12 results on '"Gustavo Carreño"'
Search Results
2. Sustained Release of Linezolid from Prepared Hydrogels with Polyvinyl Alcohol and Aliphatic Dicarboxylic Acids of Variable Chain Lengths
- Author
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Gustavo Carreño, Adolfo Marican, Sekar Vijayakumar, Oscar Valdés, Gustavo Cabrera-Barjas, Johanna Castaño, and Esteban F. Durán-Lara
- Subjects
hydrogel ,polyvinyl alcohol ,aliphatic dicarboxylic acids ,sustained release ,linezolid ,equilibrium swelling ratio ,Pharmacy and materia medica ,RS1-441 - Abstract
A series of hydrogels with a specific release profile of linezolid was successfully synthesized. The hydrogels were synthesized by cross-linking polyvinyl alcohol (PVA) and aliphatic dicarboxylic acids, which include succinic acid (SA), glutaric acid (GA), and adipic acid (AA). The three crosslinked hydrogels were prepared by esterification and characterized by equilibrium swelling ratio, infrared spectroscopy, thermogravimetric analysis, mechanical properties, and scanning electron microscopy. The release kinetics studies of the linezolid from prepared hydrogels were investigated by cumulative drug release and quantified by chromatographic techniques. Mathematical models were carried out to understand the behavior of the linezolid release. These data revealed that the sustained release of linezolid depends on the aliphatic dicarboxylic acid chain length, their polarity, as well as the hydrogel crosslinking degree and mechanical properties. The in vitro antibacterial assay of hydrogel formulations was assessed in an Enterococcus faecium bacterial strain, showing a significant activity over time. The antibacterial results were consistent with cumulative release assays. Thus, these results demonstrated that the aliphatic dicarboxylic acids used as crosslinkers in the PVA hydrogels were a determining factor in the antibiotic release profile.
- Published
- 2020
- Full Text
- View/download PDF
3. Film Dressings Based on Hydrogels: Simultaneous and Sustained-Release of Bioactive Compounds with Wound Healing Properties
- Author
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Fabian Ávila-Salas, Adolfo Marican, Soledad Pinochet, Gustavo Carreño, Oscar Valdés, Bernardo Venegas, Wendy Donoso, Gustavo Cabrera-Barjas, Sekar Vijayakumar, and Esteban F. Durán-Lara
- Subjects
sustained release ,wound healing ,crosslinking ,allantoin ,equilibrium swelling ratio ,accumulative release ,thermogravimetric analysis ,Pharmacy and materia medica ,RS1-441 - Abstract
This research proposes the rational modeling, synthesis and evaluation of film dressing hydrogels based on polyvinyl alcohol crosslinked with 20 different kinds of dicarboxylic acids. These formulations would allow the sustained release of simultaneous bioactive compounds including allantoin, resveratrol, dexpanthenol and caffeic acid as a multi-target therapy in wound healing. Interaction energy calculations and molecular dynamics simulation studies allowed evaluating the intermolecular affinity of the above bioactive compounds by hydrogels crosslinked with the different dicarboxylic acids. According to the computational results, the hydrogels crosslinked with succinic, aspartic, maleic and malic acids were selected as the best candidates to be synthesized and evaluated experimentally. These four crosslinked hydrogels were prepared and characterized by FTIR, mechanical properties, SEM and equilibrium swelling ratio. The sustained release of the bioactive compounds from the film dressing was investigated in vitro and in vivo. The in vitro results indicate a good release profile for all four analyzed bioactive compounds. More importantly, in vivo experiments suggest that prepared formulations could considerably accelerate the healing rate of artificial wounds in rats. The histological studies show that these formulations help to successfully reconstruct and thicken epidermis during 14 days of wound healing. Moreover, the four film dressings developed and exhibited excellent biocompatibility. In conclusion, the novel film dressings based on hydrogels rationally designed with combinatorial and sustained release therapy could have significant promise as dressing materials for skin wound healing.
