Porphyrin nanoemulsion for antimicrobial photodynamic therapy: effective delivery to inactivate biofilm-related infections.

The management of biofilm-related infections is a challenge in healthcare, and antimicrobial photodynamic therapy (aPDT) is a powerful tool that has demonstrated a broad-spectrum activity. Nanotechnology has been used to increase the aPDT effectiveness by improving the photosensitizer's delivery properties. NewPS is a simple, versatile, and safe surfactant-free nanoemulsion with a porphyrin salt shell encapsulating a food-grade oil core with promising photodynamic action. This study evaluated the use of NewPS for aPDT against microorganisms in planktonic, biofilm, and in vivo models of infected wounds. First, the potential of NewPS-mediated aPDT to inactivate Streptococcus pneumoniae and Staphylococcus aureus suspensions was evaluated. Then, a series of protocols were assessed against S. aureus biofilms by means of cell viability and confocal microscopy. Finally, the best biofilm protocol was used for the treatment of S. aureus in a murine-infected wound model. A high NewPS-bacteria cell interaction was achieved since 0.5 nM and 30 J/cm2 was able to kill S. pneumoniae suspension. In the S. aureus biofilm, enhanced efficacy of NewPS-aPDT was achieved when 100 µM of NewPS was applied with longer periods of incubation at the light dose of 60 J/cm2. The best single and double-session protocol reduced 5.56 logs and 6.03 logs, respectively, homogeneous NewPS distribution, resulting in a high number of dead cells after aPDT. The in vivo model showed that one aPDT session enabled a reduction of 6 logs and faster tissue healing than the other groups. In conclusion, NewPS-aPDT may be considered a safe and effective anti-biofilm antimicrobial photosensitizer.

Overall Results for a National Program of Photodynamic Therapy for Basal Cell Carcinoma: A Multicenter Clinical Study to Bring New Techniques to Social Health Care.

Along the past years, a national program to implement photodynamic therapy (PDT) for nonmelanoma skin cancer (NMSC) was performed over the Brazilian territory. Using a strategy involving companies, national bank, and medical partners, equipment, medication, and protocols were tested in a multicenter study. With results collected over 6 years, we could reach a great deal of advances concerning the use of PDT for skin cancer. We present the overall reached results of the program and discuss several aspects about it, including public politics of treatment. A discussion about advantages of this technique within conditions of health care is placed, comparing PDT with surgery, including an analysis about the implementation of PDT in countries in development as Brazil, considering not only technical but social aspects, as the distribution of medical doctor in the Brazilian territory. The program resulted in a huge dissemination of PDT in Brazil and many countries in Latin America, in a partnership among public politics, universities, companies, and hospitals and clinics and in the insertion of national technologies as option to treat NMSC. Consequence of the program is mainly the continuation of the use of PDT in Brazil and many countries in Latin America.

Vascular Effects of Photodynamic Therapy with Curcumin in a Chorioallantoic Membrane Model.

Photodynamic Therapy (PDT) is a treatment that requires light, a photosensitizing agent, and molecular oxygen. The photosensitizer is activated by light and it interacts with the oxygen that is present in the cellular microenvironment. The molecular oxygen is transformed into singlet oxygen, which is highly reactive and responsible for the cell death. Therefore, PS is an important element for the therapy happens, including its concentration. Curcumin is a natural photosensitizer and it has demonstrated its anti-inflammatory and anti-oxidant effects that inhibit several signal transduction pathways. PDT vascular effects of curcumin at concentrations varying from 0.1 to 10 mM/cm² and topical administration were investigated in a chick Chorioallantoic Membrane (CAM) model. The irradiation was performed at 450 nm, irradiance of 50 mW/cm² during 10 min, delivering a total fluence of 30 J/cm². The vascular effect was followed after the application of curcumin, with images being obtained each 30 min in the first 3 h, 12 h, and 24 h. Those images were qualitatively and quantitatively analyzed with a MatLAB®. Curcumin was expected to exhibit a vascular effect due to its angio-inhibitory effect. Using curcumin as photosensitizer, PDT induced a higher and faster vascular effect when compared to the use of this compound alone.

