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Item Biocomposite macrospheres based on strontium-bioactive glass for application as bone fillers(American Chemical Society) Oliveira, Ivone Regina de; Gonçalves, Isabela dos Santos; Santos, Kennedy Wallace dos; Lança, Maria Carmo; Vieira, Tânia; Silva, Jorge Carvalho; Cengiz, Ibrahim Fatih; Reis, Rui Luís; Oliveira, Joaquim Miguel; Borges, João Paulo Miranda RibeiroTraditional bioactive glass powders are typically composed of irregular particles that can be packed into dense configurations presenting low interconnectivity, which can limit bone ingrowth. The use of novel biocomposite sphere formulations comprising bioactive factors as bone fillers are most advantageous, as it simultaneously allows for packing the particles in a 3-dimensional manner to achieve an adequate interconnected porosity, enhanced biological performance, and ultimately a superior new bone formation. In this work, we develop and characterize novel biocomposite macrospheres of Sr-bioactive glass using sodium alginate, polylactic acid (PLA), and chitosan (CH) as encapsulating materials for finding applications as bone fillers. The biocomposite macrospheres that were obtained using PLA have a larger size distribution and higher porosity and an interconnectivity of 99.7%. Loose apatite particles were observed on the surface of macrospheres prepared with alginate and CH by means of soaking into a simulated body fluid (SBF) for 7 days. A dense apatite layer was formed on the biocomposite macrospheres’ surface produced with PLA, which served to protect PLA from degradation. In vitro investigations demonstrated that biocomposite macrospheres had minimal cytotoxic effects on a human osteosarcoma cell line (SaOS-2 cells). However, the accelerated degradation of PLA due to the degradation of bioactive glass may account for the observed decrease in SaOS-2 cells viability. Among the biocomposite macrospheres, those composed of PLA exhibited the most promising characteristics for their potential use as fillers in bone tissue repair applications.Item Development and characterization of ceramic-polymeric hybrid scaffolds for bone regeneration: incorporating of bioactive glass BG-58S into PDLLA matrix(Taylor & Francis) Aguiar, Veronica Cristina Pêgo Fiebig; Bezerra, Rayssa do Nascimento; Santos, Kennedy Wallace dos; Gonçalves, Isabela dos Santos; Costa, Karen Julie Santos Grancianinov; Lauda, Diogo Ponte; Campos, Tiago Moreira Bastos; Prado, Renata Falchete do; Vasconcellos, Luana Marotta Reis de; Oliveira, Ivone Regina deIn recent years, there has been a notable surge of interest in hybrid materials within the biomedical field, particularly for applications in bone repair and regeneration. Ceramic-polymeric hybrid scaffolds have shown promising outcomes. This study aimed to synthesize bioactive glass (BG-58S) for integration into a bioresorbable poly- meric matrix based on PDLLA, aiming to create a bioactive scaffold featuring stable pH levels. The synthesis involved a thermally induced phase separation process followed by lyophilization to ensure an appropriate porous structure. BG-58S characterization revealed vitreous, bioactive, and mesoporous structural properties. The scaffolds were analyzed for morphology, interconnectivity, chemical groups, porosity and pore size distribution, zeta potential, pH, in vitro degradation, as well as cell viability tests, total protein content and mineralization nodule production. The PDLLA scaffold displayed a homogeneous morphology with interconnected mac- ropores, while the hybrid scaffold exhibited a heterogeneous mor- phology with smaller diameter pores due to BG-58S filling. The hybrid scaffold also demonstrated a pH buffering effect on the polymer surface. In addition to structural characteristics, degrada- tion tests indicated that by incorporating BG-58S modified the acidic degradation of the polymer, allowing for increased total pro- tein production and the formation of mineralization nodules, indi- cating a positive influence on cell culture.Item Produção de Membranas no Sistema PVA-Hidroxiapatita por Eletrofiação(2023) Gonçalves, Isabela dos Santos; Lopes, João Henrique; Oliveira, Ivone Regina deItem Síntese e Caracterização de Vidro Bioativo (BG-58S) pela