- Published
- 2019
- Full Text
- View/download PDF
4. Preparation of Hydrogel/Silver Nanohybrids Mediated by Tunable-Size Silver Nanoparticles for Potential Antibacterial Applications
- Author
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Yeray A. Rodríguez Nuñez, Ricardo I. Castro, Felipe A. Arenas, Zoraya E. López-Cabaña, Gustavo Carreño, Verónica Carrasco-Sánchez, Adolfo Marican, Jorge Villaseñor, Esteban Vargas, Leonardo S. Santos, and Esteban F. Durán-Lara
- Subjects
silver nanoparticles ,hydrogel ,crosslinking ,template ,maleic acids ,polyvinyl alcohol ,antibacterial activity ,Organic chemistry ,QD241-441 - Abstract
In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied. The silver nanoparticles were synthesized into each prepared hydrogel matrix achieving three significant, different-sized nanoparticles that were spherical in shape with a narrow size distribution. It is likely that the polymer network stabilized the nanoparticles. It was determined that the hydrogel network structure can control the size and shape of the nanoparticles. The hydrogel/silver nanohybrids were characterized by swelling degree, Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Antibacterial activity against Staphylococcus aureus was evaluated, confirming antimicrobial action of the encapsulated silver nanoparticles into the hydrogels.
- Published
- 2019
- Full Text
- View/download PDF
5. Catalytic effects of p-phenylene-bridged methylated binuclear ferrocenes on thermal decomposition of the main component of composite solid propellants
- Author
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Cesar Morales-Verdejo, Ángel Norambuena, Juan M. Manriquez, María Belén Camarada, Ivonne Chávez, Juan Luis Arroyo, Paulina L. Ríos, Paula Povea, and Gustavo Carreño
- Subjects
010405 organic chemistry ,Thermal decomposition ,010402 general chemistry ,Condensed Matter Physics ,Ammonium perchlorate ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Thermogravimetry ,chemistry.chemical_compound ,chemistry ,Ferrocene ,Phenylene ,Physical chemistry ,Physical and Theoretical Chemistry ,Benzene ,Instrumentation ,Bimetallic strip - Abstract
This contribution describes the catalytic activity of homobimetallic complexes derived from p-phenylene on the thermal decomposition of ammonium perchlorate (abbreviated as AP). The complexes, [CpFe-p-Ph-FeCp] (1), [Cp*Fe-p-Ph-FeCp*] (2), [CpFe-p-Ph’-FeCp] (3) and [Cp*Fe-p-Ph’-FeCp*] (4) (with p-Ph: p-Bis(3,4-dimethylcyclopentadienyl)benzene and p-Ph’: p-Bis(2,3,4,5-tetramethylcyclopentadienyl)benzene), were compared with the catalytic activity of the catocene (cat) complex previously reported. Furthermore, in order to clarify the mechanism of the bimetallic compounds, it was tested ferrocene (Fc), frequently used as burning rate (BR) catalyst on the thermal decomposition of AP. The synthetized compounds shown a shift on the peak temperature to lower values and an increase in the released heats during thermal decomposition of AP. The burning rate catalytic activity of the compounds on thermal decomposition of AP were examined by thermogravimetry and differential scanning calorimetry techniques. Theoretical calculations of these compounds were carried out to gain further understanding of these catalysts systems.
