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Toluidine blue O (TBO) is a phenothiazine dye that, due to its photochemical characteristics and high affinity for biomembranes, has been revealed as a new photosensitizer (PS) option for antimicrobial photodynamic therapy (PDT). This points to a possible association with membranous organelles like mitochondrion. Therefore, here we investigated its effects on mitochondrial bioenergetic functions both in the dark and under photostimulation. Two experimental systems were utilized: (a) isolated rat liver mitochondria and (b) isolated perfused rat liver. Our data revealed that, independently of photostimulation, TBO presented affinity for mitochondria. Under photostimulation, TBO increased the protein carbonylation and lipid peroxidation levels (up to 109.40 and 119.87%, respectively) and decreased the reduced glutathione levels (59.72%) in mitochondria. TBO also uncoupled oxidative phosphorylation and photoinactivated the respiratory chain complexes I, II, and IV, as well as the F

In this study, we developed a bioadhesive emulsion-filled gel containing a high amount of Copaifera reticulata Ducke oil-resin as a veterinary or human clinical proposal. The phytotherapeutic system had easy preparation, low cost, satisfactory healing ability, and fly repellency, making it a cost-effective clinical strategy for wound care and myiasis prevention. Mechanical, rheological, morphological, and physical stability assessments were performed. The results highlight the crosslinked nature of the gelling agent, with three-dimensional channel networks stabilizing the Copaifera reticulata Ducke oil-resin (CrD-Ore). The emulgel presented antimicrobial activity, satisfactory adhesion, hardness, cohesiveness, and viscosity profiles, ensuring the easy spreading of the formulation. Considering dermatological application, the oscillatory responses showed a viscoelastic performance that ensures emulgel retention at the action site, reducing the dosage frequencies. In Vivo evaluations were performed using a case report to treat ulcerative skin wounds aggravated by myiasis in calves and heifers, which demonstrated healing, anti-inflammatory, and repellent performance for the emulsion-filled gel. The emulgel preparation, which is low in cost, shows promise as a drug for wound therapy.

Multifunctional P123 micelle linked covalently with spermine (SM) and folic acid (FA) was developed as a drug delivery system of hypericin (HYP). The chemical structures of the modified copolymers were confirmed by spectroscopy and spectrophotometric techniques (UV-vis, FTIR, and

Background: Breast cancer is the most relevant type of cancer and the second cause of cancer- related deaths among women in general. Currently, there is no effective treatment for breast cancer although advances in its initial diagnosis and treatment are available. Therefore, the value of novel anti-tumor therapeutic modalities remains an immediate unmet need in clinical practice. Following our previous work regarding the properties of the Pluronics with different photosensitizers (PS) for photodynamic therapy (PDT), in this study we aimed to evaluate the efficacy of supersaturated hypericin (HYP) encapsulated on Pluronic® P123 (HYP/P123) against breast cancer cells (MCF-7) and non-tumorigenic breast cells (MCF-10A). Methods: Cell internalization and subcellular distribution of HYP/P123 was confirmed by fluorescence microscopy. The phototoxicity and citototoxicity of HYP/P123 was assessed by trypan blue exclusion assay in the presence and absence of light. Long-term cytotoxicity was performed by clonogenic assay. Cell migration was determined by the wound-healing assay. Apoptosis and necrosis assays were performed by annexin VFITC/ propidium Iodide (PI) by fluorescence microscopy. Results: Our results showed that HYP/P123 micelles had high stability and high rates of binding to cells, which resulted in the selective internalization in MCF-7, indicating their potential to permeate the membrane of these cells. Moreover, HYP/P123 micelles accumulated in mitochondria and endoplasmic reticulum organelles, resulting in the photodynamic cell death by necrosis. Additionally, HYP/P123 micelles showed effective and selective time- and dose dependent phototoxic effects on MCF-7 cells but little damage to MCF-10A cells. HYP/P123 micelles inhibited the generation of cellular colonies, indicating a possible capability to prevent the recurrence of breast cancer. We also demonstrated that HYP/P123 micelles inhibit the migration of tumor cells, possibly by decreasing their ability to form metastases. Conclusion: Taken together, the results presented here indicate a potentially useful role of HYP/P123 micelles as a platform for HYP delivery to more specifically and effectively treat human breast cancers through photodynamic therapy, suggesting they are worthy for in vivo preclinical evaluations.

Hypericin (Hyp) is considered a promising photosensitizer for Photodynamic Therapy (PDT), due to its high hydrophobicity, affinity for cell membranes, low toxicity and high photooxidation activity. In this study, Hyp photophysical properties and photodynamic activity against melanoma B16-F10 cells were optimized using DPPC liposomes (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) as a drug delivery system. This nanoparticle is used as a cell membrane biomimetic model and solubilizes hydrophobic drugs. Hyp oxygen singlet lifetime (τ) in DPPC was approximately two-fold larger than that in P-123 micelles (Pluronic™ surfactants), reflecting a more hydrophobic environment provided by the DPPC liposome. On the other hand, singlet oxygen quantum yield values (ΦΔ1O2) in DPPC and P-123 were similar; Hyp molecules were preserved as monomers. The Hyp/DPPC liposome aqueous dispersion was stable during fluorescence emission and the liposome diameter remained stable for at least five days at 30 °C. However, the liposomes collapsed after the lyophilization/rehydration process, which was resolved by adding the lyoprotectant Trehalose to the liposome dispersion before lyophilization. Cell viability of the Hyp/DPPC formulation was assessed against healthy HaCat cells and high-metastatic melanoma B16-F10 cells. Hyp incorporated into the DPPC carrier presented a higher selectivity index than the Hyp sample previously solubilized in ethanol under the illumination effect. Moreover, the IC50 was lower for Hyp in DPPC than for Hyp pre-solubilized in ethanol. These results indicate the potential of the formulation of Hyp/DPPC for future biomedical applications in PDT treatment.

