23 results on '"Guimarães, Pedro P. G."'
Search Results
2. Whole bone subcutaneous transplantation as a strategy to study precisely the bone marrow niche
- Author
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Picoli, Caroline C., Martins, Patrícia Rocha, Wong, Xiao Lin Casey, Righi, Thamires, Guimarães, Pedro P. G., Pinto, Mauro C. X., Amorim, Jaime H., Azevedo, Vasco A. C., Pereira, Silma Regina, Kanashiro, Alexandre, Cruz, Fabio Cardoso, Resende, Rodrigo R., Mintz, Akiva, Frenette, Paul S., and Birbrair, Alexander
- Published
- 2023
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3. Tissue-resident glial cells associate with tumoral vasculature and promote cancer progression
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Rocha, Beatriz G. S., Picoli, Caroline C., Gonçalves, Bryan O. P., Silva, Walison N., Costa, Alinne C., Moraes, Michele M., Costa, Pedro A. C., Santos, Gabryella S. P., Almeida, Milla R., Silva, Luciana M., Singh, Youvika, Falchetti, Marcelo, Guardia, Gabriela D. A., Guimarães, Pedro P. G., Russo, Remo C., Resende, Rodrigo R., Pinto, Mauro C. X., Amorim, Jaime H., Azevedo, Vasco A. C., Kanashiro, Alexandre, Nakaya, Helder I., Rocha, Edroaldo L., Galante, Pedro A. F., Mintz, Akiva, Frenette, Paul S., and Birbrair, Alexander
- Published
- 2023
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4. E3 Ubiquitin Ligase Smurf1 Regulates the Inflammatory Response in Macrophages and Attenuates Hepatic Damage during Betacoronavirus Infection.
- Author
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Souza-Costa, Luiz P., Santos, Felipe R. S., Pimenta, Jordane C., Queiroz-Junior, Celso M., Tana, Fernanda L., Teixeira, Danielle C., Couto, Manoela G. G., Oliveira, Natalia F. M., Pereira, Rafaela D., Beltrami, Vinicius A., Costa, Pedro A. C., Lacerda, Larisse S. B., Andrade-Chaves, Josiane T., Guimarães, Pedro P. G., Aguiar, Renato S., Teixeira, Mauro M., Costa, Vivian V., and Franco, Luis H.
- Subjects
RNA regulation ,GENE expression ,PROTEOLYSIS ,ALANINE aminotransferase ,BIOCHEMICAL substrates - Abstract
The E3 ubiquitin ligase Smurf1 catalyzes the ubiquitination and proteasomal degradation of several protein substrates related to inflammatory responses and antiviral signaling. This study investigated the role of Smurf1 in modulating inflammation induced by Betacoronavirus infection. Bone marrow-derived macrophages (BMDMs) from C57BL/6 (wild-type) or Smurf1-deficient (Smurf1
−/− ) mice were infected with MHV-A59 to evaluate the inflammatory response in vitro. Smurf1 was found to be required to downregulate the macrophage production of pro-inflammatory mediators, including TNF, and CXCL1; to control viral release from infected cells; and to increase cell viability. To assess the impact of Smurf 1 in vivo, we evaluated the infection of mice with MHV-A59 through the intranasal route. Smurf1−/− mice infected with a lethal inoculum of MHV-A59 succumbed earlier to infection. Intranasal inoculation with a 10-fold lower dose of MHV-A59 resulted in hematological parameter alterations in Smurf1−/− mice suggestive of exacerbated systemic inflammation. In the lung parenchyma, Smurf1 expression was essential to promote viral clearance, downregulating IFN-β mRNA and controlling the inflammatory profile of macrophages and neutrophils. Conversely, Smurf1 did not affect IFN-β mRNA regulation in the liver, but it was required to increase TNF and iNOS expression in neutrophils and decrease TNF expression in macrophages. In addition, Smurf1−/− mice exhibited augmented liver injuries, accompanied by high serum levels of alanine aminotransferase (ALT). These findings suggest that Smurf1 plays a critical role in regulating the inflammatory response in macrophages and attenuating systemic inflammation during Betacoronavirus infection. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