- Published
- 2018
6. Development of 'on-demand' thermo-responsive hydrogels for anti-cancer drugs sustained release: Rational design, in silico prediction and in vitro validation in colon cancer models
- Author
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Diana Rafael, Maria Mercé Roca-Melendres, Fernanda Andrade, Adolfo Marican, Esteban F. Durán-Lara, Oscar Valdés, Fabián Avila-Salas, Alfredo Pereira, Simó Schwartz, Gustavo Carreño, Ibane Abasolo, and Sekar Vijayakumar
- Subjects
Drug ,Materials science ,Biocompatibility ,media_common.quotation_subject ,Radical polymerization ,Antineoplastic Agents ,Bioengineering ,Biomaterials ,chemistry.chemical_compound ,medicine ,Humans ,Doxorubicin ,media_common ,Temperature ,technology, industry, and agriculture ,Rational design ,Hydrogels ,Drug Liberation ,chemistry ,Mechanics of Materials ,Delayed-Action Preparations ,Colonic Neoplasms ,Self-healing hydrogels ,Biophysics ,Swelling ,medicine.symptom ,Ethylene glycol ,medicine.drug - Abstract
A rational design accurate based on the use of Statistical Design of the Experiments (DoE) and Molecular Dynamics Simulations Studies allows the prediction and the understanding of thermo-responsive hydrogels prepared regarding their gelation temperature and anti-cancer drug release rate. N-isopropylacrilamide (NIPAM) modified with specific co-monomers and crosslinkers, can be used to prepare “on-demand” thermo-responsive hydrogels with the ideal properties for clinical applications in which local sustained release of drugs is crucial. Two preferential formulations resulting from the predictive studies of DoE and In Silico methods were synthesized by radical polymerization, fully characterized, and loaded with the anticancer drug Doxorubicin (Dox). The hydrogel formulations were characterized by swelling rate, turbidity, FTIR, 1H NMR, SEM, gelation time, rheology, and biocompatibility assays. Both formulations demonstrated adequate morphologic, rheological, and biocompatibility properties; however, important differences in terms of drug retention were detected. As demonstrated by a Dox cumulative release study and posteriorly confirmed by an efficacy assay in an in vitro colorectal cancer model, the formulation composed by NIPAM and 4-penten-1-ol crosslinked with poly(ethylene glycol) diacrylate (PEGDA) (PNiPenPH) present a slow release over the time, presenting ideal properties to become and ideal depot system for the local sustained release of anticancer drugs as adjuvant therapy or in the case of non-resectable tumors.
- Published
- 2021
7. Use of Poly(vinyl alcohol)-Malic Acid (CLHPMA) Hydrogels and Chitosan Coated Calcium Alginate (CCCA) Microparticles as Potential Sorbent Phases for the Extraction and Quantitative Determination of Pesticides from Aqueous Solutions
- Author
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Jorge Villaseñor, Cristian Valdés, Gustavo Carreño, Daniel Bustos, Alfredo Pereira, Gustavo Cabrera-Barjas, Esteban F. Durán-Lara, Efraín Polo-Cuadrado, Oscar Valdés, Diana Abril, and Adolfo Marican
- Subjects
Vinyl alcohol ,Calcium alginate ,Sorbent ,Chromatography ,Aqueous solution ,Polymers and Plastics ,Extraction (chemistry) ,Organic chemistry ,General Chemistry ,Article ,Chitosan ,sorbent phase ,chemistry.chemical_compound ,molecular dynamics simulation ,QD241-441 ,chemistry ,Desorption ,Self-healing hydrogels ,alginate ,hydrogel ,chitosan ,CLPHMA - Abstract
Pesticides are used worldwide to increase crop yields in agriculture. However, their toxicity and accumulation capacity can make them toxic to the environment, animals and humans. In the case of workers chronically exposed to these substances, they must be sampled continuously, so urine is an excellent option. In this sense, this study proposes to use poly(vinyl alcohol)-malic acid hydrogels, and chitosan-coated calcium alginate as new sorbent phases to be used in pesticide determination processes in urine. To better understand the behavior of these materials in the capture and desorption process, molecular dynamics simulations (MDS) were used, and desorption experiments were performed, using mechanical agitation, ultrasound, and pH variation in the desorption process, in order to optimize the parameters to obtain better recoveries. Under the optimal experimental conditions, the maximum recoveries were of the order of 11% (CFN), 3% (KCF), 53% (DMT), 18% (MTD) and 35% (MTL). Although the recoveries were not exhaustive, they are a first approximation for the use of these new sorbent phases in the determination of this type of compound in aqueous solutions and urine.
