA crystals. The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks (P<0.05), the bone to implant contact (BIC) at four weeks (P<0.05), and RTQ values after four and eight weeks (P<0.05). CONCLUSIONS: The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.

Effects of magnesium-substituted nanohydroxyapatite coating on implant osseointegration.

OBJECTIVE: The objective of this study was to compare magnesium-substituted and pure hydroxyapatite coatings on the promotion of osteogenesis in vitro and on the osseointegration in vivo. METHODS: Electrochemically deposited pure hydroxyapatite (EDHA) or electrochemically deposited magnesium-substituted hydroxyapatite (EDMHA) coatings were formed on the surface of pure titanium disks or implants. MC3T3-E1 preosteoblasts were cultured in the EDHA and EDMHA coated disks, and cell growth, alkaline phosphatase (ALP) activity, and osteocalcin secretion were measured at various time points. For studies on osseointegration, 30 roughened implants coated either with EDHA or EDMHA (n = 15 for each coating) were implanted in the femurs of 15 NZW rabbits. After 2, 4, and 8 weeks, femurs were retrieved and prepared for histomorphometric evaluation (n = 5 for each coating at each time point). RESULTS: MC3T3-E1 cells cultured on EDMHA coated disks showed increased cell number, ALP, and osteocalcin secretion compared with the EDHA coated disks at all time points (P < 0.05 for all). Histologic observation of the coated implants showed woven bone in direct contact with both implant surfaces after 2 weeks and mature bone after 8 weeks. While there were no differences in the amount of bone between the threads at any time point, the percentage of implant in direct contact with bone (bone implant contact) was slightly higher along the EDMHA coated implants at 2 weeks (P = 0.086), although this difference was no longer seen at 4 and 8 weeks. CONCLUSION: Mg-substituted HA coated surfaces promote osteogenic differentiation of preosteoblasts in vitro and may improve implant osseointegration during the early stages of bone healing compared with pure EDHA coated surfaces.

Bone response to the multilayer BMP-2 gene coated porous titanium implant surface.

OBJECTIVES: Evaluate hBMP-2 expression following gene delivery from plasmid multilayers formed on sandblasted titanium in vitro and bone formation around similarly prepared implant surfaces in vivo. MATERIALS AND METHODS: Multilayers of cationic lipid/rhBMP-2 plasmid DNA complex (LDc) and anionic hyaluronic acid (HA) was assembled on sandblasted-dual acid etched pure titanium disks or implant surfaces using layer-by-layer (LBL) assembly. Gene delivery and hBMP-2 expression in cells exposed to the LDc multilayers was measured in vitro. To determine the effect of BMP delivery from such multilyaers in vivo, roughened implants coated with BMP-2 LDc multilayers or uncoated control implants (n = 15 for both) were implanted in the femurs of NZW rabbits. After 2, 4, 8 weeks, femurs were retrieved and prepared for histomorphometric evaluation (n = 5 rabbits per time point). RESULTS: MC3T3-E1 cells cultured directly on the BMP-2 LDc coated titanium disks showed EGFP and hBMP-2 expression after 48 h in culture. Increased gene delivery occurred by increasing the number of assembly layers when cells were cultured for 48 h. Cells cultured on LDc coated surfaces had significantly higher cell viability than control cells cultured on uncoated porous titanium surfaces. Histologic observation of the implants showed that after 4 weeks healing, the bone to implant contact (BIC) on the LDc coated surface was much lower than that on the control surface, but didn't reach significant. In contrast, the percentage of bone within the implant's threads was significantly higher than the control group (P = 0.047). CONCLUSION: The BMP-2 gene coated sandblasted dual acid etched titanium implants slightly accelerated early bone formation around implants.

Effect of strontium-substituted nanohydroxyapatite coating of porous implant surfaces on implant osseointegration in a rabbit model.

