Preparation of PEG-grafted immunomagnetoliposomes entrapping citrate stabilized magnetite particles and their application in CD34+ cell sorting

Immunomagnetic systems have been used for positive selection of a cell fraction from a mixture using appropriate surface markers with satisfactory results, as haematopoietic CD34+ cells. This work reports on the development of poly(ethylene glycol)-grafted (PEG) immunoliposomes loaded with citrate-magnetite stabilized particles as the separation vehicles for immunomagnetic separations. The magnetic ferrofluid was encapsulated into PEG-liposomes by the DRV methodology. The magnetoliposomes had a liposomal size of approximately 450 nm and a Fe/lipid molar ratio of 1.52+/-0.26, and were retained in the magnetic field created by the MiniMACS system. Anti-CD34 immunomagnetoliposomes with 100 mAb/vesicle were prepared by coupling the My10 mAb and bound specifically for CD34+ KG-1a cells in culture and in mixtures with CD34-cells (CHO or Jurkat). The magnetic cell sorting was carried out in cell mixtures KG-1a/CHO or KG-1a/Jurkat with different initial% of CD34+ Kg-1a cells. For 10(6) positive cells and 100 microM of immunomagnetoliposomes, the capture efficiency was > 85% and independent of the starting percentage of CD34+ cells. The decrease of the final purity, when the starting percentage of CD34+ cells decreases and, dependent of the CD34- cell line used, point to the degree of non-specific cell binding of My10-immunomagnetoliposomes as being crucial, among of the methodological aspects as the number of starting CD34+ cells. The CD34+ cells isolated retained the viability with an estimated recovery of 45-50%.     

半相合移植移植物中CD34+细胞数量与临床结果相关性

目的 探讨半相合移植移植物中CD34 细胞数量对临床结果的影响.方法 对26例半相合移植患者移植物中CD34 细胞、T、B淋巴细胞数量与临床造血重建时间、急慢性移植物抗宿主病(GVHD)及存活率进行相关性分析.结果 所有患者输入CD34 细胞是(3.66～9.29)×106/kg,其中细胞数量高组(＞5.60×106/kg,A组)和低组(＜5.60×106/kg,B组)患者移植物中T、B淋巴细胞数量均无显著性差异;两组中性粒细胞造血重建时间均为11d,血小板重建时间均为18d;急性和慢性GVHD发生率A组分别为46.2%和38.5%,B组分别为46.2%和46.2%.患者总生存率A组为61.5%,B组为69.2%.结论 半相合干细胞移植输入(3.66～9.29)×106/kg的CD34 细胞是安全的,不增加GVHD的发生率,也不降低生存率.