Ultrasonic scalpel associated with photodynamic therapy in the treatment of refractory vulvar condyloma acuminatum.

This is a case report of a patient with vulvar condyloma acuminatum associated with hyperkeratosis and folliculitis, which had been refractory to two previous therapies. The patient had been successfully treated using a combination of promising techniques: the ultrasonic scalpel and MAL photodynamic therapy.

Fast Fabrication of Multifunctional PCL/Curcumin Nanofibrous Membranes for Wound Dressings.

Therapeutic intervention to skin wounds requires covering the affected area with wound dressings. Interdisciplinary efforts have focused on the development of smart bandages that can perform multiple functions. In this direction, here, we designed a low cost (U$0.012 per cm2) multifunctional therapeutic wound dressing fabricated by loading curcumin (CC) into poly(ϵ-caprolactone) (PCL) nanofibers using solution blow spinning (SBS). The freestanding PCL/CC bandages were characterized by distinct physicochemical approaches and were successful in performing varied functions, including controlled release of CC, colorimetric indication of the wound conditions, barrier against microorganisms, being biocompatible, and providing a photosensitive platform for antimicrobial photodynamic therapy (aPDT). The chemical nature of PCL and CC and the interactions between these components allowed CC to be released for 192 h (ca. 8 days), which could be correlated with the Korsmeyer-Peppas model, with a burst release suitable to treat the inflammatory phase. Due to the CC keto-enol tautomerism, an optical indication of the healing status could be obtained using PCL/CC, which occurred immediately, ranging between red/orange and yellow shades. The effect against pathogenic microorganisms evaluated by agar disc-diffusion, affected skin wound simulation (ex vivo), and microbial penetration tests demonstrated the ability to block and inhibit microbial permeation in different environments. The biocompatibilities of PCL and PCL/CC were verified by in vitro cytotoxicity study, which demonstrated that cell viabilities average above 94 and 96% for human dermal fibroblasts. In addition, the proposed bandage responded to aPDT applied to an in vivo assay, showing that, when irritated, PCL/CC was able to reduce the bacteria present on the real wound of mice. In summary, our findings demonstrate that using PCL and CC to produce nonwovens by the SBS technique offers potential for the rapid fabrication of biocompatible and multifunctional wound dressings, paving the way for large-scale production and utilization of such dressings in the treatment of skin wounds.

Photodynamic inactivation of Streptococcus pneumoniae with external illumination at 808 nm through the ex vivo porcine thoracic cage.

Pneumonia is responsible for high mortality rates around the world, and its major treatment is based on antibiotic treatment. Antimicrobial resistance has been increasing in the last years, resulting in relevant public health concern. A promising alternative for pneumonia is antimicrobial photodynamic therapy. The purpose of this study was to investigate whether 808 nm wavelength is able to be transmitted through the biological tissues of the thoracic wall and be delivered in enough energy inside the cage to activate indocyanine green and promote photodynamic response. A light source panel was developed composed of 200 lasers centered at 808 nm with an irradiance of 77.8 ± 10.0 mW/cm2 and tested in an ex vivo thoracic cage model. Monte Carlo simulations were used to understand the photon migration through all the tissues at the thoracic wall. It was observed that tissues responsible for the major absorption of photons are the skin and subcutaneous fat. Experimental measurement of the irradiance was obtained after the light pass-through ex vivo pig thoracic cage, obtaining 3% to 5% of the emitted irradiance. Finally, it was observed that even with 3% of the initial irradiance, a 99.9% reduction of the Streptococcus pneumoniae was successfully achieved after 42.6 minutes of irradiation.

Potential of curcumin-loaded cubosomes for topical treatment of cervical cancer.

