Extended-release essential oils from poly(acrylonitrile) electrospun mats with dendritic materials

摘要

There is an increasing demand to use products based on essential oils (EOs) in many applications such as food packaging, drug delivery system, face-mask active layer, pharmaceutical, and cosmetic products. Despite their antibacterial activity, it is necessary to control the release of EOs because of their volatility. The synergetic encapsulation of EOs in dendritic polymers and electrospun fibres as embedding compounds was investigated in the present work. In situ solutions were used that consisted of 18 wt. % polyacrylonitrile polymer, 15 wt. % tea tree (TEO) or eucalyptus (EEO) essential oil, and various concentrations ranging from 10 to 20 wt. % of second and fourth generations of polyamidoamine dendritic compounds (PAMAM). The fibre diameters were analysed using scanning electron microscopy (SEM) revealing that the additions of TEO, PAMAM and simultaneous additions of the TEO/PAMAM in to the electrospun solution reduced the diameter from 899 +/- 10 to 640 +/- 14, 486 +/- 10 nm, and 395 +/- 5 nm, respectively. Furthermore, a novel temperature-modulated gas diagnosis device was applied to assess the amount of odour, in which a single chemo-resistor gas sensor functioned as an electronic nose (E-nose). This apparatus results indicate that adding PAMAM to the electrospinning solutions extends the TEO encapsulation time from 5 to 27 days. The antibacterial properties of the samples were examined against two commonly used bacteria (S. aureus and E. coli). In addition, the correlation between the odour intensity and antibacterial activity were measured by passing time. The results reveal that the antibacterial activity the EOs samples without PAMAM reduced by passing time, while the sample contacting PAMAM possessed a more durable antibacterial property. The E-nose results revealed that the PAMAM-encapsulated mats had extended releases of 6-23 days and 5-27 days for the TEO and eucalyptus, respectively. These antibacterial, scented nanofibrous mats as fragrant layer with extended release of EOs and also active biological characteristics might provide a new potential as bioactive layer for a broad spectrum of applications.