Vanessa Carla Furtado Mosqueira - Academia.edu (original) (raw)
Papers by Vanessa Carla Furtado Mosqueira
Pesquisa Veterinaria Brasileira, Apr 1, 2018
Relationship between virulence factor genes in coagulase-negative Staphylococcus spp. and failure... more Relationship between virulence factor genes in coagulase-negative Staphylococcus spp. and failure of antimicrobial treatment of subclinical mastitis in sheep.
Journal of Chromatography A, Mar 1, 2021
Fluorescent probes are used in drug nanocarrier pre-clinical studies or as active compounds in th... more Fluorescent probes are used in drug nanocarrier pre-clinical studies or as active compounds in theranostics and photodynamic therapy. In the biological medium, nanoparticles interact with proteins, which can result in the off-target release of their cargo. The present study used asymmetric flow field-flow fractionation with online multi-angle laser light scattering and fluorescence detection (AF4-MALLS-FLD) to study the release, transfer, and partition of fluorescent dyes from polymeric nanoparticles (NP). NP formulations containing the dyes Rose Bengal, Rhodamine B, DiI, 3-(α-azidoacetyl)coumarin and its polymer conjugate, Nile Red, and IR780 and its polymer conjugate were prepared. NP suspensions were incubated in a medium with serum proteins and then analyzed by AF4. AF4 allowed efficient separation of proteins (< 10 nm) from fluorescently labeled NP (range of 54 - 180 nm in diameters). The AF4 analyses showed that some dyes, such as Rose Bengal, IR780, and Coumarin were transferred to a high extent (68-77%) from NP to proteins. By contrast, for DiI and dye-polymer conjugates, transfer occured to a lower extent. The studies of dye release kinetics showed that the transfer of IR780 from NP to proteins occurs at a high extent (~50%) and rate, while Nile Red was slowly released from the NP over time with reduced association with proteins (~20%). This experiment assesses the stability of fluorescence labeling of nanocarriers and probes the transfer of fluorescent dyes from NP to proteins, which is otherwise not accessible with commonly used techniques of separation, such as dialysis and ultrafiltration/centrifugation employed in drug encapsulation and release studies of nanocarriers. Determining the interaction and transfer of dyes to proteins is of utmost importance in the pre-clinical evaluation of drug nanocarriers for improved correlation between in vitro and in vivo studies.
Pharmaceutics, Apr 2, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biomedicine & Pharmacotherapy, 2022
IR780 is a near-infrared fluorescent dye, which can be applied as a photosensitizer in photodynam... more IR780 is a near-infrared fluorescent dye, which can be applied as a photosensitizer in photodynamic (PDT) and photothermal (PTT) therapies and as a biodistribution tracer in imaging techniques. We investigated the growth and migration inhibition and mechanism of death of breast tumor cells, MCF-7 and MDA-MB-231, exposed to polymeric nanocapsules (NC) comprising IR780 covalently linked to the biodegradable polymer PLA (IR-PLA) and IR780 physically encapsulated (IR780-NC) in vitro. Both types of NC had mean diameters around 120 nm and zeta potentials around -40 mV. IR-PLA-NC was less cytotoxic than IR780 NC to a non-tumorigenic mammary epithelial cell line, MCF-10A, which is an important aspect of selectivity. Free-IR780 was more cytotoxic than IR-PLA-NC for MCF-7 and MDA-MB-231 cells after illumination with a 808 nm laser. IR-PLA NC was effective to inhibit colony formation (50%) and migration (30-40%) for both cancer cell lines. MDA-MB-231 cells were less sensitive to all IR780 formulations compared to MCF-7 cells. Cell uptake was higher with IR-PLA-NC than with IR780-NC and free-IR780 in both cancer cell lines (p < 0.05). NC uptake was higher in MCF-7 than in MDA-MB-231 cells. IR-PLA-NC induced a higher percentage of apoptosis upon illumination in MDA-MB-231 than in MCF-7 cells. The necrosis mechanism of death predominated in treatments with free-IR780 and with encapsulated IR780 NC, suggestive of damages at the plasma membrane. IR780 conjugated with PLA increased the apoptotic pathway and demonstrated potential as a multifunctional theranostic agent for breast cancer treatment with increased cellular uptake, photodynamic activity and more reliable tracking in cell-image studies.