Over the past decade, hypericin (Hy) has been used by several researchers due to its broad therapeutic potential against microorganisms and cancer cells. Considering the high hydrophobicity of Hy, ...

A hypericin (HYP) delivery system was developed based on P84 copolymeric micelles linked covalently with N-(3-aminopropyl)-2-pyrrolidone (APP). The higher monomeric amounts of HYP when loaded in di...

In this work, an educational tool to be used in solar energy courses is proposed. It consists of software, named Softsun, with educational purposes, which allows performing some tasks applicable to solar thermal and photovoltaic systems. Among other things, this software allows: obtaining the I–V curve of diode models using data from manufacturers, calculating solar radiation components to use the f-chart or utilizability methods for solar thermal and photovoltaic systems, and dealing with economic aspects. This software was developed within Matlab, being able to simulate several processes with a user-friendly platform. Softsun also has other functions, such as support, theories, conversion units and reports, if required by the user. The main purpose is an educational tool in the area of solar energy, which helps the teaching and learning process commonly used in engineering. Keywords: Education, Learning process, Software, Solar energy and teaching

Considering the multifaceted and increasing application of photodynamic therapy (PDT), in recent years the antimicrobial employment of this therapy has been highlighted, because of the antiviral, antibacterial, antiparasitic, and antifungal activities that have already been demonstrated. In this context, research focussed on antimycological action, especially for treatment of superficial infections, presents promising growth due to the characteristics of these infections that facilitate PDT application as new therapeutic options are needed in the field of medical mycology. Among the more than one hundred classes of photosensitizers the antifungal action of hypericin (Hyp) stands out due to its ability to permeate the lipid membrane and accumulate in different cytoplasmic organelles of eukaryotic cells. In this review, we aim to provide a complete overview of the origin, physicochemical characteristics, and optimal alternative drug deliveries that promote the photodynamic action of Hyp (Hyp-PDT) against fungi. Furthermore, considering the lack of a methodological consensus, we intend to compile the best strategies to guide researchers in the antifungal application of Hyp-PDT. Overall, this review provides a future perspective of new studies and clinical possibilities for the advances of such a technique in the treatment of mycoses in humans.

Biotin, spermine, and folic acid were covalently linked to the F127 copolymer to obtain a new drug delivery system designed for HY-loaded PDT treatment against B16F10 cells. Chemical structures and binders quantification were performed by spectroscopy and spectrophotometric techniques (1NMR, HABA/Avidin reagent, fluorescamine assay). Critical micelle concentration, critical micelle temperature, size, polydispersity, and zeta potential indicate the hydrophobicity of the binders can influence the physicochemical parameters. Spermine-modified micelles showed fewer changes in their physical and chemical parameters than the F127 micelles without modification. Furthermore, zeta potential measurements suggest an increase in the physical stability of these carrier systems. The phototherapeutic potential was demonstrated using hypericin-loaded formulation against B16F10 cells, which shows that the combination of the binders on F127 copolymer micelles enhances the photosensitizer uptake and potentializes the photodynamic activity.

This study presents a phytotherapeutic emulsion-filled gel design composed of Pluronic® F127, Carbopol® C934P, and high level of copaiba oil-resin (PHY-ECO). Mathematical modeling and response surface methodology (RSM) were employed to access the optimal ratio between the oil and the polymer gel-matrix constituents. The chemometric approach showed robust mechanical and thermoresponsive properties for emulsion gel. The model predicts viscosity parameters at 35.0°C (skin temperature) from PHY-ECOs. Optimized PHY-ECOs were described by 18-20% (w/w) F127, 0.25% (w/w) C934P, and 15% (w/w) copaiba oil-resin, and showed interfacial layers properties that led to high physicochemical stability. Besides, it had thermal stimuli-responsive that led large viscosity range before and after skin administration, observed by oscillatory rheology. These behaviors give the optimized smart PHY-ECO high design potential to be used as a pharmaceutical platform for CO delivery, focusing on the anti-inflammatory therapy and skin wound care.

Aim: To evaluate the efficacy of photodynamic inactivation (PDI) mediated by hypericin encapsulated in P-123 copolymeric micelles (P123-Hyp) alone and in combination with fluconazole (FLU) against planktonic cells and biofilm formation of Candida species Materials & methods: PDI was performed using P123-Hyp and an LED device with irradiance of 3.0 mW/cm2 . Results: Most of isolates (70%) were completely inhibited with concentrations up to 2.0 μmol/l of HYP and light fluence of 16.2 J/cm2. FLU-resistant strains had synergic effect with P123-HYP-PDI and FLU. The biofilm formation was inhibited in all species, in additional the changes in Candida morphology observed by scanning electron microscopy. Conclusion: P123-Hyp-PDI is a promising option to treat fungal infections and medical devices to prevent biofilm formation and fungal spread.

