Porphyrin photosensitizers in photodynamic therapy and its applications.

Infections caused by Candida albicans are of increasing concern, especially considering immunodepressed patients. The toxicity of most antifungal agents, the great number of cases with recidives, as well as the emergence of resistant samples has provoked the evaluation of new forms of therapy. In this context, the photodynamic therapy (PDT) presents auspicious antimicrobial properties, stimulating the development of trials employing several kinds of photosensitizers. In the present work, the application of different kind of Azure dyes as photosensitizer in PDT against C. albicans was evaluated through instrumental measurements of electronic spectroscopy. In fact, the values of optical density were a precise indicator of the growth inhibition of the microorganisms. Indeed, Azures are phenothiazinium derivatives that constitute a very relevant class of compounds with several biomedical applications, such as photoantimicrobial therapy against local bacterial infection, tuberculosis, trypanosomi- asis, malaria, Rickettsia, yeasts, viral infection n and cancer. Azure A, Azure B, Azure A thiocyanate, Azure B BF4 ,A zure A eosinate are the dyes tested against C. albicans. The results denoted completely distinct behaviors to the different types of Azure compound evaluated in this work. In fact, Azure A and Azure A eosinate presented significant results when irradiated with 56 J/cm 2 , since the growth inhibition of C. albicans reached approximately 60%. This Azure compounds have significant potential to be employed as photosensitizer (PS) in PDT, especially in cases of mucocutaneous candidosis. The spectroscopic evaluation was very effective to the detection of slight alterations in the growth of the microorganisms, denoting that this kind of analysis is an excellent alternative to determine growth inhibition of Candida albicans. The experimental data are discussed in details in agreement with recent results from literature.

New porphyrin photosensitizers—Synthesis, singlet oxygen yield, photophysical properties and application in PDT

Infections caused byCandida albicansare of increasing concern, especially considering immunodepressed patients. The toxicity of most antifungal agents, the great number of cases with recidives, as well as the emergence of resistant samples has provoked the evaluation of new forms of therapy. In this context, the photodynamic therapy (PDT) presents auspicious antimicrobial properties, stimulating the development of trials employing several kinds of photosensitizers. In the present work, the application of different kind of Azure dyes as photosensitizer in PDT againstC. albicanswas evaluated through instrumental measurements of electronic spectroscopy. In fact, the values of optical density were a precise indicator of the growth inhibition of the microorganisms. Indeed, Azures are phenothiazinium derivatives that constitute a very relevant class of compounds with several biomedical applications, such as photoantimicrobial therapy against local bacterial infection, tuberculosis, trypanosomiasis, malaria, Rickettsia, yeasts, viral infectionnand cancer. Azure A, Azure B, Azure A thiocyanate, Azure B BF4, Azure A eosinate are the dyes tested againstC. albicans. The results denoted completely distinct behaviors to the different types of Azure compound evaluated in this work. In fact, Azure A and Azure A eosinate presented significant results when irradiated with 56 J/cm2, since the growth inhibition ofC. albicansreached approximately 60%. This Azure compounds have significant potential to be employed as photosensitizer (PS) in PDT, especially in cases of mucocutaneous candidosis. The spectroscopic evaluation was very effective to the detection of slight alterations in the growth of the microorganisms, denoting that this kind of analysis is an excellent alternative to determine growth inhibition ofCandida albicans. The experimental data are discussed in details in agreement with recent results from literature.

Porphyrin photosensitization and phototherapy.

In this dissertation, development of new materials to the field of photonics, more specifically solar energy conversion and cancer therapy was studied. In particular, a series of group of uniform materials based on organic salts (GUMBOS) were developed for use as improved photosensitizers in dye-sensitized solar cells (DSSCs) and photodynamic therapy (PDT). GUMBOS are solid phase organic salts that are similar to ionic liquids, but with melting points ranging from 25 to 250 °C. Properties of GUMBOS can easily be tuned by changing the cation or anion used to form these materials. Thus, new materials can easily be produced with properties that are beneficial for applications in DSSCs or PDT. In this dissertation, porphyrin-based GUMBOS as well as nanomaterials derived from these GUMBOS (nanoGUMBOS) were synthesized and characterized as photosensitizers in DSSCs. These GUMBOS and nanoGUMBOS displayed interesting properties such as increased molar absorptivity and broadened absorption spectra, which are important characteristics for photosensitizers used in DSSCs. NanoGUMBOS-based photosensitizers were applied in DSSCs after precise optimization of the DSSCs structure with regard to the semiconductor (working electrode) and electrolyte. In another application, GUMBOS were developed as energy relay dyes (ERDs) in DSSCs due to the tunable properties of GUMBOS such as solubility, molar absorptivity, and fluorescence quantum yield. GUMBOS-based ERDs were applied in DSSCs, and increases in solar conversion efficiencies of up to 14.6% were observed. Interestingly, the magnitude of increase in solar conversion efficiency was found to depend on the counterion used in synthesis of GUMBOS-based ERDs. Finally, porphyrin- and phthalocyanine-based nanoGUMBOS were studied for application as photosensitizers in PDT. By using a facile, ion exchange reaction to form GUMBOS, a bulky cation was introduced to prevent aggregation of porphyrin and phthalocyanine dyes. Overall increases in singlet oxygen production were observed with GUMBOS in comparison to the parent compounds. Singlet oxygen quantum yields of porphyrin and phthalocyanine GUMBOS were 0.57 ± 0.05 and 0.55 ± 0.01 in comparison to yields from the parent dyes, which were 0.50 ± 0.02 and 0.46 ±0.04, respectively. As a whole, these studies demonstrate substantial advantages of GUMBOS-based materials in the field of photonics.