Cervical cancer is one of the most common cancers affecting women worldwide. There are an estimated 570.000 new cases of cervical cancer each year and conventional treatments can cause severe side effects. In this work, we developed a platform for vaginal administration of lipophilic drugs for cervical cancer treatment. We formulated mucoadhesive cubosomes for the delivery of curcumin, a lipophilic drug for cervical cancer treatment, to increase its bioavailability and local absorption. This study tests the use of cubosomes for vaginal drug administration and assesses their potential efficiency using the CAM (chick embryo chorioallantoic membrane) model. SAXS (small-angle X-ray scattering), cryo-TEM (cryo-transmission electron microscopy), and dynamic light scattering (DLS) were employed to characterise the system. With ex vivo permeation and retention studies, we find that the curcumin released from our system is retained in the vaginal mucosa. In vitro cytotoxicity assay and cellular uptake showed an increased cytotoxic effect of curcumin against HeLa cell line when incorporated into the cubosomes. The curcumin-loaded cubosomes also demonstrated an antiangiogenic effect evaluated in vivo by the CAM model.

One-Pot Microwave-Assisted Synthesis of Carbon Dots and in vivo and in vitro Antimicrobial Photodynamic Applications.

Carbon-based photosensitizers are more attractive than the other ones based on their low cost, high stability, broadband of light absorption, tunable emission spectra, high quantum yield, water solubility, high resistance to metabolic degradation, and selective delivery. These properties allow multiple applications in the field of biology and medicine. The present study evaluated in vitro and in vivo the antimicrobial photodynamic effect of a one-pot microwave produced C-DOTS based on citric acid. The in vitro assays assessed the effectiveness of illuminated C-DOTS (C-DOTS + light) against Staphylococcus aureus suspension and biofilm. The concentrations of 6.9 and 13.8 mg/mL of C-DOTS and light doses of 20 and 40 J/cm2 were able to reduce significantly the microorganisms. Based on these parameters and results, the in vivo experiments were conducted in mice, evaluating this treatment on wounds contaminated with S. aureus. The viability test showed that C-DOTS-mediated photodynamic inactivation reduced 104 log of the bacteria present on the skin lesions. These results, altogether, showed that antibacterial photodynamic therapy using C-DOTS is a promising and viable treatment for Gram-positive bacteria-infected wounds.

HPV-induced condylomata acuminata treated by Photodynamic Therapy in comparison with trichloroacetic acid: A randomized clinical trial.

OBJECTIVES: This is a randomized controlled clinical trial comparing Photodynamic Therapy (PDT) and the application of trichloracetic acid (TAA) in the treatment of HPV condyloma in the perianal and vulva regions. Design, Randomised controlled, open label, trial. They were allocated to each treatment following randomization by a computer program. SETTING: Women Health Ambulatory in São Carlos city, São Paulo State in the Brazil. PARTICIPANTS: 36 patients evaluated. 31 patients fulfilled the study requirements. INTERVENTION: Photodynamic Therapy (PDT) versus trichloracetic acid (TAA). The PDT protocol used the prodrug methyl aminolevulinate incubated for 3 hours and irradiation at 630 nm (100 J/cm²). In the treatment using TAA, warts received a small amount of acid using a cotton swab. Both treatments were repeated weekly until the lesions disappeared completely or until 10 sessions were completed. MAIN OUTCOME MEASURE: Clinical analysis. Follow-up between 12 and 30 months after the complete treatment. RESULTS: A total of 16 patients were treated with PDT and 15 patients with TAA. A complete response rate of 60% for TAA and 63% for PDT, with a recurrence rate of 33% for TAA and 0% for PDT. CONCLUSION: PDT appears not only to treat lesions due to physical destruction of condyloma and subclinical lesions, but also to modulate the immune system and/or also to decrease the local viral load, suggesting a lower recurrence compared to the TAA group.

MAL-associated methyl nicotinate for topical PDT improvement.

