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2019
Journal Article
Titel
Investigation of Laser Processing of Biodegradable Nanofiber Nonwovens with Different Laser Pulse Durations
Abstract
Implants or cell carriers made of biopolymers or biodegradable polymers are well suited for the regeneration of defects in various tissues. They act as an adhesion surface for autologous cells and provide sufficient stability. Electrospun nonwovens have a favourable surface to volume ratio and mimic the structure of the fiber proteins of the extracellular matrix in tissues. Their high porosity ensures a sufficient supply of nutrients to the cells while maintaining high mechanical strength. In addition, drug-release functionality can be installed in biodegradable nonwovens, which can support the regeneration. Particularly promising are flakes made of electrospun nonwovens which, in an appropriate suspension, can be injected into defective areas. For the production of such flakes, laser cutting or surface structuring can be applied. Typically, ablation by ultrashort laser pulses reduces the heat-affected zones significantly in microprocessing of many polymers. In this work, the quality of processing of electrospun gelatine and poly-lactide (PLA) nonwovens was investigated for UV-solidstate lasers with pulse durations in the nano- and picosecond range. We observed comparable ablation quality of electrospun gelatine nonwovens with UV nanosecond and with UV picosecond ablation. A similar behaviour was found for electrospun PLA nonwovens. Higher pulse energy was necessary for nanosecond ablation with the same focal spot diameter.