Nitric oxide-releasing poly(vinyl alcohol) film for increasing dermal vasodilation

Pathological conditions associated with the impairment of nitric oxide (NO) production in the vasculature, such as Raynaud's syndrome and diabetic angiopathy, have stimulated the development of new biomaterials capable of delivering NO topically. With this purpose, we modified poly(vinyl-alcohol) (PVA) by chemically crosslinking it via esterification with mercaptosuccinic acid. This reaction allowed the casting of sulfhydrylated PVA (PVA-SH) films. Differential scanning calorimetry and X-ray diffractometry showed that the crosslinking reaction completely suppressed the crystallization of PVA, leading to a non-porous film with a homogeneous distribution of -SH groups. The remaining free hydroxyl groups in the PVA-SH network conferred partial hydrophylicity to the material, which was responsible for a swelling degree of ca. 110%. The PVA-SH films were subjected to an S-nitrosation reaction of the -SH groups, yielding a PVA containing S-nitrosothiol groups (PVA-SNO). Amperometric and chemiluminescence measurements showed that the PVA-SNO films were capable of releasing NO spontaneously after immersion in physiological medium. Laser Doppler-flowmetry, used to assess the blood flow in the dermal microcirculation, showed that the topical application of hydrated PVA-SNO films on the health skin led to a dose- and time-dependent increase of more than 5-fold in the dermal baseline blood flow in less than 10 min, with a prolonged action of more than 4 h during continuous application. These results show that PVA-SNO films might emerge as a new material with potential for the topical treatment of microvascular skin disorders116643651CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP309390/2011-72008/57560-

Managing human stress level. A multimedia sequence approach

Previous literature studies demonstrated that affect can be positively or negatively influenced by single images, sounds and videos. In this study it has been investigated the effect of a software named 2VitaB-Cognitive on people stress: this software generates a multimedia sequence composed of positive images, sounds and video that can be presented on a PC, tablet, or smartphone. An experimental activity has been performed to verify the impact of the stimulation with the multimedia sequence on both affect and vigilance of 10 volunteers. Participants stress level was assessed using the PSS-10; they also filled in some scales and questionnaires (PANAS, SAM and GVAS) and completed the PVT vigilance task both before and after the administration of the multimedia sequence. The effect of the stimulation on affect and vigilance has been defined comparing answers to questionnaires and task results before and after the administration of the multimedia sequence. Results indicated that the multimedia stimulation can produce a modification on human affect and vigilance