A physiologically active substance-conjugated block copolymer having enhanced efficacy and/or safety is provided by enhancing the property of penetrating into a target diseased tissue and/or enhancing excretability, compared to known physiologically active substance-conjugated block copolymer, and suppressing sensitization of the physiologically active substance to normal tissues other than a target diseased tissue. Disclosed is a block copolymer including a polyethylene glycol segment connected with a polyamino acid derivative segment conjugated with a physiologically active substance, in which the molecular weight of the block copolymer is from 2 kilodaltons to 15 kilodaltons, and the light scattering intensity of a 1 mg/mL aqueous solution of the physiologically active substance-conjugated block copolymer as measured with a laser light scattering photometer is at least twice or more the light scattering intensity of toluene.
本发明提供了一种生理活性物质共轭嵌段共聚物,与已知的生理活性物质共轭嵌段共聚物相比,该嵌段共聚物具有更强的穿透目标病变组织的特性和/或更强的排泄性,并可抑制生理活性物质对目标病变组织以外的正常组织的敏化作用,因而具有更高的功效和/或安全性。本发明公开了一种嵌段共聚物,该嵌段共聚物包括与生理活性物质共轭的聚
氨基酸衍
生物段相连的聚
乙二醇段,其中嵌段共聚物的分子量为 2 千道尔顿至 15 千道尔顿,用激光光散射光度计测量,生理活性物质共轭嵌段共聚物的 1 毫克/毫升
水溶液的光散射强度至少是
甲苯光散射强度的两倍或更大。