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Tissue engineering (TE) demands scaffolds that have the necessary resistance to withstand the mechanical stresses once implanted in our body, as well as excellent biocompatibility. Hydrogels are postulated as interesting materials for this purpose, especially those made from biopolymers. In this study, the microstructure and rheological performance, as well as functional and biological properties of chitosan and collagen hydrogels (CH/CG) crosslinked with different coupling agents, both natural such as d-Fructose (F), genipin (G) and transglutaminase (T) and synthetic, using a combination of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride with N-hydroxysuccinimide (EDC/NHS) will be assessed. FTIR tests were carried out to determine if the proposed crosslinking reactions for each crosslinking agent occurred as expected, obtaining positive results in this aspect. Regarding the characterization of the properties of each system, two main trends were observed, from which it could be established that crosslinking with G and EDC-NHS turned out to be more effective and beneficial than with the other two crosslinking agents, producing significant improvements with respect to the base CH/CG hydrogel. In addition, in vitro tests demonstrated the potential application in TE of these systems, especially for those crosslinked with G, T and EDC-NHS.

Tissue engineering (TE) demands scaffolds that have the necessary resistance to withstand the mechanical stresses once implanted in our body, as well as excellent biocompatibility. Hydrogels are postulated as interesting materials for this purpose, especially those made from biopolymers. In this study, the microstructure and rheological performance, as well as functional and biological properties of chitosan and collagen hydrogels (CH/CG) crosslinked with different coupling agents, both natural such as d-Fructose (F), genipin (G) and transglutaminase (T) and synthetic, using a combination of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride with N-hydroxysuccinimide (EDC/NHS) will be assessed. FTIR tests were carried out to determine if the proposed crosslinking reactions for each crosslinking agent occurred as expected, obtaining positive results in this aspect. Regarding the characterization of the properties of each system, two main trends were observed, from which it could be established that crosslinking with G and EDC-NHS turned out to be more effective and beneficial than with the other two crosslinking agents, producing significant improvements with respect to the base CH/CG hydrogel. In addition, in vitro tests demonstrated the potential application in TE of these systems, especially for those crosslinked with G, T and EDC-NHS.

An increase in resistance to key antibiotics has made the need for novel treatments for the gastric colonization of Helicobacter pylori (H. pylori) a matter of the utmost urgency. Recent studies tackling this topic have focused either on the discovery of new compounds to ameliorate therapeutic regimes (such as vonoprazan) or the synthesis of gastroretentive drug delivery systems (GRDDSs) to improve the pharmacokinetics of oral formulations. The use of semi-interpenetrating polymer networks (semi-IPNs) that can act as super-porous hydrogels for this purpose is proposed in the present work, specifically those displaying low ecological footprint, easy synthesis, self-floating properties, high encapsulation efficiency for drugs such as amoxicillin (AMOX), great mucoadhesiveness, and optimal mechanical strength when exposed to stomach-like fluids. To achieve such systems, biodegradable synthetic copolymers containing acid-labile monomers were prepared and interpenetrated with guar gum (GG) in a one-pot polymerization process based on thiol-ene click reactions. The resulting matrices were characterized by SEM, GPC, TGA, NMR, and rheology studies, and the acidic hydrolysis of the acid-sensitive polymers was also studied. Results confirm that some of the obtained matrices are expected to perform optimally as GRDDSs for the sustained release of active pharmaceutical ingredients at the gastrointestinal level, being a priori facilitated by its disaggregation. Therefore, the optimal performance of these systems is assessed by varying the molar ratio of the labile monomer in the matrices.

Chitosan (CH) is a very well-known biopolymer that has been widely used for the development of biomaterials with a wide range of applications in the biomedical field, such as the preparation of hydrogels, owing to its outstanding anti-inflammatory, antibacterial and antifungal properties, biocompatibility and biodegradability, although they present limited mechanical properties. Chemical crosslinking is one of the most recurrent strategies for the reinforcement of these structures and, above all, crosslinking with natural-origin compounds that do not compromise their biocompatibility is considered a hot topic in this research field. D-fructose (F), obtained from the hydrolyzation and further isomerization of starch, an abundant raw material and genipin (G), which is extracted from the fruits of Gardenia jasminoides Ellis are used as natural crosslinkers. Chitosan-based hydrogels crosslinked with each crosslinking agent are prepared and characterized through Fourier transform infrared (FTIR) spectroscopy, crosslinking and swelling degree determination, rheological, microstructural, and biological studies. The results demonstrate that crosslinking with G is more beneficial for chitosan-based hydrogels since these samples showed more compact structures and better rheological performance. Additionally, excellent biological in vitro behavior due to the crosslinking with G, unlike that of F.

