Examinando por Autor "Morales, Victoria"

Mostrando 1 - 14 de 14

Biodiesel and biogas production from Isochrysis galbana using dry and wet lipid extraction: A biorefinery approach
(Elsevier, 2020) Sánchez-Bayo, Alejandra; López-Chicharro, Daniel; Morales, Victoria; Espada, Juan José; Puyol, Daniel; Martínez, Fernando; Astals, Sergi; Vicente, Gemma; Bautista, Luis Fernando; Rodríguez, Rosalía
Wet lipid extraction combined with residual biomass anaerobic digestion are alternatives to reduce the overall energy consumption of biodiesel production from microalgae. Solvents with different polarities have been studied to assess dry and wet lipid extraction process from Isochrysis galbana microalga. Ethyl acetate (EA) and a chloroform:methanol (CM) mixture yielded the best lipid extraction results in the dry and wet route with suitable lipid compositions. Fatty acid methyl esters (FAMEs) conversion of dry and wet extracted lipids with these solvents was performed by using both homogeneous (H2SO4) and heterogeneous (resin CT 269) catalysts. FAME production from wet extracted lipids with the EA solvent using the CT-269 resin constitutes an advantageous process because it avoids the water elimination step, and the CT-269 is a heterogeneous commercial catalyst, readily to separate after reaction. Lipid-spent microalga was anaerobically digested, obtaining that waste biomass from the wet extraction with EA had the highest methane yield (310 mL CH4/g volatile solids (VS). Energy balance analysis for FAMEs production with EA solvent (wet route) and heterogeneous catalyst yielded an energy recovery of about 80% in terms of biodiesel and biogas. Therefore, this process constitutes a promising route under an energy-driven microalga biorefinery.
Biodiesel Production (FAEEs) by Heterogeneous Combi-Lipase Biocatalysts Using Wet Extracted Lipids from Microalgae
(MDPI, 2019) Sánchez-Bayo, Alejandra; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
The production of fatty acids ethyl esters (FAEEs) to be used as biodiesel from oleaginous microalgae shows great opportunities as an attractive source for the production of renewable fuels without competing with human food. To ensure the economic viability and environmental sustainability of the microbial biomass as a raw material, the integration of its production and transformation into the biorefinery concept is required. In the present work, lipids from wet Isochrysis galbana microalga were extracted with ethyl acetate with and without drying the microalgal biomass (dry and wet extraction method, respectively). Then, FAEEs were produced by lipase-catalyzed transesterification and esterification of the extracted lipids with ethanol using lipase B from Candida antarctica (CALB) and Pseudomonas cepacia (PC) lipase supported on SBA-15 mesoporous silica functionalized with amino groups. The conversion to FAEEs with CALB (97 and 85.5 mol% for dry and wet extraction, respectively) and PC (91 and 87 mol%) biocatalysts reached higher values than those obtained with commercial Novozym 435 (75 and 69.5 mol%). Due to the heterogeneous nature of the composition of microalgae lipids, mixtures with different CALB:PC biocatalyst ratio were used to improve conversion of wet-extracted lipids. The results showed that a 25:75 combi-lipase produced a significantly higher conversion to FAEEs (97.2 mol%) than those produced by each biocatalyst independently from wet-extracted lipids and similar ones than those obtained by each lipase from the dry extraction method. Therefore, that optimized combi-lipase biocatalyst, along with achieving the highest conversion to FAEEs, would allow improving viability of a biorefinery since biodiesel production could be performed without the energy-intensive step of biomass drying.
Cultivation of Microalgae and Cyanobacteria: Effect of Operating Conditions on Growth and Biomass Composition
(MDPI, 2020) Sánchez-Bayo, Alejandra; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
The purpose of this work is to define optimal growth conditions to maximise biomass for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on cell growth: i.e., inoculum:culture medium volume ratio (5:45, 10:40, 15:35 and 20:30 mL:mL), light:dark photoperiod (8:16, 12:12 and 16:8 h) and type of culture medium, including both synthetic media (Guillard’s F/2 and Walne’s) and wastewaters. The results showed that the initial inoculum:culture medium volume ratio, within the range 5:45 to 20:30, did not affect the amount of biomass at the end of the growth (14 days), whereas high (18 h) or low (6 h) number of hours of daily light was important for cell growth. The contribution of nutrients from different culture media could increase the growth rate of the different species. A. maxima was favoured in seawater enriched with Guillard’s F/2 as well as C. vulgaris and N. gaditana, but in freshwater medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrogen was the limiting nutrient for growth at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. The growth in different synthetic culture media also determines the biochemical composition of each of the microalgae. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalga species.
