Nanocarriers have been successfully used to solubilize, deliver, and increase the bioavailability of curcumin (CUR), but slow CUR release rates hinder its use as a topical photosensitizer in antimicrobial photodynamic therapy. A... more
Nanocarriers have been successfully used to solubilize, deliver, and increase the bioavailability of curcumin (CUR), but slow CUR release rates hinder its use as a topical photosensitizer in antimicrobial photodynamic therapy. A photo-responsive polymer (PRP) was designed for the light-triggered release of CUR with an effective light activation-dependent antimicrobial response. The characterization of the PRP was compared with non-responsive micelles comprising Pluronics™ P123 and F127. According to the findings, the PRP formed photo-responsive micelles in the nanometric scale (< 100 nm) with a lower critical micelle concentration (3.74 × 10−4 M−1, 5.8 × 10−4 M−1, and 7.2 × 10−6 M−1 for PRP, F127, P123, respectively, at 25°C) and higher entrapment efficiency of CUR (88.7, 77.2, and 72.3% for PRP, F127, and P123 micelles, respectively) than the pluronics evaluated. The PRP provided enhanced protection of CUR compared to P123 micelles, as demonstrated in fluorescence quenching stud...
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Abstract B6 vitamers are important natural compounds for human life, principally for amino acid metabolism, and have been reported as potent scavenger molecules of both endogenous and exogenous reactive oxygen species (ROS). However,... more
Abstract B6 vitamers are important natural compounds for human life, principally for amino acid metabolism, and have been reported as potent scavenger molecules of both endogenous and exogenous reactive oxygen species (ROS). However, under UV-light excitation from UVC (200–280 nm) to UVA (315–400 nm), B6 vitamers act as endogenous photosensitizers that promote both cellular photodamage and enzyme inactivation. This occurs through classical photochemical mechanisms mediated by ROS, toxic photoproducts, and the formation of adducts with active protein sites. This minireview aimed to present and discuss the dual roles of B6 vitamers as generators and scavengers of singlet oxygen (an important reactive species in photodynamic processes) and various other ROS. We also examine the basic photophysical, photochemical, and protolytic equilibria principles of B6 vitamers and their role as photodamaging and photoprotecting compounds in UV-light mediated photobiological processes.
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Abstract Highly colloidal luminescent nanoparticles (NPs) 5 at% Er3+, 20 at% Yb3+:KY3F10 were prepared by EDTA assisted hydrothermal method. Spherical and monodispersed Er3+, Yb3+:KY3F10 nanoparticles with highly pure cubic phase exhibit... more
Abstract Highly colloidal luminescent nanoparticles (NPs) 5 at% Er3+, 20 at% Yb3+:KY3F10 were prepared by EDTA assisted hydrothermal method. Spherical and monodispersed Er3+, Yb3+:KY3F10 nanoparticles with highly pure cubic phase exhibit attractive optical properties for their use in long-term biological studies because of the high chemical photo-stability and strong emissions in the visible and near infrared (NIR) regions. The luminescence spectra of Er3+, Yb3+:KY3F10 as dried powder and dispersed in physiologic medium show intense green upconversion emission transition in between 510 and 570 nm (2H11/2→4I15/2 and 4S3/2→4I15/2) and red upconversion emission transition in between 635 and 680 nm (4F9/2→4I15/2) under NIR light excitation (980 nm). The cellular nontoxicity of as-prepared Er3+, Yb3+ codoped KY3F10 to glioblastoma multiforme (GBM) cells, were reported for the first time to our knowledge. This nanomaterial shows potential use for theranostic applications in early detection of brain cancer, acting as biomarkers in the visible and NIR ranges, and as drug activators for some photobiological response as a coadjuvant therapy for cancer treatment, such as photodynamic therapy (PDT).
