| 1. |
- Thorfve, Anna, 1982, et al.
(författare)
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Hydroxyapatite coating affects the Wnt signaling pathway during peri-implant healing in vivo
- 2014
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Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Owing to its bio- and osteoconductivity, hydroxyapatite (HA) is a widely used implant material, but its osteogenic properties are only partly evaluated in vitro and in vivo. The present study focused on bone healing adjacent to HA-coated titanium (Ti) implants, with or without incorporated lithium ions (Li+). Special attention was given to the Wnt signaling pathway. The implants were inserted into rat tibia for 7 or 28days and analyzed ex vivo, mainly by histomorphometry and quantitative real-time polymerase chain reaction. HA-coated implants showed, irrespective of Li+ content, bone-implant contact (BIC) and removal torque significantly higher than those of reference Ti. Further, the expressions of OCN, CTSK, COL1A1, LRP5/6 and WISP1 were significantly higher in implant-adherent cells of HA-coated implants, with or without Li+. Significantly higher β-catenin expression and significantly lower COL2A1 expression were observed in peri-implant bone cells from HA with 14ngcm-2 released Li+. Interestingly, Ti implants showed a significantly larger bone area in the threads than HA with 39ngcm-2 released Li+, but had a lower BIC than any HA-coated implant. This study shows that HA, with or without Li+ is a strong activator of the Wnt signaling pathway, and may to some degree explain its high bone induction capacity.
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| 2. |
- Åberg, Jonas, 1982-, et al.
(författare)
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Biocompatibility and resorption of a radiopaque premixed calcium phosphate cement
- 2012
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 100A:5, s. 1269-1278
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Tidskriftsartikel (refereegranskat)abstract
- Calcium phosphate cements (CPC) are used as bone void filler in various orthopedic indications; however, there are some major drawbacks regarding mixing, transfer, and injection of traditional CPC. By using glycerol as mixing liquid, a premixed calcium phosphate cement (pCPC), some of these difficulties can be overcome. In the treatment of vertebral fractures the handling characteristics need to be excellent including a high radio-opacity for optimal control during injection. The aim of this study is to evaluate a radiopaque pCPC regarding its resorption behavior and biocompatibility in vivo. pCPC and a water-based CPC were injected into a circle divide 4-mm drilled femur defect in rabbits. The rabbits were sacrificed after 2 and 12 weeks. Cross sections of the defects were evaluated using histology, electron microscopy, and immunohistochemical analysis. Signs of inflammation were evaluated both locally and systemically. The results showed a higher bone formation in the pCPC compared to the water-based CPC after 2 weeks by expression of RUNX-2. After 12 weeks most of the cement had been resorbed in both groups. Both materials were considered to have a high biocompatibility since no marked immunological response was induced and extensive bone ingrowth was observed. The conclusion from the study was that pCPC with ZrO2 radiopacifier is a promising alternative regarding bone replacement material and may be suggested for treatment of, for example, vertebral fractures based on its high biocompatibility, fast bone ingrowth, and good handling properties.
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| 3. |
- Åberg, Jonas, 1982-, et al.
(författare)
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In vitro and in vivo evaluation of an injectable premixed calcium phosphate cement : cell viability and immunological response from rat
- 2010
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Ingår i: International Journal of Nano and Biomaterials. - 1752-8941. ; 3:3, s. 203-221
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Tidskriftsartikel (refereegranskat)abstract
- By using premixed calcium phosphate cement (CPC) the handling properties of the cement are drastically improved, which is a challenge for traditional injectable CPC. In this article, a premixed acidic CPC has been compared to a conventional water mixed brushite cement to evaluate whether the premixed concept affects the biological response. The cements were evaluated regarding the pH-variation in simulated body fluid (SBF). Further, the biocompatibility of the cement with human mesenchymal stem cells (MSC) was studied in vitro and eventual inflammation properties studied in vivo, after subcutaneous material injections in rats. A larger pH decrease was seen for the conventional cement than the premixed cement in SBF. For both materials, > 90% of the MSC remained alive in vitro. No systemic or macroscopic inflammation was detected, only a mild microscopic inflammation was detected around both materials. In addition to the handling benefit of premixed cements compared to conventional water mixed CPC, the premixed CPC in the present study demonstrated high and in comparison to conventional CPC comparable biocompability, both in vitro and in vivo.
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