Thin films are superficial layers with thickness ranging from a few nanometers to micrometers. Their applications can encompass electronic devices such as transistors and solar cells, the food industry for biopolymeric packaging, smart packaging with customized properties for the product, as well as biomedical applications, enhancing biocompatibility and corrosion resistance on surfaces, as well as for wound care and implants. Understanding the properties of thin films and their production processes is crucial for the development of innovative technologies. Among various deposition techniques for thin film production, spin-coating is considered a fast and easy way to produce homogeneous films. It is performed by spreading a material on a substrate in rotation. In its application, a variety of materials that form films upon drying or solidification can be used, including liquids, suspensions, solutions, or gels. Control over coating density and thickness can be implemented by adjusting the concentration of the deposited material, substrate rotation speed, and time. This study presents the development of a spin-coating equipment with programmable options for acceleration, deposition time, rotation time, and rotation speed. The machine was built using commercial electronic components, 3D-printed parts, and recycled elements, such as the casing of a stabilizer, a plastic CD case, and a CD-ROM DC motor, significantly reducing its cost. The final prototype of the developed spin-coater exhibited functioning compatible with the intended purpose, fulfilling its basic functions as a laboratory film production machine and adding a substrate holder with customized options for different substrate sizes and formats and routine configurations for film manufacturing. The fabrication of thin films of calcium alginate with the developed spin-coater is also presented in the work, followed by the analysis of such films by atomic force microscopy to analyze their characteristics of topography and viscoelasticity. For this, film deposition tests were performed in triplicates using concentrations of sodium alginate of 1%, 2%, and 3%, followed by crosslinking with 1% calcium chloride (CaCl2), a process performed in two spin-coating steps. This allowed obtaining information on the effects of alginate film concentrations on film topographies and roughnesses. It was observed that lower concentrations of alginate resulted in more homogeneous films. Thus, the concentration of 1% alginate and 1% CaCl2 were selected for subsequent tests applying different conditions of speed, time, and deposition time. Through a full factorial experimental design, the spincoating parameters were varied for the same concentrations and material proportions. This allowed evaluating the influences of speed and rotation time on film roughness and distribution over the substrate. In this regard, a more evident influence of rotation time than speed on the roughness measurements of the films was observed. Finally, comparisons and analyses of the developed spin-coater with other equipment and similar studies were carried out, listing the advantages and disadvantages of each feature, such as substrate support type, control options, and other configurations. These characteristics are discussed considering the operation of commercial machines and their market accessibility to contextualize the developed machine. Overall, this study not only helped to expand the understanding of thin film manufacturing processes but also offered a valuable perspective on the development of innovative and accessible technologies in this growing field. 

 The central nervous system (CNS) is protected by a semipermeable dynamic structure, called the blood-brain barrier (BBB), which efficiently shields this area from possible changes caused by harmful agents from the environment. In this sense, liposomal nanosystems present gains in performance and functionality, with a view to facilitating the passage of drugs through this barrier. Among the nutraceuticals that can be therapeutically used, resveratrol (RES) is a very promising flavonoid for acting as an anti-inflammatory and antioxidant agent. In the present work, a liposomal phosphatidylcholine nanosystem was made associated with poloxamer (pluronic F127) micelles for RES encapsulation. Each step of the experiments (production of empty and RES-filled pluronic F127 micelles, empty and RES-filled liposomal nanosystems, empty and extruded extruded liposomal nanosystems with RES) were repeated at least three times to verify their reproducibility, in addition to having the diameter values hydrodynamic (Z-Ave and percentage numbers) and polydispersion (PdI) measurements accounted for. About the Z-Ave, each group obtained different results including statistical difference between then. Therefore was necessary to review the hydrodynamic diameter in numbers in order to solve this issue. The PdI showed the importance of the extrusion method to obtain a more monodisperse solution (close to 0,2). Afterwards, the encapsulation rate was evaluated in the three experiments (batches) of extruded liposomal nanosystems with RES with an encapsulation rate of 63.94%, 89.10% and 100%. Then, a new liposomal extruded structure was constructed with RES and subjected to passage through a membrane with porosity compatible with that of the BBB. This nanosystem was able to perform diapedesis and maintain its size close to before passage. The liposomal nanosystem proved to be effective for RES encapsulation with an encapsulation rate compatible with that of the reviewed literature when compared to other nanosystem types. The results confirm the initial assumptions of high efficiency of the encapsulation capacity of the in vitro analyses and in vivo future studies will be necessary to verify the functionality of RES delivery in animal models.  

