Rodrigo Lambert Oréfice

This study evaluated the physiological impacts of acute-exposure of tambaqui ( Colossoma macropomum ) to different concentrations of cellulose acetate nanoparticles at different sampling times. A total of 120 juvenile C. macropomum (38.91 ± 5.57 g and 13.76 ± 0.74 cm in total length) were distributed in 12 tanks of 150 L, in a recirculating aquaculture system (RAS). The juveniles were kept in water containing cellulose acetate nanoparticles (CANs) at four different concentrations (treatments): 0 mg L ⁻ ¹, 0.01 mg L ⁻ ¹, 0.10 mg L ⁻ ¹ and 1.00 mg L ⁻ ¹. Blood samples were collected after 1 and 24 h of exposure. The juveniles were then relocated to a tank with clean water, where they remained for another 24 h, after which a new blood sample was collected (24 h). Hemoglobin, serum protein and globulin were reduced after 1 h of exposure for the group exposed to 1.00 mg L ⁻ ¹ of CANs. Glucose levels increased after 24 h for the groups exposed to 0.10 and 1.00 mg L ⁻ ¹. Urea increased after 1 h for the groups exposed to 0.10 and 1.00 mg L ⁻ ¹. Triglycerides and cholesterol were reduced both after 1 h and 24 h of exposure for the 1.00 mg L ⁻ ¹ group, returning to baseline levels at 24 h. The activities of aspartate aminotransferase (AST) and alanine aminotransferase were altered after 24 h. Albumin was lower after 1 h and 24 h compared to after 24 h for the 1.00 mg L ⁻ ¹ group. Exposure of juvenile C. macropomum to CANs caused transient physiological changes, with partial recovery being observed after transfer to clean water.

Flexible piezoelectric sensors based on polyvinylidene fluoride (PVDF) hold great promise for monitoring human motion and the human-machine interface. Their piezoelectricity heavily relies on the electroactive β-phase, crystallinity, polymer chain and dipole alignment. Traditional fabrication methods usually require complex post-processing steps, such as mechanical stretching and electrical poling, to align the dipoles to the same direction, which increase production time, capital, and hinder real-world market demands. To address this challenge, this study proposes a facile, low-cost, fast one-step solvent casting method to produce a quaternary system with potential to high-performance strain sensor applications. PVDF was blended with secondary polymers, being polyamide 6 (PA6) or polycaprolactone (PCL), with ionic liquid (EMIBF4) and also carbon fillers as functionalized multi-walled carbon nanotubes (FMWCNT) or N-rich carbon nanodots (CND). Structural characterizations (Raman, SEM, FTIR, and DSC) revealed that the addition of these fillers significantly influenced the morphological structures and phase formation. Electrical measurements under mechanical stimulation demonstrated high sensor performance, specifically, the composite film based on PVDF/PCL with FMWCNT and 30 wt% ionic liquid (PLT30) achieved a maximum output voltage of 2.42V. These results demonstrated that the synergistic effect of polymer blending, nanofillers and ionic liquids effectively enhances the macroscopic piezoelectric response, offering a highly efficient and scalable strategy for developing flexible strain sensors based on composite design.

Electrospun nanofibrous coatings have emerged as a strategy to enhance the biological and functional performance of implantable biomaterials, but the adhesion and multifunctionality are still challenges. By mimicking the extracellular matrix architecture, these coatings improve cell adhesion and proliferation while enabling the localized and controlled delivery of therapeutic agents. This review provides a comprehensive and critical analysis of recent advances in electrospun coatings applied to metallic, ceramic, and polymeric implants. Emphasis is placed on the relationship between substrate characteristics, surface modification strategies, and coating adhesion. Polycaprolactone emerges as the most widely employed polymer, while hydroxyapatite is the predominant inorganic phase incorporated into electrospun nanofibers to enhance bioactivity and osteointegration. The review discusses passive and active surface modification by electrospun coatings, including chemical functionalization, intermediate layers deposition, and topography modification, highlighting their impact on coating stability, corrosion resistance, and biological response. Emerging trends such as piezoelectric coatings, integration with additive manufacturing, use of co‐axial electrospinning, and the application of artificial intelligence for process optimization are also addressed. Finally, current challenges and future perspectives are outlined, focusing on improving long‐term coating adhesion, developing stimuli‐responsive delivery systems, and designing multifunctional implantable devices.

