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The efficiency of a Zn(II)-phthalocyanine disulphide (C11Pc), a compound with both phthalocyanine units bearing seven hexyl chains and a sulphur terminated C11 chain, as a photodynamic therapy (PDT) agent was investigated in C57 mice bearing a sub-cutaneously transplanted amelanotic melanoma. The phthalocyanine was intravenously injected at a dose of 1.5 micromol/kg body weight either free or bound to gold nanoparticles, using a Cremophor emulsion as a delivery vehicle. Biodistribution studies at selected post-injection times showed that the nanoparticle-associated C11Pc was recovered in significantly larger amounts from all the examined tissues and the serum and yielded a greater selectivity of tumour targeting: thus, the ratio between the amount of phthalocyanine recovered from the amelanotic melanoma and the skin (peritumoural tissue) increased from 2.3 to 5.5 from the free to the gold nanoparticle-bound C11Pc at 24 h after injection. PDT studies with the C11Pc-loaded amelanotic melanoma showed a markedly more significant response of the tumour in the mice that had received the nanoparticle-bound photosensitiser; the PDT effect was especially extensive if the irradiation was performed at 3h after C11Pc injection when large phthalocyanine amounts were still present in the serum. This suggests that the PDT promoted by C11Pc predominantly acts via vascular damage at least in this specific animal model. This hypothesis was fully confirmed by electron microscopy observations of tumour specimens obtained at different times after the end of PDT, showing an extensive damage of the blood capillaries and the endothelial cells. [ABSTRACT FROM AUTHOR]

This paper investigates the heterogeneous impact of school closures during Covid-19 pandemic in Italy on academic performance across different schools, grades, subjects and groups of students. Our analysis utilises an innovative dataset that combines administrative data on standardised tests in grades 5 and 8 with a specifically-designed survey that collects information about teachers' practices between February and June 2020. Firstly, by employing a multilevel (mixed-effects) model, we estimate the extent of learning loss and examine its variability across schools, for students in primary and middle levels during the school year 2020/21. The findings confirm that learning loss has been considerable (between 0.05 and 0.27 SD) although heterogeneity across disciplines and grades exists - higher in English in grade 5, and in mathematics and reading in grade 8. Secondly, as a main contribution of the paper, we explore the mechanisms behind the substantial differences observed across schools, which can be explained by the ability of teachers in using digital tools and evaluating their students, as well as by the leadership role exerted by school principals., Competing Interests: None., (© 2023 The Authors.)

This paper describes the results of an experiment conducted in a technical university in Italy in 2019, involving the implementation and evaluation of an innovative short course on financial education. The programme applied a novel approach based on online learning and its effectiveness is compared against the effects of a traditional on-campus lecture, within an experimental setting. The findings indicate that the programme is effective: one week after taking the course, the students improved their pre-course test scores by about 4 points out of 10. No statistically significant difference in gains is found between students assigned to the online vs the on-campus mode of learning, suggesting a potential positive role of digital learning in this specific setting. An exploratory analysis of factors associated with the outcome reveal that the course has been particularly beneficial for those students initially less interested in finance., Competing Interests: Declarations of interest None., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The disruption caused by the Covid-19 pandemic generated an unprecedented situation, in which digital learning, in the form of Emergency Remote Teaching, was the only possible form of schooling. Italy soon decided to close schools as a measure to counter the spread of the virus. Although the Ministry of Education suggested general guidelines, school principals and teachers were autonomous in deciding how to best organise their educational activities. The first objective of our study is to identify subgroups of teachers, based on the use of digital tools during the Covid-19 emergency. Secondly, we explore how subgroups differ in terms of teachers' satisfaction and students' performance. To this end, we integrate information from an ad hoc survey completed by 1,407 primary and lower secondary teachers in Italy, with the students' standardised test scores provided by INVALSI. Data have been analysed through a 3-step latent class analysis. The findings reveal that one third of the teachers showed resistance to the use of digital technologies and focused mainly on asynchronous teaching. Teachers that used a broader set of digital instruments, instead, were more satisfied with their teaching practices. A more articulated use of technology for teaching activities was also positively associated with higher students' performance in 2021., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Bertoletti et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The Covid-19 pandemic coerced the closure of most schools around the world and forced teachers and students to change teaching and learning methods. Emergency Remote Teaching (ERT) generated consequences to teachers and students in terms of learning outcomes and personal well-being. This study focuses on teachers' individual and working environment well-being in ERT conditions and intends to explore which factors related to the provision of digital equipment and the implementation of digital strategies by schools explain the school effect on both typologies of well-being during the Covid-19 emergency. To do so, data collected in the Responses to Educational Disruption Survey (REDS) across three countries were used, and a two-step analysis was conducted. A first step involves the use of linear mixed effect models to assess the school effect on teachers individual and working environment well-being. In the second step Regression Trees (RT) are used to investigate which factors and policies related to digital tools explained the identified school effects. The results show that schools and countries played a role in determining teachers perceived well-being during the Covid-19 disruption, in particular the school level explains more than 7% of the work environment well-being and 8% of individual one. In the second step of the analysis results show that a high positive effect on school environment well-being is observed when the school's activity is not influenced by policies limiting the use of online tools and when teacher's readiness for remote teaching, like the development of technical skills and the provision of internet access and digital devices, is met. To the best of our knowledge, this is the first study that evaluates the impact of digital tactics and instruments provided by schools on teachers' well-being on a large scale., Competing Interests: Competing interestsNo financial interests or benefits have arisen from direct application of this research. Furthermore, the authors accept the copyright information and author’s rights. There are no competing interests., (© The Author(s) 2023.)