Chagas is a parasitic endemic disease caused by the protozoan Trypanosoma cruzi. It represents a strong threat to public health due to its strong resistance against commonly available drugs. We studied the in vitro ability to inactivate the trypomastigote form of this parasite using photodynamic inactivation of microorganisms (or antimicrobial Photodynamic Therapy, aPDT). For this, we chose to use the photosensitizer hypericin (Hyp) formulated in ethanol/water (1% v/v) and Hyp loaded in the dispersion of different aqueous nanocarrier systems. These included polymeric micelles of F-127 and P-123 (both Pluronic™ surfactants), and liposomal vesicles of phospholipid 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). These systems with Hyp had their activity compared against trypomastigote forms under light and in the dark. Hyp revealed a high level of effectiveness to eradicate protozoa in vitro. Samples at concentrations higher than 0.8 μmol L-1 of Hyp in Pluronic micelles showed efficacy even in the dark, with the EC50 around (6-8) μmol L-1. Therefore, Hyp/Pluronics can be used also as a chemotherapeutic agent. The best result for EC50 is at approximately 0.31 μmol L-1 for illuminated systems of Hyp in F-127 micelles. For Hyp in P-123 micelles under light, the results also led to a low EC50 value of 0.36 μmol L-1. The highest value of EC50 was 2.22 μmol L-1, which was found for Hyp/DPPC liposomes under light. For the Hyp-free (ethanol/water, 1% v/v)/illuminated group, the EC50 value was 0.37 μmol L-1, which also is a value that shows effectiveness. However, in free-form, Hyp is not protected against blood components, unlike when Hyp is loaded into the nanocarriers.

Photodynamic Therapy (PDT) is a medical modality that has been applied against several types of cancer, macular degeneration, pointed condyloma, actinic keratosis as well as infections caused by fungi, viruses, and bacteria. When PDT is applied against microorganisms, the technique is called as antimicrobial photodynamic therapy (aPDT). PDT/aPDT principle involves the association of a light source (performed by a LASER, LED, and optical fiber), a non-toxic photosensitizer (PS), and molecular oxygen dissolved in the tissue of interest. The photosensitizer is excited by a light source of a specific wavelength which, in the presence of oxygen, generate high-cytotoxic reactive oxygen species (ROS) as well as superoxide anion (O2·−), hydroxyl radical (HO·), hydrogen peroxide (H2O2) and singlet oxygen (1O2). These species cause damage to tumor cells and vasculatures by apoptosis, necrosis, and activating the immune responses. Among the main advantages of PDT is the specificity. This is guaranteed by the preferential accumulation of the photosensitizer in the cells of interest and the targeting of the lighting system without compromising healthy tissues. Additionally, it is a cheaper and less invasive than most known treatment, such as surgery, chemotherapy, and radiotherapy. Several classes of photosensitizers have been proposed for application in PDT treatment. It is necessary to mention phthalocyanines, porphyrins, bacteriochlorins, chlorines, chlorophyll-based compounds, phenothiazinium salts, and xanthene dyes. Generally, better PS compounds are hydrophobic once they accumulate in the interest tumors most effectively. However, the direct application of these in the body is harmful once PS can precipitate in the body, forming aggregates. Additionally, the pre-solubilization in an organic solvent before the application is not recommended once these are high toxicity in the cell. In this way, strategies have been proposed to solubilize hydrophobic PS in aqueous solutions and increase their biocompatibility. One of the most successful is the incorporation of PS in nanocarrier systems such as liposomes, copolymeric micelles, cyclodextrins, gold nanoparticles, microemulsions, self-assembled peptide-based nanomaterials, and others. Each nanocarrier has this specificity in order of its vantages and advantages. The main objective of this chapter is the description of PDT principles and understands more about formulations that have been used for PDT treatment.