5. Chemogenetic modulation of sensory neurons reveals their regulating role in melanoma progression
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Costa, Pedro A. C., Silva, Walison N., Prazeres, Pedro H. D. M., Picoli, Caroline C., Guardia, Gabriela D. A., Costa, Alinne C., Oliveira, Mariana A., Guimarães, Pedro P. G., Gonçalves, Ricardo, Pinto, Mauro C. X., Amorim, Jaime H., Azevedo, Vasco A. C., Resende, Rodrigo R., Russo, Remo C., Cunha, Thiago M., Galante, Pedro A. F., Mintz, Akiva, and Birbrair, Alexander
- Published
- 2021
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6. In vivo bone marrow microenvironment siRNA delivery using lipid–polymer nanoparticles for multiple myeloma therapy
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Guimarães, Pedro P. G., primary, Figueroa-Espada, Christian G., additional, Riley, Rachel S., additional, Gong, Ningqiang, additional, Xue, Lulu, additional, Sewastianik, Tomasz, additional, Dennis, Peter S., additional, Loebel, Claudia, additional, Chung, Amanda, additional, Shepherd, Sarah J., additional, Haley, Rebecca M., additional, Hamilton, Alex G., additional, El-Mayta, Rakan, additional, Wang, Karin, additional, Langer, Robert, additional, Anderson, Daniel G., additional, Carrasco, Ruben D., additional, and Mitchell, Michael J., additional
- Published
- 2023
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- View/download PDF
7. Whole bone subcutaneous transplantation as a strategy to study precisely the bone marrow niche
- Author
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Picoli, Caroline C., primary, Martins, Patrícia Rocha, additional, Wong, Xiao Lin Casey, additional, Righi, Thamires, additional, Guimarães, Pedro P. G., additional, Pinto, Mauro C. X., additional, Amorim, Jaime H., additional, Azevedo, Vasco A. C., additional, Pereira, Silma Regina, additional, Kanashiro, Alexandre, additional, Cruz, Fabio Cardoso, additional, Resende, Rodrigo R., additional, Mintz, Akiva, additional, Frenette, Paul S., additional, and Birbrair, Alexander, additional
- Published
- 2022
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- View/download PDF
8. Tissue-resident glial cells associate with tumoral vasculature and promote cancer progression
- Author
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Rocha, Beatriz G. S., primary, Picoli, Caroline C., additional, Gonçalves, Bryan O. P., additional, Silva, Walison N., additional, Costa, Alinne C., additional, Moraes, Michele M., additional, Costa, Pedro A. C., additional, Santos, Gabryella S. P., additional, Almeida, Milla R., additional, Silva, Luciana M., additional, Singh, Youvika, additional, Falchetti, Marcelo, additional, Guardia, Gabriela D. A., additional, Guimarães, Pedro P. G., additional, Russo, Remo C., additional, Resende, Rodrigo R., additional, Pinto, Mauro C. X., additional, Amorim, Jaime H., additional, Azevedo, Vasco A. C., additional, Kanashiro, Alexandre, additional, Nakaya, Helder I., additional, Rocha, Edroaldo L., additional, Galante, Pedro A. F., additional, Mintz, Akiva, additional, Frenette, Paul S., additional, and Birbrair, Alexander, additional
- Published
- 2022
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9. Erlotinib/hydroxypropyl-β-cyclodextrin inclusion complex: characterization and in vitro and in vivo evaluation
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Gontijo, Sávio M. L., Guimarães, Pedro P. G., Viana, Celso T. R., Denadai, Ângelo M. L., Gomes, Alinne D. M., Campos, Paula P., Andrade, Silvia P., Sinisterra, Rubén D., and Cortés, Maria E.