Environmental analysis of Spirulina cultivation and biogas production using experimental and simulation approach
(Elsevier, 2018-12) Rodríguez, Rosalía; Espada, Juan José; Moreno, Jovita; Vicente, Gemma; Bautista, Luis Fernando; Morales, Victoria
Microalgae is constituted by different compounds, interesting for the production of a wide range of endproducts by using different technologies. Many potential possibilities have been developed under the context of a biorefinery. The aim of this work is to evaluate the environmental performance of biogas production from Spirulina (Arthrospira maxima) through LCA using experimental and simulation results. For this purpose, kinetic models for batch cultivation and anaerobic digestion (AD) were determined from experimental data. Thus, Monod kinetic model and a first order model describe well microalgal biomass growth and AD, respectively. This model was used to simulate growth of Spirulina in a continuous system by using SuperPro Designer 9.5. Calculated results were compared to continuous experimental ones, obtaining good agreement in all cases. On the other hand, the whole process (cultivation, dewatering and AD of Spirulina biomass) was also simulated and the obtained results (material and energy balances) were used to construct LCA inventory data. Thereafter, environmental impacts were quantified through CML-2001 methodology using software Gabi 6.0. LCA results show that abiotic depletion of fossil resources (ADFR) category presents the highest impact, being biomass cultivation the most important contributor (about 56%). This result is directly related to the high energy consumption required for nutrient production, which also leads to increase remarkably the global warming potential (GWP) category. Main conclusion of the work is that the total/partial substitution of mineral fertilizers as nutrient source is the key to improve the environmental performance of the studied process. In this sense, a potential alternative could be the use of nutrients from wastewater or other wast
Functionalization of SBA-15 by an Acid-Catalyzed Approach. A Surface Characterization Study
(ELSEVIER, 2007) García, Nuria; Benito, Esperanza; Guzmán, Julio; Tiemblo, Pilar; Morales, Victoria; García, Rafael A.
The functionalization of a mesoporous ordered silica, SBA-15, by a grafting strategy has been successfully achieved. The derivatized SBA-15 products with trimethylmethoxy silane, vinyltrimethoxy silane and octyltrimethoxy silane have been characterized by BET analysis, DRX analysis, thermogravimetric analysis and NMR techniques. The use of p-toluenesulfonic acid as catalyst and the azeotropic distillation of the alcohol generated in the hydrolysis and condensation of the silanes allowed the incorporation of high amounts of organic loading in shorter times as compared to conventional toluene reflux method. The surface of the resulting materials has been thoroughly analyzed and the concentration of total and residual silanols and silane molecules attached on the surface has been quantitatively determined. Being the as-modified SBA-15 materials hydrophobic as a rule, the accessibility of the residual silanol population, evaluated by a deuterium exchange method and subsequent cross polarization NMR analysis, depends on the nature of the surface organic layer.
Hydrothermal Liquefaction of Microalga Using Metal Oxide Catalyst
(MDPI, 2020) Sánchez-Bayo, Alejandra; Rodríguez, Rosalía; Morales, Victoria; Nasirian, Nima; Bautista, Luis Fernando; Vicente, Gemma
The yield and composition of the biocrude obtained by hydrothermal liquefaction (HTL) of Nannocloropsis gaditana using heterogeneous catalysts were evaluated. The catalysts were based on metal oxides (CaO, CeO2, La2O3, MnO2, and Al2O3). The reactions were performed in a batch autoclave reactor at 320 C for 10 min with a 1:10 (wt/wt) microalga:water ratio. These catalysts increased the yield of the liquefaction phase (from 94.14 wt% for La2O3 to 99.49 wt% for MnO2) as compared with the thermal reaction (92.60 wt%). Consequently, the biocrude yields also raised in the metal oxides catalysed HTL, showing values remarkably higher for the CaO (49.73 wt%) in comparison to the HTL without catalyst (42.60 wt%). The N and O content of the biocrude obtained from non-catalytic HTL were 6.11 wt% and 10.50 wt%, respectively. In this sense, the use of the metal oxides decreased the N content of the biocrude (4.62–5.45 wt%), although, they kept constant or increased its O content (11.39 –21.68 wt%). This study shows that CaO, CeO2 and Al2O3 can be promising catalysts based on the remarkable amount of biocrude, the highest values of C, H, heating value, energy recovery, and the lowest content of N, O and S.
