Public exposure to artificial optical radiation in the aesthetics and the entertainment sector in Greece. Risk management actions.

Safety issues are raised from the use of low- and high-power optical radiation sources, both laser and non-laser, by non-experts for aesthetic and entertainment purposes. The Greek Atomic Energy Commission relied on the ISO 31000:2018 framework to manage the public exposure risk to such cases. Risk was evaluated as (1) intolerable for lasers and intense pulsed light sources at aesthetic procedures and in the case of laser pointers, (2) severe for lasers at laser shows and (3) moderate for light-emitting diodes (LEDs) at aesthetic procedures, home-use intense pulsed light sources/LEDs and laser/LED projectors. Operators' training, public awareness campaigns, intensive market surveillance actions and the enhancement of the regulatory framework have been proposed as risk treatment/control measures and have been prioritised in this order, according to their effectiveness in reducing the exposure risk and their urgency of implementation. The Greek Atomic Energy Commission developed public awareness campaigns regarding exposure safety to laser and non-laser light sources at aesthetic procedures and the use of laser pointers.

Assessment of natural antioxidants' effect on PDT cytotoxicity through fluorescence microscopy image analysis.

BACKGROUND AND OBJECTIVES: Photodynamic therapy (PDT) is a cancer treatment modality mediated by reactive oxygen species (ROS). However, the intracellular antioxidant defense system antagonizes PDT-generated ROS, impeding PDT efficacy. This study aimed to evaluate the enhancement of PDT cytotoxicity by its combination with natural antioxidants in pro-oxidant concentrations. METHODS: A rich natural antioxidant mixture originating from Pinus halepensis bark extract was studied for its potential to enhance the efficacy of m-tetrahydroxyphenylchlorin (m-THPC)-PDT on LNCaP prostate cancer cells, in vitro. Various P. halepensis concentrations, at two different incubation times, were used in combination with m-THPC-PDT. Assessment of cellular viability and intracellular ROS levels evaluated the treatments' outcome. A novel method was developed for the assessment of the intracellular ROS levels, based on image analysis and data extraction from fluorescence microscopy images. RESULTS: P. halepensis bark extract increased the intracellular ROS levels in a concentration-dependent but not in an incubation-dependent manner. The higher concentrations used (≥50 µg/ml) reduced cellular viability even by 50%. One hour pretreatment with 30 µg/ml P. halepensis before m-THPC-PDT exceeded the levels of cellular death by approximately 15%. CONCLUSIONS: The results provided evidence of the cytotoxic effect of P. halepensis bark extract on LNCaP cells, showing the potential of P. halepensis to be used as an anticancer agent in prostate cancer treatment. The results also provided evidence of enhancement of m-THPC-PDT by P. halepensis bark extract showed the potential to be used as a supplementary agent to improve prostate cancer PDT treatment.

Sunbeds' ultraviolet radiation measurements with different radiometers and criteria for compliance assessment set by the national competent authority in Greece.

In order to ground the credibility of the sunbeds' ultraviolet radiation compliance assessment with the 0.3W/m(2) erythema effective irradiance limit, it is highly important to use reliable measuring equipment and to justify reasonably the measurement's result. Recently, the first surveillance action of the artificial tanning sector in Greece has been finalised. The action consisted of in situ erythema effective irradiance measurements from sunbeds at commercial premises offering artificial tanning services at various cities throughout Greece. Four different broadband erythemal weighted radiometers were used in order to compare them during in situ sunbeds' radiation measurements, at commercial premises, and to choose the most suitable one for compliance inspections. Furthermore a rationale has been introduced in order to compare the measurement's result with the limit, and decide about compliance or not, taking into account the measurement's expanded uncertainty. According to this approach, compliance, probable compliance or non-compliance is verified when the measurement's result taking into account the measurement's expanded uncertainty does not, probably or does exceed the 0.3W/m(2) limit, respectively. Ultraviolet radiation exceeded the 0.3W/m(2) erythema effective irradiance limit in 63.5% (33 out of 52) of the sunbeds and probably exceeded the limit in 11.5% (6 out of 52) of the sunbeds, according to the measurements performed with the radiometer which was chosen as the most suitable one and the proposed rationale for compliance justification.

Effective ultraviolet irradiance measurements from artificial tanning devices in Greece.

