Environmentally controlled emulsion electrospinning for the encapsulation of temperature-sensitive compounds

The introduction of highly volatile fragrances within polymeric nano-scaled fibers is a promising route for efficient and simple encapsulation of temperature-sensitive materials. This work describes the investigation of selected parameters influencing the electrospinning of emulsions of poly(vinyl alcohol) (PVA) and (R)-(+) limonene or hexadecane. Thereby the influence of environmental parameters such as temperature and relative humidity on the fiber structure and encapsulation efficiency (EE) of the fragrance is demonstrated. For that purpose, the electrospinning process was carried out in a climatic cabin in which temperature and relative humidity were controlled. Studied temperatures ranged from 8 to 24°C and relative humidity varied between 55 and 85%. The influence of temperature was dependent on the PVA concentration in the emulsion. The relative humidity influenced both the obtained fiber morphology and fragrance EE to a higher extent than the temperature due to the hydrophilic nature of the PVA. This study is of importance when considering the use of emulsion electrospinning for encapsulation purposes

Fragrance encapsulation in polymeric matrices by emulsion electrospinning

We present the successful application of emulsion electrospinning for the encapsulation of a model for highly volatile fragrances, namely (R)-(+)-limonene in a poly(vinyl alcohol) (PVA) fibrous matrix. The influence of the emulsion formulation and of its colloidal properties on the fiber morphology, as well as on the limonene encapsulation efficiency, is described. The release profile of the fragrance from the electrospun nanofibers over a fifteen days range shows that this type of nanofibrous matrices with a high fragrance loading capacity is of great potential for applications in various fields, such as cosmetics or food packaging

A three year follow-up of low grade squamous intraepithelial lesions: Persistence of lesions is significantly influenced by the presence of high risk papillomaviruses

A cohort of 921 patients with low-grade squamous intraepithelial lesions (LG-SILs) was studied every six months for a period of 3 years by cytology and colposcopy. Regression of the initial cell injury to a normal cytology was observed in 585/921 cases (63.5%), while cytological abnormalities were still present at the same or higher grade, after three years, in 336/921 cases (36.5%). A sample of 122 Papanicolaou (Pap}stained cervical smears from the cohort of 921 LG-SILs were processed by an in situ hybridization (ISH) assay to search for the presence of DNA of human papillomaviruses (HPVs) considered at high oncogenic risk: 16/18 and 31/35/51. HPV DNA typization was positive for 47/122 lesions (38.5%). Among these 47 lesions associated with high risk HPV DNA, 12 (25.5%) healed and 35 (74.5%) persisted. Of the 75 HPV DNA negative lesions, 46 (61.3%) healed and 29 (38.7%) persisted. The results are discussed in order to define a correct protocol of LG-SIL follow-up

Environmentally controlled emulsion electrospinning

cited By 0International audienceno abstrac

Environmentally controlled emulsion electrospinning for the encapsulation of temperature-sensitive compounds

The introduction of highly volatile fragrances within polymeric nano-scaled fibers is a promising route for efficient and simple encapsulation of temperature-sensitive materials. This work describes the investigation of selected parameters influencing the electrospinning of emulsions of poly(vinyl alcohol) (PVA) and (R)-(+) limonene or hexadecane. Thereby the influence of environmental parameters such as temperature and relative humidity on the fiber structure and encapsulation efficiency (EE) of the fragrance is demonstrated. For that purpose, the electrospinning process was carried out in a climatic cabin in which temperature and relative humidity were controlled. Studied temperatures ranged from 8 to 24 °C and relative humidity varied between 55 and 85 %. The influence of temperature was dependent on the PVA concentration in the emulsion. The relative humidity influenced both the obtained fiber morphology and fragrance EE to a higher extent than the temperature due to the hydrophilic nature of the PVA. This study is of importance when considering the use of emulsion electrospinning for encapsulation purposes