Optimizing the osteogenic potential of electrospun PVDF matrixes

With an ageing population, the ability to easily regenerate bone defects in a manner that lessens patient site morbidity takes an even more important toll. As such the development of a biomaterial that is capable of successfully mimicking the native environment encountered in the human body is necessary in order to facilitate the regenerative process. Since traditional orthopedic materials lack some of the necessary ability to mimic the native environment, new approaches must be taken, in this regard polyvinylidene difluoride (PVDF) presents a novel alternative. Since it can be produced via electrospinning in the form of a non-woven fiber matrix that mimics the morphology of the native extracellular matrix (EMC) as well as being able to simulate electrical signals, due to the appearance of a piezoelectric phase due to the electrospinning process, that act as cues for several cellular and molecular processes, including tissue regeneration. The work developed in this thesis aims to optimize the piezoelectric response under electrical stimulation of the electrospun matrixes by adjusting the spinning parameters in order to device an optimal scaffold for bone tissue growth and regeneration. Structural analysis of the material, shows that the electrospinning process give origin to a new structural organization. When compared to the original PVDF powder, after processing the polymer presents higher crystallinity and also higher content of the piezoelectric phase. However no significant differences were found in crystalline phases, porosity and overall crystallinity for samples spun under different conditions. Cytotoxicity tests shown that PVDF mats present a non-cytotoxic behavior. Cellular tests under electric stimulus showed no statistical difference between samples with higher and lower piezoelectric response. However regardless of the sample type, the cells demonstrate a much higher metabolic activity when had received an external stimulus