Photosensitization of all tissue in sufficient quantity to generate damage is one of the limiting factors for Photodynamic Therapy (PDT) efficiency. Methyl nicotinate (MN) is a thermogenic and vasodilating substance that facilitates the topical tissue penetration of some compounds. The topical MAL (methyl aminolevulinate) PDT is commonly used as a precursor of protoporphyrin IX (PpIX). This study investigates the safety of topical use in NM, as well as its ability to improve the efficiency of topical PDT. For this, we investigate the cytotoxicity of MN, as well as its actions in increasing cellular metabolism and vasodilation. Besides, its ability to optimize the formation of PpIX in the tissue when associated with MAL cream was investigated, besides assessing the severity of necrosis obtained by treatments. The cytotoxicity of MN was tested for concentrations of 0, 0.1, 0.25, 0.5, 0.75 and 1% in cell culture. For the concentration of 0.5%, the cellular metabolism was evaluated using confocal microscopy to calculate the redox rate. In the Chorioallantoic Membrane Model, vasodilation was evaluated for concentrations of 0.5 and 1% MN during 1 h of incubation. In the animal model, the healthy skin of Wistar rat was used to evaluate the production of PpIX in the tissue and the degree of necrosis obtained by Photodynamic therapy when using NM associated with methyl aminolevulinate. It was observed the non-cytotoxicity in vitro of MN in the concentration used (0.5%) and its ability to increase cellular metabolism. In a chorioallantoic model, the MN vasodilation power was demonstrated for different caliber of vessels. In vivo studies are showing that the incorporation of MN in the MAL cream increases the amount of PpIX produced in the tissue causing a higher effect on the epidermis after PDT. This improvement of the protocol may make the procedure more effective both in the destruction of tumor tissue and in the treatment of deeper cells decreasing possible recurrence, in addition to allowing improvements in the protocol, such as reducing the cream's incubation time.

HPV condylomatosis region treated with multiple sessions of MAL-PDT: A case report.

Condyloma or genital warts affect the tissues of the genital area due to infections induced by Human papillomavirus. There are some topical therapies indicated for condyloma lesions treatment but all of them present a high rate of recurrence. Photodynamic Therapy is proving to be an interesting strategy for treating these lesions, capable also to treat virus-infected cells on subclinical lesions. A patient with a significative condylomatosis region was treated with six MAL-PDT sessions. Due to its large thickness, other topical procedures probably would have low effectiveness. After the treatment, the tissue presented clinical absence of lesion and no apparent scar, with good aesthetic result and preserving the sensitivity of the region and a follow up of eleven months without recurrence.

Long Term Effectiveness of Photodynamic Therapy for CIN Treatment.

(1) Background: Cervical cancer is the third most commonly diagnosed cancer and the fourth leading cause of cancer death in women worldwide. The highest incidence rates are in Africa, followed by South-Central Asia and South America. According to the Brazilian National Institute of Cancer (INCA), 16,370 new cases of cervical cancer were estimated for each year of the biennium of 2018-2019. About 90% of cervical cancers originate from the malignant progression of cervical intraepithelial neoplasia (CIN) which is classified based on cytohistological characteristics (low- and high-grade lesions). The present study reports the long-term effectiveness of topical photodynamic therapy (PDT) for CIN grades 1 and 2/3 with up to two years of follow up. (2) Methods: A total of 56 patients with CIN 1, ten with CIN 2, and 14 patients for the placebo group were enrolled in this study. (3) Results: 75% (n = 42) of CIN 1 patients presented a complete response to PDT and only 23.2% (n = 13) of recurrence, progression, and/or lesions remaining two years after PDT. For CIN 2/3 patients, 90% were observed to be cured after one and two years of follow up. (4) Conclusions: PDT presented best results two years after a non-invasive, fast, and low-cost procedure and in comparison with the placebo group, preventing the progression of cervical intraepithelial neoplasia and preserving the cervix.

Optical techniques for the diagnosis and treatment of lesions induced by the human papillomavirus - A resource letter.

