Publicação
Mimicking of atherosclerotic plaques by 3D printing of composites.
| Resumo: | Atherosclerosis is an inflammatory vascular disease characterized by the formation of plaques due to the accumulation of lipids, fibrous elements, and other substances within arteries. The untreated progression of atherosclerosis leads to plaque disruption, which, together with thrombosis, is the leading cause of myocardial infarction and sudden death. Current treatment options for atherosclerotic vessels include surgical procedures or cardiovascular interventions. Surgical planning utilizes medical imaging, but it cannot provide a precise representation of the spatial relationships of the tissues. As such, the creation of patient-specific physical models of these vascular conditions would greatly benefit medical training and planning. These models must be easily reproducible, have accurately specified geometries, and must be able to replicate the mechanical properties of the relevant tissues. This can be accomplished with additive manufacturing, specifically using stereolithography (SLA) technology, as it enables the use of polymeric materials for high-resolution printing and is widely accepted as the most efficient method for printing surgical models quickly and accurately. The progression of atherosclerosis and the complexity of the blood vessels result in a wide range of mechanical properties even within the same plaque type. One way to modify the mechanical properties of SLA products is to reinforce them by incorporating a material, typically metal or ceramic, in the form of powder or particles into the resin used for printing.As such, this dissertation aims to use the additive manufacturing technology of SLA, reinforced with ceramic powder, to mimic stage VII atherosclerotic plaques. It also tests a new combination of resin and ceramic powder, studying the effect of the reinforcement on the printed specimen.To achieve this, a photo-cross-linked polymer resin, Gingiva Mask, was mixed with powdered β-tricalcium phosphate (β-TCP) at different percentages (0%, 0.1%, 0.5%, and 1%), and the chemical, surface, and mechanical aspects of the 3D-printed parts were analysed.The results indicated that the incorporation of ceramic powder, especially at a 1% concentration, improved shrinkage and resistance to indentation. The composite materials were more brittle, but the steady increase in stiffness alongside the percentage of reinforcement is a promising sign in terms of material customization.The incorporation of ceramic powder at higher percentages (0.5% and 1%) also improved the overall surface roughness and reduced surface energy.This study provided favourable indications about the success of using SLA with ceramic reinforcement for manufacturing models that mimic atherosclerotic plaques in different progression stages. The implementation of higher percentages of ceramic powder could result in materials with the mechanical properties of late-stage calcified plaques, leading to improvements in the mechanical and surface properties observed in this study. |
|---|---|
| Autores principais: | Freitas, Matilde Morão de |
| Assunto: | Atherosclerotic plaques 3D Printing Composite Material Placas Ateroscleróticas Impressão 3D Material Compósito |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade de Coimbra |
| Idioma: | inglês |
| Origem: | Estudo Geral - Universidade de Coimbra |
| Resumo: | Atherosclerosis is an inflammatory vascular disease characterized by the formation of plaques due to the accumulation of lipids, fibrous elements, and other substances within arteries. The untreated progression of atherosclerosis leads to plaque disruption, which, together with thrombosis, is the leading cause of myocardial infarction and sudden death. Current treatment options for atherosclerotic vessels include surgical procedures or cardiovascular interventions. Surgical planning utilizes medical imaging, but it cannot provide a precise representation of the spatial relationships of the tissues. As such, the creation of patient-specific physical models of these vascular conditions would greatly benefit medical training and planning. These models must be easily reproducible, have accurately specified geometries, and must be able to replicate the mechanical properties of the relevant tissues. This can be accomplished with additive manufacturing, specifically using stereolithography (SLA) technology, as it enables the use of polymeric materials for high-resolution printing and is widely accepted as the most efficient method for printing surgical models quickly and accurately. The progression of atherosclerosis and the complexity of the blood vessels result in a wide range of mechanical properties even within the same plaque type. One way to modify the mechanical properties of SLA products is to reinforce them by incorporating a material, typically metal or ceramic, in the form of powder or particles into the resin used for printing.As such, this dissertation aims to use the additive manufacturing technology of SLA, reinforced with ceramic powder, to mimic stage VII atherosclerotic plaques. It also tests a new combination of resin and ceramic powder, studying the effect of the reinforcement on the printed specimen.To achieve this, a photo-cross-linked polymer resin, Gingiva Mask, was mixed with powdered β-tricalcium phosphate (β-TCP) at different percentages (0%, 0.1%, 0.5%, and 1%), and the chemical, surface, and mechanical aspects of the 3D-printed parts were analysed.The results indicated that the incorporation of ceramic powder, especially at a 1% concentration, improved shrinkage and resistance to indentation. The composite materials were more brittle, but the steady increase in stiffness alongside the percentage of reinforcement is a promising sign in terms of material customization.The incorporation of ceramic powder at higher percentages (0.5% and 1%) also improved the overall surface roughness and reduced surface energy.This study provided favourable indications about the success of using SLA with ceramic reinforcement for manufacturing models that mimic atherosclerotic plaques in different progression stages. The implementation of higher percentages of ceramic powder could result in materials with the mechanical properties of late-stage calcified plaques, leading to improvements in the mechanical and surface properties observed in this study. |
|---|