Drug Delivery and Translational Research, Jul 1, 2020
Near-infrared fluorescent dyes, such as IR780, are promising theranostics, acting as photosensiti... more Near-infrared fluorescent dyes, such as IR780, are promising theranostics, acting as photosensitizers for photodynamic therapy and in vivo tracers in image-guided diagnosis. This work compared the uptake by macrophage-like cells of IR780 either physically associated or covalently attached to poly(D,L-lactide) (PLA) formulated as polymeric nanocapsules (NC) from a blend of PLA homopolymer and PLA-PEG block copolymer. The physicochemical characterization of both NC was conducted using asymmetric flow field-flow fractionation (AF4) analysis with static and dynamic light scattering and atomic force microscopy. The interaction of IR780 with serum proteins was evidenced by AF4 with fluorescence detection and flow cytometry in cell uptake studies. The average diameters of NC were around 120 nm and zeta potentials close to-40 mV for all NC. NC uptake by cells in different media and experimental conditions shows significantly lower fluorescence intensities for IR780 covalently linked to PLA and correspondingly low quantitative uptake. Different mechanisms of internalization were evidenced depending on the IR780 type of association to NC. Serum proteins mediate IR780 interaction with cells in a dose-dependent manner. Our results show that non-covalently linked IR780 was released from NC and accumulated in macrophage cells. Oppositely, IR780 conjugated to PLA provides stable association with NC, and its fluorescence is representative of cell uptake of the nanocarrier itself. This work strongly reinforces the importance of covalent attachment of a fluorescence dye such as IR780 to the nanocarrier to study their interaction with cells in vitro and to obtain reliable tracking in image-guided therapy.
European Journal of Pharmaceutical Sciences, Mar 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Photochemistry and Photobiology B-biology, May 1, 2000
The poor selectivity of photosensitizers for tumor tissue remains a drawback in photodynamic ther... more The poor selectivity of photosensitizers for tumor tissue remains a drawback in photodynamic therapy (PDT) and could be improved by adapted formulations. The cellular uptake, localization and phototoxicity of meta-tetra(hydroxyphenyl)chlorin (mTHPC) encapsulated in submicronic colloidal carriers have been studied in macrophage-like J774 cells and HT 29 human adenocarcinoma cells. Nanocapsules with an external layer made of poly(D,L lactic acid) (PLA NCs), PLA grafted with polyethylene glycol (PLA-PEG NCs), PLA coated with poloxamer 188 (polox PLA NCs) and oil/water nanoemulsion (NE) have been examined. The cellular uptake by J774, as determined by microspectroflorimetry, is reduced with mTHPC encapsulated into surface-modified NCs-PLA-PEG and polox PLA-compared with naked PLA, indicating a possible limitation of the clearance of such carriers by the reticuloendothelial system. Encapsulation also modifies the interaction between mTHPC and HT29 cells. Compared with the manufacturer's solution (PEG, ethanol, water), the cellular uptake is strongly reduced. However, the HT29 phototoxicity is much less affected and a protecting effect against plasma proteins is observed. Fluorescence microscopy reveals a specific punctate fluorescence pattern with PLA-PEG and polox PLA NCs in contrast to a more diffuse distribution with NE and solution, indicating that photodamage targeting could be different. These findings suggest that photosensitizers encapsulated into surface-modified nanocapsules could be a promising approach for improving PDT efficacy and this has to be confirmed in vivo.
Advanced Drug Delivery Reviews, Mar 1, 2010
Despite the fact that we live in an era of advanced technology and innovation, infectious disease... more Despite the fact that we live in an era of advanced technology and innovation, infectious diseases, like malaria, continue to be one of the greatest health challenges worldwide. The main drawbacks of conventional malaria chemotherapy are the development of multiple drug resistance and the non-specific targeting to intracellular parasites, resulting in high dose requirements and subsequent intolerable toxicity. Nanosized carriers have been receiving special attention with the aim of minimizing the side effects of drug therapy, such as poor bioavailability and the selectivity of drugs. Several nanosized delivery systems have already proved their effectiveness in animal models for the treatment and prophylaxis of malaria. A number of strategies to deliver antimalarials using nanocarriers and the mechanisms that facilitate their targeting to Plasmodium spp.-infected cells are discussed in this review. Taking into account the peculiarities of malaria parasites, the focus is placed particularly on lipid-based (e.g., liposomes, solid lipid nanoparticles and nano and microemulsions) and polymer-based nanocarriers (nanocapsules and nanospheres). This review emphasizes the main requirements for developing new nanotechnology-based carriers as a promising choice in malaria treatment, especially in the case of severe cerebral malaria.