PURPOSE: This study investigated the effects of a strontium-substituted nanohydroxyapatite (Sr-HA) coating, deposited onto porous implant surfaces using an electrochemical process, on implant osseointegration in a rabbit model. MATERIALS AND METHODS: The surfaces were analyzed by field-emission scanning electron microscopy, x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), a portable surface roughness tester, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Thirty implants (half HA-coated and half Sr-HA-coated) were inserted into femurs of 15 rabbits. After 2, 4, and 8 weeks, the femurs were retrieved and prepared for histomorphometric evaluation. RESULTS: Microscopic examination showed a surface topography of rodlike crystals on both surfaces. XRD and FT-IR showed that the phase of the deposits was HA. No differences were found in surface roughness between the two groups. ICP-AES showed that the Sr/(Ca+Sr) molar ratio of Sr-HA coating was 10.1 mol%. Histologic observation showed that new bone appeared on both surfaces after 2 weeks and became mature after 8 weeks. Histomorphometric analysis showed no differences between the two groups in bone-to-implant contact at 2 weeks or in bone area within all threads at 2 and 4 weeks. The Sr-HA coated group had significantly higher bone-to-implant contact at 4 and 8 weeks. Significant differences were also found in bone area at 8 weeks. CONCLUSION: The present study showed that this Sr-HA coating, deposited using an electrochemical process, has the potential to enhance implant osseointegration.

Effect of thin nano-hydroxyapatite coating on implant osseointegration in ovariectomized rats.

PURPOSE: The purpose of this study was to investigate the effect of the thin nano-hydroxyapatite (nano-HA) coating on implant osseointegration in an ovariectomized rat model. MATERIALS AND METHODS: Implants were divided into a control group and a test group (nano-HA-coated group). Surface morphology was examined using field-emission scanning electron microscopy (FSEM). Surface roughness of both groups was performed. Sixteen ovariectomized rats randomly received 2 implants in both tibiae. After 12 weeks of implantation, tibias were retrieved and prepared for histomorphometric evaluation and removal torque tests (RTQ). RESULTS: Rodlike crystals uniformly covered the porous surfaces and the surface morphology of the implant was still clear. No significant differences were found in surface roughness between the 2 groups (P > .05). More bone tissue was formed around test implants compared with control implants. Test implants showed a significantly greater BIC, bone area within all threads, and RTQ values compared with control implants (P < .05). CONCLUSIONS: These results indicate the thin nano-HA coating by an electrochemical process has potential benefits to enhance implant osseointegration in ovariectomized rats.

Osteoblast response to porous titanium surfaces coated with zinc-substituted hydroxyapatite.

BACKGROUND: The aims of this study were to deposit a zinc-hydroxyapatite (Zn-HA) coating on titanium surfaces by using the electrochemical process and investigate the cell response to the Zn-HA-coated titanium surface. STUDY DESIGN: Surface characteristics were evaluated by scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Murine preosteoblast cell (MC3T3-E1) proliferation, alkaline phosphatase (ALP) activity, and osteocalcin release on Zn-HA-coated surfaces were compared with HA-coated surfaces. RESULTS: Field-emission SEM observation showed rod-like HA crystals with a hexagonal cross-section on the HA-coated surface, although the hexagon of the cross-section of Zn-HA crystals became irregular. ICP-AES analysis showed that Zn was present in the Zn-HA coatings at a Zn/(Ca+Zn) molar ratio of 1.04%. Significant increases in cell proliferation, ALP activity on day 7, and osteocalcin production on day 14 (P < .05) were observed for Zn(2+)-containing HA-coated surfaces. CONCLUSIONS: The present study showed that a Zn-HA coating deposited by using the electrochemical process enhances proliferation and differentiation of osteoblasts, which has the potential benefit to enhance implant osseointegration.

[Construction of a multiple-scale implant surface with super-hydrophilicity].

OBJECTIVE: To construct a multiple-scale organized implant surface with super-hydrophilicity. METHODS: The SiC paper polished titanium disc was sandblasted and treated with HF/HNO3 and HCl/H2SO4, then acid-etched with H2SO4/H2O2. The physicochemical properties of the surfaces were characterized by scanning electron microscope, static state contact angle and X-ray diffraction. MC3T3-E1 cells were used to evaluate the effects of the surface on the cell adhesion, proliferation and differentiation. RESULTS: The acid-etching process with a mixture of H2SO4/H2O2 superimposed the nano-scale structure on the micro-scale texture. The multiple-scale implant surface promoted its hydrophilicity and was more favorable to the responses of osteoprogenitor cells, characterized by increased DNA content, enhanced ALP activity and promoted OC production. CONCLUSION: A multiple-scale implant surface with super-hydrophilicity has been constructed in this study, which facilitates cell proliferation and adhesion.