Kidney-Protector Lipidic Cilastatin Derivatives as Structure-Directing Agents for the Synthesis of Mesoporous Silica Nanoparticles for Drug Delivery
(MDPI (Multidisciplinary Digital Publishing Institute), 2021-07-26) Martínez Erro, Samuel; Navas, Francisco; Romaní Cubells, Eva; Fernández García, Paloma; Morales, Victoria; Sanz, Raúl; García Muñoz, Rafael Á.
Mesoporous silica nanomaterials have emerged as promising vehicles in controlled drug delivery systems due to their ability to selectively transport, protect, and release pharmaceuticals in a controlled and sustained manner. One drawback of these drug delivery systems is their preparation procedure that usually requires several steps including the removal of the structure-directing agent (surfactant) and the later loading of the drug into the porous structure. Herein, we describe the preparation of mesoporous silica nanoparticles, as drug delivery systems from structure-directing agents based on the kidney-protector drug cilastatin in a simple, fast, and one-step process. The concept of drug-structure-directing agent (DSDA) allows the use of lipidic derivatives of cilastatin to direct the successful formation of mesoporous silica nanoparticles (MSNs). The inherent pharmacological activity of the surfactant DSDA cilastatin-based template permits that the MSNs can be directly employed as drug delivery nanocarriers, without the need of extra steps. MSNs thus synthesized have shown good sphericity and remarkable textural properties. The size of the nanoparticles can be adjusted by simply selecting the stirring speed, time, and aging temperature during the synthesis procedure. Moreover, the release experiments performed on these materials afforded a slow and sustained drug release over several days, which illustrates the MSNs potential utility as drug delivery system for the cilastatin cargo kidney protector. While most nanotechnology strategies focused on combating the different illnesses this methodology emphasizes on reducing the kidney toxicity associated to cancer chemotherapy.
L‑arginine‑containing mesoporous silica nanoparticles embedded in dental adhesive (Arg@MSN@DAdh) for targeting cariogenic bacteria
(BioMed Central, 2022-12-01) López Ruíz, Marta; Navas, Francisco; Fernández García, Paloma; Martínez Erro, Samuel; Fuentes, María Victoria; Giráldez, isabeI; Ceballos, Laura; Ferrer Luque, Carmen María; Ruíz Linares, Matilde; Morales, Victoria; Sanz, Raúl; García Muñoz, Rafael Á.
Dental caries is the major biofilm-mediated oral disease in the world. The main treatment to restore caries lesions consists of the use of adhesive resin composites due to their good properties. However, the progressive degradation of the adhesive in the medium term makes possible the proliferation of cariogenic bacteria allowing secondary caries to emerge. In this study, a dental adhesive incorporating a drug delivery system based on L-arginine-containing mesoporous silica nanoparticles (MSNs) was used to release this essential amino acid as a source of basicity to neutralize the harmful acidic conditions that mediate the development of dental secondary caries. The in vitro and bacterial culture experiments proved that L-arginine was released in a sustained way from MSNs and diffused out from the dental adhesive, effectively contributing to the reduction of the bacterial strains Streptococcus mutans and Lactobacillus casei. Furthermore, the mechanical and bonding properties of the dental adhesive did not change significantly after the incorporation of L-arginine-containing MSNs. These results are yielding glimmers of promise for the costeffective prevention of secondary caries.
Mitoxantrone-Derivative Drug Structure-Directing Agent for the Synthesis of Magnetic Mesoporous Silica Nanoparticles for Breast Cancer Treatment
(American Chemical Society, 2024-05-20) Romaní-Cubells, Eva; Martinez-Erro, Samuel; Morales, Victoria; Grieken, Rafael van; García Muñoz, Rafael A.; Sanz, Raúl
Cancer causes hundreds of thousands of deaths worldwide each year. Chemotherapy, the treatment of choice for invasive cancers, presents severe side effects related to off-target exposure that limit its dosage and, thus, its efficacy. Nanomedicine has emerged as a potential tool to overcome these problems. Among the nanocarriers, mesoporous silica nanoparticles (MSNs) have attracted much attention due to their high surface area (up to 1000 m2 g–1), the versatility in size and pore diameter, and their ease of functionalization. However, drug leakage from the MSNs usually occurs before the nanocarriers reach their target, reducing drug efficacy and causing adverse effects. Our group has developed a promising method to increase drug loading capacity while preventing premature drug release. This strategy consists of the use of a drug structure-directing agent (DSDA) that plays a dual role, acting as a pharmacological prodrug and as a template for the synthesis of MSNs. Here, we successfully synthesized a DSDA from the anticancer drug mitoxantrone (MTO), which is used in clinical practice for the treatment of metastatic breast cancer, and used it to synthesize magnetic MSNs whose porosity was fully filled with the MTO prodrug (magnetic MTO-C12@MSNs). The release behavior was pH-dependent, showing negligible drug release at physiological pH and a significant increase at the pH of the tumoral microenvironment. Finally, the efficacy of magnetic MTO-C12@MSNs in reducing breast cancer cell viability was confirmed, demonstrating the potential of this material as an efficient drug delivery system to target breast cancer tumors while avoiding side effects.
