9 documents found, page 1 of 1
Estimulação mecânica de células osteoblásticas com filmes piezoeléctricos
Reis, Joana; Frias, Clara; Capela e Silva, Fernando; Potes, José; Simões, José; Marques, AntónioCélulas osteoblásticas foram cultivadas na superfície de um substrato piezoeléctrico revestido com material biocompatível, para melhorar o isolamento eléctrico e a adesão celular, em condições estáticas e dinâmicas. Os parâmetros estudados para compreender o comportamento das culturas celulares perante estimulação dinâmica foram os níveis de proteína total, a viabilidade e proliferação celular e níveis de óxido...
ESTIMULAÇÃO MECÂNICA NA INTERFACE OSSO/IMPLANTE POR ACTUADORES PIEZOELÉCTRICOS
Reis, Joana; Frias, Clara; Capela e Silva, Fernando; Potes, José; Canto e Castro, Carlos; Botelho, Maria Luísa; Simões, José AntónioEste trabalho descreve os resultados da implantação em tíbia e fémur de ovelha de actuadores piezoeléctricos, pelo efeito piezoeléctrico inverso. A estimulação mecânica assim conseguida teve forte impacto na área ocupada por osso, bem como na taxa de mineralização.
Experimental and Numerical simulation of mechanical actuators coated with PMMA ...
Frias, Clara; Reis, Joana; Capela e Silva, Fernando; Potes, José; Torres Marques, António; Simões, José AntónioBone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. The aim of this work was to experimentally validate the possibility of using piezoelectric materials as a mean of stimulating mechanically ...
Polymeric piezoelectric actuator substrate for osteoblast mechanical stimulation
Frias, Clara; Reis, Joana; Capela silva, Fernando; Potes, José; Torres Marques, António; Simões, JoséAbstract Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. A wide variety of devices have been tested for mechanical stimulation of cells and tissues in vitro. The aim of this work was to e...
Piezoelectric actuator: searching inspiration in nature for osteoblast stimulation
Frias, Clara; Reis, Joana; Capela Silva, Fernando; Potes, José; Torres Marques, António; Simões, JoséAbstract Bone is a composite with piezoelectric properties. Bone mass and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels, but the role piezoelectricity plays in bone physiology is yet to be understood. Physical activity enhances bone density, through mechanical stimulation. Osteocytes and osteoblasts are essential for mechanosensing and mechanotransduction. Stra...
Sterilization of an Electronic Medical Device
Reis, Joana; Cabo Verde, Sandra; Capela Silva, Fernando; Frias, Clara; Potes, José; Melo, Rita; Nunes, Inês; Marcos, Helena; Silva, TelmaRadiosterilization was applied to a medical device with a “programmable memory” to allow in vivo implantation. Irradiation on a Cobalt-60 facility at 25 kGy at a dose rate of 2kGy/h corrupted the memory. Therefore an alternative sterilization method using UV was developed and validated based on ISO 11737-1 and ISO 14937. These procedures may be useful and effective for research purposes when only a small number...
Piezoelectric bone stimulation: should we move closer to nature?
Reis, Joana; Frias, Clara; Capela-Silva, Fernando; Potes, José; Simões, José; Torres Marques, AntónioThe aim of this work was to experimentally validate the use of piezoelectric materials as a mean of directly straining bone cells by converse piezoelectric effect.
Osteoblast mechanical stimulation by converse piezoelectric effect.
Reis, Joana; Frias, Clara; Capela e Silva, Fernando; Potes, José; Simões, António; Marques, AntónioThe aim of this work was to experimentally validate the use of piezoelectric materials as a mean of directly straining bone cells by converse piezoelectric effect.
Behaviour of piozoelectric devices embedded in bone cement
Frias, Clara; Marques, M.A.; Ribeiro, J.E.; Vaz, M.A.P.; Simões, J.; Marques, A.T.Bone cements based on polymethacrylate (PMMA) are essential products in joint arthroplasty. PMMA bone cement function is to locate the implants components in the body skeleton, load transition through the joint into the bone and muscle surrounding for a very for a very long period of time. Its mechanical properties are well established in the literature. Since bone cement fills the void between the prosthesis (...