SPIO标记猪脂肪干细胞的生物学特性与多向分化潜能及体外3.0T MR成像

背景：不同种类细胞的最佳化标记方案需要大量实验证明,而每种细胞对应标记策略的安全性检测至关重要。目的：应用超顺磁性氧化铁联合多聚左旋赖氨酸标记猪脂肪干细胞,探讨磁标记对细胞生物学特性和多向分化潜能的影响以及标记细胞体外3.0TMR成像特性。方法：五指山小型猪皮下脂肪分离培养脂肪干细胞;超顺磁性氧化铁-多聚左旋赖氨酸复合物标记液标记脂肪干细胞;应用3.0TMR对不同浓度标记细胞进行T1WI、T2WI及T2＊WI序列体外成像。结果与结论：普鲁士蓝染色显示标记细胞胞质内含有多少不等的蓝染铁颗粒,细胞标记率近100%;标记细胞向心肌、骨、脂肪方向诱导分化成功;不同浓度标记细胞MR扫描显示,随细胞浓度升高,3种序列信号变化率均增加;相同浓度细胞T2＊WI信号变化率最大,T1WI最小,同一浓度3种MR序列间信号变化率差异均有显著性意义（P〈0.01）;3.0TMR成像能检测到至少1×106L-1标记细胞。结果显示应用超顺磁性氧化铁联合多聚左旋赖氨酸标记方案可有效标记脂肪干细胞,不影响细胞活力、增殖及多向分化能力;T2＊WI序列检测标记细胞最敏感。

Biological characteristics and multilineage differentiation of superparamagnetic iron oxide nanoparticles labeled adipose tissue-derived stem cells from pigs and in vitro 3.0T MR imaging

BACKGROUND： Adipose tissue-derived stem cells （ADSCs） are promising for clinical application in cardiovascular cellular therapy.In vivo MR imaging of magnetically labeled ADSCs to track the survival and migration of implanted cells is important for clinical application and scientific research.However,to carefully evaluate the safety of any labeling method and investigate the characteristics of in vitro MR imaging is required before any clinical application.OBJECTIVE： To label porcine ADSCs with superparamagnetic iron oxide nanoparticles （SPIO） combined with poly-l-lysine （PLL）,and to explore the effects of magnetic cell labeling on cellular biological characteristics,multilineage differentiation potential,and the characteristics of in vitro 3.0T MR imaging.METHODS： ADSCs were isolated from the subcutaneous adipose tissue of pigs and expanded in culture medium.ADSCs were incubated with the SPIO-PLL complex for 48 hours.Cell viability,proliferation and differentiation capacity to cardiomyocytes,osteogenic and adipogenic lineage between labeled and unlabeled cells were compared.Different concentrations of labeled ADSCs and the control were scanned at a clinical 3.0T MR system by using T1WI,T2WI and T2＊WI sequences.RESULTS AND CONCLUSION： Numerous intracytoplasmic iron particles stained with Prussian blue were detected in labeled cells with labeling efficiency of nearly 100%.Both labeled and unlabeled cells were able to differentiate into cardiomyocytes,adipocytes and osteocytes.The change in MR signal intensity increased at T1WI,T2WI and T2＊WI along with elevation of the labeled cells concentration.The biggest and smallest change in signal intensity were observed at T2＊WI and T1WI respectively.There were significant differences among the change in signal intensity at T1WI,T2WI and T2＊WI for each cell concentration （P 0.01）.At least 1×106/L SPIO labeled ADSCs could be detected by 3.0T MR.Our study indicated that ADSCs are more promising cells for clinical application in repairing damaged myocardium.ADSCs can be effectively labeled by SPIO-PLL complex without affecting the cell viability,proliferation and multilineage differentiation ability.Compared with T1WI and T2WI,T2＊WI is the most sensitive sequence for MR tracking of SPIO labeled ADSCs.3.0T MR is more sensitive for cellular tracking based on the advantage of higher magnetic field strength.