European Polymer Journal, May 1, 2017
A versatile and simple strategy is presented to synthesize reactive polylactide derivatives and t... more A versatile and simple strategy is presented to synthesize reactive polylactide derivatives and their block copolymers with polyethylene glycol. Commercially available glycidyl ethers with an allyl, benzyl or propargyl functional group were copolymerised with D,L-lactide. Tin(II)-2ethylhexanoate-catalysis produced polymers with up to 4.6, 5.9 and 2.3 allyl, benzyl or propargyl groups per chain, respectively. In contrast, less than one reactive group per chain was obtained with the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene. By increasing the polymerisation feed ratio in glycidyl ether polymers with a higher number of reactive groups per chain were obtained, however a decrease in molar mass was observed. An azidocoumarin was conjugated to the propargylated polymers via copper-catalysed azide-alkyne cycloaddition. These dye-labelled polymers produced nanospheres with fluorescent properties and diameters in the 100-nm sizerange, as characterised by asymmetric flow field flow fractionation hyphenated with fluorescence, static and dynamic light scattering detection. The functionalised polymers were obtained at gram-scale in one step from commercially available reagents; therefore providing a robust and easy to implement approach for the production of multifunctional nanomaterials.
International Journal of Nanomedicine, May 1, 2017
Self-emulsifying drug delivery systems (SEDDSs) are lipid-based anhydrous formulations composed o... more Self-emulsifying drug delivery systems (SEDDSs) are lipid-based anhydrous formulations composed of an isotropic mixture of oil, surfactant, and cosurfactants usually presented in gelatin capsules. Ravuconazole (Biopharmaceutics Classification System [BCS] Class II) is a poorly water-soluble drug, and a SEDDS type IIIA was designed to deliver it in a predissolved state, improving dissolution in gastrointestinal fluids. After emulsification, the droplets had mean hydrodynamic diameters ,250 nm, zeta potential values in the range of-45 mV to-57 mV, and showed no signs of ravuconazole precipitation. Asymmetric flow field-flow fractionation with dynamic and multiangle laser light scattering was used to characterize these formulations in terms of size distribution and homogeneity. The fractograms obtained at 37°C showed a polydisperse profile for all blank and ravuconazole-SEDDS formulations but no large aggregates. SEDDS increased ravuconazole in vitro dissolution extent and rate (20%) compared to free drug (3%) in 6 h. The in vivo toxicity of blank SEDDS comprising Labrasol ® surfactant in different concentrations and preliminary safety tests in repeated-dose oral administration (20 days) showed a dose-dependent Labrasol toxicity in healthy mice. Ravuconazole-SEDDS at low surfactant content (10%, v/v) in Trypanosoma cruzi-infected mice was safe during the 20-day treatment. The anti-T. cruzi activity of free ravuconazole, ravuconazole-SEDDS and each excipient were evaluated in vitro at equivalent ravuconazole concentrations needed to inhibit 50% or 90% (IC 50 and IC 90), respectively of the intracellular amastigote form of the parasite in a cardiomyocyte cell line. The results showed a clear improvement of the ravuconazole anti-T. cruzi activity when associated with SEDDS. Based on our results, the repurposing of ravuconazole in SEDDS dosage form is a strategy that deserves further in vivo investigation in preclinical studies for the treatment of human T. cruzi infections.
Expert Opinion on Investigational Drugs, May 26, 2014
A century after its discovery, American trypanosomiasis or Chagas disease remains a serious healt... more A century after its discovery, American trypanosomiasis or Chagas disease remains a serious health problem in Latin America, where it affects around 7 - 8 million people. The prevalence of Chagas disease in the poorer parts of the world has meant that it has largely been neglected with limited progress that made in identifying new drugs for the treatment. The nitroheterocyclic drugs nifurtimox and benznidazole are first-line drugs available for Chagas disease with limitations that include variable efficacy, long treatment courses and toxicity. This review focuses on different therapeutic strategies that have been used for the discovery of new treatments for Chagas disease. These include combination chemotherapy, drug repositioning, re-dosing regimens for current drugs and the identification of new drugs with specified target profiles. There are currently several reasons for a more optimistic view about chemotherapy with Chagas disease. However, despite some progress being made in preclinical studies, there is yet to be an ideal drug or formulation for human treatment. One major drawback in the evaluation of potential Chagas disease therapeutics is the lack of tools available to perform the said evaluation. Indeed, there is a great need to discover a better biomarker that could determine the efficacy of potential chemotherapeutics in treated patients.
