Presently described are microstructured films, such as brightness enhancing films, having a microstructured surface. The microstructured surface comprises the reaction product of a polymerizable composition comprising at least 20 wt-% of inorganic nanoparticles and a non-aromatic multi-(meth)acrylate monomer comprising at least three contiguous alkylene oxide repeat units. The multi-(meth)acrylate monomer typically comprises two or three (meth)acrylate groups. The alkylene oxide repeat units have the formula —[O-L]- wherein each L is independently a C2-C6 alkylene. Also described is a polymerizable resin composition comprising at least 20 wt-% of inorganic nanoparticles having a refractive index of at least 1.68 and a non-aromatic multi-(meth)acrylate monomer comprising at least three contiguous alkylene oxide repeat units.