Azure A (AA) is a cationic molecule of the class of phenothiazines that has been applied in vitro as a photosensitising agent in photodynamic antimicrobial chemotherapy. It is a di-demethylated analogue of methylene blue (MB), which has been demonstrated to be intrinsically and photodynamically highly active on mitochondrial bioenergetics. However, as far as we know, there are no studies about the photodynamic effects of AA on mammalian mitochondria. Therefore, this investigation aimed to characterise the intrinsic and photodynamic acute effects of AA (0.5 40 μM) on isolated rat liver mitochondria, isolated hepatocytes, and isolated perfused rat liver. The effects of AA were assessed by evaluating several parameters of mitochondrial bioenergetics, oxidative stress, cell viability, and hepatic energy metabolism. The photodynamic effects of AA were assessed under simulated hypoxic conditions, a suitable way for mimicking the microenvironment of hypoxic solid tumour cells. AA interacted with the mitochondria and, upon photostimulation (10 min of light exposure), produced toxic amounts of reactive oxygen species (ROS), which damaged the organelle, as demonstrated by the high levels of lipid peroxidation and protein carbonylation. The photostimulated AA also depleted the GSH pool, which could compromise the mitochondrial antioxidant defence. Bioenergetically, AA photoinactivated the complexes I, II, and IV of the mitochondrial respiratory chain and the F1FO–ATP synthase complex, sharply inhibiting the oxidative phosphorylation. Upon photostimulation (10 min of light exposure), AA reduced the efficiency of mitochondrial energy transduction and oxidatively damaged lipids in isolated hepatocytes but did not decrease the viability of cells. Despite the useful photobiological properties, AA presented noticeable dark toxicity on mitochondrial bioenergetics, functioning predominantly as an uncoupler of oxidative phosphorylation. This harmful effect of AA was evidenced in isolated hepatocytes, in which AA diminished the cellular ATP content. In this case, the cells exhibited signs of cell viability reduction in the presence of high AA concentrations, but only after a long time of incubation (at least 90 min). The impairments on mitochondrial bioenergetics were also clearly manifested in intact perfused rat liver, in which AA diminished the cellular ATP content and stimulated the oxygen uptake. Consequently, gluconeogenesis and ureogenesis were strongly inhibited, whereas glycogenolysis and glycolysis were stimulated. AA also promoted the release of cytosolic and mitochondrial enzymes into the perfusate concomitantly with inhibition of oxygen consumption. In general, the intrinsic and photodynamic effects of AA were similar to those of MB, but AA caused some distinct effects such as the photoinactivation of the complex IV of the mitochondrial respiratory chain and a diminution of the ATP levels in the liver. It is evident that AA has the potential to be used in mitochondria-targeted photodynamic therapy, even under low oxygen concentrations. However, the fact that AA directly disrupts mitochondrial bioenergetics and affects several hepatic pathways that are linked to ATP metabolism, along with its ability to perturb cellular membranes and its little potential to reduce cell viability, could result in significant adverse effects especially in long-term treatments.

The antifungal application of photodynamic therapy (PDT) has been widely explored. According to superficial nature of tinea capitis and the facility of application of light sources, the use of nanoencapsulated hypericin in P-123 associated with PDT (P123-Hy-PDT) has been a poweful tool to treat this pathology. Thus, the aim of this study was to evaluate the efficiency of P123-Hy-PDT against planktonic cells and in a murine model of dermatophytosis caused by Microsporum canis. In vitro antifungal susceptibility and in vivo efficiency tests were performed, including a skin toxicity assay, analysis of clinical signs by evaluating score, and photoacoustic spectroscopy. In addition, tissue analyses by histopathology and levels of pro-inflammatory cytokines, such as quantitative and qualitative antifungal assays, were employed. The in vitro assays demonstrated antifungal susceptibility with 6.25 and 12.5 μmol/L P123-Hy-PDI; these experiments are the first that have used this treatment of animals. P123-Hyp-mediated PDT showed neither skin nor biochemical alteration in vivo; it was safe for dermatophytosis treatment. Additionally, the treatment revealed rapid improvement in clinical signs at the site of infection after only three treatment sessions, with a clinical score confirmed by photoacoustic spectroscopy. The mycological reduction occurred after six treatment sessions, with a statistically significant decrease compared with untreated infected animals. These findings showed that P123-Hy-PDT restored tissue damage caused by infection, a phenomenon confirmed by histopathological analysis and proinflammatory cytokine levels. Our results reveal for the first time that P123-Hy-PDT is a promising treatment for tinea capitis and tinea corporis caused by M. canis, because it showed rapid clinical improvement and mycological reduction without causing toxicity.

Hypericin (Hyp) is a potential photosensitizer drug for Photodynamic Therapy (PDT). However, the high lipophilicity of Hyp prevents its preparation in water. To overcome the Hyp solubility problem, this study uses the liposomal vesicle of DPPC. Otherwise liposome is also one of the most employed artificial systems that mimetizes cell membranes. Our present focus is the interaction of Hyp into DPPC liposome as biomimetic system. We studied the loading, interaction, and localization of Hyp (2.8 μmol L−1) in DPPC (5.4 mmol L−1) liposomes, as well as the thermodynamic aspects of Hyp-liposomes. The Hyp addition to the DPPC liposome dispersion showed a Encapsulation Efficiency for [Hyp] = 2.8 μmol L−1 in [DPPC] = 5.3 mmol L−1 of 74.3% and 89.3% at 30.0 and 50.0 °C, respectively. The encapsulation profile obeys a pseudo first-order kinetic law, with a rate constant of 1.26 × 10−3 s−1 at 30.0 °C. Also the data suggests this reaction is preceded by an extremely rapid step. A study on the binding of Hyp/DPPC liposomes (Kb), performed at several temperatures, showed results of 4.8 and 18.5 × 103 L mol−1 at 293 and 323 K, respectively. Additionally, a decrease was observed in the ΔG of the Hyp/DPPC interaction (−20.6 and − 26.4 kL mol−1 at 293 and 323 K, respectively). The resulting ΔH > 0 with ΔS

The use of natural extracts in medical treatments has grown in recent years. However, conventional extraction methodologies generate large amounts of toxic residues, which cause severe problems for human health and the environment. For this reason, in this study, the pressurized liquid extraction method was used to obtain chlorophyll-rich spinach extracts applicable for Antimicrobial Photodynamic Therapy, a medical modality aimed at pathological conditions caused by microorganisms. Several conditions were evaluated, with variations in temperature, pressure, and percentage of ethanol in water as solvent. The highest yield was achieved by the combination of 8 MPa pressure, 75 °C, and 80% (v/v) ethanol/water, for which we obtained a yield of 25.3% (w/w). The extraction of kinetic curves fitted Sovova's model. The clean methodology belongs to the green chemistry and has proven to be fast and efficient. The extract obtained has a high potential for the development of phytotherapeutic medicines.

