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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 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.