Human papillomaviruses (HPV) are the most common sexually-transmitted virus, and carcinogenic HPV strains are reported to be responsible for virtually all cases of cervical cancer and its precursor, the cervical intraepithelial neoplasia (CIN). About 30% of the sexually active population are considered to be affected by HPV. Around 600 million people are estimated to be infected worldwide. Diseases related to HPV cause significant impact from both the personal welfare point of view and public healthcare perspective. This resource letter collects relevant information regarding HPV-induced lesions and discusses both diagnosis and treatment, with particular attention to optical techniques and the challenges involved to the implementation of those approaches.

Fluorescence analysis of a tumor model in the chorioallantoic membrane used for the evaluation of different photosensitizers for photodynamic therapy.

The development of a tumor in the chicken chorioallantoic membrane (CAM) enables a more individualized understanding of the dynamics of the photosensitizer (PS) interaction with the tumor blood vessels and cells. Photogem® and 5-aminolevulinic acid (ALA), a protoporphyrin IX (PpIX) precursor, were used as PS and their red fluorescence enabled the monitoring of PS dynamic distribution in the vessels and in the tumor. With a tumor model in CAM and fluorescence assessment, the aim of this study was to evaluate the PDT parameters comparing different photosensitezers. In this model, the topical application was chosen as the best way of drug delivery and widefield fluorescence images were at every 30min. The images were processed in a MATLAB® routine for a semi-quantitative analysis of the red fluorescence. PpIX formation in the blood vessels and in the tumor region was observed after 3h and 1.5h, respectively, whereas Photogem® was accumulated in the tumor region after 2h. The illumination was performed by a diode laser with emission centered at 635nm and irradiance of 80mW/cm2 for 10min. After PDT irradiation, the photobleaching for both compounds was observed. Photogem® showed a reduced photobleaching, however, both PS induced a destruction of the tumor mass and vascular network in the treated area.

Avaliação clínica e histopatológica da eficácia do tratamento utilizando terapia fotodinâmica associada ao laser de baixa potência em pacientes portadores de queilite actínica - Um acompanhamento de 6 meses / Clinical and Histopathological Evaluation of Photodynamic Therapy Associated with The Low-Level Laser Therapy on Patients with Actinic Cheilitis - A Six-Month Follow-Up Trial

O objetivo do presente estudo foi avaliar a eficácia clínica e histopatológica da terapia fotodinâmica (TFD) associada à terapia a laser de baixa potência no tratamento de pacientes com queilite actínica (QA) após seis meses de acompanhamento. Material e Métodos: pacientes com QA ativa foram submetidos a duas sessões de TFD associadas à laserterapia de baixa potência, utilizando o 5-aminolevulinato de metila como droga fotossensibilizadora. Após seis meses de acompanhamento, uma nova biópsia incisional foi realizada para avaliar a resposta ao tratamento. Resultados: excelentes taxas de eficácia foram observadas na melhora dos sintomas neste estudo, no entanto, a análise histopatológica não foi tão promissora e apenas a melhora do grau de displasia só pode ser observada em 20% da amostra. Conclusão: de acordo com os resultados do presente estudo, pode-se concluir que a terapia fotodinâmica associada à laserterapia de baixa potência parece ser uma opção a ser considerada no tratamento da Queilite Actínica. No entanto, os pacientes devem ser acompanhados de perto clinicamente e, eventualmente, histopatologicamente

Objective: the aim of the present study was to evaluate the clinical and histopathological efficacy of photodynamic therapy (PDT) associated with the low-level laser therapy (LLLT) in the treatment of patients with Actinic Cheilitis (AC) after a six-month follow-up. Material and Methods: patients with active AC undergone through two sessions of PDT, associated with the low-level laser therapy using the Methyl 5-aminolevulinate as a photosensybilizer drug. After a six-month follow-up, a new incisional biopsy was performed in order to evaluate the response to treatment. Results: excellent efficacy rates were observed in the improvement of symptoms in this study, however, histopathological analysis was not so promising and the improvement of dysplasia degree could only be seen in 20% of the sample. Conclusion: according to the results of the present study, we concluded that the photodynamic therapy associated with low-level laser therapy is an option to be considered when treating Actinic Cheilits. However, patients should be clinically followed-up in a severing agenda and eventually, histopathologically