Single Point Incremental Forming and Electrospinning to produce biodegradable magnesium (AZ31) biomedical prostheses coated with porous PCL

Single Point Incremental Forming (SPIF) is a technology that allows producing highly customized products using conventional computer numerical control machines (CNC). Magnesium is a biocompatible and biodegradable metal with mechanical properties close to those of cortical bones: it can be a viable solution for producing temporary biomedical prostheses, avoiding a second surgery to remove it. Its major drawback is its poor formability at room temperature and low corrosion resistance. The first problem can be solved working at temperatures higher than the room one; the second, by coating the Mg substrate with a higher corrosion resistant material. In this work, Mg alloy sheets (AZ31B) were formed by SPIF at elevated spindle speeds (in order to locally heat the part by friction); in addition, a thin layer of PCL was deposited by electrospinning on the SPIFed parts. A porous coating was thus obtained: this morphology resembles the extracellular matrix of the body and promotes cell growth for tissue healing or even the electrospun fibers of PCL could be drug releaser for infection reduction. Cytotoxicity tests performed in this work revealed that oxides produced by the SPIF process delay the cytotoxic effect of the as received Mg alloy, while the presence of the PCL coating had a positive effect on the corrosion of the investigated Mg alloy