Barium sulphate-loaded p(HEMA) microspheres as artificial emboli: preparation and properties

Abstract

Poly(2-hydroxyethyl methacrylate) p(HEMA) microspheres of good spherical geometry (diameter 90-1500 μm) encapsulated with 40-50% barium sulphate to impart radiopaque properties were prepared by a solvent evaporation process. These microspheres were cross-linked by reacting with hexamethylene diisocyanate (HMDI) or by γ-irradiation in the presence of ethylene glycol dimethacrylate (EGDM) in n-heptane. Microspheres with a porous structure and a rough surface were also made by the incorporation of NaCI along with BaS0₄. The effects of concentration of the polymer solution, concentration of the stabilizing agent, concentration of BaS0₄, viscosity of the dispersion medium and ratio of the dispersed phase to the dispersion medium on the formation, stability and particle size distribution of the microspheres were investigated.