Objective: To develop and characterize nanosystems containing Naringenin as an effective alternative for controlling ticks in livestock and mites in agriculture. Methodology: The analysis of nano formulations (Nanosystem 1, Nanosystem 2 and Nanosystem 3). The positive control was represented by drug formulations, while the negative control was represented by nano formulations without the active principle. The pH, the Zeta Potential, the PDI and the droplet size were evaluated for the characterization of the nano formulations in order to verify their acaricidal activity and toxicity to seed germination as a therapeutic alternative for the control of ticks through a test dipped in washing and dipped in engorged females. Results and Discussion: The addition of components to the nano formulations resulted in the variation of the size, PDI, Zeta Potential and pH of the nanoparticles. This result is expected, since alterations in the structure of nanoparticles cause the rearrangement and variation of its parameters. The nanoformulation Nanosistema 1 NAR, Nanosistema 2 NAR, Nanosistema 3 NAR, was known to be more effective than distilled water and Amitraz (positive control) in controlling R. microplus, suggesting that they may be good options for positive control for the adult immersion test. The submerged test on larvae showed that the distilled water control did not have a deleterious effect on the larvae, while the positive control Triatox (Amitraz) showed 100% mortality, according to FAO standards (95%). The nanoformulations containing Nanosystem 1 NAR and Nanosystem 2 NAR were effective, as they generated 95% and 96% of mortality, respectively. These results suggest that the permeation of the active principle is more efficient and effective, as they allow the drug to be deposited on the skin, generating an occlusive effect, which prevents gas exchange in the mite cells. Tests appreciated that Nanosystem 3 NAR had an increase in germination by 68%. The application of nanoformulations Nanosistema 1 NAR and Nanosistema 2 NAR increased seed germination by more than 75%, exceeding the requirements of Normative Instruction No. 42 of 2019, making it effective as well as negative water control. Conclusion: Pathogenic studies that nano formulations containing naringenin as an active principle can reach the appropriate physicochemical requirements and offer effectiveness for the control of acaricide resistance in relation to teleogynes and bovine tick larvae. Lettuce seeds were also tested, revealing that the nanosystems were effective and safe in the physicochemical and biological quality of the nanoformulations. This formulation opens up opportunities for the development of new formulations and dosage forms.

The current COVID-19 pandemic, caused by the SARS-CoV-2 virus, comprises an infectious disease. Coronaviruses (CoVs), which are part of a viral family, are recognized for causing a variety of respiratory diseases in humans, ranging from the common cold to rarer and more severe conditions such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). This information is recorded by the World Health Organization panel. As far as transmission is concerned, respiratory droplets are the primary means of contamination, allowing SARS-CoV-2 to be transmitted from an infected person to a healthy person through physical contact with the sick patient or by coming into contact with their belongings. Coronaviruses (CoVs) have the ability to remain on surfaces for several days, which may explain the case of SARS-CoV-2 and represent a prolonged risk of infection. Nanotechnology has found extensive application in various fields of study, including medicine, biolabeling, and agriculture. Nowadays, this technology has been employed in different domains of medical science, such as targeted drug delivery, cancer diagnosis, and the development of agents against viral, bacterial, and fungal infections. Gold nanoparticles (AuNPs) exhibit characteristics that include the ability to provide a stable surface for the immobilization of biomolecules, which is highly useful in the preparation of biosensors. They are considered the most stable metallic nanoparticles due to their optical, electronic, and catalytic properties, as well as having high biocompatibility and an improved rate of electron transfer. For these reasons, AuNPs have found wide applications in various types of biosensors. In the present study, the development of a nanobiosensor was conducted using AuNPs that were functionalized with antibodies specific for the SARS-CoV-2 glycoprotein. The main goal of this nanobiosensor was to enable highly specific detection of the SARS-CoV-2 virus. The characterization results of the naked and functionalized AuNP50 and AuNP100 showed that the nanoparticles were stable (hydrodynamic diameter and polydispersity index). The functionalized nanoparticles showed good performance regarding binding on SARS-CoV-2 viruses. Finally, when the functionalized AuNP100 were put in contact with the samples from positive patients, there was a change in the size of the nanoparticles verified by dynamic light scattering (DLS) technique.