Though many data on the experience of care of patients and caregivers are collected, they are rarely used to improve the quality of health care delivery. One of the main causes is the widespread struggle in interpreting and enhancing these data, requiring the introduction of new techniques to extract intelligible, meaningful, and actionable information. This research explores the potentiality of the latent class analysis (LCA) statistical model in studying experience data. A cross-sectional survey was administered to 482 parents of infants hospitalized in several Italian neonatal intensive care units. Through a 3-step LCA, four subgroups of parents with specific experience profiles, sociodemographic characteristics, and levels of satisfaction were identified. These were composed of parents who reported (1) a positive experience (36%), (2) problematic communication with unit staff (30%), (3) limited access to the unit and poor participation in their baby's care (26%), and (4) a negative experience (8%). Through its explorative segmentation, LCA can provide valuable information to design quality improvement interventions tailored to the specific needs and concerns of each subgroup., Competing Interests: Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Background: This cross-sectional study aims to evaluate the prevalence and socio-demographic factors associated with workplace bullying, sexual harassment and racial harassment among Italian health workers., Methods: We recruited 3129 participants using an online Italian translation of the 'Workplace Violence in the Health Sector Country Case Studies Research Instruments Survey' (WVHS) questionnaire. Data were analyzed with univariate (chi-square) and multivariate (multiple logistic regression) analysis., Results: Univariate analysis shows that females are significantly more affected by bullying (16.4% vs. 12.3%) and sexual harassment (2.4% vs. 1.3%). On the other hand, males are significantly more affected by racial harassment (3.1% vs. 2.0%). Multivariate analysis shows higher odds of being affected by bullying (OR = 1.30; 95% CI (1.03, 1.64)) and sexual harassment (OR = 2.08; 95% CI (1.04, 4.00)) for females, and higher odds of undergoing racial harassment (OR = 1.55; 95% CI (0.95, 2.53)) for males., Conclusion: This analysis of work situations looks to identify those risk factors, existing or potential, that increase the probability of episodes of violence. A group of work or other subjects identified by direction will have to evaluate the vulnerability of workplaces and establish more effective preventive actions to be adopted.

A tetracationic meso-substituted amphiphilic porphyrin (abbreviated as C14) was encapsulated within silica microparticles to yield a conjugate with a mean particle diameter of ca. 0.9 μm. The conjugate displayed a complete stability for at least 3 months when suspended in a neutral aqueous medium. The encapsulated C14 underwent a limited photobleaching when the conjugate was exposed to full spectrum visible light. Illumination of the silica microparticle-bound C14 by visible light resulted in the generation of singlet oxygen and induced a decrease in the survival of 4 log for a 20 min irradiation of the Gram-positive bacterium meticillin-resistant Staphylococcus aureus (MRSA) and a 30 min irradiation of the Gram-negative bacterium Escherichia coli (E. coli). Under identical experimental conditions photoexcited free C14 caused a decrease in viability of 5 log for MRSA and 6 log for E. coli. When the conjugate loaded with 12 μM C14 was added to a water sample contaminated with MRSA (10(8) cells per ml) a tight association of the bacterial cells with the silica microparticle-porphyrin system was achieved. Subsequent illumination of the conjugate with visible light (30 min, 100 mW cm(-2)) caused a 3 log reduction in the population of MRSA cells in the water sample. Importantly, the conjugate was readily recovered by filtration of the aqueous suspension and shown to maintain a high antibacterial photoactivity when introduced into a new MRSA-contaminated medium and irradiated.

