Photodynamic Therapy Directed to Melanoma Skin Cancer by Thermosensitive Hydrogel Containing Chlorophyll A.

Melanoma, a severe form of skin cancer intricately linked to genetic and environmental factors, is predicted to reach 100,000 new cases worldwide by 2040, underscoring the need for effective and safe treatment options. In this study, we assessed the efficacy of a photosensitizer called Chlorophyll A (Chl-A) incorporated into hydrogels (HGs) made of chitosan (CS) and poloxamer 407 (P407) for Photodynamic Therapy (PDT) against the murine melanoma cell line B16-F10. The HG was evaluated through various tests, including rheological studies, SEM, and ATR-FTIR, along with cell viability assays. The CS- and P407-based HGs effectively released Chl-A and possessed the necessary properties for topical application. The photodynamic activity of the HG containing Chl-A was evaluated in vitro, demonstrating high therapeutic potential, with an IC50 of 25.99 µM-an appealing result when compared to studies in the literature reporting an IC50 of 173.8 µM for cisplatin, used as a positive control drug. The developed formulation of CS and P407-based HG, serving as a thermosensitive system for topical applications, successfully controlled the release of Chl-A. In vitro cell studies associated with PDT exhibited potential against the melanoma cell line.

Effect of low-level light therapy before radiotherapy in oral squamous cell carcinoma: An in vitro study.

Radiation therapy for head and neck squamous cell carcinoma (HNSCC) is associated with several complications. Although photobiomodulation (PBM) has radioprotective effects in normal tissue, it could also enhance the growth of neoplastic cells. Thus, the present study aimed to investigate the cellular response of oral squamous cell carcinoma with pre-exposure to low-level phototherapy before radiotherapy. SCC9, Cal-27, A431, and HaCaT cell lines were subjected to low-level light therapy and radiotherapy. The cells were treated with a single energy density (300 J/cm2) of a light-emitting diode (660 nm) prior to ionizing radiation at different doses (0, 2, 4, and 6 Gy). After 24 h, wound scratch, proliferation, clonogenic cell survival, cell death, and reactive oxygen species (ROS) analyses were performed to evaluate cell response. The cell lines pre-exposed to PBM at the analyzed dosage were radiosensitive. The treatment significantly reduced cell proliferation and clonogenic cell survival. Migration and cell death assays also revealed positive results, with the treatment group showing lower rate of migration and higher cell death than did the control group. Moreover, PBM effectively increased the intracellular levels of ROS. PBM at 300 J/cm2 is a promising radiosensitizing modality to reduce the radiation dose and avoid the intolerable side effects of radiotherapy for HNSCC, thus increasing the probability of successful treatment. However, further studies are needed to support and confirm the results.

Protective role of intergenerational paternal resistance training on fibrosis, inflammatory profile, and redox status in the adipose tissue of rat offspring fed with a high-fat diet.

AIMS: We evaluated the role of intergenerational paternal exercise on fibrosis, inflammatory profile, and redox status in the adipose tissue of male rat offspring fed with high-fat diet (HFD) and explored to what extent programming affects the systemic metabolic profile. MAIN METHODS: Adult wistar rats were randomly divided into two groups: sedentary fathers and trained fathers (8 weeks of resistance training (RT), three times per week). The offspring were obtained by mating with sedentary females. Upon weaning, male offspring were divided into four groups (7 animals per group): offspring of sedentary fathers exposed to either a control diet (SFO-C) or a high-fat diet (SFO-HF); offspring of trained fathers exposed to a control diet (TFO-C) or a high-fat diet (TFO-HF). KEY FINDINGS: Paternal RT was effective in attenuating body weight gain, adipocyte size, collagen deposition, as well as downregulating genes (CTGF, VEGF, C/EBPα SREBP1, MCP-1, and NF-kB), pro-inflammatory cytokine levels (Tumor Necrosis Factor alpha and Interleukin-1-beta), matrix metalloproteinase -2 activity, and ROS production in the epididymal adipose tissue of offspring fed with HFD (TFO-HF vs. SFO-HF; P < 0.05). Moreover, paternal RT increased adiponectin and superoxide dismutase (SOD) activity in the tissue. These beneficial effects were accompanied by the increase of antioxidant enzymes (SOD and α-Klotho), while decreasing pro-oxidant agents (F2-isoprostanes, protein carbonyls levels), and metabolic markers (insulin and leptin, HOMA-ß, and HOMA-IR) in the offspring blood circulation. SIGNIFICANCE: Our findings reveal protective effects of intergenerational paternal RT on adipose tissue remodeling and metabolic health of offspring fed with HFD.

