|Tipo di tesi||Tesi di laurea magistrale|
|Titolo||Studio dell’attività anti-erpetica del Laser UVA1-355 da solo e in associazione all’acido ialuronico.|
|Titolo in inglese||Study on the anti-herpetic activity of Laser UVA1-355 alone and in association with hyaluronic acid.|
|Struttura||Dipartimento di Scienze della Vita|
|Corso di studi||BIOTECNOLOGIE MEDICHE E FARMACEUTICHE (D.M. 270/04)|
|Data inizio appello||2014-12-10|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
Background Laser Alba 355 (Elettronica Valseriana, Casnigo, Italy) represents a new laser technology based on UVA1 spectrum and it is the first laser with a 355 nm wavelength. UVA1 biological effects are different from the effects related to UVB and UVA2 wavelengths, as they consist of aerobic photo-oxidation reactions with the intermediate creations of oxygen and hydrogen free radicals. Several studies have investigated the action mechanism of UVA1 in the therapy of skin disease. Our work focused on the laser interaction with Herpes Simplex Virus Type 1 (HSV-1) replication. Aim This study aims at investigating the in vitro antiviral activity of medium doses of the 355 nm radiation, both alone and in combination with hyaluronic acid (HA), a non-sulphated glycosaminoglycan which, in a previous study, showed an antiviral activity against HSV-1 (Cermelli et al., 2011). Materials and methods The experiments have been conducted using VERO cell line (African Green Monkey epithelial kidney cells). The MTT test was used to rule out the potential toxic effects of UVA1 on the cell line: the cell viability was calculated as a percentage of the optical density (OD) of the treated culture, in comparison with that of the untreated controls (100% viability). The antiviral activity of laser against HSV-1 was assessed by virus yield assays: cells infected with HSV-1 where exposed to medium doses of UVA1 laser starting at different time points from infection. Cells were exposed to laser alone or together with HA (1 mg/ml). After 24h from laser treatment, virus yield was titred on VERO cells by end point titration. Results and conclusions Initially, different doses of UVA1 were tested to find a treatment with an acceptable toxicity: treatment of 50 J/cm2 for 4’09” showed a cell viability from 85% to 87% in comparison with untreated cells. As far as the antiviral activity, treatment with UVA1 alone caused a 1Log reduction of virus yield in samples which have been exposed to HSV-1 2 hours before. Exposition to both laser and HA showed a reduction of 3Log in these samples. A longer exposition to the virus (20 hours) before laser treatment caused a lower reduction, 1Log only in samples treated with laser and HA. Kinetic experiments, which related the exposition time to HSV-1 with the antiviral activity of the radiation, showed a 1Log reduction in almost all of the samples exposed to laser alone, whereas in the samples with laser combined with HA the reduction was higher, ranging between 2 and 3Log. Usually UVA1 spectrum is well tolerated by patients. So, we can start considering the use of this laser technology for local applications in the treatment of cutaneous herpes lesions.