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Estudo do comportamento mecânico e biológico de scaffolds poliméricos com revestimento fabricados por impressão 3D
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Abstract(s)
Os defeitos ósseos causados por fraturas, osteoporose ou outro tipo de lesões,
podem desencadear dificuldades na regeneração do tecido ósseo, comprometendo a
qualidade de vida e o bem-estar do indivíduo. Os scaffolds são estruturas tridimensionais
porosas que suportam a proliferação e a regeneração tecidual, sendo biocompatíveis,
biodegradáveis, com porosidade e resistência mecânica adequada. No entanto, o
equilíbrio entre a porosidade e as propriedades mecânicas, o design da estrutura e as
propriedades de superfície, continuam a ser um desafio constante para a engenharia de
tecidos (ET).
O fabrico aditivo, particularmente a técnica de fabrico por filamento fundido
(FFF), permite a produção de scaffolds com geometrias e porosidades variadas. Este
trabalho estuda as propriedades morfológicas, físicas, químicas e mecânicas de scaffolds
de ácido polilático (PLA). Foram estudadas configurações ortogonais e isométricas, com
sequências de deposição de única e dupla camada, variando a porosidade, incluindo o
revestimento com alginato de sódio. As amostras foram caracterizadas
microscopicamente, determinadas as porosidades, molhabilidade por ângulo de contato,
ensaios mecânicos de compressão, sendo ainda realizados ensaios in vitro, analisando
particularmente a citotoxicidade e a adesão celular às amostras.
Os resultados mostram que a porosidade continua a ser um dos fatores que mais
influencia as propriedades do scaffold. Uma amostra com menor porosidade apresenta
uma maior rigidez aparente à compressão, tensão de cedência e demonstrou melhores
resultados in vitro. O PLA demonstrou ser adequado para a produção de scaffolds, uma
vez que não se revelou citotóxico, e o revestimento com alginato de sódio por sua vez,
melhorou a hidrofilicidade da superfície das amostras, embora a sua influência requeira
estudos adicionais.
Bone defects caused by fractures, osteoporosis or other types of injury can lead to difficulties in bone regeneration, compromising the individual's quality of life and wellbeing. Scaffolds are a three-dimensional porous structure, designed to induce support, cell proliferation, and tissue regeneration. They are biocompatible, biodegradable, porous and mechanically resistant. However, the balance between porosity and mechanical properties, structure design and surface properties remain a constant challenge. Additive manufacturing, particularly the fused filament fabrication technique, allows the production of scaffolds with different geometries and porosities. This work studies the morphological, physical, chemical and mechanical properties of polylactic acid (PLA) scaffolds. Orthogonal and isometric configurations were analyzed, with both single- and double-layer deposition sequences, along with variations in porosity. These configurations were also coated with sodium alginate. The samples were characterized microscopically, with determination of porosity, contact angle wettability, mechanical compression tests, and in vitro tests were also carried out, particularly analyzing cytotoxicity and cell adhesion to the samples. The results show that porosity continues to be one of the factors that most influences scaffold properties. A lower porosity leads to greater apparent compressive stiffness, yield strength and better in vitro results. PLA has proved to be suitable for the production of scaffolds, as it is not cytotoxic. Coating with sodium alginate improved the hydrophilicity of the surface of the samples, although its influence requires further study
Bone defects caused by fractures, osteoporosis or other types of injury can lead to difficulties in bone regeneration, compromising the individual's quality of life and wellbeing. Scaffolds are a three-dimensional porous structure, designed to induce support, cell proliferation, and tissue regeneration. They are biocompatible, biodegradable, porous and mechanically resistant. However, the balance between porosity and mechanical properties, structure design and surface properties remain a constant challenge. Additive manufacturing, particularly the fused filament fabrication technique, allows the production of scaffolds with different geometries and porosities. This work studies the morphological, physical, chemical and mechanical properties of polylactic acid (PLA) scaffolds. Orthogonal and isometric configurations were analyzed, with both single- and double-layer deposition sequences, along with variations in porosity. These configurations were also coated with sodium alginate. The samples were characterized microscopically, with determination of porosity, contact angle wettability, mechanical compression tests, and in vitro tests were also carried out, particularly analyzing cytotoxicity and cell adhesion to the samples. The results show that porosity continues to be one of the factors that most influences scaffold properties. A lower porosity leads to greater apparent compressive stiffness, yield strength and better in vitro results. PLA has proved to be suitable for the production of scaffolds, as it is not cytotoxic. Coating with sodium alginate improved the hydrophilicity of the surface of the samples, although its influence requires further study
Description
Keywords
Tecido ósseo Scaffolds Engenharia de tecidos Fabrico aditivo PLA Revestimento Cultura celular Bone tissue Tissue engineering Additive manufacturing Coating Cell culture