Electrical and biological characterization of PLLA-316L stainless steel electromechanical devices for bone tissue engineering

• Autor(a) principal: Ferreira, Sheila de Oliveira
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/30887
• topic: Stainless steel 316L; Poly (L-lactic acid) (PLLA); Films piezoelectricity; Silanization; Osseointegration; Orthopedic implants; Cytocompatibility; Atomic force microscopy (AFM)

Metals and their alloys are widely used in biomedical implants but the lack of osseointegration at the interface between the biomaterial and the host tissue leads to non-mechanical fixation, infection and risk of rejection. The osseointegration can be improved using a coating based on piezoelectric materials. These materials generate electrical potential in response to applied mechanical forces. The osteoblasts, which are responsible for bone growth and repair, respond to the induced surface potential. An excellent-right candidate for this application is the poly (L-lactic acid) (PLLA), a synthetic polymer that is also biocompatible and biodegradable. In this work, electrical and biological characterization of stainless steel 316L substrates covered with PLLA films were performed, using impedance spectroscopy, AFM, and cytocompatibility tests with human dental pulp stem cells (hDPSCs). The adhesion between these materials was guaranteed by using the silanization process. The PLLA films were also characterized using FTIR, XRD, surface roughness analysis, SEM, tape test, contact angle analysis, and DSC. The Presto BlueTM viability assay showed that the PLLA film increased the cell viability on the substrates. Osteogenic differentiation assay showed that PLLA film enhanced the innate osteogenic potential of the cells and the osteogenic differentiation. The SEM images allowed seeing the presence of normal morphology of fibroblast cells and its layer formation on PLLA film. Concluding, the developed functional device has a great potential for bone tissue engineering application.