AlPc/ZnPc-based oncological photodynamic therapy for a selective eradication of leukemic cells from ovarian tissue.

Due to the risk of reintroducing malignant cells, autotransplantation of cryopreserved ovarian tissue is not allowed in leukemia patients. In order to restore fertility in these patients, ex vivo purging of ovarian fragments could be proposed as a strategy to eradicate malignant cells before grafting. Photodynamic therapy (PDT), as a clinical-approved modality, is a minimally invasive and selective therapeutic for eliminating malignant cells. The present work aims therefore to evaluate the phototoxicity of two photosensitizers (aluminum phthalocyanine (AlPc) and zinc phthalocyanine (ZnPc)) on leukemia cells. To this end, two lines of malignant cells (K562 and HL-60) and isolated ovarian stromal cells (control) were treated by PDT using a diode laser with various energy densities. Cell viability after the treatment, the amount of generated reactive oxygen species, dark toxicity of the photosensitizers, and single-cell morphology were studied. Our results demonstrated that using irradiation with the energy density of 10 J/cm2, 1 µM AlPc could significantly reduce the viability of K562 (4.73 ± 0.14%) and HL-60 (2.74 ± 0.31%). Similarly, the viability of these cells was reduced (K562 cells: 3.84 ± 0.81%; HL-60 cells: 6.82 ± 3.21%) with 1 µM ZnPc and an energy density of 50 J/cm2. On the other hand, these PDT protocols had no significant effect on stromal cells. These findings indicate that our approach can be a promising strategy for the safe restoration of fertility in leukemia patients. However, further studies are necessary to assess its efficiency in ovarian fragments containing malignant cells to determine their eradication rate and the effect of our treatment on the survival of stromal cells and preantral follicles.

Characterization of the Cicatrization Process in Diabetic Foot Ulcers Based on the Production of Reactive Oxygen Species.

The present study aims at evaluating the correlation between the free radical formation and the healing action of lower limbs' ulcers in a randomized controlled trial with the use of an adhesive derived from natural latex associated with a light-emitting diode (LED) circuit. The sample consists of 15 participants with lower limb lesions divided into three groups: group 1 case (5 participants) received the proposed dressing system adhesive of the natural latex associated with the LED circuit; group 2 control (5 participants) received the dressings at home performed by nurses according to and established by the clinic of wounds (treated with calcium alginate or silver foam); and group 3 (5 participants) also received the dressing in their homes with the use of the dressing adhesive derived from the natural latex associated with the LED circuit. The collected data were analyzed qualitatively and quantitatively by electron paramagnetic resonance for determination of free radical formation. Kruskal-Wallis statistical test was used to evaluate the effect of treatment on the lower limb's ulcer cicatrization process and its correlation with free radical. The results obtained corroborated the hypothesis about the reduction of the quantity of these molecules in the end of treatment related to the healing wound.

Humic acid attenuation of silver nanoparticle toxicity by ion complexation and the formation of a Ag3+ coating.

The use of silver nanoparticles (AgNPs) result in an inevitable contact with aquatic environments. Here we study the behavior of AgNPs and the developmental toxicity in zebrafish embryos exposed to these nanoparticles (0-10 mg/L) with and without the presence of HA (20 mg/L), using zebrafish facility water (ZFW) and zebrafish growing media (ZGM). The presence of cations and HA gave rise to a decrease in Ag ion release and ζ-potential, an increase in the hydrodynamic diameter and oxidation of the AgNP surface. The results show that the presence of HA and cations in the media, as well as the silver speciation, i.e., the unusual presence of Ag3+, decreases the toxicity of AgNPs (LC50AgNPs: 1.19 mg/L; LC50AgNPs + HA: 3.56 mg/L), as well as silver bioavailability and toxicity in zebrafish embryos. Developmental alterations and the LC50 (1.19 mg/L) of AgNPs in ZFW were more relevant (p ≤ 0.05) than for AgNPs in ZGM (LC50 ˃ 10 mg/L). It was demonstrated that the bioaccumulation and toxicity of AgNPs depends on several factors including AgNPs concentration, nanoparticle aggregation, dissolved silver ions, speciation of silver ions, the amount of salt in the environment, the presence of humic substances and others, and different combinations of all of these factors.

