Estudo da esterilização de scaffolds para regeneração do tecido ósseo
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Data
2019-11-22
Autores
Francisco, Eric Mark
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O desenvolvimento de biomateriais para a regeneração de tecidos é de grande importância e sua demanda aumenta a cada dia, devido ao aumento do envelhecimento da população, da expectativa e qualidade de vida, bem como ao aumento das taxas de acidentes (trânsito e violência). Os Scaffolds são uma estrutura tridimensional, projetada para suportar infiltração, crescimento e diferenciação celular, a fim de melhorar o desenvolvimento e a formação de novos tecidos. Muitos biomateriais podem ser usados para fabricar essas estruturas, como as biocerâmicas e biopolímeros. No entanto, poucos estudos foram realizados para avaliar sua contaminação microbiológica e a influência dos métodos de esterilização podem ter sobre a estrutura e propriedades dos implantes. Dessa forma, o objetivo deste trabalho foi avaliar as propriedades mecânicas, físico-químicas e microbiológicas, antes e após três métodos de esterilização. Esses Scaffolds foram feitos de celulose bacteriana, alginato de sódio e fosfato de cálcio amorfo. Os Scaffolds foram elaborados mediante processo de liofilização. Eles foram divididos em quatro grupos: um grupo controle e três diferentes métodos de esterilização (esterilização a vapor, esterilização por irradiação ultravioleta e esterilização por micro-ondas). O número de colônias viáveis (UFC/mL) foi obtido através do plaqueamento das amostras em Ágar Dextrose Sabouraud com Cloranfenicol (SDA), Ágar Infusão Cérebro e Coração (BHI), Chromagar e Ágar Sangue. Todos os experimentos foram realizados em triplicata e analisados estatisticamente. Para avaliar se o processo de esterilização afetou a estrutura e composição química dos Scaffolds, as amostras correspondentes a cada grupo foram caracterizadas por Difração de Raios-X (DRX), Espectroscopia na Região do Infravermelho com Transformada de Fourier (FTIR) e Microscopia Eletrônica de Varredura (MEV). Os resultados mostraram que a esterilização a vapor foi eficaz na eliminação de micro-organismos, enquanto a esterilização por micro-ondas, diminuiu significativamente o número de UFC/mL, e a ultravioleta não demonstrou ação esterilizante. Conclui-se que o processo de esterilização a vapor foi o mais efetivo, não observando mudanças na estrutura e composição dos Scaffolds.
The development of biomaterials for the regeneration of tissues is of great importance and their demand increases every day, due to the increase of the aging population, of the expectation and quality of life, as well as the increase of the accident rates (traffic and violence). Scaffolds are a three-dimensional structure designed to withstand cellular infiltration, growth and differentiation in order to improve the development and formation of new tissues. Many biomaterials can be used to make these structures, such as bioceramics and biopolymers. However, few studies have been conducted to evaluate its microbiological contamination and the influence of sterilization methods may have on the structure and properties of implants. Thus, the aim of this work was to evaluate the mechanical, physicochemical and microbiological properties of Scaffolds, before and after three different sterilization methods. These Scaffolds were made of bacterial cellulose, sodium alginate and amorphous calcium phosphate. Scaffolds were made by lyophilization process. They were divided into four groups: a control group and three different sterilization techniques (steam sterilization, sterilization by ultraviolet irradiation and microwave sterilization). The number of viable colonies (CFU/mL) was obtained by plating the samples in Sabouraud Dextrose Agar with Chloramphenicol (SDA), Brain and Heart Infusion Agar (BHI), Chromagar and Blood Agar. All experiments were performed in triplicate and analyzed statistically. Later, the samples were characterized by X-ray Diffraction (XRD), Infrared Spectroscopy with Fourier Transform (FTIR) and Microscopy Scanning Electronics (SEM) in order to evaluate if the sterilization process affected the structure and chemical composition of the Scaffolds. The results showed that steam sterilization was effective in eliminating the microorganisms, whereas microwave sterilization significantly reduced the number of CFU/mL, and ultraviolet did not demonstrate sterilizing efficacy. It was concluded that the steam sterilization process was the most effective, not observing changes in the structure and composition of the Scaffolds.
The development of biomaterials for the regeneration of tissues is of great importance and their demand increases every day, due to the increase of the aging population, of the expectation and quality of life, as well as the increase of the accident rates (traffic and violence). Scaffolds are a three-dimensional structure designed to withstand cellular infiltration, growth and differentiation in order to improve the development and formation of new tissues. Many biomaterials can be used to make these structures, such as bioceramics and biopolymers. However, few studies have been conducted to evaluate its microbiological contamination and the influence of sterilization methods may have on the structure and properties of implants. Thus, the aim of this work was to evaluate the mechanical, physicochemical and microbiological properties of Scaffolds, before and after three different sterilization methods. These Scaffolds were made of bacterial cellulose, sodium alginate and amorphous calcium phosphate. Scaffolds were made by lyophilization process. They were divided into four groups: a control group and three different sterilization techniques (steam sterilization, sterilization by ultraviolet irradiation and microwave sterilization). The number of viable colonies (CFU/mL) was obtained by plating the samples in Sabouraud Dextrose Agar with Chloramphenicol (SDA), Brain and Heart Infusion Agar (BHI), Chromagar and Blood Agar. All experiments were performed in triplicate and analyzed statistically. Later, the samples were characterized by X-ray Diffraction (XRD), Infrared Spectroscopy with Fourier Transform (FTIR) and Microscopy Scanning Electronics (SEM) in order to evaluate if the sterilization process affected the structure and chemical composition of the Scaffolds. The results showed that steam sterilization was effective in eliminating the microorganisms, whereas microwave sterilization significantly reduced the number of CFU/mL, and ultraviolet did not demonstrate sterilizing efficacy. It was concluded that the steam sterilization process was the most effective, not observing changes in the structure and composition of the Scaffolds.
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Palavras-chave
Esterilização, Scaffolds, Fosfatos de cálcio, Celulose bacteriana, Sterilization, Calcium phosphates, Bacterial cellulose