A number of experimental data on biomimetic deposition CaP (BDCaP) coating implants have reported promising outcomes by histological evaluation. But little is investigated on the role of the BDCaP coating and osseointegration mechanism by interface shear strength. To make a direct biomechanical comparison between the BDCaP coating implants and the uncoated rough titanium implants (control), a well-established animal model for implants removal torque testing was employed in rabbits, using a self-matching experimental design. All implants had an identical cylindrical screw shape without any macroscopic retentive structure. 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 torqued implants were sputter-coated with gold for morphology observation and observed with a field-emission electron microscopy. Results showed that the interfacial shear strength of the BDCaP coating implants was similar to that of the uncoated rough implants at 2 and 4 weeks of healing. The mean removal torque values of the BDCaP coating implants were lower than those of control implants (P < 0.05) after 6 weeks of healing. The removal torque values for both types of implants revealed similar mean values after 8 and 12 weeks of healing; there were no significant difference between the two types of implants (P > 0.05). It can be concluded that the BDCaP coating implants had no beneficial effect on the interfacial shear strength at early bone healing stage.
The aim of this study was to deposit simvastatin-hydroxyapatite (sim-HA) coatings on titanium surfaces by an electrochemical process and evaluate osteoprogenitor cell responses to sim-HA-coated surfaces. Simvastatin was prepared onto titanium surfaces with varying concentration (10(-7), 10(-6), 10(-5) and 10(-4) mol/L). Surface characteristics were performed by FSEM, XRD and FTIR. LC-MS/MS method was used for simvastatin quantification in Sim-HA-coated surfaces. Murine calvaria-derived pre-osteoblastic cell (MC3T3-E1) proliferation, alkaline phosphatase activity (ALP) and osteocalcin release were used to measure osteoblastic activities. FSEM observation showed rod-like HA crystals covered on all surfaces. As drug concentration increased, the crystal diameter decreased. XRD and FTIR observations showed all coatings consisted of HA. LC-MS/MS test showed the simvastatin concentration in 10(-6) mol/L group was 2.77 x 10(-7) mol/L/cm2, while in 10(-7) mol/L group was 1.89 x 10(-7) mol/L/cm2. MC3T3-E1 cells grown on 10(-7) mol/L and 10(-6) mol/L Sim-HA surfaces showed increased ALP activity as compared to HA-coated surfaces on day 7 (P < 0.05) while at 10 day, all Sim-HA groups were significantly increased than HA group (P < 0.05). Two Sim-HA groups showed significant increases in osteocalcin production on 7 10 and 14 day (P < 0.05). It showed that incubation with 10(-7) mol/L simvastatin enhanced the cell proliferation to a statistically significant extent (P < 0.05) compared with the HA group at day 7. It was concluded that simvastatin was successfully deposited into HA coatings using the electrochemical process and the sim-HA coatings enhanced differentiation of osteoprogenitor cells.
To design a high-precision reference, the various error sources have been analyzed and compensated with a compact 111 mV resistor-trim scheme and the upper and lower extremes of the reference precision are also temperature-compensated. At room temperature, the yield of ±0.5% precision is 96% and ±0.2% is 78%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.