Introduction: Despite continuous advances in our knowledge of the biology of acute myelogenous leukemia (AML), the prognosis of AML patients treated with standard chemotherapy is still poor, especially in the elderly. Therefore, there is a need for novel targeted and less toxic therapies, particularly for patients who develop resistance to traditional chemotherapeutic drugs. Constitutively active phosphatidylinositol 3-kinase (PI3K) signaling characterizes many types of tumors, including AML, where it negatively influences response to therapeutic treatments., Areas Covered: The literature data showed that small inhibitor molecules targeting PI3K signaling induced cell cycle arrest, apoptosis and decreased drug-resistance in AML cells. PI3K inhibitors were also capable of targeting leukemic initiating cells (LICs), the most relevant target for leukemia eradication, whereas they tended to spare healthy hematopoietic stem cells., Expert Opinion: Data emerging from pre-clinical settings suggest that the PI3K pathway is critically involved in regulating proliferation, survival and drug-resistance of AML cells. Therefore, we propose that novel drugs targeting this signaling pathway may offer a novel and less toxic treatment option for AML patients, most likely in combination with a lower dosage of traditional chemotherapeutic agents or other innovative therapeutic agents.

Biolarvicides, such as microbial formulations based on Bacillus thuringiensis and B. sphaericus, have been found to be highly effective against mosquito larvae and are currently employed as eco-friendly alternatives to synthetic chemical insecticides for vector control. Recently, a porphyrin of natural origin has been suggested as a sunlight-activatable larvicide against the dengue vector Aedes aegypti. In order to validate the approach for the control of the malaria vector, we tested the photo-larvicidal activity of a novel porphyrin, namely meso-tri(N-methyl-pyridyl), mono(N-dodecyl-pyridyl)porphine, C12, associated with two specifically selected carriers, against Anopheles gambiae s.s. and An. arabiensis larvae, both laboratory reared and collected from malaria endemic sites in Burkina Faso. Both C12-porphyrin formulates, when administered to larvae at a 50μM porphyrin dose, were accumulated in the alimentary canal. Subsequent exposure of the porphyrin-loaded larvae to sunlight for short times (0.5-3h) led to a complete mortality. The high efficacy exhibited by a "foodstuff" porphyrin formulate also in the presence of typical larval food particles opens promising perspectives for the development of an effective photocidal larvicide., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The increasing use of photosensitized processes for disinfection of microbiologically polluted waters requires a precise definition of the factors controlling the degree of photosensitivity in target and non-target organisms. In this regard, tests with protozoa and invertebrates which have a natural habitat in such waters may be used as first screening methods for the assessment of possible hazards for the ecosystem. A new cationic porphyrin, namely meso-tri(N-methyl-pyridyl)mono(N-dodecyl-pyridyl)porphine (C12), is tested in this work on the protozoan Ciliophora Colpoda inflata and Tetrahymena thermophila and the Crustacea Branchiopoda Artemia franciscana and Daphnia magna. The protocol involved 1 h incubation with porphyrin doses in the 0.1-10.0 μM range and subsequent irradiation with visible light at a fluence rate of 10 mW cm(-2). The results indicate that C12 porphyrin has a significant affinity for C. inflata and T. thermophila; this is also shown by fluorescence microscopic analyses. C. inflata cysts were resistant to the phototreatment up to a porphyrin dose of 0.6 μM. The effects of C12 on cysts have been evaluated at 3 and 24 h after the end of the phototreatment; a delay in the excystment process was observed. T. thermophila was fairly resistant to the phototreatment with C12 porphyrin. The data obtained with the two crustaceans indicated that the effects of dark- and photo-treatment with C12 need to be closely examined for every organism. A. franciscana is more resistant, probably owing to its ability to adapt to extreme conditions, while the high level of photosensitivity displayed by Daphnia magna represents a potential drawback, as this organism is often selected as a reference standard for assessing the environmental safety. Thus, while C12 photosensitisation can represent a useful tool for inducing a microbicidal or larvicidal action on polluted waters, the irradiation protocols must be carefully tailored to the nature of the specific water basin, and in particular to its biotic characteristics., (This journal is © The Royal Society of Chemistry and Owner Societies 2012)

