European Platform for Photodynamic Medicine

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

Krishna V. Sharma, Lester M. Davids

Melanoma is the main cause of death in skin cancers. Despite combating with early detection, resection and post-operative therapy, melanoma treatment remains unsuccessful and investigations into other forms of adjuvant therapy such as photodynamic therapy (PDT) are prudent. This study proposes that depigmentation i.e. the removal of the free radical scavenging pigment, melanin, in melanotic melanoma cells increases their susceptibility to PDT-induced cell death. Two human melanoma cell lines: one pigmented (Mel-1) and one amelanotic (A375) cell lines were used. Kojic acid (KA), a tyrosinase-specific inhibitor, was optimised to 6μg/ml and shown to quantifiably inhibit melanin synthesis after a 3-day exposure. PDT on these cells resulted in a 3.82 fold increase of intracellular ROS production which correlated to 11% increase in cell death susceptibility compared to untreated controls. Moreover, cells allowed to regain their pigment failed to return to normal even after 72h thus proving the effectiveness of PDT. Using a DPPH* assay, the results confirmed the scavenging properties of melanin (IC50 18.30μg/ml) proving that this pigment may be one of the reasons for melanoma chemoresistance. Overall this study shows that pigment plays an important role in the efficacy of adjunctive PDT treatment and its removal enhances cell death susceptibility in melanomas.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

Mathias O. Senge

5,10,15,20-Tetrakis(3-hydroxyphenyl)chlorin (mTHPC, Temoporfin) is a widely investigated second generation photosensitizer. Its initial use in solution form (Foscan®) is now complemented by nanoformulations (Fospeg®, Foslip®) and new chemical derivatives related to the basic hydroxyphenylporphyrin framework. Advances in formulation, chemical modifications and targeting strategies open the way for third generation photosensitizers and give an illustrative example for the developmental process of new photoactive drugs.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

Yu Pu, Wenhui Chen, Zhengwei Yu

The second generation photosensitizer Hemoporfin (7(12)-(1-methoxyethyl) -12(7)-(1-hydroxyethyl)-3,8,13,17-tetramethyl-21H,23H-porphin-2,18-dipropionic acid) is a porphyrin derivative which processes a stable structure, high singlet oxygen yield, high photoactivity, low dark toxicity and fast clearance rate. Hemoporfin, also known as hematoporphyrin monomethyl ether (HMME) has been studied and used in photodynamic therapy (PDT) in China since 1989. This series of reports will provide an overview on the preclinical and clinical studies of this PDT photosensitizer. The first part of this series will highlight the results of preclinical studies that focused on the compound's optical characteristics, mechanism of the activities, pharmacological and toxicological properties.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Joanna Nakonieczna, Mariusz Grinholc

It is known that Staphylococcus aureus is susceptible to photodynamic inactivation in general, but the significant variation among particular strains in the response to the treatment exists. However, factors that determine the observed phenomenon remain unclear. This study was aimed to explore the PDI effect of two sensitizers (protoporphyrin diarginate and toluidine blue O) against clinical as well as reference strains of S. aureus. Obtained results indicate that the same isolate could be characterized as highly resistant or highly sensitive to PDI according to a sensitizer used. Moreover, the same sensitizing agent could be successfully used for total eradication of some isolates and could be non-effective in the case of other strains. Additionally, changing the photosensitizer, we are able to reverse the PDI “resistant” phenotype into “sensitive” one. Thus, one could conclude that photoinactivation involving several sensitizing agents and several isolates of the same bacterial species should be undertaken to make antimicrobial photodynamic inactivation reliable.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Aspasia Petri, Dido Yova, Eleni Alexandratou, Maria Kyriazi, Michail Rallis

Background m-THPC (Foscan®) is one of the most potent second generation photosensitizers used in photodynamic therapy, photoactivated at higher wavelengths (652nm). 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 (0.22μM) and energy dose (180mJ/cm2) was adequate to result in the death of 50% of the cells 24h post PDT while an approximately 10 times higher Foscan® concentration (1.8μM) 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.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Emina Besic Gyenge, Patrick Forny, Daniel Lüscher, Andrea Laass, Heinrich Walt, Caroline Maake

