PROBLEM TO BE SOLVED: To provide compositions and methods for the treatment or imaging of stenosis, stenotic lesions, occluded lumens, embolic phenomena, or thrombotic disorders, and to provide compositions and methods for the treatment of internal hemorrhage.SOLUTION: The invention relates to an aggregate for therapeutic use comprising a plurality of nanoparticles, wherein the aggregate disaggregates above a predetermined shear stress when exposed to the predetermined shear stress, to an aggregate of size of 50 μm or less, and to an aggregate in which small or large organic or inorganic molecules are encapsulated by nanoparticles or absorbed/adsorbed on or covalently linked to the surface of the nanoparticles, and the molecules are biologically active.SELECTED DRAWING: Figure 1A【課題】狭窄症、狭窄病変、閉塞管腔、塞栓事象、または血栓障害の治療またはイメージングのための組成物および方法、および内出血の治療のための組成物および方法の提供。【解決手段】複数のナノ粒子を含む、治療使用のための凝集物であって、所定の剪断応力に曝露された場合に該所定の剪断応力超で脱凝集する凝集物。50μm以下のサイズの凝集物。有機・無機の小分子又は大分子がナノ粒子に被包されているか、ナノ粒子の表面に吸収/吸着又は共有結合しており、前記分子が生物学的に活性である凝集物。【選択図】図1A