| 1. |
- Claesson, Maria, 1985, et al.
(författare)
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Improved QCM-D signal-to-noise ratio using mesoporous silica and titania
- 2012
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Ingår i: Sensors and Actuators, B: Chemical. - : Elsevier BV. - 0925-4005. ; 166, s. 526-534
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Tidskriftsartikel (refereegranskat)abstract
- In many biological and environmental applications it is crucial to detect low concentrations of low molecular weight analytes. To accomplish this a variety of surface sensing techniques, such as quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR), have been developed. These techniques provide good sensitivity and selectivity, however, there is a need to improve these even further by enhancing the signal-to-noise ratio. One suggestion to improve the QCM-D signal is to use mesoporous coated QCM-D sensor crystals as sensing substrate. Mesoporous materials are promising to use, since they possess a high specific surface area and that their properties, such as pore size, pore geometry and surface chemistry, can be controlled. Here we demonstrate a method to increase the signal-to-noise ratio of the QCM-D signal illustrated by adsorbing dendrimers on mesoporous silica and titania coated QCM-D crystals. The experiments were performed on cubic mesoporous silica having varying pore sizes and hexagonal and cubic mesoporous titania having similar pore size. The results showed that the QCM-D signal-to-noise was improved when mesoporous material was used and that the pore size and pore geometry determined the selectivity of the adsorbing analyte. These findings are important in the detection of analytes at low concentrations using QCM-D.
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| 2. |
- Karlsson, Johan, 1984, et al.
(författare)
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In vivo biomechanical stability of osseointegrating mesoporous TiO2 implants
- 2012
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Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1878-7568 .- 1742-7061. ; 8:12, s. 4438-4446
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Tidskriftsartikel (refereegranskat)abstract
- Mesoporous materials are of high interest as implant coatings to receive an enhanced osseointegration. In this study, titanium implants coated with mesoporous TiO(2) thin films have been evaluated both in vitro and in vivo. Material characterization showed that, with partly crystalline TiO(2) (anatase), long-range-ordered hydrophilic mesoporous thin films with a pore size of 6nm were obtained. Evaluation of the mechanical resistance showed that the films were robust enough to withstand the standard implantation procedure. In vitro apatite formation was studied using simulated body fluids, showing that the pores are accessible for ions and that formation of apatite was increased due to the presence of the mesopores. An in vivo study using a rabbit model was executed in which the removal torque and histomorphometry were evaluated. The results show that the biomechanical stability of the TiO(2) coating was unaffected by the presence of mesopores and that osseointegration was achieved without any signs of inflammation.
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| 3. |
- Karlsson, Johan, 1984, et al.
(författare)
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The effect of alendronate on biomineralization at the bone/implant interface
- 2016
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 104:3, s. 620-629
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Tidskriftsartikel (refereegranskat)abstract
- A recent approach to improve the osseointegration of implants is to utilize local drug administration. The presence of an osteoporosis drug may influence both bone quantity and quality at the bone/implant interface. Despite this, the performance of bone-anchoring implants is traditionally evaluated only by quantitative measurements. In the present study, the osteoporosis drug alendronate (ALN) was administrated from mesoporous titania thin films that were coated onto titanium implants. The effect that the drug had on biomineralization was explored both in vitro using simulated body fluid (SBF) and in vivo in a rat tibia model. The SBF study showed that the apatite formation was completely hindered at a high concentration of ALN (0.1 mg/mL). However, when ALN was administrated from the mesoporous coating the surface became completely covered with apatite. Ex vivo characterization of the bone/implant interface using Raman spectroscopy demonstrated that the presence of ALN enhanced the bone mineralization, and that the chemical signature of newly formed bone in the presence of ALN had a higher resemblance to the pre-existing mature bone than to the bone formed without drug. Taken together, this study demonstrates the importance of evaluating the quality of the formed bone to better understand the performance of implants.
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