Abstract Aiming to produce an antimicrobial dressing for wound healing applications, in this work Tea Tree oil (TTO) was incorporated into PHBV nanofibers by absorption. It was observed increase in the nanofiber diameter due to 5% TTO absorption efficiency, which also led to a 54% decrease in the contact angle. The releasing assay indicates a 6.8% oil release in the first 24 h – being probably the oil deposited at the polymer surface – followed by a minimal release at 48 h. The set of antimicrobial assays performed suggests the incorporation of TTO optimized the antimicrobial activity of the polymer for E. coli and C. albicans, while against S. aureus no significant difference was observed. The MTT assay showed no cytotoxicity of PHBV, but the incubation of L929 fibroblast cells with PHBV-TTO reduced cell viability. Overall, the PHBV nanofibers containing TTO present great potential as an antimicrobial dressing. applications (TTO 5 efficiency 54 angle 68 6 8 6.8 2 4 E C albicans S L L92 PHBVTTO viability Overall 6. L9

Bacterial infections after implant surgical procedures are a complication observed in many surgeries to treat bone injuries or diseases. Bacteria can attach to the surface of the implant producing biofilms, and if treatment with antibiotics does not work, further surgery is necessary to remove the infected implant. Among the biomaterials for bone implants, bioceramics based on calcium phosphates (CaPs) such as β-TCP stand out, due to their chemical similarity with bone and high bioresorbability. β-TCP has the characteristic of easily accommodating in its crystalline structure reasonable amounts of doping elements, such as monovalent and trivalent ions, which makes it an efficient transporter of drugs, molecules, and therapeutic ions The objective of this work was the incorporation of bioactive glass (BG 45S5) via sol-gel and silver nanoparticles (Ag-NPs) in β-TCP scaffolds, aiming to confer antimicrobial activity to the scaffolds, without prejudice to biocompatibility. XRD and FT-IR analysis indicated structural changes after the incorporation of BG 45S5 and Ag-NPs in β-TCP scaffolds, and these compounds induced the partial transformation of the β-TCP phase into α-TCP phase and the formation of sodium-calcium silicates and silver silicates. The FT-IR spectra showed characteristic bands of α-TCP after incorporation, in addition to the predominant bands of β-TCP. Biocompatibility after incorporation of BG 45S5 was improved, with a significant increase in cell viability. After the incorporation of Ag-NPs, cell viability was maintained at an acceptable level, no cytotoxic behavior was observed, and the scaffolds showed antibacterial and antifungal activity. The results indicate that BG 45S5 and the Ag-NPs incorporated showed a synergistic behavior, conferring antimicrobial activity to the scaffolds without compromising biocompatibility, showing great potential for applicability in tissue engineering. diseases biofilms implants CaPs (CaPs βTCP β TCP out bioresorbability elements drugs molecules S solgel sol gel AgNPs Ag NPs (Ag-NPs biocompatibility FTIR FT IR 45S αTCP α sodiumcalcium sodium βTCP. TCP. improved AgNPs, NPs, level engineering

Abstract Wastes management studies concerning slaker grits, a rich calcium carbonate landfilled residue from the pulp and paper industry, are focused on their application in the construction field due to their calcareous nature. To the best of our knowledge, slaker grits addition in a high calcium content ceramic frit formulation and their behavior as a glaze has not yet been explored, being the aim of this work. Grits were added as a calcium oxide source in 0, 50%, and 100%, and the frits were analyzed regarding their chemical composition, devitrification, sintering behavior, morphology, colorimetric coordinates, and scratch resistance. By means of comparison, the commercial frit was also characterized. The glazes were analyzed by their physical and thermal properties and scratch resistance. Grits did not prevent the vitreous phases obtention and, compared to the commercial frit, presented a similar behavior, although resulted in higher wollastonite devitrification that directly affected glazes’ thermal properties, sintering contraction, linear thermal expansion coefficient, among others. A great outcome was the quartz scratch resistance of the glaze containing the highest grits content, revealing an optimized behavior. Grits residue proved to be a promising alternative raw material capable of generating sustainable and economic perspectives for the ceramic coating sector.

