Effects of hypericin encapsulated on Pluronic F127 photodynamic therapy against triple negative breast cancer.

OBJECTIVE: Breast cancer (BC) currently has no effective treatment especially for the highly aggressive and metastatic triple negative breast cancer (TNBC). Here, we investigated the antitumoral and antimigratory effects of hypericin (HYP) encapsulated on Pluronic F127 (F127/HYP) photodynamic therapy (PDT) against TNBC cell line MDA-MB-231 compared to a nontumorigenic human breast ductal cell line (MCF-10A). METHODS: The phototoxicity/cytotoxicity was assessed by MTT assay, long-term cytotoxicity by clonogenic assay, cell uptake, subcellular distribution, and cellular oxidative stress by fluorescence microscopy, cell death with annexin V-FITC/propidium iodide, PDT mechanism using sodium azide and D-mannitol, and cell migration by wound-healing assay. RESULTS: The treatment promoted phototoxic effect on tumor cell line in a dose-dependent and selective manner. Internalization of F127/HYP was efficient and accumulation occurred in the endoplasmic reticulum and mitochondria, resulting in cellular oxidative stress mainly by the type II mechanism, induced by necrosis. Furthermore, F127/HYP decreased colony formation and reduced the cell migration ability in MDA-MB-231 cells. CONCLUSION: Our results suggest a potentially useful role of F127/HYP micelles as a platform for HYP delivery to more specifically and effectively treat TNBC.

Mechanisms of hypericin incorporation to explain the photooxidation outcomes in phospholipid biomembrane models.

Cell membranes are the first barriers for drug binding and key for the action of photosensitizers (PS). Herein, we report on the incorporation of the PS hypericin into Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) to represent eukaryotic cell membranes, and 1,2-dioleoyl-sn-glycero-3-phospho(1'-rac-glycerol) (DOPG) to mimic bacterial membranes. Surface pressure (π) vs mean molecular area (Å) isotherms showed a high degree of interaction (binding, penetration and relative solubilization) of hypericin into DPPC and DOPC monolayers. On the other hand, electrostatic repulsions govern the interactions with DOPG and DOPS, favoring hypericin self-aggregation, as visualized by Brewster angle microscopy (BAM). Indeed, the larger domains in BAM were consistent with the greater expansion of DOPG monolayers with incorporated hypericin, owing to stronger electrostatic repulsions. In contrast to DPPC, light-irradiation of DOPC monolayers containing hypericin induced loss of material due to hydrocarbon chain cleavage triggered by contact-dependent reactions between triplet excited state of hypericin and chain unsaturations. The mild effects noted for both irradiated DOPS and DOPG monolayers are attributed to hypericin self-aggregation, which may have decreased the singlet oxygen quantum yield (Φ1O2) via self-quenching, despite the increased instability induced in the monolayers.

Phthalocyanine and Its Formulations: A Promising Photosensitizer for Cervical Cancer Phototherapy.

Cervical cancer is one of the most common causes of cancer-related deaths in women worldwide. Despite advances in current therapies, women with advanced or recurrent disease present poor prognosis. Photodynamic therapy (PDT) has emerged as an effective therapeutic alternative to treat oncological diseases such as cervical cancer. Phthalocyanines (Pcs) are considered good photosensitizers (PS) for PDT, although most of them present high levels of aggregation and are lipophilic. Despite many investigations and encouraging results, Pcs have not been approved as PS for PDT of invasive cervical cancer yet. This review presents an overview on the pathophysiology of cervical cancer and summarizes the most recent developments on the physicochemical properties of Pcs and biological results obtained both in vitro in tumor-bearing mice and in clinical tests reported in the last five years. Current evidence indicates that Pcs have potential as pharmaceutical agents for anti-cervical cancer therapy. The authors firmly believe that Pc-based formulations could emerge as a privileged scaffold for the establishment of lead compounds for PDT against different types of cervical cancer.

Hypericin-P123-photodynamic therapy in an ex vivo model as an alternative treatment approach for onychomycosis caused by Fusarium spp.

BackgroundFusarium has been considered an opportunistic pathogen, causing several infections in humans, including onychomycosis. In addition, a high resistance to conventional antifungals has been linked to this genus. Photodynamic Therapy (PDT), known as a non-invasive therapy, can be an alternative treatment for fungal infections, based on the excitation of a photosensitizing compound (PS) by a specific length of light, causing damage to the target. The aim of this study was to evaluate the effects of a formulation of Hypericin (Hyp) encapsulated in Pluronic™ (P123), via photodynamic therapy (PDT), on planktonic cells and biofilms in Fusarium spp. using in vitro and ex vivo assays. Materials & Methods epidemiology studies about Fusarium spp. in onychomycosis was perfomed, carried out molecular identification, compared the antifungal activity of the conventional antifungals with PDT with encapsulated Hypericin (Hyp-P123), carried out detection of reactive oxygen species, and measured the antibiofilm effect of the Hyp-P123-PDT in vitro and in an ex vivo model of onychomycosis. Results Hyp-P123-PDT exhibited a fungicidal effect in vitro with reductions ≥ 3 log10. ROS generation increased post-Hyp-P123-PDT in Fusarium spp. Hyp-P123-PDT showed a potent inhibitory effect on adhesion-phase and mature biofilms in vitro tests and an ex vivo model of onychomycosis (p<0.0001). Conclusion Hyp-P123-PDT had a potent effect against Fusarium spp., suggesting that photodynamic therapy with Hyp-P123 is a safe and promising treatment for onychomycosis in clinical practice.