The self-aggregation process and its overcoming remain a barrier for the employment of many molecules as photosensitizers (PS) in photodynamic therapy (PDT). The B-ring isomer co-produced during the synthesis of the Verteporfin[Formula: see text] (A-ring) is an example. Although both isomers possess similar in vitro/in vivo efficiency, the strong and not well-understood self-aggregation process of the B-ring derivative impairs its clinical use. This paper reports the use of theoretical calculus and its correlation with experimental analysis to find the main differences between the A and B-ring isomers. For that purpose, micelles of Pluronic[Formula: see text] P-123 and Sodium Dodecyl Sulfate were chosen as simple membrane models and possible drug delivery system, as in the case of P-123. At physiological pH, the main reason for the high self-aggregation tendency is associated with the higher (22%) molecular volume of the B ring, which increases the van der Waals interactions. However, at mildly acidic conditions, the B ring possesses a shallow dihedral angle between the methyl ester group and the tetrapyrrolic macrocycle that favors the approach of units in the aggregate. These discrepancies directly affect the binding and stability of the isomers in the micelles. However, P-123 micelles were able to readily incorporate and monomerize/stabilize both PS over long periods. NOESY experiments confirmed a deep location of both PS inside P-123 micelles, which justifies their efficiency in preventing the self-aggregation process. These findings may substantiate new studies involving the marginalized B-ring isomers and encourage new development in formulations for their use in PDT.

Emodin reduction to emodin anthrone comprise one of three process steps involved in the hypericin synthesis, a powerful natural photosensitiser found in plants of the genus Hypericum. In this communication, an optimized protocol was established for emodin reduction enabling an efficient multigram preparation of emodin anthrone. A screening of reducing agent (SnCl2·2H2O and HClconc) under different reaction times was employed in micro-scale and monitored by electronic absorption spectroscopy technique. Data showed lower yields of emodin anthrone when some experimental conditions previously described in the literature were reproduce. However, using the optimized protocol for the emodin reduction these yields were overcoming, and a gram-scale supply experiment was reproducible for the preparation of 10 grams of emodin anthrone with excellent yield.

Curcumin (CUR) is a promising natural product in the field of biomedical applications, having a range of pharmacological effects. Despite this, clinical trials have reported poor absorption, low bioavailability, and rapid metabolism, which reduce its effectiveness. In general, these problems are related to the highly hydrophobicity of CUR, a limiting factor not only in its applications but also in its characterization. In fact, the spectroscopic description of CUR in homogeneous/microheterogenous media has a range of controversies, mainly about its self-aggregation process and its pKa determinations. To solve these drawbacks, the present work describes the concise spectroscopic analysis of CUR in different water-ethanol mixtures. The Critical Water Aggregation Percentage (CWAP), i.e., the limit percentage in which monomers are predominant is 50% of water. The Multivariate Analysis that employs the chemometric tools (MASDA) by Q-mode method was efficient in demonstrating that above 75% (water: ethanol v/v) CUR exists predominantly in self-aggregated form. In addition, the molecular modeling conducted in the ORCA 4.2 using the Hartree-Fock method associated with MASDA demonstrated that even at 30% (water: ethanol v/v) CUR dimers are present (∼6%). From these conditions, the complex protolytic equilibria of CUR was evaluated in water-ethanol (30:70 v/v) with or without ionic strength. The pKa determination was also conducted by Multivariate Analysis. The obtained pKa values in the presence or absence of ionic strength control do not differ significantly. The protolytic equilibria can be represented in terms of the principal species: CUR0 ⇌ CUR−1 (enol/enolate), CUR−1 ⇌ CUR−2 (phenol/phenolate) and CUR−2 ⇌ CUR−3 phenol/phenolate). The chemometric also allows to obtain the spectra of the pure species and the molar absorptivity for each one. This set of results is especially important to complement the literature about the basic spectroscopy and physicochemical properties of CUR.

The present study aims to evaluate the photodynamic efficiency of Safranine-O (Sf) in the inactivation of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). Sf cytotoxicity activities were evaluated against L929 fibroblasts, J774A.1 macrophages, and LLCMK2 cells (monkey [Macaca mulatta] kidney epithelial cells) by tetrazolium salt assays (MTT). Photodynamic therapy (PDT) is a therapeutic modality that has shown effectiveness in the inactivation of microorganisms. Sf-mediated photodynamic inactivation of microorganisms (PDIM) was performed at different concentrations of the photosensitizer (PS) with a minimum inhibitory concentration (MIC) of 9.4 μg mL−1 for the two bacteria evaluated and a minimum bactericidal concentration (MBC) of 9.4 μg mL−1 for E. coli and 37.5 μg mL−1 for S. aureus. The bacteria viability was analyzed by flow cytometry through staining with propidium iodide (PI). The population of 10,000 bacteria (E. coli or S. aureus) treated with PDIM showed cell mortality of 21.5% and 30.48%, respectively. The morphological analysis of the pathogens allowed the investigation of cell damage involved with PDIM by scanning electron microscopy (SEM) and transmission (MET). Sf-mediated PDT proved to be efficient with severe photodamage and effective inactivation of Gram negative and Gram-positive bacteria.

