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| 2. |
- Gallud, Audrey, et al.
(författare)
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Macrophage activation status determines the internalization of mesoporous silica particles of different sizes : Exploring the role of different pattern recognition receptors
- 2017
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 121, s. 28-40
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Tidskriftsartikel (refereegranskat)abstract
- Mesoporous silica-based particles are promising candidates for biomedical applications. Here, we address the importance of macrophage activation status for internalization of AMS6 (approx. 200 nm in diameter) versus AMS8 (approx. 2 mu m) mesoporous silica particles and the role of different phagocytosis receptors for particle uptake. To this end, FITC-conjugated silica particles were used. AMS8 were found to be non-cytotoxic both for M-CSF-stimulated (anti-inflammatory) and GM-CSF-stimulated (pro-inflammatory) macrophages, whereas AMS6 exhibited cytotoxicity towards M-CSF-stimulated, but not GMCSF-stimulated macrophages; this toxicity was, however, mitigated in the presence of serum. AMS8 triggered the secretion of pro-inflammatory cytokines in M-CSF-activated cells. Class A scavenger receptor (SR-A) expression was noted in both M-CSF and GM-CSF-stimulated macrophages, although the expression was higher in the former case, and gene silencing of SR-A resulted in a decreased uptake of AMS6 in the absence of serum. GM-CSF-stimulated macrophages expressed higher levels of the mannose receptor CD206 compared to M-CSF-stimulated cells, and uptake of AMS6, but not AMS8, was reduced following the downregulation of CD206 in GM-CSF-stimulated cells; particle uptake was also suppressed by mannan, a competitive ligand. These studies demonstrate that macrophage activation status is an important determinant of particle uptake and provide evidence for a role of different macrophage receptors for cell uptake of silica particles.
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| 3. |
- Hagman, Emilia, et al.
(författare)
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Oral intake of mesoporous silica is safe and well tolerated in male humans
- 2020
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- Background Precisely engineered mesoporous silica has been shown to induce weight loss in mice, but whether it is safe to use in humans have not investigated.Objective The aim was to determine whether oral dosing, up to 9 grams/day, of precisely engineered mesoporous silica as a food additive can be used safely in male humans.Design This single blinded safety study consisted of two study arms including 10 males each (18-35 years). One arm consisted of participants with normal weight and one with obesity. After a placebo run-in period, all subjects were given porous silica three times daily, with increasing dose up to 9 grams/day (Phase 1). Subjects with obesity continued the study with highest dose for additional 10 weeks (Phase 2).Results All participants completed Phase 1 and 90% completed Phase 2, with approximately 1% missed doses. Participants reported no abdominal discomfort, and changes in bowel habits were minor and inconsistent. The side effects observed were mild and tolerable, biomarkers did not give any safety concern, and no severe adverse events occurred.Conclusion Mesoporous silica intake of up to 9 grams/day can be consumed by males without any major adverse events or safety concerns.
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| 4. |
- Izquierdo-Barba, Isabel, et al.
(författare)
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Incorporation of antimicrobial compounds in mesoporous silica film monolith
- 2009
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 30:29, s. 5729-5736
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Tidskriftsartikel (refereegranskat)abstract
- : Incorporation of the antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES), as well as low molecular weight antimicrobial chlorhexidine, into mesoporous silica was obtained using an EISA one-pot synthesis method. FTIR confirmed efficient encapsulation of both LL-37 and chlorhexidine into mesoporous silica, while XRD and TEM showed that antimicrobial agent incorporation can be achieved without greatly affecting the structure of the mesoporous silica. The modified mesoporous silica released LL-37 and chlorhexidine slowly, reaching maximum release after about 200 h. The release rate could also be controlled through incorporation of SH groups in the pore walls, adding to pore hydrophobicity and reducing the release rate by about 50% compared to the unmodified mesoporous silica. Mesoporous silica containing either LL-37 or chlorhexidine displayed potent bactericidal properties against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. While chlorhexidine-loaded mesoporous silica displayed an accompanying high toxicity, as judged from hemolysis, LDH release, and MTT assay, the corresponding material containing LL-37 showed very low toxicity by all these assays, comparable to that observed for mesoporous silica in the absence of antibacterial drug, as well as to the negative controls in the respective assays. Mesoporous silica containing LL-37 therefore holds potential as an implantable material or a surface coating for such materials, as it combines potent bactericidal action with low toxicity, important features for controlling implant-related infections, e.g., for multi-resistant pathogens or for cases where access to the infection site of systemically administered antibiotics is limited due to collagen capsule formation or other factors.
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| 7. |
- Kupferschmidt, Natalia, et al.