Visceral leishmaniasis (VL)is a fatal disease caused by the protozoa Leishmania infantum for whic... more Visceral leishmaniasis (VL)is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, [poly (D, L-lactic) acid (PLA) polymer] loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.
Archives of Cardiovascular Diseases Supplements, Apr 1, 2017
Veterinary and Animal Science, Jun 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Vaccines, Oct 31, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
European Journal of Pharmaceutical Sciences, Nov 1, 2018
The interaction of polymer nanocapsules (NC) prepared from four biodegradable polyesters with var... more The interaction of polymer nanocapsules (NC) prepared from four biodegradable polyesters with variable polymer hydrophobicity (PCL, PLA, PLGA and PLA-PEG) was investigated in the non-phagocytic Vero, Caco-2 and HepG2 cell lines. The NC, labeled with the highly lipophilic fluorescent indocarbocyanine dye DIL, had very similar sizes (approx. 140 nm) and negative zeta-potentials. Asymmetric flow field-flow fractionation evidenced NC colloidal stability and negligible transfer of the dye to serum proteins in the incubation medium. The cytotoxicity of the NC was evaluated via MTT assay over a large polymer concentration range (0-1000 µg/mL) and time of exposure (2, 24 and 48 h). The NC were safe in vitro up to a concentration of approx. 100 µg/mL or higher, depending on the cell line and nature of the polymer. Vero cells were more sensitive to the NC, in particular NC of the more hydrophobic polymer. The cells were exposed to endocytosis inhibitors, incubated with NC, and the cellassociated fluorescence was quantified by spectrofluorometry. HepG2 cells presented a 1.5-2fold higher endocytic capacity than Caco-2 and Vero cells. The main mechanism of NC uptake was caveolin-mediated endocytosis in HepG2 and Vero cells, and macropinocytosis in Caco-2 cells. Polymer hydrophobicity had an effect on the level of NC associated to HepG2 cells and to a lesser extent on the endocytosis mechanisms in Vero and Caco-2 cells. The NC uptake levels and endocytosis mechanisms differed significantly between cell lines tested.
Revista Brasileira De Ciencias Farmaceuticas, 2007
Experimental Parasitology
International Journal of Pharmaceutics, Apr 1, 2023
Biomedicine & Pharmacotherapy, Mar 1, 2018
BACKGROUND Candida spp is an etiologic agent of fungal infections in hospitals and resistance to ... more BACKGROUND Candida spp is an etiologic agent of fungal infections in hospitals and resistance to treatment with antifungals has been extensively reported. Thus, it is very important to develop formulations that increase effectiveness with low toxicity. In this sense, nanocarriers have been investigated, once they modify drug biodistribution profile. Thus, this study aimed to evaluate the biodistribution of free and encapsulated 99mTc-fluconazole into nanocapsules (NCs) in an experimental immunosuppressed murine model of Candida albicans infection. METHODS Fluconazole was radiolabeled with technetium-99 metastable (99mTc) and encapsulated into conventional (99mTc-Fluconazole-PLA-POLOX) and surface-modified (99mTc-Fluconazole-PLA-PEG) NCs by the interfacial deposition of the preformed biodegradable polymer [poly (D,L-lactic acid) (PLA) and PLA-PEG (polyethyleneglycol)] followed by solvent evaporation. The size distribution and zeta potential of the NCs preparations were determined in a Zetasizer by photon correlation spectroscopy and laser Doppler anemometry, respectively. Free and encapsulated 99mTc-fluconazole were administered intravenously in immunosuppressed mice bearing a local infection induced by Candida Albicans inoculation in the right thigh muscle. At pre-established time intervals, tissues and organs of interest were removed and radioactivity was measured in an automatic gamma radiation counter. RESULTS The NCs diameter was between 200 and 400 nm with negative zeta potential values. Free 99mTc-fluconazole was more rapidly eliminated by the renal system compared to the encapsulated drug in NCs, which remained longer in blood circulation. The uptake of conventional NCs by mononuclear phagocyte system organs was higher than the one demonstrated by the surface-modified NCs. Both NCs remained longer in the infectious focus when compared to free 99mTc-fluconazole, but the results did not show a significant difference between NC formulations. CONCLUSION These data indicate that these NCs might represent a therapeutic alternative for the treatment of candidiasis, once they remain more time in the infectious focus, allowing high retention of 99mTc-fluconazole at this site.
