RESUMO
OBJECTIVE: To develop and study the properties of crosslinked polyvinyl alcohol microspheres (PVA-Ms) for embolization. METHODS: The PVA-Ms were produced by emulsion chemical crosslinking method. Fourier transform infrared spectroscopy (FT-IR) was used to investigate the special functional groups of PVA-Ms; the morphology and particle size of PVA-Ms were determined by optical microscope; the ratio of water absorption and the swelling ratio were also investigated; the compressibility was examined by texture analyzer. A new device was designed to measure the pressure of PVA-Ms during their delivery through catheter for embolization. RESULTS: The crosslinking reaction of PVA and formaldehyde was proved by FT-IR. The PVA-Ms were round with smooth surface. The average diameter of lyophilized PVA-Ms was 574.2 µm with a range of 80-1 800 µm and of wet PVA-Ms was 602.2 µm with a range of 100-1 900 µm. The average ratio of water absorption was 175% and the swelling ratio was 48.6%. The PVA-Ms were mechanically stable with appropriate elasticity and delivered through the catheter without any difficulty, and the pressure was higher for larger size of microspheres to be delivered. CONCLUSION: PVA-Ms prepared in this study was supposed to be suitable for clinical embolization according to the physicochemical properties. The study provides a series of methods to evaluate the properties of microspheres systemically for embolization in vitro.