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Important features are linked to the concept of antimicrobial photodynamic therapy (APDT). One approach is the need of effective strategies to overcome bacterial resistance to antibiotics. In this context, APDT has emerged as a valuable... more
Important features are linked to the concept of antimicrobial photodynamic therapy (APDT). One approach is the need of effective strategies to overcome bacterial resistance to antibiotics. In this context, APDT has emerged as a valuable method, once cellular death is mediated by the production of reactive oxygen or nitrogen species (ROS or RNS), so it is very unlikely that resistant microorganisms may be selected. Another approach regards to photobiomodulation on wound healing for, simultaneously, antibacterial and remodeling tissue effects, as severe wounds are normally compromised by infection. APDT with appropriate photoactive nanodrugs specially designed for this purpose may contribute to both the wound regenerative process of the skin and at the same time protects and eradicates bacterial infections, accelerating the healing process with less or no side effects. Several issues are involved on APDT, among the design and choice of the nanostructured photosensitizer and how to certificate that it will penetrate the cellular cytoplasm or specific cellular organelles in the target tissue. For instance, Gram-positive bacteria are sensitive to APDT with a wide range of porphyrins and phthalocyanine compounds used as nanoencapsulated photosensitizers. On the other hand, Gram-negative have considerable resistance to the APDT process, as their external membrane may act as a barrier for permeability of the drug, besides being negatively charged. New efforts to overcome this barrier are under study with good results in the eradication of microorganisms, such as bacteria, fungi, viruses, and protozoa, by photoinactivation. Therefore, the selection of an ideal nanomaterial as drug delivery system is crucial to understand and develop more efficient APDT protocols based on the mechanisms of the antimicrobial inactivation.
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The task of chemical process development in the pharmaceutical industry has grown into a multidisciplinary endeavor requiring years to complete. Increased competition in the pharmaceutical Additionally, the ever-tightening regulatory... more
The task of chemical process development in the pharmaceutical industry has grown into a multidisciplinary endeavor requiring years to complete. Increased competition in the pharmaceutical Additionally, the ever-tightening regulatory environment further compromises the business objective (ultimately, profits). This has required careful analysis of the activities within development. This work discusses the results of this analysis, which shows how a balance between minimal resource utilization and phased development achievements can be reached. The cycle of development, from inception to completion, is examined. Special emphasis is placed upon the role of chemical engineering and its appropriate deployment. Simple examples of the synergies that are possible between chemistry and chemical engineering are also given.
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Among several optical non-contact thermometry methods, luminescence thermometry is the most versatile approach. Lanthanide-based luminescence nanothermometers may exploit not only downshifting, but also upconversion (UC) mechanisms.... more
Among several optical non-contact thermometry methods, luminescence thermometry is the most versatile approach. Lanthanide-based luminescence nanothermometers may exploit not only downshifting, but also upconversion (UC) mechanisms. UC-based nanothermometers are interesting for biological applications: they efficiently convert near-infrared radiation to visible light, allowing local temperatures to be determined through spectroscopic investigation. Here, we have synthesized highly crystalline Er3+, Yb3+ co-doped upconverting KGd3F10 nanoparticles (NPs) by the EDTA-assisted hydrothermal method. We characterized the structure and morphology of the obtained NPs by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and dynamic light scattering. Nonlinear spectroscopic studies with the Er3+, Yb3+: KGd3F10 powder showed intense green and red emissions under excitation at 980 and 1,550 nm. Two- and three-photon processes were attributed to the UC mechanisms under exci...
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... Emilia CD Lima from Instituto de Química, Universidade de Goiás, Goiânia ... Excess water was absorbed with tissue paper, and the stratum corneum was removed from the diffusion surface by 15 tape strippings (Scotch 3 M). The... more
... Emilia CD Lima from Instituto de Química, Universidade de Goiás, Goiânia ... Excess water was absorbed with tissue paper, and the stratum corneum was removed from the diffusion surface by 15 tape strippings (Scotch 3 M). The tape-strips were placed in 10 ml of DMSO in a ...
Research Interests: Mechanical Engineering, Condensed Matter Physics, Materials Science, Chemistry, Drug Delivery System, and 13 morePhotodynamic Therapy, Biocompatibility, In Vitro, Magnetism, Skin Cancer, Solvent Extraction, Zinc, Magnetism and Magnetic Materials, In Vitro Studies, Drug Release, Stratum Corneum, Photosensitizer, and Magnetic Fluid
Research Interests: Pharmacology, Chemistry, Organic Chemistry, Nanoparticles, Medicine, and 15 moreSafety, Mice, Animals, Biodistribution, In Vivo, Antifungal Agents, PLGA, Materials Testing, Drug Carriers, Lactic Acid, Paracoccidioides, paracoccidioidomycosis, Pharmacology and pharmaceutical sciences, succimer, and Drug combinations
The coexistence of superparamagnetism, interacting superparamagnetism and giant diamagnetism is evidenced from the magnetic behavior of selol-loaded PLGA magnetic nanocapsules.