Pesquisa Veterinaria Brasileira, Apr 1, 2018
Relationship between virulence factor genes in coagulase-negative Staphylococcus spp. and failure... more Relationship between virulence factor genes in coagulase-negative Staphylococcus spp. and failure of antimicrobial treatment of subclinical mastitis in sheep.
Journal of Chromatography A, Mar 1, 2021
Fluorescent probes are used in drug nanocarrier pre-clinical studies or as active compounds in th... more Fluorescent probes are used in drug nanocarrier pre-clinical studies or as active compounds in theranostics and photodynamic therapy. In the biological medium, nanoparticles interact with proteins, which can result in the off-target release of their cargo. The present study used asymmetric flow field-flow fractionation with online multi-angle laser light scattering and fluorescence detection (AF4-MALLS-FLD) to study the release, transfer, and partition of fluorescent dyes from polymeric nanoparticles (NP). NP formulations containing the dyes Rose Bengal, Rhodamine B, DiI, 3-(α-azidoacetyl)coumarin and its polymer conjugate, Nile Red, and IR780 and its polymer conjugate were prepared. NP suspensions were incubated in a medium with serum proteins and then analyzed by AF4. AF4 allowed efficient separation of proteins (< 10 nm) from fluorescently labeled NP (range of 54 - 180 nm in diameters). The AF4 analyses showed that some dyes, such as Rose Bengal, IR780, and Coumarin were transferred to a high extent (68-77%) from NP to proteins. By contrast, for DiI and dye-polymer conjugates, transfer occured to a lower extent. The studies of dye release kinetics showed that the transfer of IR780 from NP to proteins occurs at a high extent (~50%) and rate, while Nile Red was slowly released from the NP over time with reduced association with proteins (~20%). This experiment assesses the stability of fluorescence labeling of nanocarriers and probes the transfer of fluorescent dyes from NP to proteins, which is otherwise not accessible with commonly used techniques of separation, such as dialysis and ultrafiltration/centrifugation employed in drug encapsulation and release studies of nanocarriers. Determining the interaction and transfer of dyes to proteins is of utmost importance in the pre-clinical evaluation of drug nanocarriers for improved correlation between in vitro and in vivo studies.
Pharmaceutics, Apr 2, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biomedicine & Pharmacotherapy, 2022
IR780 is a near-infrared fluorescent dye, which can be applied as a photosensitizer in photodynam... more IR780 is a near-infrared fluorescent dye, which can be applied as a photosensitizer in photodynamic (PDT) and photothermal (PTT) therapies and as a biodistribution tracer in imaging techniques. We investigated the growth and migration inhibition and mechanism of death of breast tumor cells, MCF-7 and MDA-MB-231, exposed to polymeric nanocapsules (NC) comprising IR780 covalently linked to the biodegradable polymer PLA (IR-PLA) and IR780 physically encapsulated (IR780-NC) in vitro. Both types of NC had mean diameters around 120 nm and zeta potentials around -40 mV. IR-PLA-NC was less cytotoxic than IR780 NC to a non-tumorigenic mammary epithelial cell line, MCF-10A, which is an important aspect of selectivity. Free-IR780 was more cytotoxic than IR-PLA-NC for MCF-7 and MDA-MB-231 cells after illumination with a 808 nm laser. IR-PLA NC was effective to inhibit colony formation (50%) and migration (30-40%) for both cancer cell lines. MDA-MB-231 cells were less sensitive to all IR780 formulations compared to MCF-7 cells. Cell uptake was higher with IR-PLA-NC than with IR780-NC and free-IR780 in both cancer cell lines (p < 0.05). NC uptake was higher in MCF-7 than in MDA-MB-231 cells. IR-PLA-NC induced a higher percentage of apoptosis upon illumination in MDA-MB-231 than in MCF-7 cells. The necrosis mechanism of death predominated in treatments with free-IR780 and with encapsulated IR780 NC, suggestive of damages at the plasma membrane. IR780 conjugated with PLA increased the apoptotic pathway and demonstrated potential as a multifunctional theranostic agent for breast cancer treatment with increased cellular uptake, photodynamic activity and more reliable tracking in cell-image studies.
