ABSTRACT
Mesoporous strontium hydroxyapatite (SrHAp) nanorods (NRs) have been successfully synthesized using a simple and efficient chemical route, i.e. the hydrothermal method. Structural and morphological characterization of the as-synthesized SrHAp NRs have been performed by transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). TEM and HAADF-STEM measurements of the NRs reveal the coexistence of longer and shorter particles with the length ranging from 50 nm to 400 nm and a diameter of about 20-40 nm. Electron tomography measurements of the NRs allow us to better visualize the mesopores and their facets. Two model drugs, hydrophobic risperidone and hydrophilic pramipexole, were loaded into the SrHAp NRs. These nanorods were coated using a modified chitosan (CS) with poly(2-hydroxyethyl methacrylate) (PHEMA), in order to encapsulate the drug-loaded SrHAp nanoparticles and reduce the cytotoxicity of the loaded materials. The drug release from neat and encapsulated SrHAp NRs mainly depends on the drug hydrophilicity. Importantly, although neat SrHAp nanorods exhibit some cytotoxicity against Caco-2 cells, the Cs-g-PHEMA-SrHAp drug-loaded nanorods show an acceptable cytocompatibility.
ABSTRACT
We want to evaluate the incidence of allergic problems in a population of catering students at the beginning and after 3 and 5 years of their course. We enrolled in the study 601 students of a professional catering school: 412 in the first year and 189 in the fifth years. We used two questionnaires to investigate respiratory problems and dermatological ones. All the subjects were also patch tested with 10 aptens. The incidence of reported symptoms of allergy was higher in fifth year than in first one. We can observe a rising in positive reaction between the two group of students to Balsam Perù, Nickel, Fragrance mix and Garlic. In particular we found an higher incidence of positive patch reaction in female population. On the contrary the rising in positive reaction to Garlic is higher in male. About two third of the subjects positive to garlic present a sensitization to diallyl disulphide. The rising of positive patch test reactions to Garlic and Balsam Perù should be caused by the contact with cooking spices. The higher incidence of allergic pathology between students during fifth year of school and students at first year is probably due to scholastic practical activity.