Introduction The toxic influence of photosensitizers in the dark is poorly investigated. In our study we used the photosensitizers liposomal meso-tetrahydroxyphenyl chlorin derivative (Foslipos®) and hypericin as well as their 1:1 combination on two different head and neck squamous cell carcinoma (HNSCC) cell lines (UMB-SCC 745 and UMB-SCC 969). Materials and methods We examined uptake, efflux and localization of the photosensitizers with confocal microscopy. Fluorescence quantification was measured with a micro-plate spectrometer. Special interest was given to effects on cell proliferation (BrdU proliferation assay), RNA quality (Bioanalyzer measurements) and DNA damage (comet assays) in the dark. Results Foslipos® uptake was linear over time and its efflux was not achieved even after 24h while uptake of hypericin reached a plateau after 5h and was almost eliminated after 24h. Localization of Foslipos® was organelle-unspecific. Hypericin was found mainly at membranes and in trans-golgi network. Foslipos® treated cells showed cell toxicity for the highest concentration (10μg/mL). In contrast, hypericin was toxic for all concentrations (10–0.6μg/mL). The photosensitizer combination was non-toxic for all concentrations (10–0.6μg/mL). No changes in RNA quality were monitored. Initial DNA damage was found only in hypericin treated UMB-SCC 745, which recovered after 3h. No significant DNA damage was found for UMB-SCC 969. Conclusion Our data shows that the combinatorial application decrease photosensitizer toxicity, which can be advantageous in PDT treatments.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Seyed Kamran Kamrava, Mohadese Behtaj, Yaser Ghavami, Shahab Shahabi, Maryam Jalessi, Elnaz Ehteshami Afshar, Shayan Maleki

Objectives We conducted a study to determine and compare the efficacy of pathology and photodynamic studies in establishing diagnosis of malignant dermal and mucosal lesions. Methods and patients This descriptive cross-sectional study was performed on 40 patients suspected of SCC (squamous cell carcinoma). First, in PDD (photodynamic diagnosis) photosensitizing agent was applied to the lesion, and after 4–5h the fluorescence spectrum was detected by laser radiation. Based on fluorescence intensity, normal area was differentiated from malignant area. Also, biopsy samples from these suspected areas were sent to pathology simultaneously. Data were analyzed with SPSS v.16. The distribution of nominal variables was compared using the Chi-square test. Diagnostic index for photodynamic diagnosis were calculated. A two-sided p-value<0.05 was considered to be statistically significant. Results In 27 cases (90%), results of pathology and photodynamic studies similarly showed malignancy. In 8 cases (80%), results of pathology and photodynamic studies similarly showed non-malignant lesion. But in five cases (12.5%) the results of pathology and photodynamic studies were not the same. This difference was not statistically significant showed by the Chi-square test analysis (p-value>0.05). A sensitivity of 90%, specificity of 80%, accuracy of 87.5%, positive predictive value (PPV) of 93%, negative predictive value (NPV) of 72%, positive likelihood ratio (PLR) of 4.5, negative likelihood ratio(NLR) of 0.125 were found in diagnosing SCC for photodynamic studies. Conclusion Photodynamic diagnosis is a useful non-invasive initial step in the diagnostic work-up of patients with suspected malignant lesions (SCC). In this work we have studied 40 SCC suspicious patients using PDD method and successfully carried out 27 cases as malignant all of which were matching with pathologic results. This outcome can prove both accuracy and reliability of PDD method for detecting SCC lesions on head and neck regions. Also PDD can fully demarcate the lesion peripheries less invasively as well as preserving much more time and effort. Although PDD method is a bit more expensive that biopsy and pathology but great advantages can easily cover this issue. We recommend PDD as a useful easy technique to visualize and detect the extension of the tumor preoperatively.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Kai-Hua Yuan, Jian-Hua Gao, Zheng Huang