New Drug-Structure-Directing Agent Concept: Inherent Pharmacological Activity Combined with Templating Solid and Hollow-Shell Mesostructured Silica Nanoparticles
(2016-10-25) Morales, Victoria; Gutiérrez-Salmerón, María; Balabasquer, M; Ortiz, J; Linder, C; Chocarro-Calvo, Ana; García-Jiménez, Custodia; García-Muñoz, RA
One of the major challenges in medicine is the delivery and control of drug release over time. Current approaches take advantage of mesostructured silica nanoparticles (MSNs) as carriers but suffer several problems including complex synthesis that requires sequential steps for (1) removal of surfactants and (2) functionalization of MSNs to allow upload of the drugs. Here, a novel solution is presented to these restrictions: the design of drug-structure-directing agents (DSDAs) with dual inherent pharmacological activity and ability to direct the formation of solid and hollow-shell MSNs. Pharmacologically active DSDAs obtained by amidation of drugs with fatty acids are allowed to form micelles, around which the inorganic species self-assembled to form MSNs. Since the DSDAs direct the formation of MSNs, the steps to remove surfactants, functionalization, and drug upload are not required. The MSNs thus prepared provide sustained release of the drug over more than six months, as well as rapid cellular internalization by both physiological and tumoral human colon cells without affecting cell viability. Moreover, the gradual intracellular release of both, the active drug and lipid moiety with potential nutraceutical properties is proved. MSN particles designed with this approach are promising vehicles for controlled and sustained intra-or extracellular drug-delivery.
Optimised phycoerythrin extraction method from Porphyridium sp. combining imidazolium-based ionic liquids
(Elsevier, 2024-07-30) Piera, Alejandro; Espada, Juan J.; Morales, Victoria; Rodríguez, Rosalía; Vicente, Gemma; Bautista, Luis Fernando
Phycoerythrin (PE) extraction from Porphyridium sp. was studied employing ultrasound-assisted extraction combined with aqueous mixtures of two imidazolium-based ionic liquids (ILs) simultaneously, marking a significant novelty. A face-centred central composite design and response surface optimised PE yield (EPE), considering the effects of ionic liquid concentration (IL), [Emim][EtSO4]/[Bmim][EtSO4] mass ratio (E/B), biomass concentration (BM), and time (t). Improvements in EPE by 300 % and 115 % were achieved compared to a phosphate buffer solution and the freeze-thaw method, respectively. Temperature and pH effects were examined independently, leading to the determination of optimal operating conditions: BM = 10 mg mL−1, IL = 18.6 wt%, E/B = 0.78/0.22, t = 10 min, T = 35 °C, and pH = 7.5. Results indicated the potential for reusing the ILs for at least five consecutive extraction cycles, maintaining an EPE of 94.2 % compared to fresh ones. This underscores the success and innovation of the developed technology in enhancing PE extraction from Porphyridium sp
Promising Anticancer Prodrugs Based on Pt(IV) Complexes with Bisorganosilane Ligands in Axial Positions
(American Chemical Society, 2024-04-09) Navas, Francisco; Chocarro Calvo, Ana; Iglesias Hernández, Patricia; Fernández García, Paloma; Morales, Victoria; García Martínez, José Manuel; Sanz, Raúl; De la Vieja, Antonio; García Jiménez, Custodia; García Muñoz, Rafael Á.