Porphyrins have been shown to act as very efficient photosensitizing agents against a broad number of microbial pathogens, including bacteria, fungi, and protozoa. This property has promising applications at a clinical level for the treatment of infectious diseases by photodynamic therapy. Moreover, this technique is also being used to address environmental problems of high significance, such as the decontamination of wastewaters, the disinfection of fish-farming tanks, the protection of animal species (e.g., amphibians and reptiles) that are endangered by pathogens whose life cycle takes place largely in aqueous media, and the control of populations of noxious insects. Such diversified applications take advantage of the availability of a truly large number of porphyrin derivatives with chemical structures that can be tailored to comply with the physical and chemical properties as well as the biological features of several milieus. In addition, the property typical of porphyrins to absorb essentially all of the wavelengths in the sun emission spectrum allows the promotion of processes largely based on natural resources with significant energy savings and low impact on ecosystems.

We describe the total synthesis and biological properties of a new carboranyl-containing chlorin (TPFC) that might find application as a dual sensitizer in the PDT and BNCT treatment of cancer. TPFC was found to be non-toxic in the dark but showed extensive photosensitizing ability both in vitro and in vivo despite its relatively low singlet oxygen quantum yield. In particular, TPFC exhibited significant photosensitizing activity against highly pigmented melanotic melanoma tumors in mice.

A water-soluble meso-substituted porphyrin (H(2)TCP) bearing 36 boron atoms, which appeared to be an efficient photodynamic sensitiser (singlet oxygen quantum yield=0.44), was studied for its accumulation by murine melanotic melanoma cells (B16F1). The amount of H(2)TCP in the cells increased with the porphyrin dose in the incubation medium up to, and at least, 100 microM concentrations with no significant cytotoxic effect in the dark. Moreover, the H(2)TCP uptake increased with the incubation time reaching a plateau value corresponding with the recovery of 0.4 nmol of H(2)TCP per mg of cell proteins after 24h incubation. Fluorescence microscopy observations showed that the porphyrin was largely localized intracellularly, exhibiting a discrete distribution in the cytoplasm with a pattern which was closely similar to that observed for the endosomal probe Lucifer yellow. The photosensitising efficiency of the H(2)TCP toward B16F1 cells was studied for different irradiation (1-15 min) and incubation (1-24 h) times. Nearly complete (>95%) cell mortality was obtained upon incubation with 20 microM H(2)TCP and 10 min irradiation with red light (600-700 nm, 20 mW/cm(2)). The porphyrin was also accumulated in appreciable amounts by the tumour tissue after intravenous injection to C57BL/6 mice bearing a subcutaneously transplanted melanotic melanoma. Maximum accumulation in the tumour was achieved by administration of H(2)TCP dissolved in the ternary mixture 20% dimethylsulfoxide (DMSO)-30% polyethyleneglycol (PEG 400)-50% water. Thus, this porphyrin could act as both a photodynamic therapy agent and a radiosensitising agent for boron neutron capture therapy.

Background and Objectives: Photodynamic therapy (PDT) appears to be endowed with several favorable features for the treatment of infections originated by microbial pathogens, including a broad spectrum of action, the efficient inactivation of antibiotic-resistant strains, the low mutagenic potential, and the lack of selection of photoresistant microbial cells. Therefore, intensive studies are being pursued in order to define the scope and field of application of this approach., Results: Optimal cytocidal activity against a large variety of bacterial, fungal, and protozoan pathogens has been found to be typical of photosensitizers that are positively charged at physiological pH values (e.g., for the presence of quaternarized amino groups or the association with polylysine moieties) and are characterized by a moderate hydrophobicity (n-octanol/water partition coefficient around 10). These photosensitizers in a micromolar concentration can induce a >4-5 log decrease in the microbial population after incubation times as short as 5-10 minutes and irradiation under mild experimental conditions, such as fluence-rates around 50 mW/cm2 and irradiation times shorter than 15 minutes., Conclusions: PDT appears to represent an efficacious alternative modality for the treatment of localized microbial infections through the in situ application of the photosensitizer followed by irradiation of the photosensitizer-loaded infected area. Proposed clinical fields of interest of antimicrobial PDT include the treatment of chronic ulcers, infected burns, acne vulgaris, and a variety of oral infections., (Copyright 2006 Wiley-Liss, Inc.)

