Supervisors info:
Ράλλης Μιχαήλ, Επίκουρος Καθηγητής, Τομέας Φαρμακευτικής Τεχνολογίας, Τμήμα Φαρμακευτικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Ρούσσης Βασίλειος, Καθηγητής, Τομέας Φαρμακογνωσίας και Χημείας Φυσικών Προϊόντων, Τμήμα Φαρμακευτικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Δάλλας Παρασκευάς, Επίκουρος Καθηγητής, Τομέας Φαρμακευτικής Τεχνολογίας, Τμήμα Φαρμακευτικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Summary:
Skin inflammation is one of the main symptoms of many skin disorders and one of the main causes of delayed healing. Inflammation caused by ultraviolet radiation is usually treated with various topical preparations such as creams and gels, while its treatment using patches has been the topic of many studies.
Based on a previous study, the anti-inflammatory effect of polymeric patches, loaded with aqueous bark extract of Pinus halepensis at a saturated concentration prepared by electrospinning, were investigated on mice. Two nanofibrous patches composed of Sodium Alginate (SA), Cellulose Acetate (CA), Polyethyleneoxide (PEO) and P. halepensis extract in 15.1% w/w and 26.2% w/w concentration were prepared. In addition, a patch with SA, CA and PEO and one with CA and PEO were prepared. Sterile gauze cut in the same dimensions as the polymeric patches was used as control group. The evaluation of the anti-inflammatory activity of the patches was performed on hairless, SKH-1 type female mice. After being divided into 5 groups of 8 animals each, they were once irradiated with 3 M.E.D. The patches were removed and replaced daily. Before irradiation, during the test and at the end, measurements of skin thickness, transepidermal water loss, hydration, sebum, redness of the skin of the mice were obtained. On day 18 the animals were sacrificed and skin sections were collected from the inflammation site for histopathological evaluation.
The results confirmed the anti-inflammatory activity of the aqueous bark extract of P. halepensis, considering that the group with the highest concentration (26.2% w/w) patch had the best anti-inflammatory activity.
Moving on, the aim of the study was confirming the healing and antimicrobial action of propolis formed into nanofibrous patches and its optimal pharmacodynamic action. Despite its beneficial effects, the use of propolis in the treatment of wounds is limited due to the toxicity of ethanol which is its usual carrier. This problem was resolved by evaporating the solvent through the electrospinning method. Initially, 6 nanofibrous paches were composed of Polycaprolactone (PCL), Polyvinylpyrrolidone (PVP) and propolis extract at 0.1%, 0.4%, 0.7%, 1%, 15% and 30% w/w concentrations, as well as a patch composed of PCL and PVP polymers. Sterile gauze cut in the same dimensions as the polymeric patches was used as control group. The assessment of the healing effect of patches was tested on hairless, SKH-1 type male mice, in two phases. In the first set, patches with the 3 highest concentrations of propolis were tested in groups of 8 animals each, on which 1cm2 wounds were induced. The patches were removed and replaced daily. Before the ulcer was induced and at the end of the test measurements of skin thickness, transepidermal water loss, hydration, elasticity and redness of the skin of the mice were obtained. On the 1st day and 14th day of the test, photographs were taken using Antera 3D camera. In the second set, the concentration of propolis in the patches was reduced due to the irritation observed in the first one. The patches were tested in groups of 8 and the same measurements were obtained. At the end of each experiment the mice were sacrificed and skin sections from the wound site were collected for histopathological evaluation.
Clinical assessment, photodocumentation, reduction in the size of the wound combined with the histopathological evaluation showed that the 0.7% w/w propolis extract patch significantly promotes the healing procedure.
As for the next step, studying the in vitro and in vivo antimicrobial and healing effect of propolis is considered worthwhile.
Keywords:
Skin inflammation, Injury, Pinus halepensis extract, Propolis, Electrospinning, Patches