Resumo Os cimentos de fosfato de cálcio (CPCs) são materiais potenciais para reparar defeitos ósseos, principalmente devido à sua excelente biocompatibilidade e osteocondutividade. No entanto, suas baixas propriedades mecânicas limitam suas aplicações clínicas. A adição de gelatina pode melhorar as propriedades mecânicas e biológicas dos CPCs, mas sua solubilidade em água pode aumentar a porosidade do cimento durante a degradação. Assim, o objetivo deste trabalho foi investigar a influência da gelatina no tempo de pega, na resistência à compressão e na taxa de degradação de um cimento de brushita. Os CPCs foram preparados com a adição de 0, 5, 10 e 20% em massa de gelatina em pó na fase sólida do cimento. Os resultados indicaram que o tempo de pega aumentou com a adição da gelatina. Além disso, o cimento com 20% de gelatina apresentou resistência à compressão inicial de 14,1±1,8 MPa, enquanto o cimento sem gelatina teve 4,5±1,2 MPa. A perda de massa, a morfologia e a resistência à compressão foram avaliadas após a degradação em solução de Ringer. De acordo com os dados da perda de massa, a gelatina adicionada foi eliminada das amostras durante a degradação. Conclui-se que a presença de gelatina melhorou as propriedades mecânicas dos CPCs; no entanto, à medida que a degradação em solução de Ringer evoluiu, a resistência à compressão dos cimentos diminuiu devido à dissolução da gelatina e, consequentemente, um aumento na porosidade das amostras.

Abstract Calcium phosphate cements (CPCs) are potential materials for repairing bone defects, mainly due to their excellent biocompatibility and osteoconductivity. Nevertheless, their low mechanical properties limit their usage in clinical applications. The gelatin addition may improve the mechanical and biological properties of CPCs, but their solubility in water may increase the porosity of the cement during degradation. Thus, the aim of this work was to investigate the influence of gelatin on the setting time, compressive strength and degradation rate of a brushite cement. CPCs were prepared with the addition of 0, 5, 10 and 20 wt% of gelatin powder in the solid phase of the cement. The results indicated that the setting time increased with gelatin. Furthermore, cement with 20 wt% of gelatin had an initial compressive strength of 14.1±1.8 MPa while cement without gelatin had 4.5±1.2 MPa. The weight loss, morphology and compressive strength were evaluated after degradation in Ringer’s solution. According to the weight loss data, gelatin was eliminated of samples during degradation. It was concluded that the presence of gelatin improved CPCs mechanical properties; however, as degradation in Ringer’s solution evolved, cement compressive strength decreased due to gelatin dissolution and, consequently, an increase in sample porosity.

Resumo Scaffolds são substratos tridimensionais que permitem a diferenciação, proliferação e crescimento celular. A fim de se atingir propriedades como biocompatibilidade, adequada porosidade e interconectividade, ideais taxas de degradação e propriedades mecânicas, este estudo teve como objetivo a produção de scaffolds de β-fosfato tricálcico (β-TCP) pelo método de freeze casting. Por meio da variação do teor de sólidos da suspensão cerâmica foi possível avaliar sua influência na microestrutura e propriedades físicas e mecânicas dos scaffolds de β-TCP. A porosidade variou entre 85 e 55% para teores de sólidos de 10 e 30 vol%, respectivamente. A morfologia dos poros foi caracterizada por um padrão lamelar, semelhante ao formato dos cristais de gelo. O aumento do teor de sólidos na suspensão cerâmica resultou na redução do número de poros lamelares. Os valores de resistência mecânica à compressão variaram entre 0,10 e 0,71 MPa. Os scaffolds com maior valor de resistência à compressão foram submetidos ao ensaio de degradação, cujos resultados revelaram que a perda de massa dos scaffolds aumentou com tempo de imersão. O maior valor de perda de massa foi de 2,89±0,64% para período de 28 dias. Os scaffolds de β-TCP apresentam grande potencial para uso na engenharia tecidual.

Abstract Scaffolds are three-dimensional substrates that allow cell differentiation, proliferation and growth. In order to achieve properties such as biocompatibility, adequate porosity and interconnectivity, ideal rates of degradation and mechanical properties, the main objective of this study was the production of β-tricalcium phosphate (β-TCP) scaffolds by freeze casting method. Through the variation of the solids content, it was possible to evaluate its influence on the microstructure and the physical and mechanical properties of the β-TCP scaffolds. The porosity varied between 85 and 55% for solids contents of 10 and 30 vol%, respectively. The pore morphology was characterized by a lamellar pattern, similar to ice crystals. By increasing solid content in the ceramic suspension, it was possible to observe a reduction of the number of lamellar pores. Mechanical compressive strength values ranged from 0.10 to 0.71 MPa. The scaffolds that presented the highest compressive strength value were characterized by degradation test. The results revealed that the weight loss increased with the immersion time. The highest value of the weight loss was 2.9±0.64% for the period of 28 days. The β-TCP scaffolds show great potential to use in tissue engineering.