- Published
- 2015
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10. Formulation of Amphotericin B in PEGylated Liposomes for Improved Treatment of Cutaneous Leishmaniasis by Parenteral and Oral Routes
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Ramos, Guilherme S., primary, Vallejos, Virgínia M. R., additional, Borges, Gabriel S. M., additional, Almeida, Raquel M., additional, Alves, Izabela M., additional, Aguiar, Marta M. G., additional, Fernandes, Christian, additional, Guimarães, Pedro P. G., additional, Fujiwara, Ricardo T., additional, Loiseau, Philippe M., additional, Ferreira, Lucas A. M., additional, and Frézard, Frédéric, additional
- Published
- 2022
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11. Strategies to target tumors using nanodelivery systems based on biodegradable polymers, aspects of intellectual property, and market
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Oliveira, Michele F., Guimarães, Pedro P. G., Gomes, Alinne D. M., Suárez, Diego, and Sinisterra, Rubén D.
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- 2013
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12. Nanomaterial Interactions with Human Neutrophils
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Bisso, Paul W., primary, Gaglione, Stephanie, additional, Guimarães, Pedro P. G., additional, Mitchell, Michael J., additional, and Langer, Robert, additional
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- 2018
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13. Polymeric mechanical amplifiers of immune cytokine-mediated apoptosis
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Mitchell, Michael J., primary, Webster, Jamie, additional, Chung, Amanda, additional, Guimarães, Pedro P. G., additional, Khan, Omar F., additional, and Langer, Robert, additional
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- 2017
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14. Materials Science and Engineering: C
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Denadai, Ângelo M. L., Silva, Jeferson G. da, Guimarães, Pedro P. G., Gomes, Leonardo Bertolini S., Mangrich, Antonio S., Rezende, Edivaltrys I. P. de, Daniel, Izabela M. P., Beraldo, Heloísa, and Sinisterra, Rubén D.
- Subjects
Coordination complex ,Hydrophobic precipitate ,Control of size ,Losartan ,Copper ,Stepwise complexation - Abstract
Texto completo: acesso restrito. p. 3916–3922 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-04-29T11:51:20Z No. of bitstreams: 1 1-s2.0-S0928493113003214-main.pdf: 912366 bytes, checksum: 3c5dc5ccd1efea5c05602185d4f5ec2f (MD5) Made available in DSpace on 2014-04-29T11:51:20Z (GMT). No. of bitstreams: 1 1-s2.0-S0928493113003214-main.pdf: 912366 bytes, checksum: 3c5dc5ccd1efea5c05602185d4f5ec2f (MD5) Previous issue date: 2013 Reaction of highly soluble orally active, non-peptide antihypertensive drug losartan with copper(II) leads to the spontaneous formation of a very insoluble 2:1 covalent complex, which self assembles in a hydrophobic supramolecular structure of nanometric dimensions. Thermal analysis showed that Los/Cu(II) complex presents intermediate stability in comparison with its precursors KLos and Cu(OAc)2·H2O. Isothermal titration calorimetry indicated complexation to be a stepwise process, driven by enthalpy and entropy. Zeta potential and DLS measurements showed that it is possible to control the size and charge of nanoprecipitates by adjusting the relative concentration of Los− and Cu(II).
- Published
- 2013
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15. Strategies to target tumors using nanodelivery systems based on biodegradable polymers, aspects of intellectual property, and market
- Author
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Oliveira, Michele F., primary, Guimarães, Pedro P. G., additional, Gomes, Alinne D. M., additional, Suárez, Diego, additional, and Sinisterra, Rubén D., additional
- Published
- 2012
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16. Production and characterization of the lipopeptide with anti-adhesion for oral biofilm on the surface of titanium for dental implants.
