Investigation of laser based processes to optimize eletrospun nanofiber nonwovens for tissue engineering

• Main Author: Costa, Carolina Pereira Lobato
• Publication Date: 2018
• Format: Master thesis
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10362/58115
• topic: Wettability; contact angle; PA nanofibres; PLA nanofibers; uv-laser; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

Polymers and especially polymeric nanofibers are widely investigated in tissue engineering. These materials can imitate the extracellular matrix. Therefore, they can be used as scaffolds for growing human cells. However, in many cases a surface treatment of the nanofiber nonwovens is useful to enhance the cell adhesion. The polar and dispersion components of surface free energy have to be adjusted to control the wettability. To optimize the cell colonization on electrospun nanofibers, polyamide (PA 6.6) and polylactide (PLA) fibers were processed with different types of pulsed UV laser radiation. For comparison polyimide (PI), PA and PLA bulk materials were also investigated. Static contact angles were measured before and after laser processing to investigate the effects of laser irradiation on the wettability. The morphology of the treated areas was evaluated by confocal and scanning electron microscopy. Chemical analyses, like FTIR-ATR were also performed. The wettability of the different materials was changed. PA nanofiber nonwovens are hydrophilic and are appropriate for good adhesion of some kind of cells. PLA nanofiber nonwovens are hydrophobic. By certain laser processes, it was also possible to make this material more hydrophilic. It was observed, that the laser generated topography of the nonwovens plays a great rule in the wettability.