Department of Biochemistry, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.
J Control Release. 2013 Sep 28;170(3):343-51. doi: 10.1016/j.jconrel.2013.05.032. Epub 2013 Jun 6.
Human red blood cells (RBCs) are emerging as a highly biocompatible microparticulate drug delivery system. So far, drugs have commonly been loaded into freshly isolated RBCs using rather disruptive methods based on hypotonic shock, and assessment of damage was restricted to hemolysis. Here, we investigated loading of RBCs from blood bank units with enzymes of various molecular weights using hypotonic dialysis (HD), pretreatment with chlorpromazine (CPZ) and fusion with liposomes. The latter two techniques have received little attention in RBC loading so far. Along with loading efficiency, all methods were tested for the induction of side effects. Very importantly, next to hemolysis, we also addressed morphological changes and phosphatidyl serine (PS) exposure, which has been recognized as a critical parameter associated with premature RBC removal and induction of transfusion-related pathologies. The efficiency of loading using hypotonic dialysis decreased with the molecular weight of the enzyme. For liposomes and chlorpromazine, loading efficiencies were higher and independent of enzyme molecular weights. While hypotonic dialysis always induced a high degree of hemolysis, irreversible modifications in the morphology of the cells and PS exposure, the side effects that were induced by loading using CPZ and liposomes were limited. In particular, PS exposure, although high immediately after treatment, returned to physiological levels after recovery. Retention and deformability studies using a spleen-mimicking device showed that RBCs treated with CPZ and liposomes behave like physiological RBCs, while HD led to very fragile and poorly deformable RBCs.
人类红细胞（RBC）正在成为一种高度生物相容的微粒药物递送系统。到目前为止，通常使用基于低渗冲击的相当具破坏性的方法将药物加载到新分离的 RBC 中，并且对损伤的评估仅限于溶血。在这里，我们使用低渗透析（HD）、氯丙嗪（CPZ）预处理和脂质体融合来研究从血库单位加载具有各种分子量的 RBC 中的酶。到目前为止，后两种技术在 RBC 加载中很少受到关注。除了加载效率外，还测试了所有方法的诱导副作用。非常重要的是，除了溶血外，我们还解决了形态变化和磷脂酰丝氨酸（PS）暴露的问题，PS 暴露已被认为是与 RBC 过早清除和诱导输血相关病理相关的关键参数。使用低渗透析的加载效率随酶的分子量降低而降低。对于脂质体和氯丙嗪，加载效率更高且与酶分子量无关。虽然低渗透析总是会引起高度溶血，但细胞形态的不可逆改变和 PS 暴露，由 CPZ 和脂质体加载引起的副作用是有限的。特别是 PS 暴露虽然在处理后立即很高，但在恢复后会恢复到生理水平。使用脾脏模拟装置进行的保留和变形研究表明，用 CPZ 和脂质体处理的 RBC 表现得像生理 RBC 一样，而 HD 导致非常脆弱且变形能力差的 RBC。
