http://hdl.handle.net/10366/156568 2026-04-23T01:43:38Z http://hdl.handle.net/10366/168905 [EN]Several studies have recommended the use of hydrogels for localized targeted delivery of chemotherapeutic drugs following tumor removal surgery. This approach aims to both fill the cavity and prevent cancer recurrence. The use of Multiphysics-based simulation emerges as a valuable strategy for minimizing experimental work, providing detailed insights into how drug release occurs in the tissue, and enabling the optimization of the design. In this study, we introduced a mathematical model, utilizing experimental data, to investigate the transport of liposomes carrying MZ1 from a thermosensitive hydrogel and their impact on the viability of breast cancer cells. The proposed comprehensive model considers not just the transport within the interstitial tissue, represented as a porous medium, but also the uptake by cells and its influence on cell viability, along with the potential lymphatic drainage. The six real patient-specific tumor shapes extracted from MRI scans were used to investigate how the size and form of the tumor can modify the transport pattern. The computational results revealed that the concentration of liposomes in the tissue is significantly influenced by their release from the hydrogel, which proved to be the limiting step. Liposome concentrations of approximately 0.1 % weight were found to be sufficient in ensuring minimal cell survival in the vicinity of the tumor. 2025-01-01T00:00:00Z http://hdl.handle.net/10366/168904 [EN]Predicting the solubility of a solid in supercritical carbon dioxide (scCO2) can be useful for many applications. However, an accurate prediction is extremely difficult since current methods require knowledge about the properties of the solid in question or lengthy computational calculations and often yield significant deviations. Here, a new approach is proposed that allows the solubility of any solid in supercritical carbon dioxide to be rapidly predicted based solely on the structural formula of the solute. This approach is based on the prediction of Chrastil’s parameters using group contribution methods (GCMs) followed by their use in Chrastil’s equation. For this purpose, group contribution methods to estimate Chrastil’s parameters were developed using more than 6000 experimental data points from 210 solids. These parameters were used to predict the solubility data of 30 solids (around 1300 experimental points) in pure scCO2 with Chrastil’s equation, obtaining a relatively accurate fit for 70 % of the experimental points. The average absolute relative deviation was 51.22 % (less than 8.31 ⋅ 10􀀀 4 in absolute deviation), while the logarithmic deviation was 10.83 %. The deviations obtained were substantially lower than other estimations proposed in the literature. This methodology is easily extended, faster, and more accurate than other methods and does not require the use of computational methods or the estimation of solid properties. Moreover, new ways to predict the solubility of solids in supercritical carbon dioxide can be developed in the future based on this methodology. 2024-01-01T00:00:00Z http://hdl.handle.net/10366/168901 [EN]Levan nanoparticles formation is a complicated phenomenon involving simultaneously polymeric reaction kinetics and nanoparticles self-assembly theory. These phenomena are studied in this work with experimental and computationalmethodologies. Specifically, the effect of different parameters on levan kinetics and nanoparticles production in a cell-free system environment have been studied. Results point out that 37 °C is the best temperature for synthesizing levan as well as the existence of a substrate inhibition effect for polymeric reaction. This work also highlights that raffinose can be used for producing and that an increase on the ratio enzymesubstrate increases the velocity of conversion. However, the previous experimental conditions did not produce an important effect on self-assembly formed levan nanoparticles (always 110 nm) as long as the required levan concentration (CAC) for nanoparticles reorganization is achieved. To have a better understanding of these results, a model was developed to explain numerically levan kinetics and nanoparticle self-assembly. This model was built by taking into account enzyme poisoning effect (also demonstrated experimentally) and a diffusion limited cluster model for the aggregation phenomenon. Simulation results fit properly experimental data and catalytic parameters as well as predicting accurately the value of CAC for producing its reorganization into nanoparticles by self-assembly. 