The objective of this work is the preparation, characterization and biomedical application of nanocomposites formed by gold nanoparticles and Pluronic® F-127. The nanocomposites were synthesized from the mixture of Pluronic® triblock copolymer solutions varying the concentrations in (0.5; 2.0 mmol.L-1), and chloroauric acid (HAuCl4) (0.1; 2. 0, 3.0, 4.0 mmol.L-1), in a UV radiation chamber (254nm), at room temperature. In this reaction, the copolymer acts in the reduction of gold ions and stabilization of gold nanoparticles, forming the AuNP-PLU colloidal nanocomposite. The ultraviolet-visible spectroscopy analysis shows that the surface plasmonic resonance band of the nanocomposites is located between 525 to 529 nm. The micrographs of the nanocomposites obtained show gold nanoparticles with a spherical, triangular or cylindrical shape, with an average diameter of 5 to 44 nm. The average hydrodynamic (DH) size obtained by dynamic light scattering ranged from 31 to 68 nm. For the biological application experiments, nanocomposites 2.0AuNP-PLU:2.0 and 2.0AuNP-PLU:0.5 were chosen, as they presented greater reproducibility and stability of the physical-chemical characteristics after synthesis. These nanocomposites were used in the photochemical test with 1,3-diphenylisobenzofuran (DPBF), in which the formation of reactive oxygen species (ROS) was observed. To carry out this test, the nanoparticles were associated with a photosensitizer, aluminum phthalocyanine chloride (AlClPc), in concentrations of 0.1 to 5.0 µg. After mixing with the photosensitizer, the nanocomposites were characterized by ultraviolet-visible spectroscopy, in which it was possible to observe a new peak at 680 nm coming from the photosensitizer. The new average hydrodynamic (DH) size of the nanocomposites with the photosensitizer was from 31 to 73 nm. The characterization was performed by Raman spectroscopy and by infrared spectroscopy (FTIR-ATR), in which changes were observed in the spectra of the nanocomposites due to the bonds between the ether groups of the pluronic with the nitrogenous groups of the aluminum phthalocyanine chloride. In another approach, the 2.0AuNP-PLU:2.0 nanocomposite was used to study the maternal and fetal toxicological effects of its administration during pregnancy in rats and fetuses. The results showed that the nanocomposite is safe for both the mother and the fetus at a dose of 137.5 μg/kg. Therefore, the administration of the nanocomposite did not result in changes in fetal development, nor changes greater than 5% in the observed organs. The same 2.0AuNP-PLU:2.0 nanocomposite was investigated as a contrast agent in computed tomography. The results showed that the contrast agent is comparable to the commercially used contrast (Optiray® 320) for the same beam energy.

Recurrent aphthous stomatitis (RAS) is the most widespread oral disease, affecting up to 25% of the global population. Triamcinolone acetonide (TA) has been widely used in the topical treatment of RAS, but current pharmaceutical forms are not efficient for this purpose, so there is a significant need to develop an improved drug administration system. This work proposes to obtain a TA-containing amorphous solid dispersion (ASD) processed by hotmelt extrusion (HME) in the form of a mucoadhesive oral film as an alternative to the RAS treatment. To this end, a detailed preformulation protocol was carried out using theoretical and experimental approaches, leading to the selection of four polymers and a plasticizer. From the Hansen solubility parameters (HSPs) the miscibility of the drug with the polymers was predicted as PVA > EUD > PVPVA > HPMCAS, while thermal analysis (DSC) showed an experimental miscibility, based on the percentage of drug in amorphous state as follows: EUD (81.07%) > PVA (67.55%) > PVPVA (45.57%) > HPMCAS (8.46%). The DTG curves showed instability problems with PVA, PVPVA and HMPCAS, as well as the plasticizer (TEC) evaporation. FTIR spectra confirm the instability and exhibit the maintenance of TEC within the HME processing temperature. The TA-EUD-TEC mixture (10:60:30, w/w) was successfully extruded forming an ASD in the form of a mucoadhesive oral film with a thickness of 0.69 ± 0.06 mm, moderate adhesive potential (0.216N ± 0.031), and 99.6% of drug content. The physicochemical characterization was carried out by DSC, TGA, FTIR and SEM. The results suggest partial evaporation of the liquid plasticizer and formation of heat-dependent anhydrides derived from the polymer chain, thus, the stability of the drug within the polymer matrix must be carefully evaluated. Notably, the pre-plasticization procedure was a key parameter for the success of the HME process.

Titanium dioxide TiO2 is one of the primary compounds for photocatalysis applications. Even though it has been extensively studied, there is still room to improve its photocatalytic properties and photoabsorption. TiO2 presents photocatalytic activity under uv-vis light; however, only 5% of solar energy is present in this region, while 45% comprises visible electromagnetic radiation. Phthalocyanines are studied due to their capacity to interact with visible light, and the copper(II)phthalocyanine tetrasulfonic acid tetrasodium salt (CuPcSO4) was associated with TiO2 and graphene (GR) attached to TiO2. TiO2-GR adsorbed CuPcSO4, and the photochemical behavior was studied. TiO2- GR adsorbed 26% more CuPcSO4 than TiO2 alone. The incorporation of CuPcSO4 onto the surface of TiO2-GR generates a bathochromic shift of the typical graphene response, which indicates that the adsorption of CuPcSO4 reduces the TiO2-GR bandgap. The CuPcSO4 presents a clearer separation of the Q band when adsorbed onto the TiO2 surface, and the Qy band becomes the primary one. The increase and shift in the Qy band indicate a stronger response for low-energy light sources for the phthalocyanine, hence improving the light-harvesting capability of the compound. TiO2-CuPcSO4 and TiO2-GR-CuPcSO4 interact with amphotericin B (amB), demonstrated by the drug absorbance's hypochromic shift, indicating a higher aggregation state. The energy and chemical compounds consumed during the synthesis contribute to the environmental impacts. It is important to elucidate the practical and economic advantages of functionalizing the material. A simplified life cycle analysis (LCA) was conducted with 1kg of catalyst production as a functional unit. The compounds with 30 wt% graphene presented 80% more impact in some categories. An applied engineering concept is added to visualize the viability of developing a pilot model for wastewater treatment. The hydraulic system idea was adopted with an effluent flow of 1 L/min to facilitate calculations. Heterogeneous catalysts are a promising process for environmental remediation.