Rota Sol-Gel sem e com a Presença de Solvente e Agente Porogênico(2023) Aguiar, Veronica Cristina Pêgo Fiebig; Gonçalves, Isabela dos Santos; Ortega, Fernando dos Santos; Grancianinov, Karen Julie Santos; Lauda, Diogo Ponte; Oliveira, Ivone Regina deItem Síntese e caracterização de vidro bioativo (BG-58S) pela rota sol-gel sem e com a presença de solvente e agente porogênico(2023-12-05) Aguiar, Veronica Cristina Pêgo Fiebig; Gonçalves, Isabela dos Santos; Ortega, Fernando dos Santos; Costa, Karen Julie Santos Grancianinov; Lauda, Diogo Ponte; Oliveira, Ivone Regina deItem Produção de Membranas no Sistema PVA-hidroxiapatita por eletrofiação(2023-12-05) Gonçalves, Isabela dos Santos; Lopes, João Henrique; Oliveira, Ivone Regina deItem Calcium aluminate cement blended to bioactive glass and strontium: in vitro and in vivo evaluation studies(Springer Nature) Gonçalves, Isabela dos Santos; Donda, Giovanni Moreira; Oliveira Filho, Hugo Gutemberg Patino de; Fernandes, Marina Santos; Barbosa, Ana Maria; Raniero, Leandro José; Vasconcellos, Luana Marotta Reis de; Oliveira, Ivone Regina deHomogeneous calcium aluminate cement–based (CH) materials hold potential as biomaterials, while bioactive glass (BG-58S) is a promising bone regeneration material with excellent bioactivity. Strontium, known for stimulating bone tissue regeneration, was incorporated into CH-BG-58S blends to enhance bioactivity, osteogenesis, and bone tissue repair. Methods Blends with only BG-58S were evaluated for viscosity, injectability, and workability. In vitro tests were performed using MG63 cells and in vivo tests utilized blends CH-7.5BG-58S and CH-7.5BG-58S/Sr to fill monocortical critical bone defects. Bactericidal capacity against Escherichia coli and Staphylococcus aureus was also evaluated. The addition of BG to CH increased viscosity, decreased injectability, and improved workability. Results All blends were non-cytotoxic, and CH-7.5BG-58S and CH-10BG-58S blends exhibited bactericidal capacity against E. coli. Osteogenic activity, confirmed by mineralization nodule formation, was observed in all blends. Histomorphometric and histological analyses revealed bone neoformation, with emphasis on SrO-containing groups, but without statistical significance among groups (p > 0.05). Conclusion This research highlights the potential of CH-BG-58S blends, particularly those with strontium, as bioactive materials for bone tissue engineering.Item Influence of manufacturing parameters on bioactive glass 45S5: Structural analysis and applications in bone tissue engineering(Elsevier) Santos, Kennedy Wallace dos; Costa, Karen Julie Santos Grancianinov; Gonçalves, Isabela dos Santos; Alves, M.; Lauda, Diogo Ponte; Vasconcellos, Luana Marotta Reis de; Campos, Tiago Moreira Bastos; Oliveira, Ivone Regina deBioactive glass (BG-45S5) production through the melting process is affected by a wide variety of parameters. This study investigated the synthesis of BG-45S5 granules and the process variables to produce a bioactive and osteoinductive BG for bone grafting applications. The melting process was initially analyzed by varying pa- rameters such as crucible type and pouring environment using P2O5 as phosphorus precursor. The obtained products were characterized by crystalline phases, characteristic chemical groups, particle size distribution, and chemical composition. Materials poured into graphite or steel molds resulted in particle sizes more suitable for applications in granular form. Using a platinum crucible yielded a chemical composition closer to the target when compared with another ceramic crucible. Subsequently, the melting process was evaluated to different phosphorus precursor (P2O5 or Na2HPO4) and melting duration (1 or 2 h) in a platinum crucible verifying their effects on the thermal behavior, chemical composition and structure of BG-45S5. Employing Na2HPO4 as a precursor led to higher glass transition and crystallization temperatures as compared to P2O5, enhancing glass homogeneity and structural stability. The product with better characteristics in terms of composition and structure was further characterized for bioactivity and cell culture behavior, showing a greater amount of mineralization nodules when compared to commercial