A5007458912- Photodynamic Therapy Research Studies
- Nanoplatforms for cancer theranostics
- Porphyrin and Phthalocyanine Chemistry
- Skin Protection and Aging
- Lipid Membrane Structure and Behavior
- Chaos control and synchronization
- Nonlinear Dynamics and Pattern Formation
- Neural dynamics and brain function
- Photochemistry and Electron Transfer Studies
- Quantum chaos and dynamical systems
- stochastic dynamics and bifurcation
- bioluminescence and chemiluminescence research
- Luminescence and Fluorescent Materials
- Analytical Chemistry and Sensors
- Photosynthetic Processes and Mechanisms
- Antioxidant Activity and Oxidative Stress
- Molecular Sensors and Ion Detection
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Autophagy in Disease and Therapy
- Complex Systems and Time Series Analysis
- Laser Applications in Dentistry and Medicine
- Nanoparticle-Based Drug Delivery
- Surfactants and Colloidal Systems
- Free Radicals and Antioxidants
Universidade de São Paulo
2015-2024
University of Aberdeen
2009-2024
Hospital Universitário da Universidade de São Paulo
2011-2023
Universidade Cidade de São Paulo
2009-2022
Instituto Butantan
2006-2017
Pontifícia Universidade Católica de São Paulo
2015
Secretaria da Segurança Pública
2015
IQ Samhällsbyggnad
2014
Universidade do Porto
2007-2010
Universidade Brasil
2010
The new tris-heteroleptic complex [Ru(bpy)(dppn)(CH3CN)2]2+ (3, bpy = 2,2′-bipyridine, dppn benzo[i]dipyrido[3,2-a;2′,3′-c]phenazine) was synthesized and characterized in an effort to generate a molecule capable of both singlet oxygen (1O2) production ligand exchange upon irradiation. Such dual reactivity has the potential be useful for increasing efficacy photochemotherapy drugs by acting via two different mechanisms simultaneously. photochemical properties photoinduced cytotoxicity 3 were...
Although the general mechanisms of lipid oxidation are known, chemical steps through which photosensitizers and light permeabilize membranes still poorly understood. Herein we characterized products photooxidation their effects on bilayers, also giving insight into formation pathways. Our experimental system was designed to allow two phenothiazinium-based (methylene blue, MB, DO15) deliver same amount singlet oxygen molecules per second 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine...
We have employed a combination of steady-state and time-resolved spectroscopic techniques to explore the effect protein binding on photophysical photochemical properties three triarylmethane dyes: ethyl violet, crystal malachite green. Our results indicate that sites bovine serum albumin (BSA) are very efficient in preventing fast nonradiative relaxation processes occur via rotational motion aromatic rings these triarylmethanes. As result, remarkable enhancements fluorescence quantum yield...
Methylene Blue (MB+) is a sensitizer that has been used for variety of applications including energy conversion and photodynamic therapy (PDT). Although its photochemical properties in isotropic solution are well established, effect vivo restricted reaction environments somewhat erratic. In order to understand behavior when it interacts with biomolecules, particular membranes, MB+ were studied sodium dodecyl sulfate (SDS) cetyl trimethylammonium bromide (CTAB) solutions. Because an...
We present the preparation and characterization of methylene blue-containing silica-coated magnetic particles. The entrapment blue (MB), a photodynamic therapy drug under study in our group, silica matrix took place during growth layer over core composed magnetite nanoparticles. resulting material was charaterized by transmission electron microscopy (TEM), light scattering, X-ray diffraction. It is ∼30 nm spheres containing particles 11 ± 2 entrapped matrix. imobilized can generate singlet...
Abstract Methylene Blue (MB) has well‐established photochemical properties and been used in a variety of applications including photodynamic therapy. Despite the fact that most MB's cytotoxic effects cells are attributed to mitochondrial damage, interactions this dye with mitochondria consequent on have not yet fully determined. We monitored MB binding, aggregation its ability release singlet oxygen ( 1 O 2 ) irradiation when interacting suspensions. actively binds enters matrix manner...