Influence of multilayer rhBMP-2 DNA coating on the proliferation and differentiation of MC3T3-E1 cells seeded on roughed titanium surface.

For bone morphogenetic protein (BMP) gene therapy to be a viable approach for enhancing implant osseointegration clinically, requires the development of efficient nonviral delivery vectors that can coat the implant. This study evaluated a multilayer cationic liposome-DNA complex (LDc) coating as a delivery vehicle for recombinant human BMP-2 (rhBMP-2). Multilayered coatings, comprising hyaluronic acid (HA) and LDc, were fabricated onto titanium using a layer-by-layer (LBL) assembly technique. Preosteoblastic MC3T3-E1 cells were cultured on the roughened titanium surfaces coated with multilayers of HA/LDc, or on uncoated or HA/liposome only surfaces as controls. The amount of rhBMP-2 secreted by the MC3T3-E1 cells and the effect of the various surfaces on cell viability, proliferation, alkaline phosphatase (ALP) activity, osteocalcin (OC) secretion, and calcium deposition were evaluated. Messenger RNA levels of OC, ALP, Runx2, and Osx were also investigated. The results demonstrated that rhBMP-2 protein secreted into culture medium at 3 days was significantly higher than control groups. MC3T3-E1 cells cultured on the HA/LDc coating displayed significantly higher ALP activity and OC secretion at 7 days and 14 days culture, respectively. MC3T3-E1 cells cultured on HA/LDc upregulated expression of the osteoblast differentiation markers, especially on days 12 for OC and on days 6 and 12 for ALP and Osx. In conclusion, MC3T3-E1 cell cultured on the multilayer HA/LDc coating surface can secret rhBMP-2 protein and the protein levels were effective in inducing early osteogenic differentiation.

Mechanical and histomorphometric evaluations of rough titanium implants treated with hydrofluoric acid/nitric acid solution in rabbit tibia.

PURPOSE: The aim of this study was to investigate the bone response to rough titanium implants treated with hydrofluoric acid/nitric acid (HF/HNO3) solution. MATERIALS AND METHODS: Implants were treated with HF/HNO3 solution (test implants) or without HF/HNO3 solution (control implants). Forty-five test and 45 control implants were inserted into both tibias of 15 rabbits. After 2, 4, and 8 weeks in situ, tibias were retrieved and prepared for removal torque testing and histomorphometric evaluation. The removed implants were prepared and observed with an electron microscope. RESULTS: Mechanical tests showed that mean removal torque values for the test implants were higher than those of the control implants after 8 weeks (33.1 Ncm versus 25.7 Ncm, P = .012). Histomorphometric analysis showed that the bone area in the threads of the cortical bone region was significantly higher for test implants (81.99% and 86.38%) than for control implants (75.33% and 81.62%) after 4 and 8 weeks of healing, respectively. The implant-bone contact rate in the cortical region was higher for test implants than for control implants after 8 weeks in situ (79.56% versus 68.45%, P = .003). CONCLUSIONS: The treatment with HF/HNO3 solution promotes bone formation and osseointegration after 4 and 8 weeks of bone healing in the rabbit tibia model.

Fabrication, characterization, and biological assessment of multilayer DNA coatings on sandblasted-dual acid etched titanium surface.

As local gene therapy has received attention, immobilizing functional gene onto irregular oral implant surface has become an advanced challenge. Electrostatic layer-by-layer (LBL) assembly technique could achieve this goal and allow local and efficient administration of genes to the target cells. In this study, multilayers of cationic lipid/plasmid DNA (pEGFP-C1) complex (LDc) and anionic hyaluronic acid were assembled onto sandblasted-dual acid etched titanium disks by the LBL technique. Surface characteristics of the coatings were performed by x-ray photospectroscopy (XPS), contact angle measurements, and scanning electron microscopy (SEM). The cell biological characteristics of the coatings were evaluated by in vitro experiments. SEM results demonstrated that the porous titanium surface was gradually flattened with the increase of the multilayer. The XPS survey indicated that the N element was found from the coating. The coating degradation and pEGFP-C1 releasing kinetics showed that the more assembled layer numbers were, the larger the amount of DNA released in the first 30 h. MC3T3-E1 cells were cultured directly on the DNA-loaded surface. Higher enhanced green fluorescent protein (EGFP) expression efficiency was achieved by increasing the number of layers when cells were cultured after 24 or 72 h. The MC3T3-E1 cell viability on the surface of multilayer DNA coatings was significantly higher than that on control porous titanium surface. It was concluded that the approach established by the LBL technique had great potential in immobilizing gene coatings onto the porous titanium surface and subsequently influenced the function of the cultured cell.