Chitosan (CTS) is a polysaccharide with a wide variety of applications in the biomedical field, owing to its outstanding disinfectant properties, biocompatibility and biodegradability, but with limited mechanical properties. The proposed strategy to improve CTS-based hydrogel properties in this study is the formation of a semi-interpenetrating polymer network (semi-IPN). In this way, a photo-initiated radical click reaction was proposed to obtain a synthetic polymer, whose components were included in a CTS solution, resulting in the semi-IPN network after UV illumination. Different crosslinking degrees (CD) and CTS/polymer ratios were evaluated through rheological characterization, along with an assessment of both variables based on an experimental model design, obtaining that, for every CTS/polymer ratio, intermediate values of CD (8 %) offered the best rheological properties. In addition, chemical and microstructural characterization were carried out for selected hydrogels, obtaining consistent results according to rheological characterization, as the 1/1 CTS/polymer ratio with CD 8 % hydrogel displayed the most homogeneous pore size and distribution, consequently leading to the best rheological performance.

Chitosan (CH) is a very well-known biopolymer that has been widely used for the development of biomaterials with a wide range of applications in the biomedical field, such as the preparation of hydrogels, owing to its outstanding anti-inflammatory, antibacterial and antifungal properties, biocompatibility and biodegradability, although they present limited mechanical properties. Chemical crosslinking is one of the most recurrent strategies for the reinforcement of these structures and, above all, crosslinking with natural-origin compounds that do not compromise their biocompatibility is considered a hot topic in this research field. D-fructose (F), obtained from the hydrolyzation and further isomerization of starch, an abundant raw material and genipin (G), which is extracted from the fruits of Gardenia jasminoides Ellis are used as natural crosslinkers. Chitosan-based hydrogels crosslinked with each crosslinking agent are prepared and characterized through Fourier transform infrared (FTIR) spectroscopy, crosslinking and swelling degree determination, rheological, microstructural, and biological studies. The results demonstrate that crosslinking with G is more beneficial for chitosan-based hydrogels since these samples showed more compact structures and better rheological performance. Additionally, excellent biological in vitro behavior due to the crosslinking with G, unlike that of F.

The development of biodegradable plastics and eco-friendly biomaterials derived from renewable resources is crucial for reducing environmental damage. Agro-industrial waste and rejected food can be polymerized into bioplastics, offering a sustainable solution. Bioplastics find use in various industries, including for food, cosmetics, and the biomedical sector. This research investigated the fabrication and characterization of bioplastics using three types of Honduran agro-wastes: taro, yucca, and banana. The agro-wastes were stabilized and characterized (physicochemically and thermically). Taro flour presented the highest protein content (around 4.7%) and banana flour showed the highest moisture content (around 2%). Furthermore, bioplastics were produced and characterized (mechanically and functionally). Banana bioplastics had the best mechanical properties, with a Young’s modulus around 300 MPa, while taro bioplastics had the highest water-uptake capacity (200%). In general, the results showed the potential of these Honduran agro-wastes for producing bioplastics with different characteristics that could add value to these wastes, promoting the circular economy.

Hydrogels are considered good biomaterials for soft tissue regeneration. In this sense, collagen is the most used raw material to develop hydrogels, due to its high biocompatibility. However, its low mechanical resistance, thermal stability and pH instability have generated the need to look for alternatives to its use. In this sense, the combination of collagen with another raw material (i.e., polysaccharides) can improve the final properties of hydrogels. For this reason, the main objective of this work was the development of hydrogels based on collagen and chitosan. The mechanical, thermal and microstructural properties of the hydrogels formed with different ratios of collagen/chitosan (100/0, 75/25, 50/50, 25/75 and 0/100) were evaluated after being processed by two variants of a protocol consisting in two stages: a pH change towards pH 7 and a temperature drop towards 4 °C. The main results showed that depending on the protocol, the physicochemical and microstructural properties of the hybrid hydrogels were similar to the unitary system depending on the stage carried out in first place, obtaining FTIR peaks with similar intensity or a more porous structure when chitosan was first gelled, instead of collagen. As a conclusion, the synergy between collagen and chitosan improved the properties of the hydrogels, showing good thermomechanical properties and cell viability to be used as potential biomaterials for Tissue Engineering.

In the last few years, electrospinning has proved to be one of the best methods for obtaining membranes of a micro and nanometric fiber size. This method mainly consists in the spinning of a polymeric or biopolymeric solution in solvents, promoted by the difference in the electric field between the needle and collector, which is finally deposited as a conjunction of randomly oriented fibers. The present work focuses on using cellulose derivatives (namely cellulose acetate and ethylcellulose), based on the revaluation of these byproducts and waste products of biorefinery, to produce nanostructured nanofiber through electrospinning with the objective of establishing a relation between the initial solutions and the nanostructures obtained. In this sense, a complete characterization of the biopolymeric solutions (physicochemical and rheological properties) and the resulting nanostructures (microstructural and thermal properties) was carried out. Therefore, solutions with different concentrations (5, 10, 15, and 20 wt%) of the two cellulose derivatives and different solvents with several proportions between them were used to establish their influence on the properties of the resulting nanostructures. The results show that the solutions with 10 wt% in acetic acid/H2O and 15 wt% in acetone/N,N-dimethylformamide of cellulose acetate and 5 wt% of ethylcellulose in acetone/N,N-dimethylformamide, exhibited the best properties, both in the solution and nanostructure state.