Nanographene oxide-methylene blue as phototherapies platform for breast tumor ablation and metastasis prevention in a syngeneic orthotopic murine model.

BACKGROUND: In the photodynamic therapy (PDT), the photosensitizer absorbs light and transfers the energy of the excited state to the oxygen in the cell environment producing reactive oxygen species (ROS), that in its turn, may cause cell damage. In the photothermal therapy (PTT), light also is responsible for activating the photothermal agent, which converts the absorbed energy in heat. Graphene oxide is a carbon-based material that presents photothermal activity. Its physical properties allow the association with the photosensitizer methylene blue and consequently the production of ROS when submitted to light irradiation. Therefore, the association between nanographene oxide and methylene blue could represent a strategy to enhance therapeutic actions. In this work, we report the nanographene oxide-methylene blue platform (NanoGO-MB) used to promote tumor ablation in combination with photodynamic and photothermal therapies against a syngeneic orthotopic murine breast cancer model. RESULTS: In vitro, NanoGO-MB presented 50% of the reactive oxygen species production compared to the free MB after LED light irradiation, and a temperature increase of ~ 40 °C followed by laser irradiation. On cells, the ROS production by the nanoplatform displayed higher values in tumor than normal cells. In vivo assays demonstrated a synergistic effect obtained by the combined PDT/PTT therapies using NanoGO-MB, which promoted complete tumor ablation in 5/5 animals. Up to 30 days after the last treatment, there was no tumor regrowth compared with only PDT or PTT groups, which displayed tumoral bioluminescence 63-fold higher than the combined treatment group. Histological studies confirmed that the combined therapies were able to prevent tumor regrowth and liver, lung and spleen metastasis. In addition, low systemic toxicity was observed in pathologic examinations of liver, spleen, lungs, and kidneys. CONCLUSIONS: The treatment with combined PDT/PTT therapies using NanoGO-MB induced more toxicity on breast carcinoma cells than on normal cells. In vivo, the combined therapies promoted complete tumor ablation and metastasis prevention while only PDT or PTT were unable to stop tumor development. The results show the potential of NanoGO-MB in combination with the phototherapies in the treatment of the breast cancer and metastasis prevention.

The cytotoxic activity of miltefosine against Leishmania and macrophages is associated with dynamic changes in plasma membrane proteins.

In this study, we combined electron paramagnetic resonance (EPR) spectroscopy with an analysis of biophysical cellular parameters to study the mechanisms underlying the in vitro anti-leishmanial activity of miltefosine (MT). A thiol-specific spin label attached to membrane-bound proteins of Leishmania amazonensis and peritoneal macrophages indicated that MT may bind to plasma membrane proteins in large quantities via a detergent-like action and cause structural changes associated with a marked increase in dynamics and exposure to an aqueous environment. EPR spectra of a spin-labeled stearic acid indicated strong interactions between the probe and membrane proteins and a marked increase in the membrane fluidity of MT-treated cells. The cytotoxicity of MT was found to depend on the cell concentration used in the assay. This dependence was described by an equation involving the 50% inhibitory concentrations of MT in the aqueous medium (cw50) and the cell membrane (cm50) and the membrane-aqueous medium partition coefficient of MT (K). With a cw50 of 8.7µM, macrophages were less sensitive to MT than amastigotes and promastigotes of Leishmania, which had cw50 values of 2.4-3.1µM. The estimated cm50 of MT for Leishmania was 1.8M, which appears sufficient to cause ruptures or formation of pores in the plasma membrane. Additionally, we demonstrated that the changes in the plasma membrane detected by EPR spectroscopy occurred at cytotoxic concentrations of MT, as assessed through in vitro assays.