Simvastatin-loaded porous implant surfaces stimulate preosteoblasts differentiation: an in vitro study.

OBJECTIVE: Recent studies demonstrate that simvastatin stimulates bone formation, suggesting the potential application in dental implantology. In this study, our lab developed a simvastatin-loaded titanium porous surface. The aim was to investigate the effect of simvastatin-loaded titanium surfaces on the promotion of osteogenesis in preosteoblasts (MC3T3-E1) in vitro. STUDY DESIGN: The control group consisted of cells cultured on titanium disks without any intervention for different time intervals (4, 7, and 14 days), and the experimental groups (simvastatin-loaded groups) consisted of cells cultured on titanium disks that were preincubated in varying concentration (10(-7) mol/L, 10(-6) mol/L, 10(-5) mol/L, and 10(-4) mol/L) of simvastatin for the same time intervals of the control group. Alkaline phosphatase (ALP) activity, type I collagen synthesis, and osteocalcin release were used to measure the cellular osteoblastic activities. RESULTS: All simvastatin-loaded groups showed increased ALP activity compared with the control group at every time point, especially the 10(-7) mol/L group, which significantly increased the activity almost fourfold at 4 days (P < .05). In the type I collagen synthesis assay, all simvastatin-loaded groups showed an increase, and the effect was inverse dose dependent (maximal at 10(-7) mol/L). This stimulatory effect of simvastatin was also observed in the osteocalcin release assay (P < .05; at 10(-7) mol/L, 10(-6) mol/L, maximal at 10(-7) mol/L). CONCLUSION: These results indicate that simvastatin-loaded porous implant surfaces promote accelerated osteogenic differentiation of preosteoblasts, which have the potential to improve the nature of osseointegration.

In vivo comparison of bone formation on titanium implant surfaces coated with biomimetically deposited calcium phosphate or electrochemically deposited hydroxyapatite.

PURPOSE: The purpose of this study was to investigate and compare bone formation on titanium implant surfaces coated with biomimetically deposited calcium phosphate (BDCaP) or electrochemically deposited hydroxyapatite (EDHA). MATERIALS AND METHODS: The implants were separated into three groups: a control group, a BDCaP group, and an EDHA group. Surface analysis was performed by field-emission scanning electron microscopy, x-ray diffractometry, and Fourier transform infrared spectroscopy. Implants were inserted in a randomized arrangement into rabbit tibiae. After 2, 4, and 8 weeks, the tibiae were retrieved and prepared for histomorphometric evaluation. RESULTS: Field-emission scanning electron microscopy showed that the BDCaP crystals were flakelike and the EDHA crystals were rodlike with a hexagonal cross section. X-ray diffractometric patterns and Fourier transform infrared spectroscopy spectra showed that the BDCaP coating consisted of HA and octacalcium phosphate, whereas the EDHA coating consisted of HA. Histologic observation showed that new bone on the EDHA-coated implant became mature after 4 weeks, while new bone on the control and BDCaP-coated implants was mature after 8 weeks. The EDHA implant showed significantly greater BIC and bone area compared to the control and BDCaP implants during 4 to 8 weeks. The BDCaP coating failed to show increased bone formation during the test period. CONCLUSION: The present EDHA coating has good bone formation properties, while the BDCaP coating has weaker bone formation properties.

Cell response of titanium implant with a roughened surface containing titanium hydride: an in vitro study.

