Enhanced response of the fricke solution doped with hematoporphyrin under X-rays irradiation

The vials filled with Fricke solutions were doped with increasing concentrations of Photogem®, used in photodynamic therapy. These vials were then irradiated with low-energy X-rays with doses ranging from 5 to 20 Gy. The conventional Fricke solution was also irradiated with the same doses. The concentration of ferric ions for the Fricke and doped-Fricke irradiated solutions were measured in a spectrophotometer at 220 to 340 nm. The results showed that there was an enhancement in the response of the doped-Fricke solution, which was proportional to the concentration of the photosensitizer. The use of such procedure for studying the radiosensitizing property of photosensitizers based on the production of free radicals is also discussed.Tubos de ensaio foram preenchidos com a solução Fricke dopada com Fotogem® em concentrações crescentes; essa hemotoporfirina é utilizada na terapia fotodinâmica. Esses tubos foram irradiados com doses de 5 a 20 Gy. A solução Fricke convencional também foi irradiada com as mesmas doses. As concentrações de íons férricos nas soluções Fricke convencional e dopadas irradiadas foram medidas num espectrofotômetro com comprimento de onda entre 220 e 340 nm. Os resultados mostraram que quando comparado o Fricke convencional com o Fricke dopado irradiado, as amostras dopadas demonstraram um aumento na resposta da dose absorvida que é proporcional a concentração do Photogem® na solução Fricke. Concluímos que esse procedimento pode ser utilizado para propósitos de dosimetria na terapia com radiossensibilizadores

Application of benzo[a]phenoxazinium chlorides in antimicrobial photodynamic therapy of Candida albicans biofilms

The use of Antimicrobial Photodynamic Therapy (APDT) as a new approach to treat localized Candida infections is an emerging and promising field nowadays. The aim of this study was to verify the efficacy of photodynamic therapy using two new benzo[a]phenoxazinium photosensitizers against Candida albicans biofilms: N-[5-(3-hydroxypropylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene]ethanaminium chloride (FSc) and N-(5-(11-hydroxyundecylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride (FSd). The photodynamic activity of dyes against C. albicans biofilms was evaluated by incubating biofilms with dyes in the range of 100-300 μM for 3 or 18 h followed by illumination at 12 or 36 J cm-2, using a xenon arc lamp (600 ± 2 nm). A total photoinactivation of C. albicans biofilm cells was achieved using 300 μM of FSc with18 h of incubation, followed by illumination at 36 J cm-2. Contrarily, FSd had insignificant effect on biofilms inactivation by APDT. The higher uptake of FSc than FSd dye by biofilms during the dark incubation may explain the greater photodynamic effectiveness achieved with FSc. The results obtained stresses out the FSc-mediated APDT potential use to treat C. albicans infections.This work was supported by the research grant SFRH/BD/72742/2010 from "Fundacao para a Ciencia e Tecnologia" (FCT), Portugal. The authors also thank the Project "BioHealth - Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 - 0 Novo Norte), QREN, FEDER and the FCT Strategic Project PEst-OE/EQB/LA0023/2013. In addition, financial to Centre of Chemistry and Centre of Physics through CQ/UM [PEst-C/QUI/UI0686/2013 (FCOMP-01-0124FEDER-037302)] and CFUM [PEst-C/FIS/UI0607/2013 (F-COMP-01-0124-FEDER-037291)], as well as a post-doctoral grant to B.R. Raju (SFRH/BPD/62881/2009) is also acknowledged to FCT, POPH-QREN, FSE

New Approaches to Photodynamic Therapy from Type I, II and III to Type IV Using One or More Photons

Photodynamic therapy (PDT) is an alternative cancer treatment to conventional surgery, radiotherapy and chemotherapy. It is based on activating a drug with light that triggers the generation of cytotoxic species that promote tumour cell killing. At present, PDT is mainly used in the treatment of wet age-related macular degeneration, for precancerous conditions of the skin (e.g. actinic keratosis) and in the palliative care of advanced cancers, for instance of the bladder or the oesophagus. PDT is still not used as a first line cancer treatment, which is surprising given the first clinical trials by Dougherty’s group dating back to the 1970’s. PDT has significant advantages over surgery or radiation therapy for low lying tumours due to better cosmetic outcome and localised treatment for the patients. However, despite these advantages and significant developments in optical technology that has enabled light penetration to deeper lying tumours, in excess of 5 cm, a lack of phase III clinical trials has slowed down the uptake of PDT by the healthcare sector as a frontline treatment in cancer. However research continues to demonstrate the potential benefits of PDT and the need to stimulate funding and uptake of clinical studies using next generation photosensitizers offering advanced targeted delivery, improved photodynamic dose combined with modern light delivery technologies. This review surveys the available PDT treatments and emerging novel developments in the field with a particular focus on two-photon techniques that are anticipated to improve the effectiveness of PDT in tissues at depth and on next generation drugs that work without the need of the presence of oxygen for photosensitization making them effective where hypoxia has taken hold