Drug Delivery and Translational Research, Jul 1, 2020
Near-infrared fluorescent dyes, such as IR780, are promising theranostics, acting as photosensiti... more Near-infrared fluorescent dyes, such as IR780, are promising theranostics, acting as photosensitizers for photodynamic therapy and in vivo tracers in image-guided diagnosis. This work compared the uptake by macrophage-like cells of IR780 either physically associated or covalently attached to poly(D,L-lactide) (PLA) formulated as polymeric nanocapsules (NC) from a blend of PLA homopolymer and PLA-PEG block copolymer. The physicochemical characterization of both NC was conducted using asymmetric flow field-flow fractionation (AF4) analysis with static and dynamic light scattering and atomic force microscopy. The interaction of IR780 with serum proteins was evidenced by AF4 with fluorescence detection and flow cytometry in cell uptake studies. The average diameters of NC were around 120 nm and zeta potentials close to-40 mV for all NC. NC uptake by cells in different media and experimental conditions shows significantly lower fluorescence intensities for IR780 covalently linked to PLA and correspondingly low quantitative uptake. Different mechanisms of internalization were evidenced depending on the IR780 type of association to NC. Serum proteins mediate IR780 interaction with cells in a dose-dependent manner. Our results show that non-covalently linked IR780 was released from NC and accumulated in macrophage cells. Oppositely, IR780 conjugated to PLA provides stable association with NC, and its fluorescence is representative of cell uptake of the nanocarrier itself. This work strongly reinforces the importance of covalent attachment of a fluorescence dye such as IR780 to the nanocarrier to study their interaction with cells in vitro and to obtain reliable tracking in image-guided therapy.
European Journal of Pharmaceutical Sciences, Mar 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Photochemistry and Photobiology B-biology, May 1, 2000
The poor selectivity of photosensitizers for tumor tissue remains a drawback in photodynamic ther... more The poor selectivity of photosensitizers for tumor tissue remains a drawback in photodynamic therapy (PDT) and could be improved by adapted formulations. The cellular uptake, localization and phototoxicity of meta-tetra(hydroxyphenyl)chlorin (mTHPC) encapsulated in submicronic colloidal carriers have been studied in macrophage-like J774 cells and HT 29 human adenocarcinoma cells. Nanocapsules with an external layer made of poly(D,L lactic acid) (PLA NCs), PLA grafted with polyethylene glycol (PLA-PEG NCs), PLA coated with poloxamer 188 (polox PLA NCs) and oil/water nanoemulsion (NE) have been examined. The cellular uptake by J774, as determined by microspectroflorimetry, is reduced with mTHPC encapsulated into surface-modified NCs-PLA-PEG and polox PLA-compared with naked PLA, indicating a possible limitation of the clearance of such carriers by the reticuloendothelial system. Encapsulation also modifies the interaction between mTHPC and HT29 cells. Compared with the manufacturer's solution (PEG, ethanol, water), the cellular uptake is strongly reduced. However, the HT29 phototoxicity is much less affected and a protecting effect against plasma proteins is observed. Fluorescence microscopy reveals a specific punctate fluorescence pattern with PLA-PEG and polox PLA NCs in contrast to a more diffuse distribution with NE and solution, indicating that photodamage targeting could be different. These findings suggest that photosensitizers encapsulated into surface-modified nanocapsules could be a promising approach for improving PDT efficacy and this has to be confirmed in vivo.
Advanced Drug Delivery Reviews, Mar 1, 2010
Despite the fact that we live in an era of advanced technology and innovation, infectious disease... more Despite the fact that we live in an era of advanced technology and innovation, infectious diseases, like malaria, continue to be one of the greatest health challenges worldwide. The main drawbacks of conventional malaria chemotherapy are the development of multiple drug resistance and the non-specific targeting to intracellular parasites, resulting in high dose requirements and subsequent intolerable toxicity. Nanosized carriers have been receiving special attention with the aim of minimizing the side effects of drug therapy, such as poor bioavailability and the selectivity of drugs. Several nanosized delivery systems have already proved their effectiveness in animal models for the treatment and prophylaxis of malaria. A number of strategies to deliver antimalarials using nanocarriers and the mechanisms that facilitate their targeting to Plasmodium spp.-infected cells are discussed in this review. Taking into account the peculiarities of malaria parasites, the focus is placed particularly on lipid-based (e.g., liposomes, solid lipid nanoparticles and nano and microemulsions) and polymer-based nanocarriers (nanocapsules and nanospheres). This review emphasizes the main requirements for developing new nanotechnology-based carriers as a promising choice in malaria treatment, especially in the case of severe cerebral malaria.