- Published
- 2021
8. Effect of the homo- and heterobimetallic compounds derived from s-indacene on the thermal decomposition of ammonium perchlorate
- Author
-
Juan M. Manriquez, María Belén Camarada, Paula Povea, Juan Luis Arroyo, Cesar Morales-Verdejo, and Gustavo Carreño
- Subjects
010405 organic chemistry ,Inorganic chemistry ,Thermal decomposition ,010402 general chemistry ,Condensed Matter Physics ,Ammonium perchlorate ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Catalysis ,Thermogravimetry ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Ferrocene ,Physical and Theoretical Chemistry ,Bimetallic strip - Abstract
This contribution describes an approaching about the catalytic activity of the homo- and heterobimetallic complexes derived from s-indacene on the thermal decomposition of ammonium perchlorate (abbreviate AP). The complexes, anti-[Cp*Fe-s-Ic′-FeCp*] (1), anti-[Cp*Fe-s-Ic′-CoCp*] (2), anti-[Cp*Fe-s-Ic′-NiCp*] (3) and anti-[Cp*Fe-s-Ic′-Mn(CO)3] (4) (with s-Ic′: 2,6-diethyl-4,8-dimethyl-s-indaceneiide), were compared with the catalytic activity of the catocene (cat) complex previously reported. Furthermore, in order to clarify the mechanism of the bimetallic compounds, it was tested ferrocene (Fc) compound as burning rate (BR) catalyst on the thermal decomposition of AP. These compounds shown a shift on the peak temperature to left and an increase released heats during thermal decomposition of AP. The burning rate catalytic activity of Fc, 1, 2, 3 and 4 on thermal decomposition of AP was examined by thermogravimetry and differential scanning calorimetry techniques.
- Published
- 2017
9. Film Dressings Based on Hydrogels: Simultaneous and Sustained-Release of Bioactive Compounds with Wound Healing Properties
- Author
-
Esteban F. Durán-Lara, Oscar Valdés, Soledad Pinochet, Gustavo Carreño, Gustavo Cabrera-Barjas, Adolfo Marican, Sekar Vijayakumar, Fabián Avila-Salas, Wendy Donoso, and Bernardo Venegas
- Subjects
accumulative release ,Thermogravimetric analysis ,Biocompatibility ,Pharmaceutical Science ,lcsh:RS1-441 ,wound healing ,allantoin ,02 engineering and technology ,macromolecular substances ,Polyvinyl alcohol ,Article ,lcsh:Pharmacy and materia medica ,03 medical and health sciences ,chemistry.chemical_compound ,Allantoin ,In vivo ,crosslinking ,sustained release ,030304 developmental biology ,thermogravimetric analysis ,0303 health sciences ,technology, industry, and agriculture ,021001 nanoscience & nanotechnology ,Chemical engineering ,chemistry ,Self-healing hydrogels ,equilibrium swelling ratio ,Dexpanthenol ,0210 nano-technology ,Wound healing - Abstract
This research proposes the rational modeling, synthesis and evaluation of film dressing hydrogels based on polyvinyl alcohol crosslinked with 20 different kinds of dicarboxylic acids. These formulations would allow the sustained release of simultaneous bioactive compounds including allantoin, resveratrol, dexpanthenol and caffeic acid as a multi-target therapy in wound healing. Interaction energy calculations and molecular dynamics simulation studies allowed evaluating the intermolecular affinity of the above bioactive compounds by hydrogels crosslinked with the different dicarboxylic acids. According to the computational results, the hydrogels crosslinked with succinic, aspartic, maleic and malic acids were selected as the best candidates to be synthesized and evaluated experimentally. These four crosslinked hydrogels were prepared and characterized by FTIR, mechanical properties, SEM and equilibrium swelling ratio. The sustained release of the bioactive compounds from the film dressing was investigated in vitro and in vivo. The in vitro results indicate a good release profile for all four analyzed bioactive compounds. More importantly, in vivo experiments suggest that prepared formulations could considerably accelerate the healing rate of artificial wounds in rats. The histological studies show that these formulations help to successfully reconstruct and thicken epidermis during 14 days of wound healing. Moreover, the four film dressings developed and exhibited excellent biocompatibility. In conclusion, the novel film dressings based on hydrogels rationally designed with combinatorial and sustained release therapy could have significant promise as dressing materials for skin wound healing.