Enhancement of the photokilling effect of TiO2 in photodynamic therapy by conjugating with reduced graphene oxide and its mechanism exploration

Photodynamic Therapy (PDT) has emerged as a highly efficient and non-invasive cancer treatment, which is crucial considering the significant global mortality rates associated with cancer. The effectiveness of PDT primarily relies on the quality of the photosensitizers employed. When exposed to appropriate light irradiation, these photosensitizers absorb energy and transition to an excited state, eventually transferring energy to nearby molecules and generating Reactive Oxygen Species (ROS), including singlet oxygen [1O2]. The ability to absorb light in visible and nearinfrared wavelengths makes porphyrins and derivatives useful photosensitizers for PDT. Chemically, Porphyrins, composed of tetra-pyrrole structures connected by four methylene groups, represent the typical photosensitizers. The limited water solubility and bio-stability of porphyrin photosensitizers and their non-specific tumor-targeting properties hinder PDT effectiveness and clinical applications. Therefore, a wide range of modification and functionalization techniques have been used to maximize PDT efficiency and develop multidimensional porphyrin-based functional materials. Recent progress in porphyrin-based functional materials has been investigated in this review paper, focusing on two main aspects including the development of porphyrinic amphiphiles that improve water solubility and biocompatibility, and the design of porphyrin-based polymers, including block copolymers with covalent bonds and supramolecular polymers with noncovalent bonds, which provide versatile platforms for PDT applications. The development of porphyrin-based functional materials will allow researchers to significantly expand PDT applications for cancer therapy by opening up new opportunities. With these innovations, porphyrins will overcome their limitations and push PDT to the forefront of cancer treatment options.

Carboxymethyl chitosan/ionic liquid imidazolium-based nanoparticles as nanocarriers for zinc phthalocyanine and its photodynamic activity

Interaction of aluminum phthalocyanine with aziridinyl quinone in biomimicking micellar microenvironment for the application in photodynamic therapy: Effect of micellar hydration

Glucose-functionalized amino-OPEs as biocompatible photosensitizers in PDT

Abstract

Synthesis and applications of metal organic frameworks in photodynamic therapy

Highly efficient near-IR cyclohexene cyanine photosensitizers for antibacterial photodynamic therapy

The treatment of glial brain tumors is an unresolved problem in neurooncology, and all existing methods (tumor resection, chemotherapy, radiotherapy, radiosurgery, fluorescence diagnostics, photodynamic therapy, etc.) are directed toward increasing progression-free survival for patients. Fluorescence diagnostics and photodynamic therapy are promising methods for achieving gross total resection and additional treatment of residual parts of the tumor. However, sometimes the use of one photosensitizer for photodynamic therapy does not help, and the time until tumor relapse barely increases. This translational case report describes the preliminary results of the first combined use of 5-ALA and chlorin e6 photosensitizers for fluorescence-guided resection and photodynamic therapy of glioblastoma, which allowed us to perform total resection of tumor tissue according to magnetic resonance and computed tomography images, remove additional tissue with increased fluorescence intensity without neurophysiological consequences, and perform additional therapy. Two months after surgery, no recurrent tumor and no contrast uptake in the tumor bed were detected. Additionally, the patient had ischemic changes in the access zone and along the periphery and cystic-glial changes in the left parietal lobe.

Introduction: Photodynamic therapy (PDT) involves the application of a topical photosensitizer, irradiation with light, and oxygen to produce cytotoxic reactive oxygen species that selectively destroy damaged cells while leaving normal skin intact. Topical PDT is a commonly used treatment for non-melanoma skin cancers (NMSCs) due to its excellent clearance rate and cosmetic outcomes. However, PDT is emerging as an off-label treatment modality for many dermatological conditions.Methods: A literature review using MEDLINE was performed to identify randomized controlled trials conducted for currently approved and off-label clinical indications and photosensitizers for PDT between 2012 and 2018.Results: The photosensitizer indole-3 acetic acid reduces the incubation time (<30 min), avoids the need for photoprotection after irradiation, and inflicts minimal pain. Cyclic PDT in individuals with evidence of field cancerization delays the mean time of actinic keratosis (AK) appearance and reduces the total number of new actinic keratoses. Substantial evidence exists outlining the utility of PDT in photorejuvenation due to its ability to improve skin texture, wrinkles, and firmness. The addition of microdermabrasion, microneedling, curettage, or various lasers improves clinical efficacy and cosmetic outcomes.Discussion: PDT applications are expanding rapidly. Clinicians must stay up to date regarding the efficacy and safety of PDT applications.