This work focuses on the development of a system to control the formation of bone to complement developments that have enabled potent regeneration of bony tissue. Scaffolds were fabricated with chemically modified RNA encoding for bone morphogenetic protein-9 (cmBMP9) and capped with salicylic acid (SA)-containing polymer (SAPAE). The goal was to determine if SAPAE could inhibit the formation of bone in a pilot animal study since cmBMP9 has been demonstrated to be highly effective in regenerating bone in a rat calvarial defect model. The results indicated that cmBMP9 increased bone formation (30% increase in area covered compared to control) and that SAPAE trended toward reducing the bone formation. These results suggest SAPAE could be useful as a chemical agent in reducing unwanted bone formation in implants loaded with cmBMP9.

Due to their excellent properties, aerogel has attracted the attention of the scientific community to use it in the biomedical area as a drug delivery system. This work reports on the synthesis and characterization of ZrO2 aerogels and cryogels obtained by the sol-gel method. The influence of different cetyltrimethylammonium bromide (CTAB) and the type of drying on structural, morphological and texture properties of ZrO2 aerogels and cryogels was investigated. SEM images reveal that a porous interconnected three-dimensional network was formed into aerogels due to supercritical drying. Zirconia aerogel sample has a specific surface area (SBET) larger than zirconia cryogels. Therefore, our results indicate that zirconia aerogel is an adequate material for applications in drug delivery systems.

In recent years, modified graphene has been used in various biomedical applications due to its excellent properties that allow the development of devices capable of detecting macromolecules within the human organism, also for biomolecular analysis, discovery of biomarkers, bioimaging and target delivery. These applications involve interactions between enzymes, proteins, peptides, DNA, RNA, etc. and modified graphene, therefore the study and the theoretical and experimental investigation of these interactions is essential for the development of nanobio-technology. For example, many applications based on using modified graphene to detect macromolecules require studying the changes in the properties of doped graphene when interacting with macromolecules. In this work, DFT and molecular dynamics methods were used to obtain results of the changes in energy density of states of graphene doped with iron when it is made to interact with coenzyme A. Besides, we presented a study of molecular dynamics in order to determine the quantum factors that guide the interaction graphene-coenzyme A. The system was studied in aqueous medium which it was simulated by the dielectric constant of water. The results confirm that the methodology presented in this work can be used to theoretically detect various macromolecules.

We describe the use of immobilized deoxyribonucleic acid (DNA) in a silica matrix as a biorecognition agent for the detection of albendazole sulfoxide (ASU), the primary metabolite of albendazole and a suspected teratogenic and embryotoxic agent. The biomaterial (DNA-containing gel) was synthesized by physical entrapment of salmon sperm in an inorganic silicate matrix by the sol-gel method. Functionality of the DNA-containing gel was evaluated by comparative offline frontal chromatography followed by HPLC analysis of ASU and caffeine (CAF, control) using DNA-containing gel and DNA-free gel. The DNA-containing gel showed relatively high specific retention for ASU, while CAF showed no retention using frontal analysis. We anticipate that the DNA-containing gel can be implemented to identify the interactions of DNA with other active pharmaceutical ingredients (APIs) and their metabolites in a readily available, sensitive and selective frontal chromatography experiment.

Reported conversion efficiencies of lead based perovskite solar cells keep increasing steadily. But next to the demand for high efficiency, the need for analogue non-toxic material systems remains. One promising lead free absorber material is the double perovskite Cs2AgBiBr6. Interest in this and other double perovskites has been increasing in the last three years and several solar cells using different device structures have been reported. However, the efficiency of these solar cells is merely in the range of 2%. To further improve solar cell performance we prepared mixed bismuth-antimony double perovskite Cs2AgBi1-xSbxBr6 where different fractions of antimony (x=0.125, 0.25, 0.375, 0.50) are used. This was motivated by reports of lower bandgap values in these mixed system. After the optimization of preparation of these thin films, we have carefully analysed the effects on the structure, composition, electronic structure, as well as optical properties. Finally, we have fabricated Bi-Sb mixed double perovskite solar cells in a mesoscopic device architecture.

The adsorption/degradation of caffeine and irgasan from aqueous artificial solutions by using.Lignocellulosic residues (LR) impregnated with TiO2 nanoparticles was studied. Three different LR were used: bamboo (Guadua angustifolia), laurel (Cordia allidora) and moringa (Moringa oleifera Lam.), each one with three nominal particle size ranges: 75–149, 45–75, and ≤45 μm. Commercially available TiO2 nanoparticles were added to these residues using the wet impregnation technique. The chemical composition of the LR was determined according to ASTM standards. FTIR spectroscopy and scanning electron microscopy were used to determine the functional groups and morphology of the modified materials, respectively. Adsorption/degradation tests were carried out in batch systems as a function of adsorbent concentration, contact time, nanoparticle content on the impregnated residues and light type influence. The maximum adsorption capacity was (37.1 mg. g-1/55.3 mg.g-1), using 40 wt.% nanoparticle-impregnated ≤45 μm laurel residues during 180 minutes, for a (7.0/0.7 g.L-1) concentration of (caffeine/irgasan). The caffeine adsorption isotherms were well described by the Langmuir and Freundlich models, while the Freundlich model describes irgasan adsorption. The use of UV radiation accelerated threefold the removal process.

According to the UNEP, mercury pollution is one of the main contamination problems of the world. The UN showed that more than 1,870 tons of this metal are released into the environment annually. This material arrives to water bodies where fish consume it and then reaches humans, producing negative effects on their health. The hydroxyapatite is one of the main components of bones and has proven itself to be useful in the removal of mercury from polluted sources. The aim of this research project is to synthesize and characterize different formulations of this substance and to determine which is the best selective formulation to remove mercury in water. Currently, twenty-one formulations have been produced. The experimental variables examined are the pH, the temperature and the time of calcination. These variables are characterized with Infrared Spectrophotometry (IR), Scanning Electron Microscope (SEM) and X-ray diffraction (XRD). Before calcination the samples contained 70% of hydroxyapatite. This concentration increased in some of them after calcination. The analysis of the results allowed to test the efficiency of these formulations at removing mercury from water. These materials will also be combined, in future stages of the research, with other substances such as activated carbon and organic fibers to improve their performance. The material will be used to coat a filter so that it can become a piping accessory to remove mercury from polluted waters as it is being recirculated.

This work presents the synthesis and characterization of a pearylated polysiloxane material (PAP) from a polycondensation reaction, followed by functionalization with HClSO3 by an electrophilic substitution reaction. According to the characterization techniques applied, a sulfonated pearylated polysiloxane was also obtained, (SPAP). The purpose of this sulfonated material is to obtain an ionomer able to be applied in hydrogen fuel cells of the proton exchange membrane kind (PEMFC). The reaction to produce the polysiloxane precursor was carried out with the commercial reagents: PhSiCl3, Ph2SiCl2 and Ph3SiCl in anhydrous THF at 75 °C and the SPAP material was obtained by sulfonation of the precursor with chlorosulfonic acid. PAP and SPAP were characterized by 1H, NMR for liquids, 29Si NMR for solids, IR-ATR, SEM, and cyclic voltammetry. The NMR 29Si spectra show that PAP and PAPS contain crosslinking regions due to PhSiCl3, growing chain zones due to Ph2SiCl2 and polymer termination zones due to Ph3SiCl, obtaining a mixture of siloxanes. The analysis by cyclic voltammetry indicates that by integrating the area under the curve of the adsorption peaks of H2, a value of 0.062 mC/cm2 is obtained, a value close to the commercial ionomer of Nafion®.