Dermatological formulations can enable a more efficient therapy by directly delivering the active ingredient to the action site. Photodynamic therapy is a promising technique to eliminate the microorganism in wounds. The present work aims to obtention a dermatological bioadhesive and stimuli-responsive platform that efficiently solubilizes aluminum phthalocyanine hydroxide (AlPcOH) photosensitizer. A better formulation for dermatological application was obtained after evaluation of the formulation polymeric composition and mechanical characterization. Ex-vivo permeation and complete rheological assays were carried out. The photodynamic potential of AlPcOH was evaluated quantitatively and qualitatively. AlPcOH was shown to be incorporated mostly in monomeric form when subjected to the solid dispersion method. Satisfactory results were achieved for the formulation composed of 0.05, 20, and 0.20 % w/w of AlPcOH, F127 and Carbopol. This formulation was easily administered and presented adequate retention at the application site. Furthermore, the system showed a gelation temperature of 29.1 °C, ensuring the preparation, filling, and administration in the bodýs temperature. The nanostructured thermo-responsive platform promoted AlPcOH skin permeation effects and demonstrated a high capacity to generate reactive oxygen species (ФΔ1O2 for AlPcOH of 0.68 in ethanol). All the information provided in this study supports the potential of the AlPcOH-containing platform designed to treat wounds aggravated by microbial infections. It suggests future in vitro and in vivo applications of the platform developed.

Background The present study aimed to characterize the intrinsic and photodynamic effects of azure B (AB) on mitochondrial bioenergetics, as well as the consequences of its intrinsic effects on hepatic energy metabolism. Methods Two experimental systems were utilized: (a) isolated rat liver mitochondria and (b) isolated perfused rat liver. Results AB interacted with mitochondria regardless of photostimulation, but its binding degree was reduced by mitochondrial energization. Under photostimulation, AB caused lipid peroxidation and protein carbonylation and decreased the content of reduced glutathione (GSH) in mitochondria. AB impaired mitochondrial bioenergetics in at least three distinct ways: (1) uncoupling of oxidative phosphorylation; (2) photoinactivation of complexes I and II; and (3) photoinactivation of the FoF1–ATP synthase complex. Without photostimulation, AB also demonstrated mitochondrial toxicity, which was characterized by the induction of lipid peroxidation, loss of inner mitochondrial membrane integrity, and uncoupling of oxidative phosphorylation. The perfused rat liver experiments showed that mitochondria were one of the major targets of AB, even in intact cells. AB inhibited gluconeogenesis and ureagenesis, two biosynthetic pathways strictly dependent on intramitochondrially generated ATP. Contrariwise, AB stimulated glycogenolysis and glycolysis, which are required compensatory pathways for the inhibited oxidative phosphorylation. Similarly, AB reduced the cellular ATP content and the ATP/ADP and ATP/AMP ratios. Conclusions Although the properties and severe photodynamic effects of AB on rat liver mitochondria might suggest its usefulness in PDT treatment of liver tumors, this possibility should be considered with precaution given the toxic intrinsic effects of AB on mitochondrial bioenergetics and energy-linked hepatic metabolism.

The photodynamic properties of Hypericin (Hyp) may be used as an alternative treatment for malignancies of the lower gastrointestinal tract and for the prevention of surgical-site infection; however, its use in photodynamic therapy has been limited because of its poor hydrosolubility. Therefore, in order to improve its water solubility and its photodynamic effect, Hyp was encapsulated in Pluronic P123 (P123) and the photodynamic effects against intestinal and epidermal bacteria and against two lineages of intestinal colon carcinoma cells were investigated. Two response surface methods (RSM) were used to achieve the best in vitro photodynamic activity against Enterococcus faecalis, Escherichia coli and Staphylococcus aureus: in the first (full 23 RSM), Hyp concentration (HC*), incubation time (IT*) and LED-light time (LT*) were considered as the independent variables and E. faecalis inhibition as the dependent variable. In the second (full 32 RSM), Hyp concentration (HC*) and P123 concentration (CC*) were considered as independent variables and E. faecalis, E. coli and S. aureus inhibition as dependent variables. The optimized experimental conditions achieved were: Hyp concentration=37.5μmol/L; P123 concentration=21.5 μmol/L and 6.3J/cm2, which resulted in 2.86±0.12 and 2.30±0.31CFU log-reductions of E. faecalis and S. aureus. No effect was seen against E. coli. The cytotoxic effects of Hyp/P123 were also investigated for Caco-2 and HT-29 intestinal colon carcinoma cells at Hyp/P123 concentrations of 1, 0.5, 0.25 and 0.1μmol/L for Caco-2 cells and 4, 3, 2 and 1μmol/L for HT-29 cells. The cytotoxic concentrations for 50% (CC50) and 90% (CC90) of Hyp/P123 were 0.443 and 0.870μmol/L for Caco-2 cells and 1.4 and 2.84μmol/L for HT-29 cells. The P123 nanocarrier played a significant role in the permeation of Hyp through the cell membrane leading to significant cell death, and showed itself to be a promising photosensitizer for PDT that could be suitable for the treatment of colonic diseases since it is effective against positive Gram bacteria and intestinal colon carcinoma cells.

