1,721,076 research outputs found
Questione di pelle: il rischio da esposizione cutanea a sostanze tossiche
No full textIn passato la cute veniva generalmente considerata come una barriera impenetrabile dall’esterno, invece, nel tempo, si è rivelata come una possibile via d’ingresso di sostanze tossiche all’interno dell’organismo. Tale fenomeno - sfruttato anche in ambito farmaceutico per somministrare alcuni tipi di medicinali mediante veicolazione transdermica - presenta un rischio non trascurabile per la salute, soprattutto in particolari ambiti professionali, dove il lavoratore è esposto quotidianamente a composti potenzialmente dannosi.
A differenza della penetrazione per via respiratoria, il rischio legato all’assorbimento cutaneo è scarsamente percepito, di conseguenza non viene data la giusta importanza all’utilizzo di dispositivi di protezione individuali per la pelle, con conseguenze anche molto gravi, fino alla comparsa di patologie invalidanti. Cerchiamo di capire assieme questo fenomeno poco conosciuto e vediamo alcuni esempi di contaminanti che possono entrare nel nostro organismo attraverso la cute
Povidone iodine skin absorption: An ex-vivo study
No full textPovidone iodine is a water-soluble complex used to disinfect the skin surface and it exerts prolonged germicidal action against a broad spectrum of germs. Indeed, it is often applied on burned skin, large wounds, deep tissues or mucosa. Notably some surgical hand-scrub solutions, which are considered safe antiseptics, contain large amounts of iodine that can be absorbed by skin. The aim of present study was to study the skin absorption of iodine after the application on the skin of povidone-iodine solution, used by health care workers during surgical procedure. We use Franz diffusion static cells with human skin. After 24h from the beginning of our measurement the iodine concentration in the receiving compartment was 11.59±6.3μg/cm(2). The medium flux calculated was 0.73±0.33μg/cm(2)/h with a lag time of 8.9±1.5h. These in vitro results confirmed that povidone iodine could pass through the skin in a relevant amount that can explain the clinical findings in burned or surgically treated patients. In professional use the repetitive contact with povidone iodine, also as soap, can cause iodine skin permeation that must be considered when the washing procedures are repeated more than 20 times a day
ICP-AES analysis of Bizantine anonymous copper coins from the XI century and comparison wih micro-EDXRF non-destructive analysis
No full textIron Gall Inks: is copper a key element for historical and archaeometric information on medioeval manuscripts? An applied reserach focused on Guarnerio D’Artegna
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Core-shell electrospun polycaprolactone nanofibers, loaded with rifampicin and coated with silver nanoparticles, for tissue engineering applications
Full text linkIn the field of tissue engineering, the use of core-shell fibers represents an advantageous approach to protect and finely tune the release of bioactive compounds with the aim to regulate their efficacy. In this work, core-shell electrospun polycaprolactone nanofiber-based membranes, loaded with rifampicin and coated with silver nanoparticles, were developed and characterized. The membranes are composed by randomly oriented nanofibers with a homogeneous diameter, as demonstrated by scanning electron microscopy (SEM). An air-plasma treatment was applied to increase the hydrophilicity of the membranes as confirmed by contact angle measurements. The rifampicin release from untreated and air-plasma treated membranes, evaluated by UV spectrophotometry, displayed a similar and constant over-time release profile, demonstrating that the air-plasma treatment does not degrade the rifampicin, loaded in the core region of the nanofibers. The presence and the distribution of silver nanoparticles on the nanofiber surface were investigated by SEM and Energy Dispersive Spectroscopy. Moreover, SEM imaging demonstrated that the produced membranes possess a good stability over time, in terms of structure maintenance. The developed membranes showed a good biocompatibility towards murine fibroblasts, human osteosarcoma cells and urotheliocytes, reveling the absence of cytotoxic effects. Moreover, doble-functionalized membranes inhibit the growth of E. coli and S. aureus. Thanks to the possibilities offered by the coaxial electrospinning, the membranes here proposed are promising for several tissue engineering applications
In vitro absorption of metal powders through intact and damaged human skin
No full textThe bioavailability of metals, which are known as important contact allergens, is decisive for the development
and the maintenance of contact dermatitis. The aim of this study was to evaluate the percutaneous
penetration of metal powders of cobalt (Co), nickel (Ni) and chromium (Cr) and the effect of skin
lesions on skin absorption. In vitro permeation experiments were performed using the Franz diffusion
cells with intact and damaged human skin. Physiological solution was used as receiving phase and metal
powders (Co, Ni and Cr) dispersed in synthetic sweat at pH 4.5 were applied as donor phase to the outer
surface of the skin for 24 h. The amount of each metal permeating the skin was analysed by electro-thermal
atomic absorption spectroscopy (ETAAS). Donor solution analysis demonstrated that metals were
present as ions. Measurements of metals skin content were also exploited. Median Co and Ni concentrations
found in the receiving phase were significantly higher when Co and Ni powders were applied on the
abraded skin than after application on the intact skin (3566 and 2631 ngcm2 vs. 8.4 and 31 ngcm2,
respectively). No significant difference was found in Cr permeation through intact and damaged skin.
The measurement of metals skin content showed that Co, Ni and Cr concentrations were significantly
higher in the damaged skin than in the intact skin. Co and Ni ions concentrations increased significantly
when the donor solutions were applied on the damaged skin, while Cr ions concentrations did not
increase. This study demonstrated that Co and Ni powders can permeate through damaged skin more
easily than Cr powder, which has probably a stronger skin proteins binding capacity. Therefore, our
results suggest that is necessary to prevent skin contamination when using toxic substances because a
small injury to the skin barrier can significantly increase skin absorption
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