“Synthetic antibodies” prepared using polymers imprinted with biological molecules can provide an attractive alternative compared to natural antibodies when integrated in sensors, since they can be more resistant to variations in pH, temperature, and organic solvents. The objective of this work was to produce “synthetic antibodies” based on the SARS‐CoV‐2 epitope as biofunctionalized nanofibers to test the hypothesis that the high surface area of nanofibers imprinted with SARS‐CoV‐2 epitope would improve the capability of detection of the synthetic antibody. To this end, a SARS‐CoV‐2 epitope peptide (J5) was designed, simulated through bioinformatics tools (in silico), and synthesized as a model molecule (MM) for imprinting. Epitope‐imprinted polymers (EIPs) based on J5 and non‐imprinted polymers (NIPs) were prepared with polymeric networks in the form of bulk samples and electrospun fibers using a reactive electrospinning setup. Bovine serum albumin was also used as a MM for the preparation of molecularly imprinted polymers (MIPs). The rebinding capacity ( Q ) for bovine serum albumin (BSA)‐imprinted nanofibers (49 074 ± 2374 µg/g) was substantially higher than that of bulk BSA‐imprinted polymers (9241 ± 5112 µg/g). Similarly, J5‐imprinted nanofibers exhibited a higher Q value (11 923 ± 1762 µg/g) compared to J5‐imprinted bulk samples (6065 ± 755 µg/g).

The growing volume of electronic waste (e-waste) poses a significant environmental challenge, demanding innovative recycling solutions. This study investigates the feasibility of incorporating monitor cabinet scraps (CS) from liquid crystal display (LCD) as a partial substitute for virgin polypropylene (PP), with the goal of developing sustainable and low-cost materials. PP/CS blends were prepared by melt mixing and injection molding. Morphological and rheological analyses revealed phase segregation and the amorphous nature of the CS, while thermal analysis indicated a reduction in PP’s crystallinity at high CS concentrations. Mechanical tests demonstrated that both composition and processing method critically influence the material’s performance. Notably, the direct injection molding of a blend with 10% CS resulted in a balanced set of properties, highlighting the potential for creating useful and environmentally friendly materials. This sample presented mechanical properties statistically equal to virgin PP. This approach not only offers a practical solution for recycling e-waste, in alignment with the principles of the circular economy, but also opens up new opportunities for producing value-added composite materials for industrial applications, thereby reducing environmental impact and production costs.

Introdução e objetivos: As doenças bacterianas são uma preocupação crescente devido à resistência microbiana e à baixa seletividade dos medicamentos. A nanotecnologia, especialmente as nanopartículas, surge como alternativa promissora para um tratamento mais eficaz1. A nanopartícula de sílica mesoporosa (MSN), com alta estabilidade térmica e grande área de superfície, destaca-se por ser biodegradável e não tóxica2. Sua funcionalização com quitosana, um polímero biocompatível e de baixo custo3-4, melhora a interação com alvos biológicos. Esse sistema pode incorporar o fármaco ciprofloxacino, antibiótico que inibe enzimas essenciais para a sobrevivência bacteriana. Material e Método: As nanopartículas foram sintetizadas utilizando o co-polímero F127 como template, dissolvido em água e NH4F, seguido pela adição de TEOS a 80°C. Após extração do surfactante com etanol/ácido clorídrico, as MSN foram funcionalizadas com quitosana, obtida a partir de resíduos de camarão mediante desmineralização, desproteinização e desacetilação assistida por micro-ondas. A ciprofloxacina foi incorporada (4000 μg/mL) e o revestimento com quitosana foi realizado por coagulação em solução alcalina. Resultados e Discussão: A síntese da sílica e a funcionalização dessas partículas com a quitosana e o ciprofloxacino ocorreram de modo esperado e após esses processos foram geradas as amostras MSNQuit 300, MSN Cipro Quit 300. Pode-se afirmar que a funcionalização ocorreu de forma satisfatória para ambas as amostras, proporcionando ao composto uma ancoragem a partir da interação dos grupos aminos e grupos hidroxila. No entanto, no estudo de liberação do fármaco ciprofloxacino das nanopartículas de sílica com e sem a quitosana, houve a percepção que mesmo possuindo uma liberação significativa do sistema como um todo, no caso levando em conta as duas amostras analisadas (MSNCipro, MSNCipro Quit 300) a amostra sem a quitosana houve uma liberação maior da molécula. O estudo de atividade microbiana foi feito com as amostras descritas anteriormente, como também, foram testadas as amostras controles dos fármacos ciprofloxacino e oxacilina, e as amostras de sílica mesoporosa funcionalizadas com a quitosana sem a presença do fármaco.Houve a formação do halo de inibição em todos os discos que possuíam a amostra principal (MSN Cipro Quit 300) frente das duas bactérias estudadas de em média 20 mm de diâmetro, além disso, as amostras controles possuíam também a formação do halo de inibição. Conclusões: As nanopartículas têm desempenhado um papel cada vez mais proeminente como carregadores de fármacos na pesquisa farmacêutica, demonstrando uma crescente evidência científica de seu potencial. No presente estudo as análises levantaram resultados promissores, o FTIR mostra as formações ideais das ligações da quitina e quitosana usadas tal qual o MEV que mostra a estrutura característica da sílica. Além disso, nos ensaios de liberação também foram obtidos resultados significativos em relação à porcentagem de liberação das amostras, fato esse que pode vir a ser ponto de outro estudo. Ademais, a eficácia antimicrobiana também é pauta para novas hipóteses visto que a inibição aconteceu mas não foi a esperada. Isso pode ser devido a escolha do antimicrobiano em concomitante a escolha da bactéria. O sucesso desse sistema de nanopartículas é evidenciado por uma série de estudos notáveis, como o mencionado aqui, que ilustram as potenciais contribuições das nanopartículas para a eficácia, seletividade e segurança no tratamento de diversas doenças. No entanto, é importante ressaltar que esses avanços não confirmam todas as hipóteses e desafiam a necessidade contínua de investigação em profundidade nesse campo.