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Carvalho FS, Tarabal VS, Livio DF, Cruz LF, Monteiro APF, Parreira AG, Guimarães PPG, Scheuerman K, Chagas RCR, da Silva JA, Gonçalves DB, Granjeiro JM, Sinisterra RD, Segura MEC, and Granjeiro PA
- Subjects
- Humans, Anti-Bacterial Agents pharmacology, Staphylococcus aureus drug effects, Staphylococcus aureus physiology, Bacillus subtilis drug effects, Porphyromonas gingivalis drug effects, Porphyromonas gingivalis physiology, Porphyromonas gingivalis growth & development, Aggregatibacter actinomycetemcomitans drug effects, Surface Properties, Fibroblasts drug effects, Fusobacterium nucleatum drug effects, Cell Survival drug effects, Osteoblasts drug effects, Surface-Active Agents pharmacology, Titanium pharmacology, Titanium chemistry, Biofilms drug effects, Biofilms growth & development, Bacterial Adhesion drug effects, Dental Implants microbiology, Lipopeptides pharmacology, Microbial Sensitivity Tests
- Abstract
Titanium implants are subject to bacterial adhesion and peri-implantitis induction, and biosurfactants bring a new alternative to the fight against infections. This work aimed to produce and characterize the biosurfactant from Bacillus subtilis ATCC 19,659, its anti-adhesion and antimicrobial activity, and cell viability. Anti-adhesion studies were carried out against Streptococcus sanguinis, Staphylococcus aureus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Proteus mirabilis as the minimum inhibitory concentration and the minimum bactericidal concentration. Cell viability was measured against osteoblast and fibroblast cells. The biosurfactant was classified as lipopeptide, with critical micelle concentration at 40 µg mL
- 1 , and made the titanium surface less hydrophobic. The anti-adhesion effect was observed for Staphylococcus aureus and Streptococcus sanguinis with 54% growth inhibition and presented a minimum inhibitory concentration of 15.7 µg mL- 1 for Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans. The lipopeptide had no cytotoxic effect and demonstrated high potential application against bacterial biofilms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2024
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17. Pamidronate, a promising repositioning drug to treat leishmaniasis, displays antileishmanial and immunomodulatory potential.
- Author
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Ribeiro JM, Rodrigues-Alves ML, Oliveira E, Guimarães PPG, Maria Murta Santi A, Teixeira-Carvalho A, Murta SMF, Peruhype-Magalhães V, and Souza-Fagundes EM
- Subjects
- Animals, Drug Repositioning, Humans, Interleukin-10 therapeutic use, Mice, Mice, Inbred BALB C, Pamidronate, Antiprotozoal Agents pharmacology, Antiprotozoal Agents therapeutic use, Leishmania infantum, Leishmaniasis drug therapy, Leishmaniasis, Visceral drug therapy
- Abstract
Visceral leishmaniasis (VL) is an infectious disease caused by Leishmania infantum (L. infantum). Currently, there are no vaccines and/or prophylactic therapies against VL, and the recentpharmacological approaches come from the drug repositioning strategy. Here, we evaluated the anticancer drug pamidronate (PAM) to identify a new therapeutic option for the treatment of human VL. We assessed its in vitro antileishmanial activity against the promastigote and amastigote forms of L. infantum by evaluating cell cytotoxicity. The antileishmanial and immunomodulatory activities were assessed using human peripheral blood leukocytes ex vivo. PAM induced the formation of vacuoles in the cytoplasm of the promastigotes and alterations in the morphology of the kinetoplast and mitochondria in vitro, which indicates anti-promastigote activity. PAM also reduced the number of infected macrophages and intracellular amastigotes in a concentration-dependent manner, with cell viability above 70%. In ex vivo, PAM reduced the internalized forms of L. infantum in the classical monocyte subpopulation. Furthermore, it enhanced IL-12 and decreased IL-10 and TGF-β by monocytes and neutrophils. Increased IFN-γ and TNF levels for CD8
- and CD8+ T lymphocytes and B lymphocytes, respectively, were observed after the treatment with PAM, as well as a reduction in IL-10 by the lymphocyte subpopulations evaluated. Taken together, our results suggest that PAM may be eligible as a potential therapeutic alternative for drug repurposing to treat human visceral leishmaniasis., (Copyright © 2022. Published by Elsevier B.V.)- Published
- 2022
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18. Biotechnological approach to induce human fibroblast apoptosis using superparamagnetic iron oxide nanoparticles.