PURPOSE: The purpose of this study was to investigate the effect of surface chemistry of a sandblasted and acid-etched implant (with and without titanium hydride [TiH(2)]) on cell attachment, proliferation, and differentiation of preosteoblasts (MC3T3-E1). MATERIALS AND METHODS: Sandblasted and dual acid-etched titanium discs comprised the test group, whereas sandblasted, acid-etched, and heat-treated discs comprised the control group. Both groups' discs were sent for surface characterization. MC3T3-E1 cells were cultured on these 2 groups' discs, and then cell attachment, cell proliferation, and cell differentiation were analyzed. RESULTS: Scanning electron microscope analysis showed that the titanium discs in the 2 groups shared the same surface topography; however, x-ray diffraction examination showed that the TiH(2) diffractions only appeared in the test group. Cell attachment and cell proliferation were much better in the test group than in the control group at all time points investigated (P < .05). The expressions of alkaline phosphatase and osteocalcin were significantly higher in the test group than in the control group for both protein and transcription level at every time point (P < .05 or P < .01). CONCLUSIONS: These results suggested that surface chemistry played a significant role in cell response to the sandblasted and acid-etched surface and the presence of TiH(2) might promote the attachment, proliferation, and differentiation of preosteoblasts.

[Study on the effects of overexpression of exogenous Notch1 in tongue squamous cell carcinoma cells on cell growth and expression of epidermal growth factor receptor in vitro].

OBJECTIVE: To investigate the effects of overexpression of exogenous Notch1 in human tongue squamous cell carcinoma (TSCC) cells on cell growth and expression of epidermal growth factor receptor (EGFR) in vitro. METHODS: Human TSCC cell line Tca8113 cells were transiently transfected with the eukaryotic expression plasmid pRAMIC-IRES2-EGFP encoding exogenous intracellular fragment of Notch1 and control plasmid pIRES2-EGFP by Lipofectamine 2000, respectively. Untransfected parental Tca8113 cells served as control. The cell proliferation was evaluated by methyl thiazolyl tetrazolium(MTT) assay. The apoptosis was assessed by flow cytometry. The mRNA and protein levels of Notch1 and EGFR in Tca8113 cells were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. The expression of EGFR protein in Tca8113 cells was detected by immunocytochemistry. RESULTS: MTT assay showed that the cell proliferation of Tca8113 cells transfected with pRAMIC-IRES2-EGFP was significantly inhibited as compared with controls (P < 0.05). After transfected with pRAMIC-IRES2-EGFP for 48 h, the apoptosis rate of Tca8113 cells was significantly higher than those of Tca8113 cells transfected with pIRES2-EGFP and untransfected Tca8113 cells (P < 0.05), and Notch1 expression was significantly increased at mRNA (P < 0.05) and protein (P < 0.05) levels, while EGFR expression was significantly decreased at mRNA (P < 0.05) and protein (P < 0.05) levels. CONCLUSION: Overexpression of exogenous Notch1 may inhibit cell growth and down-regulate EGFR expression in TSCC cells.

Biomechanical comparison of biomimetically and electrochemically deposited hydroxyapatite-coated porous titanium implants.

PURPOSE: The purpose of this study was to investigate the effects of biomimetically and electrochemically deposited hydroxyapatite on the fixation of an implant with bone tissue. MATERIALS AND METHODS: Implants were separated into 3 groups: roughened group, biomimetically deposited calcium-phosphorus (BDCaP) group, and electrochemically deposited hydroxyapatite (EDHA) group. We randomly inserted 90 implants into the femurs of 45 rabbits. After 2, 4, and 8 weeks, the femurs were retrieved and prepared for removal torque tests (RTQs) and field-emission scanning electron microscopy observation. RESULTS: During the test period, the EDHA group showed significantly greater RTQ values than did the roughened group and BDCaP group. The BDCaP group failed to increase the RTQ values compared with the roughened group. Field-emission scanning electron microscopy observation showed that the amount of attached bone tissue on the EDHA-coated implant surface was more than that on the roughened and BDCaP-coated implant surfaces during the test period. CONCLUSION: The electrochemical hydroxyapatite coating contributes to the fixation between bone and implant compared with the roughened surface, whereas the biomimetic calcium-phosphorus coating has little effect on the fixation.

Downregulation of Notch1 and its potential correlation with epidermal growth factor receptor signalling in tongue squamous cell carcinoma.