Two tetrasubstituted (RLP024 and RLP040) and one monosubstituted (MRLP101) Zn-phthalocyanines were readily accumulated by three skin-derived cell lines (HT-1080 transformed human fibroblasts, 3T3 mouse embryo fibroblasts and HaCaT human keratinocytes) upon 1 h-incubation with 0.5-5 microM phthalocyanine concentrations. The affinity was markedly larger for the tetra- as compared with the mono-substituted phthalocyanine, even though smaller phthalocyanine amounts were generally recovered from keratinocytes. As a consequence, the two tetra-substituted phthalocyanines exhibited a higher phototoxicity against all the three cell lines. Typically, the cell survival decreased by at least 80% after 1 min irradiation with 600-700 nm light at a fluence-rate of 50 mW/cm2 in the presence of 5 microM phthalocyanine. Fluorescence microscopy and caspase-3 activation studies indicate that cell death of fibroblasts largely occurred by a random-necrotic process while the keratinocytes underwent cell death predominantly via apoptosis in spite of a very similar pattern of subcellular distribution of the phthalocyanines.

The synthesis of a Zn(ii)-phthalocyanine derivative bearing four 10B-enriched o-carboranyl units (10B-ZnB4Pc) and its natural isotopic abundance analogue (ZnB4Pc) in the peripheral positions of the tetraazaisoindole macrocycle is presented. The photophysical properties of ZnB4Pc, as tested against model biological systems, were found to be similar with those typical of other photodynamically active porphyrin-type photosensitisers, including a singlet oxygen quantum yield of 0.67. The carboranyl-carrying phthalocyanine was efficiently accumulated by B16F1 melanotic melanoma cells in vitro, appeared to be partitioned in at least some subcellular organelles and, upon red light irradiation, induced extensive cell mortality. Moreover, ZnB4Pc, once i.v.-injected to C57BL/6 mice bearing a subcutaneously transplanted pigmented melanoma, photosensitised an important tumour response, provided that the irradiation at 600-700 nm was performed 3 h after the phthalocyanine administration, when appreciable concentrations of ZnB4Pc were still present in the serum. Analogously, irradiation of the 10B-ZnB4Pc-loaded pigmented melanoma with thermal neutrons 24 h after injection led to a 4 day delay in tumour growth as compared with control untreated mice. These results open the possibility to use one chemical compound as both a photosensitising and a radiosensitising agent for the treatment of tumours by the combined application of photodynamic therapy and boron neutron capture therapy.

An amphiphilic tetracationic derivative of Zn(II)-phthalocyanine (RLP068) was prepared by means of chemical synthesis and was showed to possess efficient photophysical and photosensitizing properties against model biological substrates. RLP068 was incorporated into a gel formulation, which allowed its ready penetration into the epidermal layers, but not into the dermis, of both Balb/c and hairless SKH1 mice after 1-2 h of topical deposition. Pharmacokinetic studies showed that the phthalocyanine thus formulated does not enter the general blood circulation. The epidermis-associated amount of phthalocyanine was sufficient to cause an important cutaneous damage upon irradiation with red light (600-700 nm; 100-180 mW/cm(2), 160 J/cm(2)); the latter was confined to the epidermal area with no apparent diffusion to the underlying dermal layers or appearance of photosensitivity in distal skin areas. A systematic investigation of the interplay among the different parameters (deposition time of the formulated phthalocyanine on mouse skin, irradiation fluence rate and total light fluence) allowed us to identify the minimal phototoxic dose, as well as to define irradiation protocols allowing the repeatability of the phototherapeutic treatment. The potential of RLP068 to act as a PDT agent for cutaneous diseases is briefly discussed.

Studies on the synthesis, structural elucidation, and biological evaluation of new conjugates of poly-S-lysine with meso-substituted porphyrins are described. The new conjugates were used in the photoinactivation of antibiotic-resistant Gram-positive bacteria (Staphylococcus aureus strains ATCC 25923 and MRSA 110) and Gram-negative bacteria (Escherichia coli strain O4). The results show that the cationic conjugates are able to photosensitize the efficient inactivation of both types of bacteria.