2020-01-01T00:00:00Z http://hdl.handle.net/10366/168899 [EN]Polydopamine nanoparticles (PD NPs) have been synthesized in the present work through the oxidative polymerization of dopamine in aqueous media containing five different types of alcohol in a constant solvent volume ratio. We have shown that the type of alcohol, along with the ammonium hydroxide concentration used in the synthesis process, conditions particle size. Additionally, it has been found that the type of alcohol employed influences the well-known capacity of polydopamine nanoparticles to adsorb iron. As a consequence, since a ferroptosis-like mechanism may account for the cytotoxicity of these nanoparticles, the type of alcohol could also have a determining role in their antineoplastic activity. Here, the existence of a correlation between the ability of polydopamine nanoparticles to load Fe3+ and their toxic effect on breast cancer cells has been proven. For instance, nanoparticles synthesized using 2-propanol adsorbed more Fe3+ and had the greatest capacity to reduce breast tumor cell viability. Moreover, none of the nanoparticle synthesized with the different alcohols significantly decreased normal cell survival. Cancer cells present greater iron-dependence than healthy cells and this fact may explain why polydopamine nanoparticles toxicity, in which Fenton chemistry could be implicated, seems tumor-specific. 2021-01-01T00:00:00Z http://hdl.handle.net/10366/168895 [EN]Chitosan aerogels were obtained after using supercritical carbon dioxide to dry physical hydrogels, studying the effect of the rheological behavior of hydrogels and solutions on the final aerogels properties. An increase on the solutions pseudoplasticity increased the subsequent hydrogels physical entanglement, without showing a significant effect on aerogels morphology (nanoporous) and textural properties (pores of about 10 nm). However, an increase of hydrogel physical entanglement promoted the formation of aerogels with a higher compressive strength (from 0.2 to 0.80 MPa) and higher thermal decomposition range, while decreasing the porosity (from 90 % to 94 %). Aerogels stress-strain responses were also successfully fitted using a hyperelastic equation with three adjustable parameters (Yeoh), showing that this type of models must be taken into account when large stresses are studied. 2020-01-08T00:00:00Z http://hdl.handle.net/10366/156839 [EN]A global release model is proposed to study the drug release from porous materials for pharmaceutical applications. This model is defined by implementing a compartmental model where the release profile could be explained as the combination of mass transfer phenomena through three compartments as well as a desorption process or dissolution process from the support. This model was validated with five different systems produced with supercritical CO 2 (aerogels, membranes, and fibers), showing different release processes. Numerical results indicate that this compartmental approach can be useful to determine adsorption and desorption constants as well as mass transfer resistances within the material. Likewise, this model can predict lag phases and imbibition phenomena. Therefore, the development of compartmental models can be an alternative to traditional models to successfully predict the drug profile of porous materials, achieving a complete understanding of the involved phenomena regardless of the material characteristics. 2023-01-01T00:00:00Z http://hdl.handle.net/10366/156838 [EN]In order to reduce the side effects of traditional chemotherapy in the treatment of colorectal cancer (CRC), a newdrug delivery system has been developed in this work, based on exosomes that can host two drugs that act synergistically: farnesol (that stops the cell cycle) and paclitaxel (prevents microtubule system depolymerization). Firstly, exosomes were isolated from different cell cultures (from colorectal cancer and from f ibroblast as example of normal cell line) by different methods and characterized by western blot, TEM and DLS, and results showed that they express classical protein markers such as CD9 and HSP-70 and they showed spherical morphology with sizes from 93 nm to 129 nm depending on the source. These exosomes were loaded with both drugs and its effect was studied in vitro. The efficacy was studied by comparing the viability of cell cultures with a colorectal cancer cell line (HCT-116) and a normal cell line (fibroblast HS-5). Results showed that exosomes present a specific effect with more reduction in cell viability in tumour cultures than healthy ones. In summary, exosomes are presented in this work as a promising strategy for colorectal cancer treatment 2024-01-01T00:00:00Z http://hdl.handle.net/10366/156837 [EN]The aim of this work was to try to implement a new laboratory class for Chemical Engineering students in which they could analyze how it is possible to revalue some organic residues. Concretely, the objective was to show them how to revalue olive leaves by extracting their polyphenols, since these leaves, being an abundant organic waste in Spain, were well-known by the students to whom this study was addressed. With the aim of improving student understanding of the basic Chemical Engineering concepts, two extraction techniques (solvent extraction process and ultrasound-assisted extraction) as well as their combination were investigated during the class. In addition, the effect that different pre-treatments had on polyphenol extraction efficiency was also studied to show students how important research is before fine-tuning an industrial process. To do this, students were divided into working groups to carry out polyphenol extraction under different experimental conditions. Ultimately, student groups compared and discussed the efficiency of the different employed extraction techniques. Likewise, students were surveyed to evaluate the suitability and training-usefulness of the proposed class. Obtained assignments revealed that it could be an interesting option to improve students’ hands-on experience while strengthening some theoretical concepts explained in the degree lectures. 