(författare)
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In vivo oral toxicological evaluation of mesoporous silica particles
- 2013
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Ingår i: Nanomedicine. - 1743-5889 .- 1748-6963. ; 8:1, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mesoporous silica particles are highly promising nanomaterials for biomedical applications. They can be used to improve bioavailability, solubility and drug stability and to protect drugs from the acidic conditions of the stomach, leading to increased drug effectiveness. Their biocompatibility in vivo has recieved little attention, in particular regarding oral administration. Aim: To study the oral tolerance of micron-sized nanoporous folic acid-templated material-1 (cylindrical, 2D hexagonal pore structure) and nanometer-sized anionic-surfactant-templated mesoporous silica material-6 (cylindrical, 3D cubic pore structure) mesoporous silica particles in Sprague Dawley rats. Materials & methods: A dose stepwise procedure or range finding test was followed by a consequent confirmatory test. The confirmatory test included daily administrations of 2000 and 1200 mg/kg doses for nanoporous folic acid-templated material-1 and anionic-surfactant-templated mesoporous silica material-6, respectively. Results: The maximum tolerated dose for anionic-surfactant-templated mesoporous silica material-6 was not reached. Similar results were observed for nanometer-sized anionic-surfactant-templated mesoporous silica material-1 in most of the animals, although adverse effects were observed in some animals that are most probably due to the administration by oral gavage of the formulated particles. Conclusion: The results are promising for the use of mesoporous silica materials as drug-delivery systems in oral administration.
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| 8. |
- Kupferschmidt, Natalia, et al.
(författare)
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In vivo oral toxicological evaluation of mesoporous silica particles
- 2013
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Ingår i: Nanomedicine. - : Future Medicine Ltd. - 1743-5889 .- 1748-6963. ; 8:1, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mesoporous silica particles are highly promising nanomaterials for biomedical applications. They can be used to improve bioavailability, solubility and drug stability and to protect drugs from the acidic conditions of the stomach, leading to increased drug effectiveness. Their biocompatibility in vivo has recieved little attention, in particular regarding oral administration. Aim: To study the oral tolerance of micron-sized nanoporous folic acid-templated material-1 (cylindrical, 2D hexagonal pore structure) and nanometer-sized anionic-surfactant-templated mesoporous silica material-6 (cylindrical, 3D cubic pore structure) mesoporous silica particles in Sprague Dawley rats. Materials & methods: A dose stepwise procedure or range finding test was followed by a consequent confirmatory test. The confirmatory test included daily administrations of 2000 and 1200 mg/kg doses for nanoporous folic acid-templated material-1 and anionic-surfactant-templated mesoporous silica material-6, respectively. Results: The maximum tolerated dose for anionic-surfactant-templated mesoporous silica material-6 was not reached. Similar results were observed for nanometer-sized anionic-surfactant-templated mesoporous silica material-1 in most of the animals, although adverse effects were observed in some animals that are most probably due to the administration by oral gavage of the formulated particles. Conclusion: The results are promising for the use of mesoporous silica materials as drug-delivery systems in oral administration.
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| 9. |
- Kupferschmidt, Natalia, et al.
(författare)
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Large pore mesoporous silica induced weight loss in obese mice
- 2014
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Ingår i: Nanomedicine. - 1743-5889 .- 1748-6963. ; 9:9, s. 1353-1362
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a need for medical treatments to curb the rising rate of obesity. Weight reduction is correlated with a decrease in associated risk factors and cholesterol levels in humans. Amorphous silica particles have been found to exert a hypocholesterolemic effect in humans, making them popular dietary additives. Aim: To investigate the effect of mesoporous silica, which possess sharp pore size distributions, on: weight loss, cholesterol, triglycerides and glucose blood levels in obese mice. Materials & methods: Mesoporous silicas with differing pore size were mixed in the high-fat diet of obese mice. Results: Animals receiving large pore mesoporous silica with a high-fat diet show a significant reduction in body weight and fat composition, with no observable negative effects. Conclusion: Pore size is an important parameter for reduction of body weight and body fat composition by mesoporous silica, demonstrating promising signs for the treatment of obesity.
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| 10. |
- Kupferschmidt, Natalia, et al.
(författare)
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Large pore mesoporous silica induced weight loss in obese mice
- 2013
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Ingår i: Nanomedicine. - : Future Medicine Ltd. - 1743-5889 .- 1748-6963. ; 9:9, s. 1353-1362
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a need for medical treatments to curb the rising rate of obesity. Weight reduction is correlated with a decrease in associated risk factors and cholesterol levels in humans. Amorphous silica particles have been found to exert a hypocholesterolemic effect in humans, making them popular dietary additives. Aim: To investigate the effect of mesoporous silica, which possess sharp pore size distributions, on: weight loss, cholesterol, triglycerides and glucose blood levels in obese mice. Materials & methods: Mesoporous silicas with differing pore size were mixed in the high-fat diet of obese mice. Results: Animals receiving large pore mesoporous silica with a high-fat diet show a significant reduction in body weight and fat composition, with no observable negative effects. Conclusion: Pore size is an important parameter for reduction of body weight and body fat composition by mesoporous silica, demonstrating promising signs for the treatment of obesity.
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