Alvarez F J, Jordán J A, Calleja P, Lotero L A, Olmos G, Díez J C, Tejedor M C
Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.
Biotechnol Appl Biochem. 1998 Apr;27(2):139-43.
Previous investigation has shown that osmotically loaded erythrocytes can act as drug carriers in systemic circulation, whereas chemically modified erythrocytes can be targeted to organs of the mononuclear phagocytic system because of changes introduced in the membrane that are recognized by macrophage cells. In this study we have examined the delivery of 125I-labelled carbonic anhydrase (125I-CA) carried by mouse erythrocytes, either loaded, or loaded and cross-linked with bis(sulphosuccinimidyl)suberate (BS3) and 3,3'-dithiobis-(sulphosuccinimidyl propionate), into homologous peritoneal macrophages maintained in culture. The hypotonically loaded mouse erythrocytes show a slight recognition by macrophages, similar to native erythrocytes. CA loaded into erythrocytes is thus delivered to a limited extent into macrophages. Neither the number of recognized loaded 51Cr-labelled erythrocytes nor the amount of delivered 125I-CA is affected by the presence of serum components or IgG. In contrast, cross-linking these loaded erythrocytes results in a greater phagocytosis by macrophages as assessed by microscopic observations, producing a markedly increased amount of targeted enzyme. The amount of CA delivered into macrophages, after BS3 cross-linker treatment of erythrocytes, is dependent on the presence of serum components in the incubation medium. Thus these cross-linking treatments improve the capacity of loaded mouse erythrocytes to deliver significant amounts of targeted enzyme to macrophage cells, increasing the therapeutic potential of carrier erythrocytes.
先前的研究表明，经渗透压加载的红细胞可在体循环中充当药物载体，而化学修饰的红细胞可靶向单核吞噬系统的器官，这是因为细胞膜发生的变化能被巨噬细胞识别。在本研究中，我们检测了小鼠红细胞携带的125I标记的碳酸酐酶（125I-CA）的递送情况，这些红细胞要么是经加载的，要么是经加载后用辛二酸双（磺基琥珀酰亚胺酯）（BS3）和3,3'-二硫代双（磺基琥珀酰亚胺丙酸酯）交联的，将其递送至培养的同源腹膜巨噬细胞中。低渗加载的小鼠红细胞与天然红细胞类似，仅表现出被巨噬细胞轻微识别。因此，加载到红细胞中的CA仅在有限程度上被递送至巨噬细胞。无论是被识别的加载51Cr标记红细胞的数量，还是递送的125I-CA的量，均不受血清成分或IgG的影响。相比之下，通过显微镜观察评估发现，将这些加载的红细胞交联会导致巨噬细胞吞噬作用增强，从而使靶向酶的量显著增加。在用BS3交联剂处理红细胞后，递送至巨噬细胞的CA量取决于孵育培养基中血清成分的存在。因此，这些交联处理提高了加载的小鼠红细胞向巨噬细胞递送大量靶向酶的能力，增加了载体红细胞的治疗潜力。
