RESUMO
Accidents, trauma, bone defects, and oncological processes significantly impact patients' health and quality of life. While calcium phosphates and bioactive glasses are commonly used as bone fillers to facilitate bone regeneration in orthopedics and traumatology, they exhibit certain disadvantages compared to calcium silicophosphate phases. This study evaluates the in vitro cytocompatibility and in vivo osteogenic properties of two-third-generation ceramic phases: silicocarnotite (SC) and nagelschmidtite (Nagel). These phases were synthesized via a solid-state reaction and characterized using X-ray diffraction and scanning electron microscopy. In vitro behavior was assessed through bioactivity tests, cell viability, proliferation, and inflammatory profiles by detecting cytokines and reactive oxygen species. Osteogenic properties were evaluated by detecting bone-associated proteins in MG-G3, hFOB1.19, and MC3T3-E1 cell lines after 3, 7, and 14 days. 45S5 Bioactive glass (BG), hydroxyapatite (HAp), and osteogenic medium were employed as control standards for bone formation. SC and Nagel phases exhibited higher viability percentages as well as osteoconductive and osteoinductive behavior. Finally, SC and Nagel bone grafts were implanted in a Wistar rat model to assess their in vivo ability to induce bone formation, demonstrating complete osseointegration after 12 weeks. Histological evaluation revealed osteocytes forming osteons and the presence of blood vessels, particularly in rats implanted with Nagel. Given their favorable biological performance, SC and Nagel emerge as promising candidates for bone grafts in orthopedics, traumatology, and maxillofacial surgery.
Assuntos
Fosfatos de Cálcio , Teste de Materiais , Ratos Wistar , Animais , Ratos , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Tamanho da Partícula , Camundongos , Transplante Ósseo , Sobrevivência Celular/efeitos dos fármacos , Humanos , Silicatos/química , Silicatos/farmacologia , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Substitutos Ósseos/síntese química , Proliferação de Células/efeitos dos fármacos , Linhagem Celular , Compostos de Cálcio/química , Compostos de Cálcio/farmacologia , Osteogênese/efeitos dos fármacos , Cerâmica/química , Cerâmica/farmacologia , MasculinoRESUMO
This work presents the effect of the silicocarnotite (SC) and nagelschmidtite (Nagel) phases on in vitro osteogenesis. The known hydroxyapatite of biological origin (BHAp) was used as a standard of osteoconductive characteristics. The evaluation was carried out in conventional and osteogenic media for comparative purposes to assess the osteogenic ability of the bioceramics. First, the effect of the material on cell viability at 24 h, 7 and 14 days of incubation was evaluated. In addition, cell morphology and attachment on dense bioceramic surfaces were observed by fluorescence microscopy. Specifically, alkaline phosphatase (ALP) activity was evaluated as an osteogenic marker of the early stages of bone cell differentiation. Mineralized extracellular matrix was observed by calcium phosphate deposits and extracellular vesicle formation. Furthermore, cell phenotype determination was confirmed by scanning electron microscope. The results provided relevant information on the cell attachment, proliferation, and osteogenic differentiation processes after 7 and 14 days of incubation. Finally, it was demonstrated that SC and Nagel phases promote cell proliferation and differentiation, while the Nagel phase exhibited a superior osteoconductive behavior and could promote MC3T3-E1 cell differentiation to a higher extent than SC and BHAp, which was reflected in a higher number of deposits in a shorter period for both conventional and osteogenic media.
Assuntos
Diferenciação Celular , Cerâmica , Durapatita , Osteoblastos , Osteogênese , Silicatos , Animais , Camundongos , Durapatita/química , Durapatita/farmacologia , Cerâmica/química , Cerâmica/farmacologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteoblastos/efeitos dos fármacos , Silicatos/química , Silicatos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Materiais Biocompatíveis/química , Fosfatase Alcalina/metabolismo , Compostos de Cálcio/farmacologia , Compostos de Cálcio/química , Sobrevivência Celular/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Células 3T3 , Linhagem CelularRESUMO
The COVID-19 pandemic has caused major disturbances to human health and economy on a global scale. Although vaccination campaigns and important advances in treatments have been developed, an early diagnosis is still crucial. While PCR is the golden standard for diagnosing SARS-CoV-2 infection, rapid and low-cost techniques such as ATR-FTIR followed by multivariate analyses, where dimensions are reduced for obtaining valuable information from highly complex data sets, have been investigated. Most dimensionality reduction techniques attempt to discriminate and create new combinations of attributes prior to the classification stage; thus, the user needs to optimize a wealth of parameters before reaching reliable and valid outcomes. In this work, we developed a method for evaluating SARS-CoV-2 infection and COVID-19 disease severity on infrared spectra of sera, based on a rather simple feature selection technique (correlation-based feature subset selection). Dengue infection was also evaluated for assessing whether selectivity toward a different virus was possible with the same algorithm, although independent models were built for both viruses. High sensitivity (94.55%) and high specificity (98.44%) were obtained for assessing SARS-CoV-2 infection with our model; for severe COVID-19 disease classification, sensitivity is 70.97% and specificity is 94.95%; for mild disease classification, sensitivity is 33.33% and specificity is 94.64%; and for dengue infection assessment, sensitivity is 84.27% and specificity is 94.64%.
RESUMO
The physicochemical properties and biological behavior of sintered-bovine-derived hydroxyapatite (BHAp) are here reported and compared to commercial synthetic-HAp (CHAp). Dense ceramics were sintered for 2 h and 4 h at 1200 °C to investigate their microstructure-structure-in-vitro behavior relationship for both HAp ceramics. Densification was directly proportional to sintering time, showing a grain coarsening behavior with a greater effect on BHAp. Lattice parameters, crystallite size, cell volume and Ca/P ratio were determined by Rietveld refinement of X-ray diffraction (XRD) patterns using GSAS®. Ionic substitutions (Naâº, Mg2+, CO32-) related to BHAp structure were associated with their position changes in the vibrational modes and correlated with the structural parameters obtained from the XRD analysis. Variations in the structural parameters and surface morphology were also evaluated after different soaking periods in simulated body fluid, which is associated with the formation of bone-like apatite layer and thus bioactivity. Mitochondrial activity (MTS) and lactate dehydrogenase (LDH) assays showed that the material released by the ceramics does not induce toxicity after exposure in human fetal osteoblastic (hFOB) cells. Furthermore, no statistically significant differences were found between the HAp obtained from different sources. These results show that BHAp can be used with no restrictions for the same biomedical applications as CHAp.