Biomaterials：新技术攻克心脏干细胞疗法的一大困难

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2014年8月16日讯 /生物谷BIOON/--干细胞治疗是一种很有前途的手段，用于修复由心脏病发作导致的心脏组织损坏。然而，心脏干细胞疗法目前还存在着一大技术障碍。 5 g1 `$ n& U0 X- A
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. [5 w/ }  l% \5 Z4 v当进行细胞移植后，细胞保留永远是有问题的，特别是对于心脏修复来说是特别困难的，因为心脏泵可以将移植细胞“冲洗”出器官，那么移植的细胞要么消失，要么会在其他器官中死亡。
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研究人员一直试图解决保留心脏干细胞的问题，让这些细胞在它们应该呆的地方，呆足够长的时间，并让它们“安顿”下来，开始工作。在2010年，研究表明，将铁纳米颗粒附加在心脏干细胞上，并使用磁场，有可能将这些移植细胞保持在应该呆的地方。
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现在Biomaterials杂志上最近发表的一项研究，科学家使用纳米粒子（来源于从FDA批准的贫血症药物Feraheme），来标记心脏干细胞，然后用磁铁引导细胞到达有心脏疾病大鼠的心脏。 " h+ @! B# z& s; e, D, @" H% I' \
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研究发现，磁场显著提高细胞的保留时间和治疗效果。: j9 E/ P. k1 E. ]: {

坤明

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doi:10.1016/j.biomaterials.2014.06.031
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Magnetic targeting of cardiosphere-derived stem cells with ferumoxytol nanoparticles for treating rats with myocardial infarction; P* s: X- L: R

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Adam C. Vandergriff, et al. ! F) D6 w; Z: V+ f# |6 q5 `* M2 s
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Stem cell transplantation is a promising therapeutic strategy for acute or chronic ischemic cardiomyopathy. A major limitation to efficacy in cell transplantation is the low efficiency of retention and engraftment, due at least in part to significant early “wash-out” of cells from coronary blood flow and heart contraction. We sought to enhance cell retention and engraftment by magnetic targeting. Human cardiosphere-derived stem cells (hCDCs) were labeled with FDA-approved ferumoxytol nanoparticles Feraheme? (F) in the presence of heparin (H) and protamine (P). FHP labeling is nontoxic to hCDCs. FHP-labeled rat CDCs (FHP-rCDCs) were intracoronarily infused into syngeneic rats, with and without magnetic targeting. Magnetic resonance imaging, fluorescence imaging, and quantitative PCR revealed magnetic targeting increased cardiac retention of transplanted FHP-rCDCs. Neither infusion of FHP-rCDCs nor magnetic targeting exacerbated cardiac inflammation or caused iron overload. The augmentation of acute cell retention translated into more attenuated left ventricular remodeling and greater therapeutic benefit (ejection fraction) 3 weeks after treatment. Histology revealed enhanced cell engraftment and angiogenesis in hearts from the magnetic targeting group. FHP labeling is safe to cardiac stem cells and facilitates magnetically-targeted stem cell delivery into the heart which leads to augmented cell engraftment and therapeutic benefit.
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