- Published
- 2019
- Full Text
- View/download PDF
10. Preparation of Hydrogel/Silver Nanohybrids Mediated by Tunable-Size Silver Nanoparticles for Potential Antibacterial Applications
- Author
-
Esteban Vargas, Leonardo S. Santos, Ricardo I. Castro, Gustavo Carreño, Felipe A. Arenas, Jorge Villaseñor, Yeray A. Rodríguez Núñez, Verónica Carrasco-Sánchez, Esteban F. Durán-Lara, Adolfo Marican, and Zoraya Lopez-Cabana
- Subjects
Thermogravimetric analysis ,silver nanoparticles ,Materials science ,Polymers and Plastics ,Maleic acid ,Scanning electron microscope ,Nanoparticle ,macromolecular substances ,Polyvinyl alcohol ,complex mixtures ,Silver nanoparticle ,Article ,lcsh:QD241-441 ,chemistry.chemical_compound ,antibacterial activity ,lcsh:Organic chemistry ,crosslinking ,technology, industry, and agriculture ,template ,General Chemistry ,polyvinyl alcohol ,chemistry ,Chemical engineering ,Transmission electron microscopy ,Self-healing hydrogels ,maleic acids ,hydrogel - Abstract
In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied. The silver nanoparticles were synthesized into each prepared hydrogel matrix achieving three significant, different-sized nanoparticles that were spherical in shape with a narrow size distribution. It is likely that the polymer network stabilized the nanoparticles. It was determined that the hydrogel network structure can control the size and shape of the nanoparticles. The hydrogel/silver nanohybrids were characterized by swelling degree, Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Antibacterial activity against Staphylococcus aureus was evaluated, confirming antimicrobial action of the encapsulated silver nanoparticles into the hydrogels.
- Published
- 2019
11. Sustained Release of Linezolid from Prepared Hydrogels with Polyvinyl Alcohol and Aliphatic Dicarboxylic Acids of Variable Chain Lengths
- Author
-
Sekar Vijayakumar, Esteban F. Durán-Lara, Oscar Valdés, Gustavo Carreño, Johanna Castaño, Gustavo Cabrera-Barjas, and Adolfo Marican
- Subjects
accumulative release ,Thermogravimetric analysis ,Kinetics ,lcsh:RS1-441 ,Pharmaceutical Science ,linezolid ,macromolecular substances ,02 engineering and technology ,Glutaric acid ,010402 general chemistry ,complex mixtures ,01 natural sciences ,Polyvinyl alcohol ,Article ,lcsh:Pharmacy and materia medica ,chemistry.chemical_compound ,sustained release ,thermogravimetric analysis ,chemistry.chemical_classification ,Adipic acid ,technology, industry, and agriculture ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,aliphatic dicarboxylic acids ,polyvinyl alcohol ,Dicarboxylic acid ,chemistry ,Succinic acid ,Self-healing hydrogels ,equilibrium swelling ratio ,hydrogel ,0210 nano-technology ,Nuclear chemistry - Abstract
A series of hydrogels with a specific release profile of linezolid was successfully synthesized. The hydrogels were synthesized by cross-linking polyvinyl alcohol (PVA) and aliphatic dicarboxylic acids, which include succinic acid (SA), glutaric acid (GA), and adipic acid (AA). The three crosslinked hydrogels were prepared by esterification and characterized by equilibrium swelling ratio, infrared spectroscopy, thermogravimetric analysis, mechanical properties, and scanning electron microscopy. The release kinetics studies of the linezolid from prepared hydrogels were investigated by cumulative drug release and quantified by chromatographic techniques. Mathematical models were carried out to understand the behavior of the linezolid release. These data revealed that the sustained release of linezolid depends on the aliphatic dicarboxylic acid chain length, their polarity, as well as the hydrogel crosslinking degree and mechanical properties. The in vitro antibacterial assay of hydrogel formulations was assessed in an Enterococcus faecium bacterial strain, showing a significant activity over time. The antibacterial results were consistent with cumulative release assays. Thus, these results demonstrated that the aliphatic dicarboxylic acids used as crosslinkers in the PVA hydrogels were a determining factor in the antibiotic release profile.
- Published
- 2020
12. Situación epidemiológica de la leptospirosis humana en Centroamérica, Suramérica y el Caribe
- Author
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Paola Ramírez-Bulla, Marcela Mercado-Reyes, Adriana Pulido-Villamarín, and Gustavo Carreño-Beltrán
- Subjects
Multidisciplinary - Published
- 2014
Catalog
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