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Ferraz FS, López JL, Lacerda SMSN, Procópio MS, Figueiredo AFA, Martins EMN, Guimarães PPG, Ladeira LO, Kitten GT, Dias FF, Domingues RZ, and Costa GMJ
- Subjects
- Cancer-Associated Fibroblasts drug effects, Cell Death drug effects, Cell Line, Cell Survival drug effects, Citric Acid chemistry, Endocytosis, Ferric Compounds chemistry, Flow Cytometry, Humans, Hyperthermia, Induced, Magnetic Iron Oxide Nanoparticles chemistry, Microscopy, Electron, Transmission, Neoplasms metabolism, Neoplasms pathology, Apoptosis drug effects, Ferric Compounds pharmacology, Fibroblasts drug effects, Magnetic Iron Oxide Nanoparticles administration & dosage
- Abstract
Cancer-Associated Fibroblasts (CAFs) contribute to tumour progression and have received significant attention as a therapeutic target. These cells produce growth factors, cytokines and chemokines, stimulating cancer cell proliferation and inhibiting their apoptosis. Recent advances in drug delivery have demonstrated a significant promise of iron oxide nanoparticles in clinics as theranostic agents, mainly due to their magnetic properties. Here, we designed superparamagnetic iron oxide nanoparticles (SPIONs) to induce apoptosis of human fibroblasts. SPIONs were synthesized via co-precipitation method and coated with sodium citrate (SPION_Cit). We assessed the intracellular uptake of SPIONs by human fibroblast cells, as well as their cytotoxicity and ability to induce thermal effects under the magnetic field. The efficiency and time of nanoparticle internalization were assessed by Prussian Blue staining, flow cytometry and transmission electron microscopy. SPIONs_Cit were detected in the cytoplasm of human fibroblasts 15 min after in vitro exposure, entering into cells mainly via endocytosis. Analyses through Cell Titer Blue assay, AnnexinV-fluorescein isothiocyanate (FITC) and propidium iodide (PI) cellular staining demonstrated that concentrations below 8 × 10
-2 mg/mL of SPIONs_Cit did not alter cell viability of human fibroblast. Furthermore, it was also demonstrated that SPIONs_Cit associated with alternating current magnetic field were able to induce hyperthermia and human fibroblast cell death in vitro, mainly through apoptosis (83.5%), activating caspase 8 (extrinsic apoptotic via) after a short exposure period. Collectively these findings suggest that our nanoplatform is biocompatible and can be used for therapeutic purposes in human biological systems, such as inducing apoptosis of CAFs., Competing Interests: Declaration of competing interest There is no conflict of interest neither competing interest among the Institutions and the researchers involved in this study., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
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19. Nanoparticles for Immune Cytokine TRAIL-Based Cancer Therapy.
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Guimarães PPG, Gaglione S, Sewastianik T, Carrasco RD, Langer R, and Mitchell MJ
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- Animals, Apoptosis drug effects, Cell Proliferation drug effects, Drug Delivery Systems, Humans, Neoplasms pathology, Particle Size, Surface Properties, TNF-Related Apoptosis-Inducing Ligand chemistry, Nanoparticles chemistry, Neoplasms drug therapy, TNF-Related Apoptosis-Inducing Ligand pharmacology
- Abstract
The immune cytokine tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has received significant attention as a cancer therapeutic due to its ability to selectively trigger cancer cell apoptosis without causing toxicity in vivo. While TRAIL has demonstrated significant promise in preclinical studies in mice as a cancer therapeutic, challenges including poor circulation half-life, inefficient delivery to target sites, and TRAIL resistance have hindered clinical translation. Recent advances in drug delivery, materials science, and nanotechnology are now being exploited to develop next-generation nanoparticle platforms to overcome barriers to TRAIL therapeutic delivery. Here, we review the design and implementation of nanoparticles to enhance TRAIL-based cancer therapy. The platforms we discuss are diverse in their approaches to the delivery problem and provide valuable insight into guiding the design of future nanoparticle-based TRAIL cancer therapeutics to potentially enable future translation into the clinic.