According to the literature, methylene blue (MB) is a photosensitizer (PS) with a high affinity for mitochondria. Therefore, several studies have explored this feature to evaluate its photodynamic effects on the mitochondrial apoptotic pathway under normoxic conditions. We are aware only of limited reports regarding MB's photodynamic effects on mitochondrial energy metabolism, especially under hypoxic conditions. Thus, the purposes of this study were to determine the direct and photodynamic acute effects of MB on the energy metabolism of rat liver mitochondria under hypoxic conditions and its direct acute effects on several parameters linked to energy metabolism in the isolated perfused rat liver. MB presented a high affinity for mitochondria, irrespective of photostimulation or proton gradient formation. Upon photostimulation, MB demonstrated high in vitro oxidizing species generation ability. Consequently, MB damaged the mitochondrial macromolecules, as could be evidenced by the elevated levels of lipid peroxidation and protein carbonyls. In addition to generating a pro-oxidant environment, MB also led to a deficient antioxidant defence system, as indicated by the reduced glutathione (GSH) depletion. Bioenergetically, MB caused uncoupling of oxidative phosphorylation and led to photodynamic inactivation of complex I, complex II, and F1FO-ATP synthase complex, thus decreasing mitochondrial ATP generation. Contrary to what is expected for an ideal PS, MB displayed appreciable dark toxicity on mitochondrial energy metabolism. The results indicated that MB acted via at least three mechanisms: direct damage to the inner mitochondrial membrane; uncoupling of oxidative phosphorylation; and inhibition of electron transfer. Confirming the impairment of mitochondrial energy metabolism, MB also strongly inhibited mitochondrial ATP production. In the perfused rat liver, MB stimulated oxygen consumption, decreased the ATP/ADP ratio, inhibited gluconeogenesis and ureogenesis, and stimulated glycogenolysis, glycolysis, and ammoniagenesis, fully corroborating its uncoupling action in intact cells, as well. It can be concluded that even under hypoxic conditions, MB is a PS with potential for photodynamic effect-induced mitochondrial dysfunction. However, MB disrupts the mitochondrial energy metabolism even in the dark, causing energy-linked liver metabolic changes that could be harmful in specific circumstances.

Hypericin (HYP) is an active compound of Hypericum perforatum. Associated with photodynamic therapy (PDT), HYP has shown a broad therapeutic potential against microorganisms and cancer cells. Due to the low water solubility of HYP, its application in the biological medium becomes limited. To solve this limitation, our research group has been used copolymeric micelles to carrier HYP with high efficiency. However, there is no elucidated mechanism for HYP delivery mediated by copolymeric micelles. In this sense, we believed that the study of binding-sites of copolymeric micelles and HYP is the first step to its understanding. For this purpose, in this work, we employed 1D and 2D NMR techniques to investigate the behaviour of HYP-loaded P84 micelles in different concentrations . 1D and 2D NMR analysis revealed that HYP molecules were arrangement in a π-stacked aggregation form with a specific location on the core of P84 micelles.

Hypericin (Hy) compound presents a high photoactivity in photodynamic therapy (PDT), photodiagnosis and theranostics applications. The maintenance of this compound in monomeric form could undermine the potential benefits of its photophysical and photodynamic activity. In this study, we demonstrated that the Hy formulated in a system based on the use of the F127 copolymer and the 1,2-dipalmitoyl-sn-3-glycerol-phosphatidylcholine (DPPC) as micelles, liposomal vesicles and Copolymer-Lipid coated systems, have improved its photophysical properties for many clinical modalities. Based on the results of the triplet state lifetime values (τt), the singlet oxygen quantum yield (ΦΔ1O2), the fluorescence lifetime (τF) and the fluorescence quantum yield (ΦF), all Hy formulations had its photophysical properties described in different models of drug delivery systems (DDS). In addition, the transient spectra profile of those formulations was unaffected by the Hy incorporation process, except for the liposomal system, which demonstrated to be the less stable one by flash photolysis technique. The cytotoxic effects of those formulations were also investigated for CaCo-2 and HaCat cells line. The cytotoxic concentrations for 50% (CC50) were 0.56, 1.05, 1.33 and 4.80 µmol L-1 for Copolymer-Lipid/Hy, DPPC/Hy, F127/Hy and ethanol/Hy for CaCo-2 cells, respectively, and 0.69, 2.02, 1.45 and 1.16 µmol L-1 for Copolymer-Lipid/Hy, DPPC/Hy, F127/Hy and ethanol/Hy for HaCat cells, respectively. The F127 copolymer had a significant role in many photophysical parameters determined for Copolymer-Lipid/Hy coated system. Although all those formulations had shown satisfactory results, Copolymer-Lipid/Hy proved to be superior in many aspects, being the most promising formulation for PDT, photodiagnosis and theranostics applications.