Hydrogels are considered good biomaterials for soft tissue regeneration. In this sense, collagen is the most used raw material to develop hydrogels, due to its high biocompatibility. However, its low mechanical resistance, thermal stability and pH instability have generated the need to look for alternatives to its use. In this sense, the combination of collagen with another raw material (i.e., polysaccharides) can improve the final properties of hydrogels. For this reason, the main objective of this work was the development of hydrogels based on collagen and chitosan. The mechanical, thermal and microstructural properties of the hydrogels formed with different ratios of collagen/chitosan (100/0, 75/25, 50/50, 25/75 and 0/100) were evaluated after being processed by two variants of a protocol consisting in two stages: a pH change towards pH 7 and a temperature drop towards 4 °C. The main results showed that depending on the protocol, the physicochemical and microstructural properties of the hybrid hydrogels were similar to the unitary system depending on the stage carried out in first place, obtaining FTIR peaks with similar intensity or a more porous structure when chitosan was first gelled, instead of collagen. As a conclusion, the synergy between collagen and chitosan improved the properties of the hydrogels, showing good thermomechanical properties and cell viability to be used as potential biomaterials for Tissue Engineering.

Different composites based on ZnO/Ag3 PO4 and ZnO–malachite (Cu2 (OH)2 CO3 ) were synthesized in order to determine their effectiveness in the treatment of municipal and industrial wastewaters (mainly polluted by enteropathogenic bacteria, dyes, and heavy metals). The addition of Ag3 PO4 and malachite did not significantly modify the physicochemical properties of ZnO; however, the optical properties of this oxide were modified as a result of its coupling with the modifiers. The modification of ZnO led to an improvement in its effectiveness in the treatment of municipal and industrial wastewater. In general, the amount of malachite or silver phosphate and the effluent to be treated were the determining factors in the effectiveness of the wastewater treatment. The highest degree of elimination of bacteria from municipal wastewater and discoloration of textile staining wastewater were achieved by using ZnO/Ag3 PO4 (5%), but an increase in the phosphate content had a detrimental effect on the treatment. Likewise, the highest Fe and Cu photoreduction from coal mining wastewater was observed by using ZnO–malachite (2.5%) and ZnO/Ag3 PO4 (10%), respectively. Some of the results of this work were presented at the fourth Congreso Colombiano de Procesos Avanzados de Oxidación (4CCPAOx).

In recent years, tissue engineering research has led to the development of this field by designing scaffolds with better properties that can fulfill its purpose of better and faster tissue regeneration, consequently improving people’s quality of life. Scaffolds are matrices, predominantly composed of polymeric materials, whose main function is to offer support for cell adhesion and subsequent growth, leading to the regeneration of the damaged tissue. The widely used biopolymer in tissue engineering is collagen, which is the most abundant protein in animals. Its use is due to its structure, biocompatibility, ease of modification, and processability. In this work, collagen-based scaffolds were developed with different concentrations and processing techniques, by obtaining hydrogels and aerogels that were characterized with an emphasis on their morphology and mechanical properties. Moreover, fructose was added in some cases as a chemical crosslinking agent to study its influence on the scaffolds’ properties. The obtained results revealed that the scaffolds with higher collagen concentrations were more rigid and deformable. Comparing both systems, the aerogels were more rigid, although the hydrogels were more deformable and had higher pore size homogeneity. Fructose addition produced a slight increase in the critical strain, together with an increase in the elastic modulus.