Background Several Chinese studies suggest that Hemoporfin-mediated photodynamic therapy (PDT) is an alternative treatment for port-wine stain (PWS) birthmarks. Objective To evaluate treatment responses and adverse effects associated with Hemoporfin PDT for the treatment of PWS and their management. Method The medical records of 700 patients who underwent PDT treatment in our center were retrospectively examined. Treatment-related reactions and adverse effects were reviewed. Result Different types of PWS lesions and different individuals showed different immediate responses (e.g. swelling, color change, pain). To certain extents these reactions were a useful indicator of the treatment endpoint. Edema and scabbing were the most common post-treatment responses. Short-term (e.g. blister, eczematous dermatitis, cutaneous photosensitivity) and long-term (e.g. pigmentation change, scar formation) adverse effects were generally caused by the phototoxicity associated with the combination of photosensitizer and light exposure. Conclusion Although PDT is a safe treatment alternative for PWS birthmarks, treatment parameters must be selected for each individual patient and cutaneous changes must be monitored during light irradiation to minimize the risk of adverse effects. Over estimation of required light dosage or failure to recognize cutaneous changes associated with adverse effects can increase the risk of a poor outcome.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Cadman L. Leggett, Emmanuel C. Gorospe, Mohammad H. Murad, Victor M. Montori, Todd H. Baron, Kenneth K. Wang

Background Photodynamic therapy (PDT) with placement of a biliary stent may improve bile duct patency in patients with cholangiocarcinoma (CCA). We aimed to determine the effectiveness of biliary stenting with PDT compared to biliary stenting alone in the palliative treatment of CCA. Materials and methods Several databases were searched from inception to December 2011 for prospective studies comparing biliary stenting with PDT vs. biliary stenting only for CCA. Outcomes of interest included patient survival, quality of life (using Karnofsky score), and serum bilirubin levels. The relative risk (RR) for dichotomous outcomes and the weighted mean difference (WMD) for continuous outcomes were estimated using DerSimonian and Laird random-effects model. Inconsistency was quantified using I 2 statistics. The extent of publication bias was ascertained by visual inspection of funnel plots and Egger's test. Results There were six studies that met inclusion criteria. A total of 170 participants received PDT and 157 had biliary stenting only. Compared with biliary stenting, PDT was associated with a statistically significant increase in the length of survival (WMD 265 days; 95%CI: 154–376; p =0.01; I 2 =65%), improvement in Karnofsky scores (WMD 7.74; 95%CI: 3.73–11.76; p =0.01; I 2 =14%), and a trend for decline in serum bilirubin (WMD −2.92mg/dL; 95%CI: −7.54 to 1.71; p =0.22; I 2 =94%). The pooled event rate for biliary sepsis was 15% and was similar between PDT and control groups. Conclusion Palliative treatment of CCA with PDT is associated with increased survival benefit, improved biliary drainage, and quality of life. However, the quality of this evidence is low.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Yih-Chih Hsu, Deng-Fu Yang, Chun-Pin Chiang, Jeng-Woei Lee, Meng-Kai Tseng

Background Our previous studies found that topical 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (ALA-PDT) with a light dose of 100J/cm2 is very effective for human oral precancerous lesions. Methods In this study, 20 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch precancerous lesions were treated by topical ALA-PDT with a light dose of either 75J/cm2 (n =10) or 100J/cm2 (n =10) using a 640-nm light-emitting diode (LED) light to test which light dose could achieve a better clinical outcome. Results The 10 precancerous lesions treated by 75-J ALA-PDT showed complete response in 8 after an average of 3.4 (range, 2–6) treatments and partial response in 2. The 10 precancerous lesions treated by 100-J ALA-PDT demonstrated complete response in 7 after an average of 4.4 (range, 3–6) treatments and partial response in 3. Fisher exact test showed no significant difference in clinical outcome between these two treatment modalities (p =1.000). One complete-response precancerous lesion in the 75-J ALA-PDT group recurred at the end of 19-week follow-up and another complete response precancerous lesion in the 100-J ALA-PDT group recurred at the end of 16-week follow-up. Both recurrence lesions were treated by the original topical ALA-PDT regimen and demonstrated complete response after 3 PDT treatments. Furthermore, the 5 partial-response precancerous lesions developed into squamous cell carcinomas after 30-week follow-up. Conclusion Our findings indicate that both the 75-J and 100-J topical ALA-PDT treatment modalities are very effective for DMBA-induced hamster buccal pouch precancerous lesions and no significant difference in clinical outcome between these two treatment modalities.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Florent Poyer, Carole D. Thomas, Guillaume Garcia, Alain Croisy, Danièle Carrez, Philippe Maillard, Mihaela Lupu, Joël Mispelter

