Navegando por Palavras-chave "Bioceramics"
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- ItemSomente MetadadadosInjetabilidade De Grânulos De β-Tcp E Wollastonita Obtidos Pelo Método De Spray Drying Para Preenchimento De Defeito Ósseo(Universidade Federal de São Paulo (UNIFESP), 2017-05-29) Almeida, Gleice Ellen Morais De [UNIFESP]; Motisuke, Mariana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The need for biomaterials to treat bone defects is growing considerably. Thereby, the importance of studies that seek alternatives to treat bone tissue and postpone the need for more severe surgeries increases every day. To this end, the use of bioceramics, such as calcium silicates (wollastonite - CaSiO3) and β-TCP becomes interesting since they are bioactive and osteoconductive. There are many studies in the literature evaluating the possibility of using these bioceramics for filling bone defects. Therefore, the production of granules with controlled shape and porosity becomes interesting since it may allow cell adhesion, assist bone growth and facilitates the filling of an irregular defect. The granules can be obtained by spray drying, which is a granulation process widely used in industry and, in the last recent years, this process has been used to the manufacture of granules for biomedical applications because it is a versatile process that allows the production in a large scale, with low risk of contamination and high reproducibility. The application of granules for filling bone defects through minimally invasive surgical techniques becomes interesting since its spherical morphology improves the fluidity of the material and, consequently, improves the injectability of the material. The use of minimally invasive surgical techniques allows quick recovery of the paicent due to rapid bone repair and more simple procedures. From this context, the objective of this work is to obtain and characterize wollastonite and β-TCP granules obtained by the spray drying process to be applied in bone defects by means of minimally invasive techniques. It was possible to obtain cohesive granules when using β-TCP and calcium silicate samples with PEG binder. It was possible to obtain spherical granules and with high fluidity when using gelatin as a binder. The mixture of granules and with a sodium alginate solution lead to an injectable paste, which was homogenized by two different mixing methods, amalgamator and glass plate. After mixing, it observed greater presence of intact granules when the paste was mixed in the glass plate. Injectable pastes obtained by calcined granules and a polymer phase with lower viscosity favored the injectability and cohesion of the paste, becoming the best condition analyzed. The calcination of the granules resulted in higher mechanical properties and, consequently, granules integrity after mixing and injection, being the best condition to be used.
- ItemSomente MetadadadosProcessamento e Caracterização de Scaffolds de β-Fosfato Tricálcico pelo Método de Gelcasting com Incorporação de Nanopartículas para Atividade Antimicrobiana(Universidade Federal de São Paulo (UNIFESP), 2020-02-14) Barbosa, Lucas [UNIFESP]; Triches, Eliandra De Sousa [UNIFESP]; Universidade Federal de São PauloTissue engineering and regenerative medicine are highly relevant to the science of biomaterials, promoting advances in the treatment and recovery of patients with problems caused by diseases, injuries and fractures. Recent studies in tissue engineering have sought to develop multifunctional scaffolds that in addition to having regenerative capacity, have antimicrobial properties through the incorporation of antimicrobial agents, providing a better recovery to the patient and avoiding new surgical procedures for treatment or removal of the implant, since inflammations and infections are often caused by microorganisms. For the production of ceramic scaffolds for bone tissue regeneration, tricalcium β-phosphate (β-TCP) stands out due to its chemical stability and more suitable resorption speed for bone implants. Among the antimicrobial agents that have been studied are metallic nanoparticles, such as silver, and chemical compounds, such as methylene blue. Thus, this work aimed to obtain β-TCP scaffolds by the gelcasting method applied to foams with the incorporation of methylene blue and silver nanoparticles in order to confer antimicrobial properties. For this, the obtained β-TCP scaffolds were immersed in the silver nanoparticles solution and stirring by ultrasonic. Methylene blue was incorporated by dripping the solution into the scaffolds. The synthesized ceramic powder presented the crystalline phase of interest, β-TCP, average particle size after grinding 1.56 μm and density 2.99 g/cm³. Regarding antimicrobial agents, silver nanoparticles had an average hydrodynamic diameter of 39 ± 2 nm, with maximum absorption in the UV-visible spectrum at 429 nm and the methylene blue solution had a concentration of 1.044 mM, with maximum absorption in the UV-visible spectrum at 654 nm. In turn, the β-TCP scaffolds had porosity of 81 ± 2 % and mechanical compressive strength of 1.3 ± 0.5 MPa with spherical and interconnected pores. The test to evaluate the antimicrobial activity, in relation to S. aureus bacteria, of the scaffolds incorporated with antimicrobial agents revealed that the studied samples had little inhibitory action. It is understood that it is not enough to just incorporate an agent with a high antimicrobial capacity into the scaffold, but to understand how this agent will be incorporated into the scaffold and whether this incorporation will leave it in contact with the microorganism during the antimicrobial activity test. Therefore, it was possible to obtain β-TCP scaffolds, incorporate them with antimicrobial agents and although they have little inhibitory action, it was possible to observe the relevance of the research and guide the studies for future work.
- ItemSomente MetadadadosSíntese E Caracterização De Cimentos De "-Tcp Aditivados Com Vidros Bioativos(Universidade Federal de São Paulo (UNIFESP), 2018-12-04) Silva, Luciana Pereira Da [UNIFESP]; Motisuke, Mariana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Regenerative Medicine Is Becoming An Emerging Field Due To Population Aging In The Last Decades. Therefore, It Is Possible To Visualize Its Impacts On The Development Of New Treatments For Patients With Orthopedic And Dental Diseases. Calcium Phosphate Cements (Cpc), Besides Of Being Resorbable, Is Also Injectable And Can Be Molded Into Any Form, Which Ensures Complete Filling Of Bone Defects Cavities, Reducing The Number Of Surgical Interventions Or Even Eliminating Their Need. Several Studies Have Shown That The Incorporation Of Other Additives Into Cfcs May Lead To Changes On Their Properties. Bioactive Glasses (Bgs) Have Been Extensively Investigated For Bone Repair. The Dissolution Of The Silicate Network Together With The Formation Of A Silica Gel Rich Layer Would Be The Path For The Formation Of An Apatite Layer On Bg"S Surface. There Are Few Studies On The Incorporation Of Bgs Into Cpcs Where The Introduction Of Bgs Was Aimed To Increase The Materials Bioactivity And Osteogenic Potential. Nevertheless