Like a bolt from the blue : phthalocyanines in biomedical optics

The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo-stability. In particular, this is mostly relevant for their in vivo activation in deeper tissular regions. However, most Pcs present two major limitations, i.e., a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation combined with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e., aluminium-, zinc- and silicon-based Pcs

Conjugation with L, L-diphenylalanine Self-Assemblies Enhances In Vitro Antitumor Activity of Phthalocyanine Photosensitizer

We present the synthesis and characterization of new peptide conjugates obtained by hierarchical co-assembly of L,L-diphenylalanine (FF) and zinc phthalocyanine complexes (ZnPc) in water. Self-assembly capabilities under defined conditions were investigated by scanning electron microscopy, and photophysical properties were evaluated using UV-Vis and fluorescence spectroscopy. AFM observations demonstrated that these ZnPcs form different highly ordered arrays on the crystalline faces of the FF microplates and that surface roughness significantly changes with the presence of differently substituted phthalocyanine units. XRD assays showed that the overall molecular packing of the conjugates is organized according to a hexagonal symmetry, with ZnPcs hosted in the interstices of the peptide phase. In vitro photodynamic studies were conducted on human breast cancer MCF-7 cells to investigate both cellular uptake and cytotoxicity. It was shown that FF self-assemblies are not toxicity and enhance accumulation of ZnPc in MCF-7 cells, improving apoptotic cell death upon irradiation. Our findings demonstrate enhancement of ZnPc antitumor efficiency by FF conjugates and a proof-of-concept for new photosensitizer carriers based on peptide conjugates

Development of Brugada Syndrome Following Photodynamic Therapy in a Patient with Cholangiocarcinoma

Brugada syndrome can be unmasked by several conditions including a febrile state, marked leukocytosis, and electrolyte disturbances. Herein, we describe a 62-year-old man with cholangiocarcinoma in the first reported case of Brugada syndrome onset following photodynamic therapy

Фотодинамическая терапия больного базальноклеточным раком кожи ушной раковины стадии T3N0M0 (клиническое наблюдение)

The article presents a clinical observation. The patient, 72 years old, applied to the MNII them. P.A. Herzen with complaints about the presence of an ulcerated tumor of the left ear. After further examination, a diagnosis was made - basal cell carcinoma of the ear skin with spread to the skin of the parotid region T3N0M0. On July 9, 2021, the patient underwent a course of photodynamic therapy (PDT) using a photosensitizer based on chlorin e6 and a diode laser with a wavelength of 662 nm. After one course of PDT, complete regression of the tumor was recorded.В статье представлено клиническое наблюдение. Больной, 72 лет, обратился в МНИОИ им. П.А. Герцена с жалобами на наличие изъязвленной опухоли левого уха. После дообследования поставлен диагноз – базальноклеточный рак кожи уха с распространением на кожу околоушной области T3N0M0. Больному 09.07.2021 был выполнен курс фотодинамической терапии (ФДТ) с использованием фотосенсибилизатора на основе хлорина е6 и диодного лазера с длиной волны 662 нм. После проведения одного курса ФДТ была зарегистрирована полная регрессия опухоли

Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis

Objective:\ud \ud In vivo studies of antimicrobial PDT in animal models of oral candidosis are scarce and the association of porphyrin and LED light has not been evaluated for in vivo photoinactivation of Candida. In this study the effectiveness of photodynamic therapy (PDT) on the inactivation of Candida albicans in vivo was evaluated.\ud Study design:\ud \ud Seventy-one 6-week-old female Swiss mice were immunosuppressed, provided tetracycline to their drinking water, then orally swabbed with a suspension of C. albicans (107 CFU/mL). Four days after oral inoculation, PDT was performed on the dorsum of the tongue after topical administration of Photogem at 400, 500, or 1000 mg/L and followed 30 minutes later by illumination with LED light (305 J/cm2) at 455 or 630 nm (n = 5 each). After swabbing to recover yeast from the tongue, the number of surviving yeast cells was determined (CFU/mL) and analyzed by ANOVA and Holm-Sidak tests (P < .05). Animals were humanely killed, and the tongues surgically removed and processed for histological evaluation of presence of yeast and inflammatory reaction.\ud Results:\ud \ud PDT resulted in a significant reduction in C. albicans recovered from the tongue (P < .001) when compared with mice from the positive control group. There was no difference between the concentrations of Photogem and LED light wavelengths used. Histological evaluation of the tongue revealed that PDT causes no significant adverse effects to the local mucosa.\ud Conclusion:\ud \ud PDT promoted significant reduction in the viability of C. albicans biofilm without harming the tongue tissue.FAPESP (05/02193-4; 05/03226-3)CePOF - CEPI