Binary Mg-Ca alloys, with a low Ca content (0.6 - 3 wt.%) have demonstrated to be very promising for orthopedic applications [1]. The main problem is that these alloys exhibit fast degradation when inserted in bones. The best way to minimize corrosion processes seems the coating of the alloy surface by biocompatible materials, which could also improve the biocompatibility of Mg-Ca surface [2]. Among the different materials which can be used as biocompatible coatings, bioactive glasses are very promising since, compared to synthetic hydroxyapatite, the surface layer in this case is more similar, in terms of crystallinity, to the apatite of bone tissue [3]. In this paper we have used RKKP glass ceramic (SiO2 - 43.68, ?-Ca3(PO4)2 - 24.00, CaO - 18.40, CaF2 - 4.92, Na2O - 4.53, MgO - 2.78, K2O - 0.19, Ta2O5 - 1.00, La2O3 - 0.50, all in wt%) as coating material for a Mg-Ca substrate. The technique used to deposit the coatings was Pulsed Laser Deposition (PLD). In fact, PLD have already successfully used to deposit films of a large number of materials with technological interest [4]. In particular, RKKP glass ceramic films, deposited by PLD on titanium substrates, have shown a composition reflecting very well that of the ablation target [5]. The deposition experiments have been performed in high vacuum by a frequency doubled Nd:YAG laser (? = 532 nm, ? = 7 ns, repetition rate = 10 Hz). The deposited films have been characterized using different techniques like Scanning Electron Microscopy, Atomic Force Microscopy, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, in order to characterize the coatings from chemical composition, structural and morphological point of view. The obtained results confirm us the potential of bioactive glass coatings for Mg-Ca alloys, due to a good homogeneity of the coatings, good adhesion to the substrate and a reduced rate of hydrogen release in simulated medium. Future studies will be performed in order to observe the influence of the coatings on biodegradation and biocompatibility properties.
Pulsed laser deposition of RKKP bioglass coatings on Mg-Ca substrates for biomedical applications
A Santagata;
2015
Abstract
Binary Mg-Ca alloys, with a low Ca content (0.6 - 3 wt.%) have demonstrated to be very promising for orthopedic applications [1]. The main problem is that these alloys exhibit fast degradation when inserted in bones. The best way to minimize corrosion processes seems the coating of the alloy surface by biocompatible materials, which could also improve the biocompatibility of Mg-Ca surface [2]. Among the different materials which can be used as biocompatible coatings, bioactive glasses are very promising since, compared to synthetic hydroxyapatite, the surface layer in this case is more similar, in terms of crystallinity, to the apatite of bone tissue [3]. In this paper we have used RKKP glass ceramic (SiO2 - 43.68, ?-Ca3(PO4)2 - 24.00, CaO - 18.40, CaF2 - 4.92, Na2O - 4.53, MgO - 2.78, K2O - 0.19, Ta2O5 - 1.00, La2O3 - 0.50, all in wt%) as coating material for a Mg-Ca substrate. The technique used to deposit the coatings was Pulsed Laser Deposition (PLD). In fact, PLD have already successfully used to deposit films of a large number of materials with technological interest [4]. In particular, RKKP glass ceramic films, deposited by PLD on titanium substrates, have shown a composition reflecting very well that of the ablation target [5]. The deposition experiments have been performed in high vacuum by a frequency doubled Nd:YAG laser (? = 532 nm, ? = 7 ns, repetition rate = 10 Hz). The deposited films have been characterized using different techniques like Scanning Electron Microscopy, Atomic Force Microscopy, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, in order to characterize the coatings from chemical composition, structural and morphological point of view. The obtained results confirm us the potential of bioactive glass coatings for Mg-Ca alloys, due to a good homogeneity of the coatings, good adhesion to the substrate and a reduced rate of hydrogen release in simulated medium. Future studies will be performed in order to observe the influence of the coatings on biodegradation and biocompatibility properties.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
