In Vitro Study on Effects of Physico-Chemo-Mechanical Properties of Embolic Microspheres on Embolization Performances

In this study, the effects of physico-chemical-mechanical properties of embolic microspheres on embolization performances are systematically investigated for the first time in a self-designed and 3D-printed transparent in vitro embolization chip. With droplet microfluidic devices, monodisperse poly(lactic-co-glycolic acid) (PLGA), chitosan, calcium alginate (Ca-ALG), and poly(vinyl alcohol) (PVA) microspheres with uniform shapes and controllable diameters are successfully fabricated. The embolization performances of microspheres with different physico-chemical-mechanical properties, including the elastic properties, surface adhesion properties, and sizes, are evaluated by observing the embolization positions of microspheres in the microchannels inside the chip and measuring the embolization-induced decreases of trans-channel water fluxes of the chip. The results show that for the microspheres with large Young's moduli and low surface adhesion properties, the microchannel diameters that can be embolized by microspheres are almost the same as the corresponding microsphere diameters; however, when the microspheres have very low Young's moduli, they can deform in the microchannels and pass through microchannels with diameters much smaller than the microsphere diameters. Generally, embolic microspheres with good elastic property, low surface adhesion property, and suitable size can achieve desired embolization performances. This work provides a new platform for controllable fabrication and performance characterization of future materials for embolization, and the results provide valuable guidance for designing efficient embolic materials for the transcatheter arterial embolization therapy.