La Ingeniería de Tejidos ha propiciado el desarrollo de andamios con mejores propiedades que pueden cumplir su propósito de una mejor regeneración de tejidos, mejorando consecuentemente la calidad de vida de las personas. Los andamios son matrices cuya función principal es dar soporte a la adhesión celular y su posterior crecimiento, lo que lleva a la regeneración del tejido dañado. El colágeno es una de las proteínas más abundantes en animales y biopolímero ampliamente utilizado en Ingeniería de Tejidos, por su estructura, biocompatibilidad y la facilidad de su modificación y procesabilidad. En este estudio se prepararán y caracterizarán andamios de colágeno con diferentes concentraciones y técnicas de procesamiento, mediante la obtención de hidrogeles y aerogeles, atendiendo especialmente a su morfología y propiedades mecánicas. Además, se utilizó fructosa como agente químico de entrecruzamiento para estudiar su influencia en las propiedades de los andamios. Los resultados obtenidos revelaron que los andamios con mayores concentraciones de colágeno eran más rígidos y deformables. Comparando ambos sistemas, los aerogeles eran más rígidos pero los hidrogeles, aunque más deformables y con mayor homogeneidad de tamaño de poro. La adición de fructosa produjo un ligero aumento de la deformación crítica, junto con un aumento del módulo elástico., Tissue Engineering has led to the development of this field by designing scaffolds with better properties that can fulfill its purpose of better tissue regeneration, consequently improving people’s quality of life. Scaffolds are matrix, predominantly composed by polymeric materials, which main function is giving support to cell adhesion and the subsequently growth, leading to the regeneration of the damaged tissue. Collagen is one of the most abundant proteins in animals and widely used biopolymer in Tissue Engineering, due to its structure, biocompatibility and the ease of its modification and processability. In this study, collagen scaffolds with different concentrations and processing techniques, by obtaining hydrogels and aerogels, will be prepared and then characterized, specially looking at its morphology and mechanical properties. Moreover, fructose was added as a chemical crosslinking agent to study the influence on scaffolds’ properties. The results obtained revealed that scaffolds with higher collagen concentrations were stiffer and more deformable. Comparing both systems, aerogels were stiffer but hydrogels were more deformable and with higher pore size homogeneity. Fructose addition produced a slight increase in the critical strain, together with an increase in the elastic modulus.

El desarrollo de biomateriales abarca tres etapas diferentes: selección de materia prima, técnica de procesado y caracterización del producto final. Entre ellos, los hidrogeles se han presentado como candidatos potenciales en aplicaciones farmacéuticas y biomédicas por sus propiedades fisicoquímicas. La mayor parte de los estudios sobre hidrogeles se basan en polímeros naturales por sus excelentes propiedades biológicas. Sin embargo, su procesado es complejo, puesto que se han de controlar parámetros como el tiempo de gelificación, el pH de la disolución y la temperatura de gelificación. No obstante, también es importante seleccionar y caracterizar adecuadamente la materia prima, ya que afecta a las propiedades de los hidrogeles obtenidos. Por tanto, el objetivo de este trabajo es optimizar el proceso de fabricación de hidrogeles de colágeno, evaluando tanto la materia prima a utilizar como los parámetros de procesado que pueden influir en el proceso. Dicha evaluación se ha llevado a cabo mediante el estudio de sus propiedades mecánicas, morfológicas y biológicas. Los resultados muestran como los parámetros definidos durante el procesado del hidrogel son claves en las propiedades finales obtenidas. Además, algunos de ellos presentan adecuadas propiedades para su potencial uso en Ingeniería de Tejidos., The development of biomaterials encompasses three different stages: selection of the raw material, processing technique and characterization of the final product. Among them, hydrogels have been presented as potential candidates in pharmaceutical and biomedical applications due to their physicochemical properties. Most of the studies about hydrogels are based on natural polymers for their excellent biological properties. However, their processing is complex, since several parameters need to be controlled such as gelation time, pH of the solution and gelation temperature. Nevertheless, it is also important to select and characterize the raw material before the fabrication of the hydrogels. Therefore, the objective of the work is to optimize the hydrogel fabrication, evaluating both the raw material to be used and the processing parameters that can influence the process. This evaluation has been carried out by studying its mechanical, morphological and biological properties. Results show how the parameters defined during the hydrogel processing are essential in the final properties obtained. In addition, some of the systems have suitable properties for their potential use in Tissue Engineering.

Different composites based on ZnO/Ag3PO4 and ZnO–malachite (Cu2(OH)2CO3) were synthesized in order to determine their effectiveness in the treatment of municipal and industrial wastewaters (mainly polluted by enteropathogenic bacteria, dyes, and heavy metals). The addition of Ag3PO4 and malachite did not significantly modify the physicochemical properties of ZnO; however, the optical properties of this oxide were modified as a result of its coupling with the modifiers. The modification of ZnO led to an improvement in its effectiveness in the treatment of municipal and industrial wastewater. In general, the amount of malachite or silver phosphate and the effluent to be treated were the determining factors in the effectiveness of the wastewater treatment. The highest degree of elimination of bacteria from municipal wastewater and discoloration of textile staining wastewater were achieved by using ZnO/Ag3PO4 (5%), but an increase in the phosphate content had a detrimental effect on the treatment. Likewise, the highest Fe and Cu photoreduction from coal mining wastewater was observed by using ZnO–malachite (2.5%) and ZnO/Ag3PO4 (10%), respectively. Some of the results of this work were presented at the fourth Congreso Colombiano de Procesos Avanzados de Oxidación (4CCPAOx)