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In this work, we performed the synthesis and characterization of a new class of drug delivery system denominated magnetic nanoemulsion (MNE), which allows the combined action of photodynamic therapy (PDT) and hyperthermia therapy (HPT),... more
In this work, we performed the synthesis and characterization of a new class of drug delivery system denominated magnetic nanoemulsion (MNE), which allows the combined action of photodynamic therapy (PDT) and hyperthermia therapy (HPT), designed to work in a synergic way, leading to an expected enhancement of the tumor damage after minimum doses of heat dissipation and/or visible light photosensitization
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Abstract This article presents a complete review of phthalocyanine compounds, ranging from the basic synthesis and design of new molecules to biological applications, covering three of the most popular areas of study: (1) photodynamic... more
Abstract This article presents a complete review of phthalocyanine compounds, ranging from the basic synthesis and design of new molecules to biological applications, covering three of the most popular areas of study: (1) photodynamic therapy (PDT) for cancer treatment, (2) nanobiotechnology and magnetohyperthermia, and (3) photodiagnosis (theranostics). All of the results summarized in this study demonstrate the potential to develop new molecules for new applications in the basic and applied sciences, including pharmaceutical and medical applications. More than thousands of products in the market use phthalocyanine dyes in a broad range of applications. The required level of purity and the challenges in the scaling up of production are the most limiting drawbacks for these proposed applications.
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Pluronic/lipid mix promises stealth liposomes with long circulation time and long-term stability for pharmaceutical applications. However, the influence of Pluronics on several aspects of lipid membranes has not been fully elucidated.... more
Pluronic/lipid mix promises stealth liposomes with long circulation time and long-term stability for pharmaceutical applications. However, the influence of Pluronics on several aspects of lipid membranes has not been fully elucidated. Herein it was described the effect of Pluronics on the structured water, alkyl chain conformation, and kinetic stability of dimyristoylphosphatidylcholine (DMPC) liposomes using interfacial and deeper fluorescent probes along with computational molecular modeling data. Interfacial water changed as a function of Pluronics' hydrophobicity with polypropylene oxide (PPO) anchoring the copolymers in the lipid bilayer. Pluronics with more than 30-40 PO units had facilitated penetration at the bilayer while shorter PPO favored a more interfacial interaction. Low Pluronic concentrations provided long-term stability of vesicles by steric effects of polyethylene oxide (PEO), but high amounts destabilized the vesicles as a sum of water-bridge cleavage at the polar head group and the reduced alkyl-alkyl interactions among the lipids. The high kinetic stability of Pluronic/DMPC vesicles is a proof-of-concept of its advantages and applicability in nanotechnology over conventional liposome-based pharmaceutical products for future biomedical applications.
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Aim: To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods: The study was performed in a split-mouth,... more
Aim: To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods: The study was performed in a split-mouth, randomized and double-blinded model with 20 patients with 40 erosive lesions. The patient’s teeth were randomized into two groups (n=20) according to the surface treatment: 1) Without biomodification (control), and 2) Biomodification with NanoCsQ solution (experimental). The lesions were restored with adhesive (Tetric N-bond, Ivoclar) and composite resin (IPS Empress Direct, Ivoclar). The restorations were polished and 7 days (baseline), 6 months, and 12 months later were evaluated according to the United States Public Health Service (USPHS) modified criteria, using clinical exam and photographics. Data were analyzed by Friedman’s and Wilcoxon signed-rank tests. Results: No significant differences were found between the control and experimental group...
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Parkinson's disease (PD) is a progressive and chronic neurodegenerative disease of the central nervous system. Early treatment for PD is efficient; however, long-term systemic medication commonly leads to deleterious side-effects.... more
Parkinson's disease (PD) is a progressive and chronic neurodegenerative disease of the central nervous system. Early treatment for PD is efficient; however, long-term systemic medication commonly leads to deleterious side-effects. Strategies that enable more selective drug delivery to the brain using smaller dosages, while crossing the complex brain-blood barrier (BBB), are highly desirable to ensure treatment efficacy and decrease/avoid unwanted outcomes. Our goal was to design and test the neurotherapeutic potential of a forefront nanoparticle-based technology composed of albumin/PLGA nanosystems loaded with dopamine (ALNP-DA) in 6-OHDA PD mice model. ALNP-DA effectively crossed the BBB, replenishing dopamine at the nigrostriatal pathway, resulting in significant motor symptom improvement when compared to Lesioned and L-DOPA groups. Notably, ALNP-DA (20 mg/animal dose) additionally up-regulated and restored motor coordination, balance, and sensorimotor performance to non-lesio...