Malignant melanoma is the most aggressive type of skin cancer, in which genetic and environmental factors are closely involved in its development. The World Health Organization (WHO), predict an average increase of 100,000 new cases worldwide by the year 2040. This shows the challenges that government agencies will face over these years, requiring new treatment strategies with greater effectiveness and with fewer side effects. Thus, this study aimed to evaluate the anticancer activity of the photosensitizer (PS) Chlorophyll a (Chl a) incorporated into hydrogels (HGs) based on chitosan (CS) and poloxamer 407 (P407) using Photodynamic Therapy (PDT) against the murine melanoma cell line B16-F10. The formulation of HG based on CS and P407 containing Chl a was evaluated through rheological studies, such as: sol-gel (Tsol-gel) transition phase temperature, Tsol-gel phase time, viscosity and bioadhesion. Morphological characterization studies were also carried out by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) studies to identify interactions at the level of functional groups of the polymers used and to identify any contaminating compound. In addition, the photodynamic activity of HG containing Chl a was evaluated by in vitro PDT. The HG based on QS and P407 proved to be effective in releasing PS Chl a. In addition, it presented essential characteristics for topical applications, such as a temperature of 32 ºC in the Tsol-gel phase, a time of 10.20 s in the Tsol-gel phase and a displacement force of 50 mN. All these properties favored the bioavailability of the drug, controlled release of the active ingredient and an increase in the permanence time of the PS at the applied site due to its low fluidity. It also provided effectiveness in vitro PDT in which PS showed high photodynamic activity with an IC50 of 25.99 µM, a significant reduction in the cell viability of melanoma cells compared to the IC50 of 173.8 µM of Cisplatin (CDDP). Therefore, it was possible to evidence the effectiveness of the formulation of a HG based on QS and P407 as a thermosensitive system in topical applications for the release of PS Chl a in PDT against melanoma. Allowing us to infer that this thermosensitive system of topical application also provides a controlled release of drugs, requiring further studies to confirm this evidence.

This study reports the success of the fabrication and characterization of a novel magnetic nanocarrier based on association of magnetite nanoparticles with poly(amidoamine) (PAMAM) dendrimers loading dirhodium(II) tetraacetate complex (DiRh(II)). Interaction between PAMAM dendrimers and DiRh(II) and its effects on magnetic properties and biological activities in 4T1 and MCF7 cancer cells were investigated. Magnetite spinel phase is confirmed via x-ray diffraction (XRD) and Raman spectroscopy data analysis. Magnetite mean crystallite size of 9.5 ± 0.3 nm is assessed from XRD data, which is close to values obtained via dynamic light scattering (DLS) and transmission electron microscopy micrographs. Our findings strongly suggest that Rh(II) ions interact with lone electron pairs of nitrogen atoms in amide-II and primary amines of PAMAM surface-terminated moieties. Magnetization data indicate that the presence of DiRh(II) attached to PAMAM dendrimer leads to strong weakening of magnetic dipole-dipole interaction in ATPS- and ATPS+PAMAM coated magnetite nanoparticles. In vitro assays performed on 4T1 and MCF7 cells show that both the DiRh(II) complex and MAPP systems do not show statistically significant cytotoxicity in the range of DirRh(II) concentration studied. On the other hand, the noanostructured MAPPRh and PPDiRh(II) systems show high cytotoxic activity in both cell lines, with the IC50 observed for the MAPPRh system being 15 times lower than that observed for the PPDiRh(II) system. Studies of the internalization profile of nanostructured systems in 4T1 and MPF7 cells show that for both cell lines the internalization of the MAPPRh and PPDiRh(II) systems was much higher than that observed for the MAPP system. Finally, apoptosis is identified as the main mechanism of cell death after treatment with the MAPPRh and PPDiRh(II) systems. This result is more pronounced for 4T1 cells when compared to MCF7 cells.