2023-01-01T00:00:00Z http://hdl.handle.net/10366/156835 [EN]At present, colorectal cancer (CRC) is the second deadliest type of cancer, partly because a high percentage of cases are diagnosed at advanced stages when tumors have already metastasized. Thus, there is an urgent need to develop novel diagnostic systems that allow early detection as well as new therapeutic systems that are more specific than those currently available. In this context, nanotechnology plays a very important role in the development of targeted platforms. In recent decades, many types of nanomaterials with advantageous properties have been used for nanooncology applications and have been loaded with different types of targeted agents, capable of recognizing tumor cells or biomarkers. Indeed, among the different types of targeted agents, the most widely used are monoclonal antibodies, as the administration of many of them is already approved by the main drug regulatory agencies for the treatment of several types of cancer, including CRC. In this way, this review comprehensively discusses the main drawbacks of the conventional screening technologies and treatment for CRC, and it presents recent advances in the application of antibody-loaded nanoplatforms for CRC detection, therapy or theranostics applications. 2023-01-01T00:00:00Z http://hdl.handle.net/10366/156820 [EN]This work proposes the development of a thermosensitive local drug release system based on Polaxamer 407, also known as Pluronic® F-127 (PF-127), Gellan Gum (GG) and the inclusion complex Sulfobutylated-β-cyclodextrin (CD) with Farnesol (FOH). Rheological properties of the hydrogels and their degradation were studied. According to the rheological results, a solution of 20% w/v of PF-127 forms a strong gel with a gelling temperature of about 25 C (storage modulus of 15,000 Pa). The addition of the GG increased the storage modulus (optimal concentration of 0.5 % w/v) twofold without modifying the gelling temperature. Moreover, including 0.5% w/v of GG also increased 6 times the degradation time of the hydrogel. Regarding the inclusion complex, the addition of free CD decreased the viscosity and the gel strength since polymer chains were included in CD cavity without affecting the gelling temperature. Contrarily, the inclusion complex CD-FOH did not significantly modify any property of the formulation because the FOH was hosted in the CD. Furthermore, a mathematical model was developed to adjust the degradation time. This model highlights that the addition of the GG decreases the number of released chains from the polymeric network (which coincides with an increase in the storage modulus) and that the free CD reduces the degradation rate, protecting the polymeric chains. Finally, FOH release was quantified with a specific device, that was designed and printed for this type of system, observing a sustainable drug release (similar to FOH aqueous solubility, 8 μ M) dependent on polymer degradation. 2023-01-01T00:00:00Z http://hdl.handle.net/10366/156819 [EN]This work proposes the use of supercritical CO2 to impregnate starch (potato and corn) aerogels with quercetin for a potential fungistatic application. Starch aerogels were successfully produced with supercritical drying, but different results were found depending on the amylose/amylopectin ratio. A higher amount of amylose increases aerogels' specific surface area (with a structure with nanofibrils and nodes) due to the linear and amorphous character of this polymer, whereas a higher amount of amylopectin decreases this property until values of only 25 m2·g−1, obtaining an aerogel with a rough surface. These results were explained with XRD, thermogravimetric, and rheological results (triple step with two temperature sweeps and a time sweep and steady state analysis) concerning hydrogel formation. In fact, retrogradation step plays a more important role in hydrogel formation for a starch source with a higher amount of amylopectin due to an increase in the different polymers' interactions. Supercritical impregnation of quercetin on the aerogels was successfully performed (a loading around 0.30 % with respect to the amount of polymer), and in vitro results indicated that the aerogels produced a fungistatic effect on different types of fungi, but only in the first 12 h because the microorganisms adapted to the surrounding environment. Finally, a compartmental model was used to fit the drug release, which is controlled by quercetin aqueous solubility, indicating the main mass transfer resistances (mass transfer through aerogels was always around 500 min−1 and dissolution process mass transfer from 5·10−3 to 1.65·10−3 s−1) and how an increase in the specific surface area of the aerogels (in the case of corn aerogel) provided a stronger initial burst (70–80 % in 20 min). In fact, this initial burst release was mathematically related to a parameter, that varies from 0.178 to 0.036 depending on the aerogel composition. This study shows that starch aerogels can be impregnated with a hydrophobic compound with fungistatic effect by using supercritical CO2, modifying in addition the drug release by changing the native starch. 2023-01-01T00:00:00Z