We present a study on whether and to what extent subcellular localization may compete favorably with photosensitization efficiency respect the overall of photoinduced cell death. have compared which two cationic photosensitizers, namely methylene blue (MB) crystal violet (CV), induce death human cervical adenocarcinoma (HeLa) cells. Whereas MB is well known generate singlet oxygen related triplet excited species high quantum yields in variety biological chemical environments (i.e., acting as...
The present study is focused on developing a nanoparticle carrier for the photosensitizer protoporphyrin IX use in photodynamic therapy. entrapment of (Pp IX) silica spheres was achieved by modification Pp molecules with an organosilane reagent. immobilized drug preserved its optical properties and capacity to generate singlet oxygen, which detected direct method from characteristic phosphorescence decay curve at near-infrared chemical using 1,3-diphenylisobenzofuran trap oxygen. lifetime...
Breast cancer is the main cause of mortality among women. The disease presents high recurrence mainly due to incomplete efficacy primary treatment in killing all cells. Photodynamic therapy (PDT), an approach that causes tissue destruction by visible light presence a photosensitizer (Ps) and oxygen, appears as promising alternative could be used adjunct chemotherapy surgery for curing cancer. However, PDT treat breast tumours well molecular mechanisms lead cell death remain unclear. In this...
Cells challenged by photosensitized oxidations face strong redox stresses and rely on autophagy to either survive or die. However, the use of macroautophagy/autophagy improve efficiency photosensitizers, in terms inducing cell death, remains unexplored. Here, we addressed concept that a parallel damage membranes mitochondria lysosomes leads scenario malfunction can greatly photosensitizer cause death. Specific these organelles was induced irradiation cells pretreated with 2 phenothiazinium...
Oxidation can intimately influence and structurally compromise the levels of biological self-assembly embodied by intracellular plasma membranes. Lipid peroxidation, a natural metabolic outcome life with oxygen under light, is also salient oxidation reaction in photomedicine treatments. However, effect peroxidation on fate lipid membranes remains elusive. Here we use new photosensitizer that anchors disperses membrane to achieve spatial control oxidizing species. We find, surprisingly,...
Protecting human skin from sun exposure is a complex issue that involves unclear aspects of the interaction between light and tissue. A persistent misconception visible safe for skin, although several lines evidence suggest otherwise. Here, we show can damage melanocytes through melanin photosensitization singlet oxygen (1O2) generation, thus decreasing cell viability, increasing membrane permeability, causing both DNA photo-oxidation necro-apoptotic death. UVA (355 nm) (532 photosensitize...
Abstract Mobilization of specific mechanisms regulated cell death is a promising alternative to treat challenging illness such as neurodegenerative disease and cancer. The use light activate these may provide route for target-specific therapies. Two asymmetric porphyrins with opposite charges, the negatively charged TPPS 2a positively CisDiMPyP were compared in terms their properties membrane mimics cells. interacts larger extent model membranes cells than , due favorable electrostatic...
Structure-activity relationships have been widely reported for porphyrin and phthalocyanine photosensitizers, but not phenothiazinium derivatives. Here, four salts (methylene blue, toluidine blue O, 1,9-dimethyl methylene the pentacyclic derivative DO15) were used to investigate how ability damage membranes is affected by membrane/solution partition, photophysical properties tendency aggregation of photosensitizer. These two latter aspects studied both in isotropic solutions membranes....
The antiproliferative activity of four Ru(II) dyes incorporating the cyclometallated ligand phpy– (deprotonated 2-phenylpyridine) have been tested against HeLa cells. All compounds exhibit cytotoxic similar to that cisplatin. most active compound, [Ru(phpy)(bpy)(dppn)]+ (4; bpy = 2,2′-bipyridine, dppn benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine), is 6 times more than platinum drug, and it able disrupt mitochondria membrane potential. In addition, [Ru(phpy)(biq)2]+ (3; biq 2,2′-biqinoline), with...