A number of Zn(II)- phthalocyanines bearing peripheral substituents of cationic nature due to the presence of quaternarized anilinium or ammonium groups were shown to be efficient photoantimicrobial agents: a 4-5 log decrease in the survival of both wild-type or methicillin-resistant Staphylococcus aureus was obtained upon short irradiation times in the presence of phthalocyanine concentrations as low as 0.1 microM. A careful selection of the experimental protocol, and in particular the use of short (5 min) incubation times and mild irradiation parameters, allowed one to achieve a high selectivity of S. aureus photoinactivation as compared with important constituents of potential host tissues, such as human fibroblasts and keratinocytes. The efficiency and selectivity of the photoprocess were not affected by the presence of 5% human serum.

Cu(II)-hematoporphyrin (CuHp) was efficiently accumulated by B78H1 amelanotic melanoma cells upon incubation with porphyrin concentrations up to 52 microM. When the cells incubated for 18 h with 13 microM CuHp were irradiated with 532 nm light from a Q-switched Nd: YAG laser operated in a pulsed mode (10 ns pulses, 10 Hz) a significant decrease in cell survival was observed. The cell photoinactivation was not the consequence of a photodynamic process, as CuHp gave no detectable triplet signal upon laser flash photolysis excitation and no decrease in cell survival was observed upon continuous wave irradiation. Thus, it is likely that CuHp sensitization takes place by photothermal pathways. The efficiency of the photoprocess was modulated by different parameters; thus, while varying the amount of added CuHp in the 3.25-26 microM range had little effect, pulse energies larger than 50 mJ and irradiation times of at least 120 s were necessary to induce a cell inactivation of about 50%. The porphyrin-cell incubation time prior to irradiation had a major influence on cell survival, suggesting that the nature of the CuHp microenvironment can control the efficiency of photothermal sensitization.

Irradiation of B16 pigmented melanoma subcutaneously transplanted in C57 mice with a single 650 mJ pulse (10 ns) of 1064 nm light from a Q-switched Nd: YAG laser caused instantaneous bleaching of the pigmented tissue. Visual and histological examination of the resulting gray-colored tumor revealed the breakdown of melanosomes with no detectable alteration of the normal and tumor-overlying skin. Histological examination of the irradiated tumor showed some degree of vascular damage; the depth of the photodamage was not affected by the successive delivery of three consecutive light pulses. The bleached tumor grew at a modestly slower rate but the high-peak-power (HPP) laser treatment did not affect the tumor concentration of a photodynamic sensitizer Si(i.v.)-naphthalocyanine (isoBO-SiNc) intravenously injected 24 h before Nd:YAG irradiation. Treatment of the B16 pigmented melanoma by photodynamic therapy (PDT: 1 mg/kg isoBO-SiNc, 300 mW/cm2, 520 J/cm2) from a 774 nm diode laser immediately after the 1064 nm irradiation resulted in a 16 day delay of tumor regrowth, which was markedly longer than the delay (ca 6 days) obtained after PDT under identical conditions without the preirradiation. Thus, pretreatment of pigmented tumors with HPP 1064 nm light appears to enhance their susceptibility to conventional PDT. The tumor response was further enhanced by repeating the combined HPP/PDT treatment at an interval of 10 days (regrowth delay: 27 days), as well as by applying hyperthermia immediately after HPP/PDT (regrowth delay: ca 34 days).

Previous studies (Biolo et al., Photochem. Photobiol. 59, 362-365, 1994) showed that liposome-delivered Si(IV)-naphthalocyanine (SiNc) photosensitizes B16 pigmented melanoma subcutaneously transplanted in C57 mice to the action of 776 nm light. However, the efficacy of the phototreatment was limited by a lack of selectivity of tumor targeting by SiNc as well as by incomplete necrosis of the neoplastic mass. The present investigations show that the use of a different delivery system (Cremophor emulsion vs liposomes of dipalmitoylphosphatidylcholine) causes no significant increase in the selectivity of tumor targeting for three injected doses of SiNc (0.5, 1, 2 mg/kg). However, upon 776 nm light irradiation (300 mW/cm2; 520 J/cm2), the delay in the rate of tumor growth was maximal (7-8 days) for the highest naphthalocyanine dose. On the other hand, a remarkable improvement in the tumor response was obtained by inducing an intratumoral temperature increase to 44 degrees C immediately after PDT. The thermal effect appeared to be due to photoexcitation of melanin by 776 nm light (550 mW/cm2; 520 J/cm2) and subsequent partial conversion of absorbed energy into heat.