Ottimizzazione della mucoadesivita' di miscele di polisaccaridi come veicoli oftalmici

Polisaccaridi mucomimetici, come xiloglucano (tamarind seed polysaccaride TSP) e acido ialuronico (HA), attualmente utilizzati in sostituti lacrimali possono prolungare la residenza dei farmaci nell'area precorneale grazie alle loro proprietà mucoadesive. Inoltre, in recenti test chimico-fisici, si è osservata un’interazione tra TSP e HA in soluzione nella proporzione TSP-HA 3:2. A tale scopo sono state preparate e studiate quattro miscele dei due polimeri: TSP-HA(1:4), TSP-HA(2:3), TSP-HA(3:2), TSP-HA(1:4) in tampone fosfato pH 7.4, isotonico (TF), che sono state medicate con KEF (0.07%) o con DS (0.3%) In questo lavoro di tesi le soluzioni TSP-HA sono state confrontate per il tempo di residenza medio nel fluido lacrimale dei conigli (MRT) e per la capacità di prolungare il tempo di residenza di KEF o di DS in tale fluido.Poi e’ stato studiato in vitro con dialisi dinamica il binding in soluzione tra KEF o DS, e le miscele polimeriche allo studio. E' stato confrontato, inoltre, l’ordine dei valori di MRT con quello dell’interattività mucina-polimero, quest’ultima determinata in base all’aumento della viscosità di una dispersione di mucina causato dall’interazione mucina-polimero(metodo Hassan-Gallo). La presente tesi ha mostrato che c'è un effeto sinergico tra i due polimeri TSP-HA e in virtù della sua mucoadesività, TSP-HA(3:2) si suppone stabilizzi il film lacrimale. I presenti risultati hanno mostrato che formulazioni oftalmiche di KF e DS contenenti TSP hanno la potenzialità di diminuire la frequenza delle instillazioni

Development of In Vitro Corneal Models: Opportunity for Pharmacological Testing

The human eye is a specialized organ with a complex anatomy and physiology, because it is characterized by different cell types with specific physiological functions. Given the complexity of the eye, ocular tissues are finely organized and orchestrated. In the last few years, many in vitro models have been developed in order to meet the 3Rs principle (Replacement, Reduction and Refinement) for eye toxicity testing. This procedure is highly necessary to ensure that the risks associated with ophthalmic products meet appropriate safety criteria. In vitro preclinical testing is now a well-established practice of significant importance for evaluating the efficacy and safety of cosmetic, pharmaceutical, and nutraceutical products. Along with in vitro testing, also computational procedures, herein described, for evaluating the pharmacological profile of potential ocular drug candidates including their toxicity, are in rapid expansion. In this review, the ocular cell types and functionality are described, providing an overview about the scientific challenge for the development of three-dimensional (3D) in vitro models

Conjunctivally Applied BDNF Protects Photoreceptors from Light-Induced Damage

Purpose: To test whether the topical eye treatment with BDNF prevents the effects of continuous light exposure (LE) in the albino rat retina. Methods: Two groups of albino rats were used. The first group of rats received an intraocular injection of BDNF (2 lL, 1 lg/lL) before LE, while the second group was treated with one single drop of BDNF (10 lL, 12 lg/lL) dissolved in different types of solutions (physiological solution, the polysaccharide fraction of Tamarind gum, TSP, and sodium carboxy methyl cellulose), at the level of conjunctival fornix before LE. The level of BDNF in the retina and optic nerve was determined by enzyme-linked immunosorbent assay. We recorded the flash electroretinogram (fERG) in dark adapted rats 1 week after LE. At the end of the recording session, the retinas were removed and labeled so that the number of photoreceptors nuclear rows and thickness of the outer nuclear layer was analyzed. Results: Intravitreal injection of BDNF before LE prevented fERG impairment. Different ophthalmic preparations were used for topical eye application; the TSP resulted the most suitable vehicle to increase BDNF level in the retina and optic nerve. Topical eye application with BDNF/TSP before LE partially preserved both fERG response and photoreceptors. Conclusions: Topical eye treatment with BDNF represents a suitable, noninvasive tool to increase the retinal content of BDNF up to a level capable of exerting neuroprotection toward photoreceptors injured by prolonged LE. Translational Relevance: A collyrium containing BDNF may serve as an effective, clinically translational treatment against retinal degeneration

Predicting needlestick and sharps injuries in nursing students: Development of the SNNIP scale

© 2020 The Authors. Nursing Open published by John Wiley & Sons Ltd. Aim: To develop an instrument to investigate knowledge and predictive factors of needlestick and sharps injuries (NSIs) in nursing students during clinical placements. Design: Instrument development and cross-sectional study for psychometric testing. Methods: A self-administered instrument including demographic data, injury epidemiology and predictive factors of NSIs was developed between October 2018–January 2019. Content validity was assessed by a panel of experts. The instrument's factor structure and discriminant validity were explored using principal components analysis. The STROBE guidelines were followed. Results: Evidence of content validity was found (S-CVI 0.75; I-CVI 0.50–1.00). A three-factor structure was shown by exploratory factor analysis. Of the 238 participants, 39% had been injured at least once, of which 67.3% in the second year. Higher perceptions of “personal exposure” (4.06, SD 3.78) were reported by third-year students. Higher scores for “perceived benefits” of preventive behaviours (13.6, SD 1.46) were reported by second-year students

La sicurezza sul lavoro dei ricercatori in zone a rischio geopolitico Cos\u2019\ue8 la normalit\ue0 tra intelligence e terrorismo?

Il volume presenta una questione non ancora adeguatamente analizzata, proponendo una connessione tra conoscenze e strategie gi\ue0 in possesso e abitualmente utilizzate da varie e diverse organizzazioni, ognuna delle quali ha proprie esperienze e punti vista. Questo con la consapevolezza che la condivisione pu\uf2 risultare estremamente utile e importante per contribuire a costruire una cultura, anche in questo particolare ambito. L\u2019intento del volume \ue8 quello di fornire una metodica riflessione che, a partire dalle esperienze, possa fornire un quadro di riferimento costituito da regole e normative, un\u2019utile base di riferimento per chi, per lavoro o studio, debba recarsi per lavoro in zone a rischio geopolitic