We investigated the expression of Notch1 in human oral squamous cell carcinoma (SCC) and explored its potential correlation with epidermal growth factor receptor (EGFR) signalling in oral SCC. Paraffin sections of primary SCC of the tongue and normal mucosa were screened immunohistochemically for Notch1 and EGFR proteins. Human SCC of the tongue Tca8113 cells were treated with AG1478 to block EGFR signalling, and were transfected with the vector that encodes the specific short hairpin RNA (shRNA) that targets EGFR. In SCC of the tongue expression of Notch1 was cancelled except in sites of squamous metaplasia where it was raised, while expression of EGFR was found in the peripheral cells of carcinomas, but not in sites of squamous metaplasia. In normal tongue mucosa, Notch1 was expressed mainly in the stratum corneum, but not in the stratum basale, while EGFR was expressed mainly in the stratum basale, but not in the stratum granulosum or stratum corneum. The blocking of EGFR signalling or the silencing of the EGFR gene resulted in upregulation of Notch1 at mRNA and protein levels in Tca8113 cells. These observations suggest that downregulation of Notch1 in oral SCC may be associated with upregulation of EGFR signalling.

[Effects of epidermal growth factor receptor gene silencing mediated by short hairpin RNA on proliferation and apoptosis of human tongue carcinoma cells].

OBJECTIVE: To investigate the effects of epidermal growth factor receptor (EGFR) gene silencing mediated by short hairpin RNA (shRNA) on proliferation and apoptosis of human tongue carcinoma cells. METHODS: shRNA eukaryotic expression vector targeting the specific sequence of human EGFR gene was constructed and termed shEGFR. The control vector targeting the unrelated sequence was also constructed and termed shNC. The vectors were transiently transfected into Tca8113 cells of human tongue squamous cell carcinoma by Lipofectamine 2000, respectively. The mRNA and protein levels of EGFR in Tca8113 cells were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. The cell proliferation of Tca8113 cells was evaluated by methyl thiazolyl tetrazolium (MTT) assay. The apoptosis of Tca8113 cells was assessed by flow cytometry. RESULTS: EGFR expression in Tca8113 cells transfected with shEGFR were obviously decreased at mRNA level (81.6%) and protein level (72.0%) (P < 0.05) 48 h after transfection of shEGFR compared with untransfected Tca8113 cells. The proliferation activity of Tca8113 cells transfected with shEGFR was significantly lower than that of Tca8113 cells transfected with shNC and untransfected Tca8113 cells (P < 0.05). The early apoptotic rate of Tca8113 cells transfected with shEGFR was significantly higher than that of Tca8113 cells transfected with shNC and untransfected Tca8113 cells [(39.4 +/- 7.7)%, (4.3 +/- 1.2)%, (2.5 +/- 0.9)%, P < 0.05] 48 h after transfection of shEGFR. CONCLUSIONS: EGFR gene silencing mediated by shRNA may inhibit cell proliferation and induce apoptosis in human tongue carcinoma cells.

Effects of biomimetically and electrochemically deposited nano-hydroxyapatite coatings on osseointegration of porous titanium implants.

OBJECTIVE: The objective of this study was to evaluate and compare the effects of biomimetically and electrochemically deposited nano-hydroxyapatite (HA) coatings on the osseointegration of porous titanium implants after 6 and 12 weeks of insertion in a rabbit bone model. STUDY DESIGN: Forty-two roughened implants were separated into 3 groups: roughened group, biomimetically deposited CaP (BDCaP) group, and electrochemically deposited HA (EDHA) group. Implant surface morphology of 3 groups (n = 6) was performed by field-emission scanning electron microscope (FSEM). Thirty-six implants were randomly inserted into tibias of 18 rabbits. After 6 and 12 weeks, tibias were retrieved and prepared for histomorphometric evaluation. RESULTS: FSEM showed the BDCaP crystals were flakelike, whereas the EDHA crystals were rodlike with a hexagonal cross section. Histological observation showed bone growth along the surfaces after 6 weeks. New bones were also seen on the BDCaP and EDHA implant surfaces in the marrow space. New bone on the roughened and EDHA implants became mature after 12 weeks. The EDHA implant showed significantly greater BIC and bone area compared with the roughened and BDCaP implants during 6 to 12 weeks (P < .05). The BDCaP implants did not evidently increase BIC and bone area compared to the roughened implants during the test period (P > .05). CONCLUSION: These results suggest that the EDHA coating has a better bone integration potential than does the BDCaP coating.