A systematic review of photodynamic therapy as an antiviral treatment: Potential guidance for dealing with SARS-CoV-2.

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.

Strain pattern and T-wave alterations are predictors of mortality and poor neurologic outcome following stroke.

BACKGROUND: Stroke is associated with electrocardiogram (ECG) abnormalities. However, the role of strain pattern as predictor of poor neurologic outcome and mortality after stroke has not yet been demonstrated. HYPOTHESIS: ECG abnormalities, with a particular focus on ST-segment changes, are predictors of mortality and neurologic disability 90 days after stroke. METHODS: Patients with up to 24 hours of stroke were prospectively recruited. An ECG was taken at the time of admission. The patients' clinical evolution was evaluated during hospitalization and after discharge by means of a prescheduled return in 90 days. The degree of disability was measured by the modified Rankin scale (mRs). In relation to the mRs, patients were divided into those with scores from 0 to 2 and those with scores equal to or greater than 3 at the end of the observation period. RESULTS: Of the 112 patients studied, 29 (25.8%) died during the study period. Patients who died presented higher National Institute of Health Stroke Scale and mRs scores on admission, elevated biomarkers of myocardial necrosis, and abnormalities on the ECG. The prevalence of ECG abnormalities was 63%. A logistic regression model showed that strain pattern and T-wave alterations were predictors of mortality (odds ratio [OR]: 12.970, 95% confidence interval [CI]: 1.519-110.723, P = .019; OR: 3.873, 95% CI: 1.135-13.215, P = .031, respectively) and mRs at 90 days (OR: 12.557, 95% CI: 1.671-94.374, P = .014; OR: 15.970, 95% CI: 3.671-69.479, P < .001, respectively) after stroke, adjusted by sex, age, stroke subtype, entrance NIH, previous mRs score, and stroke thrombolysis. CONCLUSION: Strain pattern and T-wave alterations were predictors of mortality and poor neurologic outcome 90 days after stroke.

From Protohypericin to Hypericin: Photoconversion Analysis Using a Time-Resolved Thermal Lens Technique.

Hypericin (Hyp) is a natural compound with interesting photophysical and pharmacological properties, which has been used in photodynamic therapy and photodynamic inactivation of microorganisms. Its synthesis is based on a series of chemical processes that ends with a light-drug interaction by the photoconversion of protohypericin (pHyp) to Hyp. Although this photosensitizer is used in a variety of medical applications, the photophysical and photochemical mechanisms involved in the final step related to the photo production of Hyp are not completely understood at the molecular level. Protohypericin concentration, solvents, light irradiation under different wavelengths, and a sort of variables could play an important role in predicting the yielding of this photoconversion process. Here, we used the high-sensitive and remote measurement characteristics of the time-resolved thermal lens technique to investigate the relation between the light-induced photoconversion rate of pHyp to Hyp and the initial concentration pHyp. The results show a linear dependence of the photoreaction rate with the concentration of pHyp, indicating that the overall reaction process includes steps comprising the formation of distinct intermediate species. We demonstrate the applicability of the thermal lens technique for the photochemical characterization of photosensitive drugs at low concentration levels.

Copolymeric micelles as efficient inert nanocarrier for hypericin in the photodynamic inactivation of Candida species.

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.

Hypericin photodynamic activity in DPPC liposome. PART I: biomimetism of loading, location, interactions and thermodynamic properties.

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 < 0 shows that the entropy is driven the process. Studies of Hyp location in the liposome at 298 K revealed the existence of two different Hyp populations with a Stern-Volmer constant (Ksv) of 4.65 and 1.87 L mol-1 using iodide as an aquo-suppressor at concentration ranged from 0 to 0.025 mol L-1 and from 0.025 to 0.150 mol L-1, respectively. Furthermore, studies of Fluorescence Resonance Energy Transfer, using DPH as a donor and Hyp as an acceptor, revealed that Hyp is allocated in different binding sites of the liposome. This is dependent on temperature. Thermal studies revealed that the Hyp/DPPC formulation presented reasonable stability. Size and morphological investigations showed that Hyp incorporation increases the average size of DPPC liposomes from 116 to 154 nm. The study demonstrated the ability of the Hyp-DPPC liposome as an interesting system for drug delivery system that can be applied to PDT.

Synthesis of potentially bioactive PABA-related N-(aminoalkyl)lactamic amino acids and esters via selective S(N)Ar reactions.

Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by S(N)Ar reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition-elimination S(N)Ar mechanism was confirmed by NMR and MS measurements.