We report two novel prodrug Pt(IV) complexes with bis-organosilane ligands in axial positions: cis-dichloro(diamine)-trans-[3-(triethoxysilyl)propylcarbamate]- platinum(IV) (Pt(IV)-biSi-1) and cis-dichloro(diisopropylamine)-trans-[3-(triethoxysilyl) propyl carbamate]platinum(IV) (Pt(IV)-biSi-2). Pt(IV)-biSi-2 demonstrated enhanced in vitro cytotoxicity against colon cancer cells (HCT 116 and HT-29) compared with cisplatin and Pt(IV)-biSi-1. Notably, Pt(IV)-biSi-2 exhibited higher cytotoxicity toward cancer cells and lower toxicity on nontumorigenic intestinal cells (HIEC6). In preclinical mouse models of colorectal cancer, Pt(IV)-biSi-2 outperformed cisplatin in reducing tumor growth at lower concentrations, with reduced side effects. Mechanistically, Pt(IV)- biSi-2 induced permanent DNA damage independent of p53 levels. DNA damage such as double-strand breaks marked by histone gH2Ax was permanent after treatment with Pt(IV)-biSi-2, in contrast to cisplatin's transient effects. Pt(IV)-biSi-2's faster reduction to Pt(II) species upon exposure to biological reductants supports its superior biological response. These findings unveil a novel strategy for designing Pt(IV) anticancer prodrugs with enhanced activity and specificity, offering therapeutic opportunities beyond conventional Pt drugs.
Surface-functionalization of mesoporous SBA-15 silica materials for controlled release of methylprednisolone sodium hemisuccinate: Influence of functionality type and strategies of incorporation
(Elsevier, 2017-03-01) Ortiz-Bustos, Josefa; Martín, Antonio; Morales, Victoria; Sanz, Raúl; García-Muñoz, Rafael Á.
Mesoporous SBA-15 silica materials functionalized with several organic moieties, that include different polarities and hydrophobicities, were investigated as matrices for controlled drug delivery. The functionalities were incorporated into SBA-15 using two methods: direct synthesis or co-condensation route and post-synthesis grafting. Methylprednisolone sodium hemisuccinate, a synthetic pharmaceutical compound used as anti-inflammatory and immunosuppressant, was loaded onto the pristine and functionalized mesoporous SBA-15 silica materials. The influence of the type of organic moieties as well as their incorporation method onto the inorganic silica framework has been evaluated. The results show that SBA-15 functionalized with aminopropyl trimethoxysilane groups has the largest capacity of drug adsorption, clearly higher than the provided by materials functionalized with other groups, independently of the synthesis route. Additionally, materials synthesized by the co-condensation approach show a lower degree of drug retention than the same material synthesized by grafting technique. This fact is attributed to the distinct localization of the functionality, more accessible in the case of the grafting procedure, and hence suggesting that stronger interactions among the SBA-15 functionalized surfaces and the model drug are established. To ascertain whether other organosilanes containing amino groups can provide more effective loading and controlled drug delivery, at neutral and acidic conditions (pH of 7.4 and 4.6, respectively), it was also investigated the incorporation by grafting of several amino organic moieties onto the SBA-15 silica materials. It was concluded that as the number of amino groups incorporated into SBA-15 material increased, not only the drug loading capacity was higher, but the functionalized silica material vehicles slowed down the drug delivery. Finally, it was confirmed that cell viability was largely unaffected by amino-functionalized mesoporous SBA-15 silica materials after 72 h of incubation time.
The effect of the lipid extraction method used in biodiesel production on the integrated recovery of biodiesel and biogas from Nannochloropsis gaditana, Isochrysis galbana and Arthrospira platensis
(Elsevier, 2020) Mendoza, Álvaro; Morales, Victoria; Sánchez-Bayo, Alejandra; Rodríguez, Rosalía; Fernández-González, Cristina; Bautista, Luis Fernando; Vicente, Gemma
The integrated production of biodiesel and biogas has been explored by using N. gaditana, I. galbana and A. platensis as substrate. Three fatty acid ethyl ester (FAEE) production approaches were assessed, namely an indirect process with previously extracted lipids (IPPEL), an indirect process with extracted lipids as free fatty acids (IPELFFA) and a direct process (DP) without a previous lipid extraction stage. Besides de FAEE production, these approaches are considered as pre-treatments of the microbial biomasses evaluated in this study with the objective of increasing the methane yield during the anaerobic digestion. Biogas yields of the residues generated under the three FAEE production methodologies were compared to the biogas yield of the raw feedstock. In all cases, the biodiesel and biogas yields were higher after the FAEE production process from the previously extracted lipids as free fatty acids (IPELFFA). Therefore, this constitutes an interesting and promising route in the joint production of biodiesel and biogas.