Background Previous in vivo studies on photodynamic therapy (PDT)-treated, high cellular density tumors showed evidences of a bystander effect accompanying the therapy, cellular death continuing beyond the limits of the photochemical reactions in time and space. This process is generated by the initially damaged cells on the light pathway. The aim of this study was to determine if the bystander effect may be induced as well in colorectal xenografted tumors (less compact structure) and if the cellular signaling depends primarily on cellular proximity or not. Methods The photosensitizer was a glycoconjugated, meso substituted porphyrin derivative synthesized at Institut Curie. The longitudinal follow-up of the tumors was carried out by 23Na/1H MRI, ideal imaging modality for mapping the extracellular compartment. Two regimens were followed in order to target either blood vessels alone or blood vessels and cancer cells simultaneously. Results The antivascular PDT did not succeed to arrest the tumors growth at the end of the follow-up. For double targeting PDT, we managed to stop the tumoral evolution. Sodium MRI evidenced a bystander effect. Conclusion The results obtained showed that the bystander effect is more difficult to induce for the type of colorectal tumors used in this work. It needs a double treatment, 4 days apart, in order to be promoted.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

Syedda Abbas, Waseem Jerjes, Tahwinder Upile, Francis Vaz, Colin Hopper

We report on the application of photodynamic therapy in the management of recurrent advanced carcinoma of the nasopharynx. A selected cohort of 7 patients, only suitable for palliative therapy, was offered this modality to assess the palliative role of PDT. All 7 patients had at least 2 previous recurrences, which were managed with surgery and chemoradiotherapy but ultimately failed to respond. PDT was offered after careful discussion at a multidiscipline meeting. The photosensitiser “mTHPC” was introduced intravenously 96h prior to delivering the light with nasoendoscopic guidance. Six patients’ symptoms were reduced markedly post photodynamic therapy. Five patients have to had another round of treatment which was found to be as effective as the first round in terms of controlling disease progression as well as symptoms. Magnetic resonance images showed variable reduction of tumour volume with the majority of the patients having moderate to significant response. Photodynamic therapy was very successful palliative therapy for this small group of recurrent advanced nasopharyngeal cancer patients.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy

Nobue Nakajima, Norimichi Kawashima

The effect of photo dynamic therapy (PDT) using hypericin as a photosensitiser and the effect of PDT on intracellular ATP levels using different lamps in a human leukemic monocyte lymphoma cell line (U937) were studied. The time required for hypericin to penetrate into the cancer cells was 1h, and incubation for more than 3h post-irradiation with hypericin-PDT was required to observe effects. Thus, if cancer cell death does not occur immediately following irradiation, it is unnecessary to perform additional irradiation, as most of the cells die via apoptosis during the incubation period post-irradiation. When hypericin-PDT was performed using a Na–Li lamp as a light source, the cell viability decreased approximately 55% immediately following irradiation for 5min; however, after a 5-h post-irradiation incubation, the cell viability approached 0%. Concurrently, intracellular ATP levels increased markedly; thus, irradiation (0.225J/cm2) for 5min provided the best results in terms of the highest degree of cancer cell apoptosis. Similar experiments were performed using three different LED lamps respectively. When cells were treated with the LED lamps, with maximum peaks of 599nm and 595nm, the cell viability approached 0% after incubation for 5h following 15min of irradiation (0.04J/cm2 and 0.099J/cm2, respectively). We confirmed that incubating the cells for more than 3h in a 100× diluted hypericin solution was the most effective for PDT and that a LED lamp of low light intensity led to the highest apoptosis rate in the U937 cells.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 2

B.J. Osiecka, P. Nockowski, K. Jurczyszyn, P. Ziólkowski

Lichen sclerosus et atrophicus (LSA) is disease of skin and mucosa, its pathogenesis remains unknown. Itching, pain and burning sensations and atrophy of vulva impair quality of life. Treatment is symptomatic. We report case of 30-year old woman with lesions in vulva in which series of topical PDT were carried out. We applied Levulan®Kerastick® for 4h and after that lesions were illuminated with red light. Along with above treatment patient started receiving Euthyrox®, because of recently diagnosed hypothyreosis. Significant relief from subjective symptoms was achieved and lesions in vulvar region disappeared. Combination of topical PDT with hormonal therapy allowed controlling course of disease and minimizing symptoms, and thus improved quality of life.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 1

