Vesicular systems incorporating magnetic nanoparticles (MNPs) have been attracting much interest for their possible application in active drug delivery. To this aim, suitable procedures have to benn developed to enhance the efficiency of inclusion of MNPs into vesicular systems. Therefore, it is crucial to dispose of reliable control tools to quantify the presence of MNPs in such systems. To verify the homogeneity of the nanosystems, such techniques are required to give information not only about the overall amount of MNPs in the sample, but also about the presence/absence into the single vesicle. To this aim, we developed a methodology based on magnetic force microscopy (MFM), which is a particular atomic force microscopy (AFM) based technique where a tip coated with a magnetic ultrathin film is used to probe the sample magnetic properties. Firstly, the sample surface is scanned in semi-contact mode to reconstruct its morphology. Then, the same area is scanned again imposing a constant tip-sample distance during the image, the cantilever is oscillating and the cantilever oscillation phase shift is recorded. This is related to the gradient along the vertical direction of the tip sample interaction force, which is dominated by the magnetic interaction. Vesicular systems incorporating MNPs have been produced by the thin film technique, hydrating with the MNPs solution. The presence of MNPs in the samples have been previously verified and quantified by inductively coupled plasma mass spectrometry (ICP-MS), which nevertheless does not allow the identification of their position and distribution into the vesicles. Drops of vesicles/MNPs sample have been poured on glass substrates and imaged by AFM either in water (using an ad hoc designed and realized cell) or in air (after dehydration). MFM has been used to investigate the sample. The MFM phase images revealed the presence of MNPs into the vesicles. By analyzing such phase images using a phenomenological calibration specifically developed for the purpose, we quantified the amount of MNPs incorporated in the vesicles.
Visualization and quantification of magnetic nanoparticles into vesicular systems by atomic force microscopy / Passeri, Daniele; Dong, Chunhua; S., Corsetti; Angeloni, Livia; Rossi, Marco; Rinaldi, Federica; Marianecci, Carlotta; Carafa, Maria; Pantanella, Fabrizio; A., Sorbo. - ELETTRONICO. - (2012), pp. P20-P20. (Intervento presentato al convegno Nanomedicine: from molecules to diagnosis and therapy tenutosi a Roma nel 1-3 ottobre 2012).
Visualization and quantification of magnetic nanoparticles into vesicular systems by atomic force microscopy
PASSERI, Daniele;DONG, CHUNHUA;ANGELONI, LIVIA;ROSSI, Marco;RINALDI, FEDERICA;MARIANECCI, CARLOTTA;CARAFA, Maria;PANTANELLA, Fabrizio;
2012
Abstract
Vesicular systems incorporating magnetic nanoparticles (MNPs) have been attracting much interest for their possible application in active drug delivery. To this aim, suitable procedures have to benn developed to enhance the efficiency of inclusion of MNPs into vesicular systems. Therefore, it is crucial to dispose of reliable control tools to quantify the presence of MNPs in such systems. To verify the homogeneity of the nanosystems, such techniques are required to give information not only about the overall amount of MNPs in the sample, but also about the presence/absence into the single vesicle. To this aim, we developed a methodology based on magnetic force microscopy (MFM), which is a particular atomic force microscopy (AFM) based technique where a tip coated with a magnetic ultrathin film is used to probe the sample magnetic properties. Firstly, the sample surface is scanned in semi-contact mode to reconstruct its morphology. Then, the same area is scanned again imposing a constant tip-sample distance during the image, the cantilever is oscillating and the cantilever oscillation phase shift is recorded. This is related to the gradient along the vertical direction of the tip sample interaction force, which is dominated by the magnetic interaction. Vesicular systems incorporating MNPs have been produced by the thin film technique, hydrating with the MNPs solution. The presence of MNPs in the samples have been previously verified and quantified by inductively coupled plasma mass spectrometry (ICP-MS), which nevertheless does not allow the identification of their position and distribution into the vesicles. Drops of vesicles/MNPs sample have been poured on glass substrates and imaged by AFM either in water (using an ad hoc designed and realized cell) or in air (after dehydration). MFM has been used to investigate the sample. The MFM phase images revealed the presence of MNPs into the vesicles. By analyzing such phase images using a phenomenological calibration specifically developed for the purpose, we quantified the amount of MNPs incorporated in the vesicles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