European Polymer Journal, May 1, 2017
A versatile and simple strategy is presented to synthesize reactive polylactide derivatives and t... more A versatile and simple strategy is presented to synthesize reactive polylactide derivatives and their block copolymers with polyethylene glycol. Commercially available glycidyl ethers with an allyl, benzyl or propargyl functional group were copolymerised with D,L-lactide. Tin(II)-2ethylhexanoate-catalysis produced polymers with up to 4.6, 5.9 and 2.3 allyl, benzyl or propargyl groups per chain, respectively. In contrast, less than one reactive group per chain was obtained with the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene. By increasing the polymerisation feed ratio in glycidyl ether polymers with a higher number of reactive groups per chain were obtained, however a decrease in molar mass was observed. An azidocoumarin was conjugated to the propargylated polymers via copper-catalysed azide-alkyne cycloaddition. These dye-labelled polymers produced nanospheres with fluorescent properties and diameters in the 100-nm sizerange, as characterised by asymmetric flow field flow fractionation hyphenated with fluorescence, static and dynamic light scattering detection. The functionalised polymers were obtained at gram-scale in one step from commercially available reagents; therefore providing a robust and easy to implement approach for the production of multifunctional nanomaterials.
International Journal of Nanomedicine, May 1, 2017
Self-emulsifying drug delivery systems (SEDDSs) are lipid-based anhydrous formulations composed o... more Self-emulsifying drug delivery systems (SEDDSs) are lipid-based anhydrous formulations composed of an isotropic mixture of oil, surfactant, and cosurfactants usually presented in gelatin capsules. Ravuconazole (Biopharmaceutics Classification System [BCS] Class II) is a poorly water-soluble drug, and a SEDDS type IIIA was designed to deliver it in a predissolved state, improving dissolution in gastrointestinal fluids. After emulsification, the droplets had mean hydrodynamic diameters ,250 nm, zeta potential values in the range of-45 mV to-57 mV, and showed no signs of ravuconazole precipitation. Asymmetric flow field-flow fractionation with dynamic and multiangle laser light scattering was used to characterize these formulations in terms of size distribution and homogeneity. The fractograms obtained at 37°C showed a polydisperse profile for all blank and ravuconazole-SEDDS formulations but no large aggregates. SEDDS increased ravuconazole in vitro dissolution extent and rate (20%) compared to free drug (3%) in 6 h. The in vivo toxicity of blank SEDDS comprising Labrasol ® surfactant in different concentrations and preliminary safety tests in repeated-dose oral administration (20 days) showed a dose-dependent Labrasol toxicity in healthy mice. Ravuconazole-SEDDS at low surfactant content (10%, v/v) in Trypanosoma cruzi-infected mice was safe during the 20-day treatment. The anti-T. cruzi activity of free ravuconazole, ravuconazole-SEDDS and each excipient were evaluated in vitro at equivalent ravuconazole concentrations needed to inhibit 50% or 90% (IC 50 and IC 90), respectively of the intracellular amastigote form of the parasite in a cardiomyocyte cell line. The results showed a clear improvement of the ravuconazole anti-T. cruzi activity when associated with SEDDS. Based on our results, the repurposing of ravuconazole in SEDDS dosage form is a strategy that deserves further in vivo investigation in preclinical studies for the treatment of human T. cruzi infections.
Expert Opinion on Investigational Drugs, May 26, 2014
A century after its discovery, American trypanosomiasis or Chagas disease remains a serious healt... more A century after its discovery, American trypanosomiasis or Chagas disease remains a serious health problem in Latin America, where it affects around 7 - 8 million people. The prevalence of Chagas disease in the poorer parts of the world has meant that it has largely been neglected with limited progress that made in identifying new drugs for the treatment. The nitroheterocyclic drugs nifurtimox and benznidazole are first-line drugs available for Chagas disease with limitations that include variable efficacy, long treatment courses and toxicity. This review focuses on different therapeutic strategies that have been used for the discovery of new treatments for Chagas disease. These include combination chemotherapy, drug repositioning, re-dosing regimens for current drugs and the identification of new drugs with specified target profiles. There are currently several reasons for a more optimistic view about chemotherapy with Chagas disease. However, despite some progress being made in preclinical studies, there is yet to be an ideal drug or formulation for human treatment. One major drawback in the evaluation of potential Chagas disease therapeutics is the lack of tools available to perform the said evaluation. Indeed, there is a great need to discover a better biomarker that could determine the efficacy of potential chemotherapeutics in treated patients.