hydroxyapatite. This is particularly due to its behavior as the solubility and interaction in biological environments.Item Incorporation of calcium aluminate and zirconia in polymethylmethacrylate (PMMA) bone cement for biomedical applications: study of in vitro osteogenesis(Universidade Estadual Paulista) Lupp, Juliana Dos Santos; Silva, Luis Augusto de Almeida; Ramos, Nathalia de Souza; Oliveira, Ivone Regina de; Oliveira, Felipe Eduardo de; Avelino, Sarah de Oliveira Marco; Gonçalves, Isabela dos Santos; Vaconcellos, Luana Marotta Reis deObjective: To evaluate the effects of incorporating calcium aluminate cement (CAC) and monoclinic zirconia (Z) into polymethylmethacrylate (PMMA) bone cement on in vitro osteogenesis. Material and Methods: Samples of pure PMMA, PMMA+CAC 7.5% (wt%) and PMMA+Z 7.5% (wt%) were prepared. The formulations were characterized by scanning electron microscopy, energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, and wettability analysis. For biological assessment, mesenchymal stem cells derived from Wistar rat femurs were cultured on the samples. Cellular response was analyzed by cell viability assay, protein synthesis, alkaline phosphatase (ALP) activity, tumor necrosis factor-alpha (TNF-α) expression by ELISA, and mineralized nodule formation. Results: All groups exhibited cell viability greater than 70% (p>0.05). ALP activity and protein synthesis showed no significant differences (p>0.05). TNF-α expression was significantly higher in the control group (41.25 ± 17.00 pg/mL) compared with PMMA (22.97 ± 7.08; p<0.01), PMMA+Z (25.76 ± 13.08; p<0.05), and PMMA+CAC (28.99 ± 14.71; p<0.05), suggesting inflammatory modulation. All groups presented mineralized nodules. In the wettability analysis, a numerical reduction in the contact angle was observed for PMMA+Z compared with pure PMMA, but without statistical significance (p>0.05). Conclusion: The addition of CAC and Z to PMMA resulted in more homogeneous surfaces, a trend toward increased wettability, and reduced TNF-α expression, without impairing cell viability or osteogenic potential, highlighting the promising potential of these formulations for bone regeneration.Item Hydrolytically synthesized chlorinated bioactive glasses: Structural reticulation and controlled ion release without alkaline shift(Elsevier) Oliveira, Ivone Regina de; Gonçalves, Isabela dos Santos; Abdala, Julia Marinzeck de Alcantara; Abreu, Bianca Lapadula Heckert Franklin de; Cardoso, Gustavo Luiz Bueno; Thim, Gilmar Patrocínio; Campos, Tiago Moreira BastosBioactive glasses are recognized for their ability to release ions and induce apatite formation in physiological media. However, conventional glasses often cause a marked increase in pH during dissolution, which may lead to cytotoxic effects. In this study, chlorinated bioactive glasses were synthesized via a hydrolytic sol–gel route using tetraethyl orthosilicate (TEOS) and calcium chloride, aiming to obtain materials with efficient ionic release and controlled pH response. Samples were thermally treated at 500 ◦C, 600 ◦C, and 700 ◦C and characterized by FTIR, Raman spectroscopy, specific surface area (BET), scanning electron microscopy (SEM), and ionic release tests. The chlorinated bioactive glass calcined at 500 ◦C exhibited the most promising combination of charac- teristics: presence of hydroxyl groups (–OH), a structure predominantly composed of Q2 units, high specific surface area (31.75 m2 g−1), well-defined mesoporosity, high ionic release (~2000 μS cm−1), and effective control of pH increase in aqueous media. These properties directly contribute to bioactivity and indicate that this ma- terial can be incorporated into biomedical formulations without the need for prior neutralization steps, in contrast to many conventional bioactive glasses. The results also demonstrate that the hydrolytic sol–gel route enables the synthesis of chlorinated bioactive glasses with tunable structure and dissolution profiles, overcoming limitations associated with more complex routes, such as those based on ion-exchange resins or precursors like metasilicate. The ability to combine high ionic release with low impact on pH represents a relevant advance in the design of bioceramics for regenerative and dental applications.