Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Mostofi, S.
CELLULAR & MOLECULAR REACTIONS OF PRE-OSTEOBLASTS TO DIFFERENT MAGNESIUM IMPLANTS
PhD-Studium (Doctor of Philosophy); Humanmedizin; [ Dissertation ] Graz Medical University; 2017. pp. 146
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Schäfer Ute
- Weinberg Annelie-Martina
- Altmetrics:
- Abstract:
- Background: Among biodegradable implants, Magnesium based implants showed suitable potential, due to their proper mechanical, physical, chemical and biological properties. However, in spite of their adequate qualification as bone implants, their fast corrosion rate and vast hydrogen gas release can be considered as a big disadvantage. Material and methods: Degradation profile of Pure Mg, Mg2Ag and Mg10Gd was studied based on evaluation of Mg ion release over time with ICP-OES method. Alteration in surface morphology and surface chemical elemental composition was determined by scanning electron microscopy equipped with EDX. Effect of surface modification on cell viability was identified by cultivation of MC3T3-E1 cells on 1, 2 and 3 days corroded specimens. Moreover morphology of the cells were analysed on these surfaces by F-actin staining and scanning electron microscopy. The stimulatory and inhibitory effect of Mg ions derived from Pure Mg, Mg2Ag and Mg10Gd extracts on pre-osteoblast cells were analysed by MTT assay with and without pH adjustment. Expression of two osteogenic markers (Collagen I and Runx2) was evaluated on non-corroded specimens at longer immersion times (up to 12 days) by western blot and Immunocytochemistry. Antibacterial activity of Mg2Ag, Mg4Ag and Mg6Ag was assessed towards two most prevalent microbial species (S.aureus and S. epidermidis) up to 3 days of culture with Bio-screen device. Results: Mg2Ag and Pure Mg were shown similar pattern of corrosion. Needle shape crystals were detected at day 3 of immersion which were covered the surface of both materials entirely at day 8. There was no evidence of crystal formation on the surface of Mg10Gd at any immersion time. High atomic percentage of Calcium and Phosphor adsorbed to the surface by this material (Mg10Gd) can suppress the surface from crystal formation. Cellular Reaction: pre-corrosion of materials in cell culture medium did not improve cellular behavior as compared to the non-corroded control. Metabolic activity: Low concentration of Mg derived from all specimens had stimulatory effect on MC3T3-E1 cells, while high concentration seemed negatively influence the cells. Gene expression: The cells showed steady down-regulation when cultured on Pure Mg and Mg2Ag up to 12 days. Although similar down-regulation was observed when the cells were cultured on Mg10Gd, but at day 12, the osteogenic potential of the cells came back to the normal level. Antibacterial activity: all silver containing Mg implants exhibited suitable antibacterial properties at low dilutions; however increase in silver content did not result in increase of antibacterial activity.