- Published
- 2018
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20. Sub-additive effects of photodynamic therapy combined with erlotinib for the treatment of epidermoid carcinoma: An in vitro study.
- Author
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Gontijo SML, Felizali RC, Guimarães PPG, Santos RAS, Sinisterra RD, Cortés ME, and Araújo PV
- Subjects
- Antineoplastic Agents administration & dosage, Apoptosis drug effects, Apoptosis radiation effects, Cell Line, Tumor, Cell Survival drug effects, Cell Survival radiation effects, Combined Modality Therapy methods, Dose-Response Relationship, Drug, Dose-Response Relationship, Radiation, Humans, Photosensitizing Agents administration & dosage, Radiation Dosage, Treatment Outcome, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell pathology, Chemoradiotherapy methods, Erlotinib Hydrochloride administration & dosage, Photochemotherapy methods
- Abstract
Background: Photodynamic therapy (PDT) is an antitumour treatment that employs the combination of a photosensitive compound, oxygen and visible light. To improve the antitumour activity of PDT, the present study used the strategy of combining PDT with erlotinib (ERL), a drug frequently used in the treatment of epidermoid carcinoma., Methods: An MTT cell viability assay was used to evaluate the cytotoxicity of PDT combined with ERL on A431 epidermoid carcinoma cells in vitro. This study evaluated the cytotoxicity of the following treatments: red laser irradiation (660nm) at different power densities (1.25-180J/cm
2 ), the photosensitizer methylene blue (MB) at concentrations of 0.39-100μM, PDT (12.5μM MB and laser power densities from 1.25 to 180J/cm2 ), and PDT (12.5μM MB and a laser density of 120J/cm2 ) plus ERL (1μM)., Results: The laser power densities that were tested showed no cytotoxicity in A431 cells. MB showed a dose-dependent cytotoxicity. In PDT, an increase in the dose of light resulted in an increase in the cytotoxicity of MB. In addition, there was a sub-additive effect between PDT and ERL compared to the effect of each therapy alone., Conclusions: The sub-additive effect between PDT and ERL suggests that their combination may be an important strategy in the treatment of epidermoid carcinoma., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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21. PLGA nanofibers improves the antitumoral effect of daunorubicin.
- Author
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Guimarães PP, Oliveira MF, Gomes AD, Gontijo SM, Cortés ME, Campos PP, Viana CT, Andrade SP, and Sinisterra RD
- Subjects
- Animals, Cell Line, Cell Line, Tumor, Humans, Male, Mice, Microscopy, Electron, Scanning, Microscopy, Fluorescence, Polylactic Acid-Polyglycolic Acid Copolymer, X-Ray Diffraction, Antibiotics, Antineoplastic pharmacology, Daunorubicin pharmacology, Lactic Acid chemistry, Nanofibers, Polyglycolic Acid chemistry
- Abstract
The objective of this study was to evaluate the in vivo anti-inflammatory angiogenesis activity and in vitro cytotoxicity on normal and cancer cell models of a drug delivery system consisting of poly(lactic-co-glycolic acid) nanofibers loaded with daunorubicin (PLGA-DNR) that were fabricated using an electrospinning process. The PLGA-DNR nanofibers were also characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and confocal fluorescence microscopy. In vitro release of DNR from the nanofibers and its corresponding mechanism were also evaluated. Sixty-five percent of the DNR was released in an initial burst over 8h, and by 1224 h, eighty-five percent of the DNR had been released. The Higuchi model yielded the best fit to the DNR release profile over the first 8h, and the corresponding data from 24 to 1224 h could be modeled using zero-order kinetics. The PLGA-DNR nanofibers exhibited a higher cytotoxicity to A431 cells than free DNR but a cytotoxicity similar to free DNR against fibroblast cells. A higher antiangiogenic effect of PLGA nanofibers was observed in the in vivo data when compared to free DNR, and no inflammatory potential was observed for the nanofibers., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
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22. Structural and thermodynamic characterization of doxycycline/β-cyclodextrin supramolecular complex and its bacterial membrane interactions.