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 1

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 1

Sally Ibbotson

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 1

Karolina Sieroń-Stołtny, Sebastian Kwiatek, Wojciech Latos, Aleksandra Kawczyk-Krupka, Grzegorz Cieślar, Agata Stanek, Damian Ziaja, Andrzej M. Bugaj, Aleksander Sieroń

Background Oesophageal papilloma and Barrett's oesophagus are benign lesions known as risk factors of carcinoma in the oesophagus. Therefore, it is important to diagnose these early changes before neoplastic transformation. Method Autofluorescence endoscopy is a fast and non-invasive method of imaging of tissues based on the natural fluorescence of endogenous fluorophores. The aim of this study was to prove the diagnostic utility of autofluorescence endoscopy with digital image processing in histological diagnosis of endoscopic findings in the upper digestive tract, primarily in the imaging of oesophageal papilloma. Results During the retrospective analysis of about 200 endoscopic procedures in the upper digestive tract, 67 cases of benign, precancerous or cancerous changes were found. White light endoscopy (WLE) image, single-channel (red or green) autofluorescence images, as well as green and red fluorescence intensities in two modal fluorescence image and red-to-green (R/G) ratio (Numerical Colour Value, NCV) were correlated with histopathologic results. The NCV analysis in autofluorescence imaging (AFI) showed increased R/G ratio in cancerous changes in 96% vs. 85% in WLE. Simultaneous analysis with digital image processing allowed us to diagnose suspicious tissue as cancerous in all of cases. Barrett's metaplasia was confirmed in 90% vs. 79% (AFI vs. WLE), and 98% in imaging with digital image processing. In benign lesions, WLE allowed us to exclude tissue as malignant in 85%. Using autofluorescence endoscopy R/G ratio was increased in only 10% of benign changes causing the picture to be interpreted as suspicious, but when both methods were used together, 97.5% were cases excluded as malignancies. Mean R/G ratios were estimated to be 2.5 in cancers, 1.25 in Barrett's metaplasia and 0.75 in benign changes and were statistically significant (p =0.04). Conclusion Autofluorescence imaging is a sensitive method to diagnose precancerous and cancerous early stages of the diseases located in oesophagus. Especially in two-modal imaging including white light endoscopy, autofluorescence imaging with digital image processing seems to be a useful modality of early diagnostics. Also in observation of papilloma changes, it facilitates differentiation between neoplastic and benign lesions and more accurate estimation of the risk of potential malignancy.

Publication year: 2012
Source:Photodiagnosis and Photodynamic Therapy, Volume 9, Issue 1

Nasim Kashef, Gita Ravaei Sharif Abadi, Gholamreza Esmaeeli Djavid

Background Photodynamic inactivation (PDI) has been investigated to cope with the increasing incidence of multidrug-resistant (MDR) pathogens. Here we studied the PDI mediated by methylene blue (MB) and toluidine blue O (TBO) in clinical methicillin-resistant Staphylococcus aureus and MDR Escherichia coli, together with their corresponding American Type Culture Collection (ATCC) strains. Methods Effect of photosensitizer concentration (12.5,25,50μg/ml) and laser irradiation time (10, 20 and 30min) on lethal photosensitization was investigated. Results TBO was more effective. TBO at 50μg/ml, 46.8Jcm−2, exhibited 0.7log killing for MDR E. coli and 1.7log killing for E. coli (ATCC 25922); 3.1log killing for MRSA, and 4.2log killing for S. aureus (ATCC 25923). MB at 50μg/ml, 163.8Jcm−2, only exhibited 2.2log killing in MRSA and 3.1log killing in S. aureus (ATCC 25923). MB (50μg/ml, 163.8Jcm−2) induced 0.2log killing for MDR E. coli and 0.3log killing for E. coli (ATCC 25922). After TBO-PDI, MDR isolates were more susceptible to some antibiotics than control groups. Conclusion Our studied clinical isolates were more resistant to PDI-mediated killing than their ATCC reference strains. Thus, TBO/MB-mediated PDI in other MDR isolates deserves further investigation.