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In this paper, we introduce a new drug delivery system (DDS) called magneto low-density nanoemulsion (MLDE), which can carry maghemite nanoparticles and Chlorin e6 as an active photosensitizer drug. This design can enhance tumor damage... more
In this paper, we introduce a new drug delivery system (DDS) called magneto low-density nanoemulsion (MLDE), which can carry maghemite nanoparticles and Chlorin e6 as an active photosensitizer drug. This design can enhance tumor damage after minor heat dissipation and/or minimum visible light photosensitization doses by classical magnetic hyperthermia (MHT) and photodynamic therapy (PDT), respectively. We establish protocols to prepare the MLDE and to load the drug combination onto it. The MLDE prepared herein is nanometric (<200 nm), has high encapsulation efficiency, and is stable for at least 12 months in water dispersions. Flow cytometry results demonstrated that MLDE presents targeted selectivity toward the MCF-7 breast cancer cell line but not in NHI-3T3 mouse fibroblast cell lines, because the MCF-7 cancer cell surface contains overexpressed low density lipoprotein (LDL) receptors. Despite this targeted effect, MHT or PDT alone does not prompt significant antiproliferative...
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Neste trabalho investigou-se a atividade fotodinâmica de octaetilporfirina (OEP), octaetilporfirina de vanadil (VOOEP) e meso-tetramesitilporfirina (m-TMP). Este estudo foi realizado através da determinação da constante da velocidade de... more
Neste trabalho investigou-se a atividade fotodinâmica de octaetilporfirina (OEP), octaetilporfirina de vanadil (VOOEP) e meso-tetramesitilporfirina (m-TMP). Este estudo foi realizado através da determinação da constante da velocidade de fotoxidação (k f) do aminoácido triptofano (Trp). A participação do oxigênio singlete nesta fotoxidação foi determinada através da adição de azida de sódio e água deuterada no meio de reação. Os valores de k f/10-4s-1 para a fotoxidação de Trp demonstraram que OEP (2,80 ± 0.05) é mais eficiente do que m-TMP (1,62 ± 0,07) e VOOEP (0,81 ± 0,08). Os valores de k f foram menores na presença de azida de sódio e maiores na presença de água deuterada, sugerindo que o oxigênio singlete é o responsável pela atividade fotodinâmica de OEP, VOOEP e m-TMP. Estes resultados sugerem também que as diferenças na atividade fotodinâmica entre as porfirinas podem ser associadas com as diferenças na estrutura molecular das mesmas. A presença do grupo vanadil (V=O) interf...
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Research Interests: Biology, Cell Biology, Mitochondria, Apoptosis, Medicine, and 14 morePhotodynamic Therapy, Cell line, Humans, Cell Death, Programmed cell death, Clinical Sciences, Photochemotherapy, Organometallic Compounds, Acridine Orange, Cardiolipin, DNA fragmentation, Mitochondrion, Laser surgery, and coloring agents
Photodynamic therapy (PDT) is a therapeutic modality for the treatment of tumors. This technique uses a visible light to activate a photosensitizer compounds, leading to a photo-oxidation process of biological tissue that can induce... more
Photodynamic therapy (PDT) is a therapeutic modality for the treatment of tumors. This technique uses a visible light to activate a photosensitizer compounds, leading to a photo-oxidation process of biological tissue that can induce apoptosis or necrosis both in vivo and in vitro. However many of the cytotoxic effects remain an open question to be investigated. The cytotoxicity to specific cellular targets of classical photosensitizers used in the PDT in vitro has been analyzed in this work. The photosensitizing effects of Chloroaluminum Phthalocyanine Tetrasulfonate (AlPcS(4)) were studied on the mitochondria, cytoskeleton and endoplasmic reticulum of HeLa cells. The cells were irradiated with a diode laser (working at 670 nm; energy density of 4.5 J/cm(2 )and power density of 45 mW/cm(2)). The spectrofluorimetric analysis of the mitochondria showed changes in membrane potential. Cytoskeleton and endoplasmic reticulum showed basic alterations in distribution after PDT treatment, as an indicator of cellular death process.