Electrospun poly(ε-caprolactone) nanofibers for bone regeneration and other biomedical applications

• Autor(a) principal: Valente, Tiago António Martins
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/1037
• topic: Nanofibras - Aplicações médicas; Regeneração óssea - Nanofibras de policaprolactona; Electrospinning - Nanofibras de policaprolactona; Revestimento de Scaffolds

Bone tissue is a complex and hierarchical structure with many functions in the body. Although this tissue has the capability for self-generation, large bone defects due to various diseases or fractures may need clinical treatment. However, the current clinical treatments are based on bone grafts and other bone substitutes, which have several limitations. Tissue engineering is a multidisciplinary field that emerged from the need to extinguish these clinical limitations. This vast field of science uses various tools in seeking for effective tissue regeneration. In this context, this work aimed the production of functional materials that mimic the nanostructure of bone tissue and therefore the cellular microenvironment, promoting bone regeneration. In this way, an electrospinning apparatus was mounted and optimized for the production of polycaprolactone nanofibers. Additionally, several electrospinning parameters that influence the morphology of the electrospun nanofibers produced were studied. For application in bone regeneration, the combination of polycaprolactone nanofibers with β-tricalcium phosphate scaffolds, mechanically more resistant, was investigated. Moreover, a preliminary study about the capacity for this system to allow controlled release of biomolecules was conducted through the incorporation of a model protein into the nanofibers. In order to characterize the biological properties of the systems produced, in vitro cytotoxicity assays were performed. These assays revealed that the polycaprolactone nanofibers produced are biocompatible and that the coating of β-tricalcium phosphate scaffolds with these nanofibers improve this biological performance, when compared to ceramic scaffolds without coating. The potentiality of nanofibers herein produced was also evaluated for the modification of microfiltration membranes. These membranes showed a large increase in the plasmid DNA rejection.