Visceral leishmaniasis (VL)is a fatal disease caused by the protozoa Leishmania infantum for whic... more Visceral leishmaniasis (VL)is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, [poly (D, L-lactic) acid (PLA) polymer] loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.
Archives of Cardiovascular Diseases Supplements, Apr 1, 2017
Veterinary and Animal Science, Jun 1, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Vaccines, Oct 31, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
European Journal of Pharmaceutical Sciences, Nov 1, 2018
The interaction of polymer nanocapsules (NC) prepared from four biodegradable polyesters with var... more The interaction of polymer nanocapsules (NC) prepared from four biodegradable polyesters with variable polymer hydrophobicity (PCL, PLA, PLGA and PLA-PEG) was investigated in the non-phagocytic Vero, Caco-2 and HepG2 cell lines. The NC, labeled with the highly lipophilic fluorescent indocarbocyanine dye DIL, had very similar sizes (approx. 140 nm) and negative zeta-potentials. Asymmetric flow field-flow fractionation evidenced NC colloidal stability and negligible transfer of the dye to serum proteins in the incubation medium. The cytotoxicity of the NC was evaluated via MTT assay over a large polymer concentration range (0-1000 µg/mL) and time of exposure (2, 24 and 48 h). The NC were safe in vitro up to a concentration of approx. 100 µg/mL or higher, depending on the cell line and nature of the polymer. Vero cells were more sensitive to the NC, in particular NC of the more hydrophobic polymer. The cells were exposed to endocytosis inhibitors, incubated with NC, and the cellassociated fluorescence was quantified by spectrofluorometry. HepG2 cells presented a 1.5-2fold higher endocytic capacity than Caco-2 and Vero cells. The main mechanism of NC uptake was caveolin-mediated endocytosis in HepG2 and Vero cells, and macropinocytosis in Caco-2 cells. Polymer hydrophobicity had an effect on the level of NC associated to HepG2 cells and to a lesser extent on the endocytosis mechanisms in Vero and Caco-2 cells. The NC uptake levels and endocytosis mechanisms differed significantly between cell lines tested.
Revista Brasileira De Ciencias Farmaceuticas, 2007
Experimental Parasitology
International Journal of Pharmaceutics, Apr 1, 2023
Biomedicine & Pharmacotherapy, Mar 1, 2018
BACKGROUND Candida spp is an etiologic agent of fungal infections in hospitals and resistance to ... more BACKGROUND Candida spp is an etiologic agent of fungal infections in hospitals and resistance to treatment with antifungals has been extensively reported. Thus, it is very important to develop formulations that increase effectiveness with low toxicity. In this sense, nanocarriers have been investigated, once they modify drug biodistribution profile. Thus, this study aimed to evaluate the biodistribution of free and encapsulated 99mTc-fluconazole into nanocapsules (NCs) in an experimental immunosuppressed murine model of Candida albicans infection. METHODS Fluconazole was radiolabeled with technetium-99 metastable (99mTc) and encapsulated into conventional (99mTc-Fluconazole-PLA-POLOX) and surface-modified (99mTc-Fluconazole-PLA-PEG) NCs by the interfacial deposition of the preformed biodegradable polymer [poly (D,L-lactic acid) (PLA) and PLA-PEG (polyethyleneglycol)] followed by solvent evaporation. The size distribution and zeta potential of the NCs preparations were determined in a Zetasizer by photon correlation spectroscopy and laser Doppler anemometry, respectively. Free and encapsulated 99mTc-fluconazole were administered intravenously in immunosuppressed mice bearing a local infection induced by Candida Albicans inoculation in the right thigh muscle. At pre-established time intervals, tissues and organs of interest were removed and radioactivity was measured in an automatic gamma radiation counter. RESULTS The NCs diameter was between 200 and 400 nm with negative zeta potential values. Free 99mTc-fluconazole was more rapidly eliminated by the renal system compared to the encapsulated drug in NCs, which remained longer in blood circulation. The uptake of conventional NCs by mononuclear phagocyte system organs was higher than the one demonstrated by the surface-modified NCs. Both NCs remained longer in the infectious focus when compared to free 99mTc-fluconazole, but the results did not show a significant difference between NC formulations. CONCLUSION These data indicate that these NCs might represent a therapeutic alternative for the treatment of candidiasis, once they remain more time in the infectious focus, allowing high retention of 99mTc-fluconazole at this site.