Background SARS-CoV-2, which causes the coronavirus disease (COVID-19), presents high rates of morbidity and mortality around the world. The search to eliminate SARS-CoV-2 is ongoing and urgent. This systematic review seeks to assess whether photodynamic therapy (PDT) could be effective in SARS-CoV-2 inactivation. Methods The focus question was: Can photodynamic therapy be used as potential guidance for dealing with SARS-CoV-2?”. A literature search, according to PRISMA statements, was conducted in the electronic databases PubMed, EMBASE, SCOPUS, Web of Science, LILACS, and Google Scholar. Studies published from January 2004 to June 2020 were analyzed. In vitro and in vivo studies were included that evaluated the effect of PDT mediated by several photosensitizers on RNA and DNA enveloped and non-enveloped viruses. Results From 27 selected manuscripts, 26 publications used in vitro studies, 24 were exclusively in vitro, and two had in vitro/in vivo parts. Only one analyzed publication was exclusively in vivo. Meta-analysis studies were unfeasible due to heterogeneity of the data. The risk of bias was analyzed in all studies. Conclusion The in vitro and in vivo studies selected in this systematic review indicated that PDT is capable of photoinactivating enveloped and non-enveloped DNA and RNA viruses, suggesting that PDT can potentially photoinactivate SARS-CoV-2.

In this work, a chemical data collections is regarding the synthesis, purification and characterization of water-soluble fluorescent probes based on (5)6-carboxyfluorescein (CF)-conjugated with normal and reverse triblock copolymers (F127 and 10R5). Due to the fact that F127 shows low solubility in organic solvents, most studies involve the removal of dicyclohexylurea (side product) using ether solution, resulting in an unclean material for to medicinal applications. In our study, cleaner purification protocols were performed by using dialysis and size-exclusion column chromatography (SEC) in a water medium for obtaining F127-CF and 10R5-CF copolymers with in good yields (80–85%). Proton nuclear magnetic resonance (1H NMR) was employed to confirm the chemical structures of the final products.

At present, cervical cancer is the fourth leading cause of cancer among women worldwide with no effective treatment options. In this study we aimed to evaluate the efficacy of hypericin (HYP) encapsulated on Pluronic® P123 (HYP/P123) photodynamic therapy (PDT) in a comprehensive panel of human cervical cancer-derived cell lines, including HeLa (HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16 and 18-positive), and C33A (HPV-negative), compared to a nontumorigenic human epithelial cell line (HaCaT). Were investigated: (i) cell cytotoxicity and phototoxicity, cellular uptake and subcellular distribution; (ii) cell death pathway and cellular oxidative stress; (iii) migration and invasion. Our results showed that HYP/P123 micelles had effective and selective time- and dose-dependent phototoxic effects on cervical cancer cells but not in HaCaT. Moreover, HYP/P123 micelles accumulated in endoplasmic reticulum, mitochondria and lysosomes, resulting in photodynamic cell death mainly by necrosis. HYP/P123 induced cellular oxidative stress mainly via type II mechanism of PDT and inhibited cancer cell migration and invasion mainly via MMP-2 inhibition. Taken together, our results indicate a potentially useful role of HYP/P123 micelles as a platform for HYP delivery to more specifically and effectively treat cervical cancers through PDT, suggesting they are worthy for in vivo preclinical evaluations.

In line with environmental concerns, in this study we propose a new protocol to perform the photosynthesis of Hypericin (Hyp) from protohypericin (Protohyp) in aqueous medium. The kinetic parameters of the Protohyp-to-Hyp photoconversion were investigated in aqueous nanostructured systems formed by the non-polymeric surfactants SDS, CTAB and TX-100 as well as the P-123, F-127 and P-84 copolymers. In all surfactant systems evaluated it was possible to obtain Hyp from the Protohyp irradiation using a low power light source. The kinetic model of pseudo-first order was used for the theoretical fits of kinetic experimental data. Values of kinetic constants (k) in acetone (6.6 ms−1) and ethanol (7.8 ms−1) were used as references. Highest rate of Protohyp-to-Hyp photoconversion in non-polymeric systems were verified in SDS (k = 21.9 ms−1). As for copolymeric systems, the photoreaction happened more quickly in F-127 (k = 6.7 ms−1). Concomitantly with kinetic studies, investigations were conducted to evaluate the potential of Protohyp in a prodrug strategy aiming for Hyp. The photoconversion process was investigated in situ in a biological environment composed by Caco-2 intestinal colon carcinoma cells incubated with Protohyp (0.5 μmol L−1) formulated in P-123, F-127 and P-84 aqueous copolymeric system. The in vitro assays showed photodynamic activity in all systems evaluated, indicating that Hyp has been formed under suitable conditions to trigger the photosensitization process that results in cell death, without requiring the use of organic solvents.

Different from works described in the literature, which use expansive analytical methods to separation of anthraquinones derivatives (AQs), this communication reported a simple and inexpensive methodology to get them. In this way, the expensive commercial AQs: Chrysophanol, physcione and emodine were extracted from plant material (Rhamnus frangula L.) and isolated by classical column chromatography technique under optimised binary mobile phase gradients (CHCl3 : AcOEt(a), a = 1 to 5%) in excellent yields.