Abstract:Photodynamic therapy (PDT) is a promising therapeutic modality that involves the administration of a photosensitizer followed by local illumination with a specific wavelength of light in the presence of oxygen. PDT is minimally invasive, has high selectivity for cancer, and has good patient compliance due to the simplicity of the procedure; therefore, PDT is widely used as a palliative and salvage treatment in patients with various gastrointestinal malignancies. When used as a salvage treatment for locoregiona… Show more
“…PDT is a method widely used in dermatology and periodontics, less frequently in ophthalmology, gastroenterology, or other medicine branches [21][22][23][24]. This method is also successfully used against gram-positive and gram-negative bacteria in in vitro studies [25][26][27][28][29][30][31].…”
Photodynamic therapy (PDT) has been proven to kill different microbial cells. However, to our knowledge, none of the available reports describes the modulatory effect of this therapy on the antibacterial activity of antibiotics against Escherichia coli rods being the main causative agent of urinary tract infections (UTIs). Therefore, the aim of our study was to verify if the PDT can enhance the antibacterial activity of antibiotics recommended in the treatment of UTIs. An attempt to determine the optimal conditions of PDT to enhance the bactericidal activity of ciprofloxacin, amikacin, and colistin has been made. In order to find the optimal antimicrobial conditions, the efficacy of four protocols associated with the use of different energy doses (70 and 120 J/ cm 2 ) and chlorin e6 (Ce6) concentrations (50 and 100 μg/mL) has been verified. The antibacterial effect of combined PDT and antibiotics was assessed by the time-kill assay. The best results were achieved for Ce6 at a concentration of 100 μg/mL and the energy dose 120 J/cm 2 for bacterial suspensions treated with ciprofloxacin. Taken together, our results showed that PDT using Ce6 improves the antibacterial activity of antibiotics effectively inhibiting bacterial growth and being promising in the elimination of bacterial UTIs in humans.
“…PDT is a method widely used in dermatology and periodontics, less frequently in ophthalmology, gastroenterology, or other medicine branches [21][22][23][24]. This method is also successfully used against gram-positive and gram-negative bacteria in in vitro studies [25][26][27][28][29][30][31].…”
Photodynamic therapy (PDT) has been proven to kill different microbial cells. However, to our knowledge, none of the available reports describes the modulatory effect of this therapy on the antibacterial activity of antibiotics against Escherichia coli rods being the main causative agent of urinary tract infections (UTIs). Therefore, the aim of our study was to verify if the PDT can enhance the antibacterial activity of antibiotics recommended in the treatment of UTIs. An attempt to determine the optimal conditions of PDT to enhance the bactericidal activity of ciprofloxacin, amikacin, and colistin has been made. In order to find the optimal antimicrobial conditions, the efficacy of four protocols associated with the use of different energy doses (70 and 120 J/ cm 2 ) and chlorin e6 (Ce6) concentrations (50 and 100 μg/mL) has been verified. The antibacterial effect of combined PDT and antibiotics was assessed by the time-kill assay. The best results were achieved for Ce6 at a concentration of 100 μg/mL and the energy dose 120 J/cm 2 for bacterial suspensions treated with ciprofloxacin. Taken together, our results showed that PDT using Ce6 improves the antibacterial activity of antibiotics effectively inhibiting bacterial growth and being promising in the elimination of bacterial UTIs in humans.
“…It can be applied in various fields, for example, hospitals, food industries, or wastewater treatment. The penetration depth and efficiency of light are critical, especially in clinical PDT applications [49], and orange light (wavelength 590-620 nm) is known to penetrate approximately 1.5 mm into tissue [50]. We are also screening new Ps candidates from natural products that can react with red light (wavelength 620-750 nm), which has an effective penetration depth of up to 3 mm [50].…”
Section: Apdt Rescued Intestinal Permeability Dysfunction In C Elegansmentioning
Bacterial antibiotic resistance is an alarming global issue that requires alternative antimicrobial methods to which there is no resistance. Antimicrobial photodynamic therapy (APDT) is a well-known method to combat this problem for many pathogens, especially Gram-positive bacteria and fungi. Hypericin and orange light APDT efficiently kill Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and the yeast Candida albicans. Although Gram-positive bacteria and many fungi are readily killed with APDT, Gram-negative bacteria are difficult to kill due to their different cell wall structures. Pseudomonas aeruginosa is one of the most important opportunistic, life-threatening Gram-negative pathogens. However, it cannot be killed successfully by hypericin and orange light APDT. P. aeruginosa is ampicillin resistant, but we hypothesized that ampicillin could still damage the cell wall, which can promote photosensitizer uptake into Gram-negative cells. Using hypericin and ampicillin cotreatment followed by orange light, a significant reduction (3.4 log) in P. aeruginosa PAO1 was achieved. P. aeruginosa PAO1 inactivation and gut permeability improvement by APDT were successfully shown in a Caenorhabditis elegans model.
“…Стандартом лечения поверхностного рака пищевода, особенно при его распространении в пределах слизистой оболочки, в настоящее время является эндоскопическая резекция (EMR) и эндоскопическая диссекция в подслизистом слое (ESD) [7]. Однако в случае кольцевых поражений, распространившихся более чем на две трети окружности пищевода, применение данных технологий (EMR и ESD) не рекомендуется вследствие высокого риска развития стойких стриктур пищевода после проведения терапии [7,8]. Также актуальной проблемой остается разработка эндоскопических методов разрешения дисфагии, позволяющих восстановить пероральное питание и улучшить качество жизни больных со стенозирующим раком пищевода [8,9].…”
Section: Introductionunclassified
“…Однако в случае кольцевых поражений, распространившихся более чем на две трети окружности пищевода, применение данных технологий (EMR и ESD) не рекомендуется вследствие высокого риска развития стойких стриктур пищевода после проведения терапии [7,8]. Также актуальной проблемой остается разработка эндоскопических методов разрешения дисфагии, позволяющих восстановить пероральное питание и улучшить качество жизни больных со стенозирующим раком пищевода [8,9]. Наиболее перспективными в настоящее время являются малоинвазивные эндоскопические технологии (дилатация, реканализация, вызванная воздействием электролазерной деструкции, аргоноплазменной коагуляции или фотодинамической терапии) и эндопротезирование [3,5].…”
Photodynamic therapy (PDT) is a worthy alternative to surgical esophageal resection or endoscopic mucosal resection and dissection (EMR, ESD) in patients with superficial esophageal cancer with severe concomitant diseases as well as in patients with a common form of esophageal cancer with severe malignant dysphagia. Patients with superficial (7) and advanced (15) esophageal cancer received PDT as an independent method and as a supplement to complex treatment. Radachlorin was used as a photosensitizer at a dose of 0.6–0.8 mg/kg, administered intravenously 3 hours before irradiation. A PDT session was carried out using a laser with a wavelength of 662 nm. The light dose used was 150–300 J/cm2 . The use of PDT made it possible to achieve the full effect in 7 (100%) patients in the group of superficial (T1a-T1b) esophageal cancer where PDT was either the only method of treatment or in combination with radiation therapy. In the group of patients with stenotic cancer the use of PDT made it possible to achieve full recovery of food intake after recanalization for 20% of patients, and partial – for 66.7%. Thus, complete natural food intake was restored for 86.7% of patients which improved their quality of life. PDT is also a method of choice for cancer of the upper esophagus as esophageal stenting in this situation can cause unwanted subjective sensations.
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