The presence of proteins in aqueous media intensifies the activities of bacteria and other microorganisms increasing the use of antibiotics, making processes more expensive due to the formation of biofouling. To mitigate contaminations by proteins of water resources, bio‐based castor oil polyurethane foams were customized to improve the adsorption and recovery of water of pollutants. Hybrid ordered nanoporous coatings of self‐assemble copolymers of poly(styrene‐b‐4‐vinyl pyridine) (PS‐b‐P4VP) having titanium dioxide (TiO ₂ ) nanoparticles, were produced through the self‐assembly nonsolvent induced phase separation (SNIPS) process and were deposited on the surface of the polyurethane foams to enhance the separation of contaminants. The added TiO ₂ nanoparticles could provide photocatalytic behavior to the foam and be explored for other functions. The performance of the material in water media enhanced at least 65% of the adsorption capacity of dispersed myoglobin on water and was then compared with another coated foam with a non‐ordered copolymer. In addition, the flux of the water solutions through the modified foams was investigated to check if the obtained coatings were effective in the water transport and selection of pollutant substances. To our knowledge, this is the first modulated polyurethane coated with a copolymer aiming for multiple water‐cleaning approaches.

Chain stretching, interpenetration, and entanglement are crucial for adhesion between polymer surfaces and the performance of adhesives, fiber‐reinforced composites, self‐healing polymers, and elastomers. The goal of this work was to study the effect of different structural parameters of surfaces containing attached polymer chains on these phenomena in order to design adhesives and self‐healing polymers, among others, with improved performances. To this end, atomic force microscopy was used to measure the forces between surfaces with attached poly(tetramethylene oxide)‐based soft polyurethane chains. Chains were grafted onto both an atomic force microscopy probe and the impenetrable surfaces of inorganic substrates with varying areal densities. Results showed that the density of grafts fundamentally affected the adhesion process between the grafted surfaces. Larger adhesion forces were observed for surfaces with lower values of areal density of grafts due to interpenetration. Thus, applications (adhesives, composite interfaces, etc.) that depend upon adhesion should pursue high levels of chain interpenetration. The atomic force microscopy results were successfully fitted to the ideal rubber elasticity theory. This suggests that the experimental setup allowed the unraveling of many factors associated with the behavior of interacting soft polymers: affine deformation, chain stretching, temporary crosslinks, and the random coil conformation of polymer strands.

The expansion of human population in many parts of the world is increasing the demand for fresh water and the contamination of water by contaminants such as dye, and others requires efficient, easy‐to‐use, cheap and environmentally sustainable technologies to perform water purification tasks. In this work, nanostructured eco‐friendly bio‐based castor oil polyurethane foams that can remove heavy metal ions from contaminated water were customized to add another function associated with the photodegradation of organic molecules. To this end, nanostructured polyurethane foams (containing cellulose‐halloysite nanocomposite units) were coated with poly(styrene)‐b‐(polyethylene‐ran‐butylene)‐b‐polystyrene (SEBS) by non‐solvent induced phase separation (NIPS) process for the first time. The deposition of the coating also allowed the incorporation of titanium dioxide (TiO₂) nanoparticles by applying a new strategy, in which the nanoparticles were suspended in the non‐solvent prior to the NIPS process. These modulated and mixed technologies have generated polyurethane foams capable of degrading at least 10% of methylene blue dye through photocatalysis. The photocatalytic system is inactivated by pH where pH = 2.0 does not promote photocatalysis but the process is activated in water pH. The effect of photocatalysis generated with only 0.5% by mass of TiO₂ in the foam, approximately 10 mg of TiO₂, was 9.22% and 10.02% for approximately 20 mg.