Artificial tanning remains very popular worldwide, despite the International Agency for Research on Cancer classification of ultraviolet (UV) radiation from sunbeds as 'carcinogenic to humans'. Greek Atomic Energy Commission has initiated a surveillance action of the artificial tanning devices in Greece in order to record the effective irradiance levels from the sunbeds and to inform and synchronise the domestic artificial tanning business sector with the requirements of the European Standard EN 60335-2-27:2010. In this direction, in situ measurements of UV emissions from sunbeds in solaria businesses all over Greece were performed from October 2013 until July 2014, with a radiometer and a portable single-monochromator spectrophotometer. Analysis of the measurements' results revealed that effective irradiance in ∼60 % of the measured sunbeds exceeded the 0.3 W m(-2) limit value set by EN 60335-2-27:2010 and only 20 % of the devices could be categorised as UV type 3.

Comparative characterization of the cellular uptake and photodynamic efficiency of Foscan® and Fospeg in a human prostate cancer cell line.

BACKGROUND: m-THPC (Foscan(®)) is one of the most potent second generation photosensitizers used in photodynamic therapy, photoactivated at higher wavelengths (652 nm). However, its strongly hydrophobic nature causes aggregation of the molecules and prevents its unbiased bioavailability in the biological media, resulting in lower accumulation in the tumor cells. Several strategies have been adopted to improve the photodynamic characteristics of the photosensitizer. Among them, very promising seems to be the encapsulation of the molecule into liposomes, due to the superior properties of liposomes as drug carriers. METHODS: In this paper the photodynamic characteristics of the PEGylated liposomal formulation of m-THPC, Fospeg, using the human prostate cancer cell line LNCaP, as an in vitro model, were investigated. In addition the spectral characteristics, cellular uptake and localization, dark and light induced cytotoxicity and photodynamic efficacy of Foscan(®) and Fospeg were compared. RESULTS: Fospeg, compared with Foscan, showed higher intracellular uptake at any concentration and incubation time. Regarding PDT efficacy, Fospeg produced more severe cytotoxicity than Foscan(®) at any concentration and energy dose. Using Fospeg, the lowest concentration (0.22 µM) and energy dose (180 mJ/cm(2)) was adequate to result in the death of 50% of the cells 24h post PDT while an approximately 10 times higher Foscan(®) concentration (1.8 µM) was needed to result in the same cytotoxicity. CONCLUSIONS: The use of the PEGylated liposomal formulation of m-THPC resulted in the improvement of its intracellular uptake and the enhancement of its photodynamic activity. Fospeg, compared to Foscan(®), proved to be a more advantageous photosensitizer for photodynamic therapy.

Combination of Fospeg-IPDT and a natural antioxidant compound prevents photosensitivity in a murine prostate cancer tumour model.

BACKGROUND: The aim of the present research was to investigate the potential use of a natural compound rich in antioxidant agents, derived from Pinus halepensis (P. halepensis), to prevent PDT induced photosensitivity. The present research progressed in two levels. The first one evolved the optimization of Fospeg-interstitial photodynamic therapy (IPDT) in a prostate cancer animal model. In the second one, P. halepensis bark extract, was evaluated for its potential use to prevent photosensitivity. METHODS: Two sets of experiments were performed, IPDT only and IPDT in the presence of antioxidant. For both of them, Fospeg was administrated intravenously to SCID mice bearing prostate cancer, followed by IPDT after 6 h. For the IPDT+antioxidant experiments, P. halepensis was injected intratumourously 1 h prior the tumour illumination. Treatment outcome was monitored twice a week by an imaging system and by measuring tumour dimensions using a caliper. Photosensitivity was assessed by monitoring erythema of the tail using the imaging system. RESULTS: IPDT with Fospeg and 15 J total light energy is a therapeutic scheme that can eliminate tumours in the murine model of prostate cancer. Two months after complete tumour remission no tumour recurrence was observed. Also, the cosmetic outcome of the research was excellent. The major drawback of this treatment scheme was that 90% of the animals developed photosensitivity. The addition of P. halepensis bark extract resulted in prevention of the photosensitivity, leaving PDT outcome unaffected. CONCLUSIONS: The combined use of PDT and the used antioxidant agent could broaden the implementation of photodynamic therapy, by eliminating photosensitivity.