Study of magnesium metal and its alloys as a biodegradable material for medical and electrical applications
Sahinoja, Mikko (2013)
2013
Materiaalitekniikan koulutusohjelma
Tieto- ja sähkötekniikan tiedekunta - Faculty of Computing and Electrical Engineering
Teknisten tieteiden tiedekunta - Faculty of Engineering Sciences
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Hyväksymispäivämäärä
2013-12-04
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201312191502
https://urn.fi/URN:NBN:fi:tty-201312191502
Tiivistelmä
The goal of the work was to review known metallic materials and especially magnesium that are used for medical purposes. The intention was to review the role of the current metallic materials, covering the field from medical utensils to actual implant products and to find if there are any degradable metals used. Other purpose was to determine if magnesium is suitable for medical applications with a focus on the alloy's degradation properties in the practical section. Here the Mg-10Gd-1Nd-1Zn alloy's degradation behavior was studied when it was used in composite structure with poly(l-lactide-co-dl-lactide) (PLDLA) 50:50.
Magnesium metal is well-known and commonly used material. Its influence in different fields has made it an important material with applications that are used due to the light weight of the material when compared to other metal materials. Magnesium’s biocompatibility has made the material gain attention in the medical field. On the other hand, due to magnesium’s fast degradation rate, it has been difficult to use the material for medical applications. Recently, though, magnesium has been studied and planned to be used for medical implants for bone and electrical applications. The material has been used for certain implant application already but only in pre-clinical testings. These tests have shown that the material is almost suitable as it is for some applications but conflicting results from different sources and safety aspects have prevented its use. Studies propose that, for safe in vivo use, a suitable degradation rate should be under 0.01 ml/cm2/day.
Testing the Mg-10Gd-1Nd-1Zn alloy by itself and as a composite with 67-92 wt-% PLDLA 50:50 polymer resulted in various results. Work was focused on pH-measurements and microscope imaging. Results indicated that the alloy degraded more rapidly in a "Sørensen" buffer solution than in di-ionized water immersion. The alloy also gained a phosphate layer on top of the metal in a few days in the buffer solution. It was also noticed that the polymer was able to hinder degradation of the magnesium material heavily. In that respect the magnesium alloy in a composite might be promising for implant applications for its electrical properties but further research is needed to determine this.
Magnesium metal is well-known and commonly used material. Its influence in different fields has made it an important material with applications that are used due to the light weight of the material when compared to other metal materials. Magnesium’s biocompatibility has made the material gain attention in the medical field. On the other hand, due to magnesium’s fast degradation rate, it has been difficult to use the material for medical applications. Recently, though, magnesium has been studied and planned to be used for medical implants for bone and electrical applications. The material has been used for certain implant application already but only in pre-clinical testings. These tests have shown that the material is almost suitable as it is for some applications but conflicting results from different sources and safety aspects have prevented its use. Studies propose that, for safe in vivo use, a suitable degradation rate should be under 0.01 ml/cm2/day.
Testing the Mg-10Gd-1Nd-1Zn alloy by itself and as a composite with 67-92 wt-% PLDLA 50:50 polymer resulted in various results. Work was focused on pH-measurements and microscope imaging. Results indicated that the alloy degraded more rapidly in a "Sørensen" buffer solution than in di-ionized water immersion. The alloy also gained a phosphate layer on top of the metal in a few days in the buffer solution. It was also noticed that the polymer was able to hinder degradation of the magnesium material heavily. In that respect the magnesium alloy in a composite might be promising for implant applications for its electrical properties but further research is needed to determine this.