- Author
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Suárez DF, Consuegra J, Trajano VC, Gontijo SM, Guimarães PP, Cortés ME, Denadai ÂL, and Sinisterra RD
- Subjects
- Animals, Calorimetry, Cell Death drug effects, Cell Proliferation drug effects, Differential Thermal Analysis, Hydrodynamics, Light, Magnetic Resonance Spectroscopy, Microbial Sensitivity Tests, Osteoblasts cytology, Osteoblasts drug effects, Osteoblasts metabolism, Proton Magnetic Resonance Spectroscopy, Rats, Wistar, Scattering, Radiation, Spectroscopy, Fourier Transform Infrared, Staphylococcus aureus drug effects, Static Electricity, Thermodynamics, Thermogravimetry, Cell Membrane drug effects, Doxycycline chemistry, Doxycycline pharmacology, Staphylococcus aureus cytology, beta-Cyclodextrins chemistry, beta-Cyclodextrins pharmacology
- Abstract
Doxycycline is a semi-synthetic antibiotic commonly used for the treatment of many aerobic and anaerobic bacteria. It inhibits the activity of matrix metalloproteinases (MMPs) and affects cell proliferation. In this study, the structural and thermodynamic parameters of free DOX and a DOX/βCD complex were investigated, as well as their interactions and effects on Staphylococcus aureus cells and cellular cytotoxicity. Complexation of DOX and βCD was confirmed to be an enthalpy- and entropy-driven process, and a low equilibrium constant was obtained. Treatment of S. aureus with higher concentrations of DOX or DOX/βCD resulted in an exponential decrease in S. aureus cell size, as well as a gradual neutralization of zeta potential. These thermodynamic profiles suggest that ion-pairing and hydrogen bonding interactions occur between DOX and the membrane of S. aureus. In addition, the adhesion of βCD to the cell membrane via hydrogen bonding is hypothesized to mediate a synergistic effect which accounts for the higher activity of DOX/βCD against S. aureus compared to pure DOX. Lower cytotoxicity and induction of osteoblast proliferation was also associated with DOX/βCD compared with free DOX. These promising findings demonstrate the potential for DOX/βCD to mediate antimicrobial activity at lower concentrations, and provides a strategy for the development of other antimicrobial formulations., (Copyright © 2014. Published by Elsevier B.V.)
- Published
- 2014
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23. Control of size in losartan/copper(II) coordination complex hydrophobic precipitate.
- Author
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Denadai ÂM, Da Silva JG, Guimarães PP, Gomes LB, Mangrich AS, de Rezende EI, Daniel IM, Beraldo H, and Sinisterra RD
- Subjects
- Calorimetry, Differential Scanning, Electron Spin Resonance Spectroscopy, Kinetics, Light, Nonlinear Dynamics, Regression Analysis, Scattering, Radiation, Solubility, Solutions, Static Electricity, Thermodynamics, Thermogravimetry, Titrimetry, Water chemistry, Chemical Precipitation, Coordination Complexes chemistry, Copper chemistry, Hydrophobic and Hydrophilic Interactions, Losartan chemistry, Particle Size
- Abstract
Reaction of highly soluble orally active, non-peptide antihypertensive drug losartan with copper(II) leads to the spontaneous formation of a very insoluble 2:1 covalent complex, which self assembles in a hydrophobic supramolecular structure of nanometric dimensions. Thermal analysis showed that Los/Cu(II) complex presents intermediate stability in comparison with its precursors KLos and Cu(OAc)2·H2O. Isothermal titration calorimetry indicated complexation to be a stepwise process, driven by enthalpy and entropy. Zeta potential and DLS measurements showed that it is possible to control the size and charge of nanoprecipitates by adjusting the relative concentration of Los(-) and Cu(II)., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
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