Scaffolds are models designed to aid the interaction between cells and extracellular bone matrix, providing structural support for newly formed bone tissue. In this work, wollastonite with β‐TCP porous ceramic scaffolds was developed by the polymer sponge replication. Their microstructure, cell viability and bioactivity were tested. in vivo was performed to evaluate the use of a calcium silicate‐based implant in the repair of rabbit tibias. Holes were made in the both proximal and distal tibial metaphysis of each animal and filled with calcium silicate‐based implant, and in the left tibia, no implant were used, serving as control group. Animals underwent euthanasia after 30 and 60 days of study. The animals were submitted to clinical‐radiographic evaluations and their histology was analyzed by optical and scanning electron microscope. The studied calcium silicate implant provided biocompatibility and promoted bone formation, stimulating the process of bone repair in rabbits, features observed by gradual radiopacity shown in the radiographic evaluations.

The aim of this research was to evaluate the process of bone regeneration in rabbits, using chitosan and beta-tricalcium phosphate (β-TCP) independently and in combination. A total of 12 New Zealand rabbits of both sexes, with average weight of 3.0 ± 0.57 kg were used. Animals were randomly divided into two experimental time points, with six animals euthanized 45 days after surgery and six euthanized 90 days after surgery. We performed two osteotomies in each tibia. The left tibia was used for the chitosan (QUI) and control groups, and the right tibia was used for the β-TCP alone and in combination with chitosan (QUI+TCP) groups. Tomographic evaluation showed no statistically significant difference among groups; however radiopacity was higher in the treated groups. Comparative descriptive histological evaluation found that treatment groups stimulated a more pronounced tissue repair reaction and accelerated bone repair. Morphometric analysis showed that treatment groups presented statistically higher bone formation compared with the control group.

Biocerâmicas porosas tem aplicações biomédicas importantes como preenchimento de defeitos ósseos e scaffolds na engenharia de tecidos. A hidroxiapatita (HA, Ca10(PO4)6(OH)2) que apresenta semelhança química e estrutural com a fase mineral dos ossos e dos dentes, é biocompatível e osteocondutiva, e tem excelente afinidade química e biológica com os tecidos ósseos. Este trabalho teve como objetivo desenvolver biocerâmicas porosas HA para utilização como scaffold para regeneração óssea empregando-se a técnica de réplica da esponja polimérica. A pasta biocerâmica de HA foi obtida por via úmida utilizando hidróxido de cálcio [Ca(OH)2] e ácido fosfórico (H3PO4) e impregnada em esponjas de poliuretano com diferentes densidades. Tratamento térmico a 600°C por 1h foi realizado para eliminação da esponja seguido da sinterização a 1100°C por 2 horas. Os scaffolds apresentaram a HA como fase majoritária, elevada porosidade (> 70%) e poros com tamanhos variando na ordem de macro (>100μm) e microporosidade (1-20μm), sendo estes fatores adequados para a aplicação como scaffolds para regeneração óssea.

The hydroxyapatite (HAp) is a ceramic biomaterial with wide application in the bone regeneration. It can be obtained by different routes and different precursors. In this study, the synthesis of HAp was carried out by precipitation and subsequent thermal treatment using different calcium precursors: calcium hydroxide from synthetic origin and calcium oxide obtained from the eggshell. The obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. By SEM, variations of the crystal size and the concentration of agglomerates were observed. FTIR and XRD analyses proved the formation of HAp and how the (mineral and biological) precursors affected the microstructure. The thermal decomposition process of the calcium oxide obtained from the eggshell showed to be more effective for the synthesis of the hydroxyapatite, resulting in more stable morphology and microstructure.