In Vivo Therapeutic Cell Tracking by Advanced Magnetic Particle Imaging

摘要 细胞疗法一直受到严重挑战的阻碍，在实现特定的交付到受损 器官，实现治疗有效性和安全性问题。一种非侵入性成像技术， 亚治疗剂量（比如10个细胞），并报告细胞的活力， 大大加快了方案优化，加快了细胞治疗的临床采用。 今天的全动物细胞跟踪成像方法（例如，MRI、光学、超声、核医学）所有 有其优势和技术局限性。一种新的非侵入性成像方法，称为磁粒子 成像（MPI）使用零辐射。MPI显示出作为补充细胞跟踪的非凡前景 报告方法。需要说明的是，MPI图像无法在MRI扫描仪中获得。今年， 我们在伯克利的研究小组首次在活体动物中展示了干细胞的MPI跟踪， 200-细胞“阳性对比”敏感性。MPI显示出理想的定量对比度，在空气或 像其他方式一样。MPI的灵敏度已经是当今非侵入性细胞成像的100倍 方法，在这里，我们的目标是使它更加敏感。200细胞灵敏度和MPI的空间 分辨率仍然可以大大提高。我们的总体目标是改进MPI以达到真正的物理极限 MPI，特别是20细胞检测和280微米的空间分辨率。最后，我们计划验证这些 通过跟踪干细胞治疗脱髓鞘疾病的体内模型进行创新 专家、加州大学伯克利分校教授大卫·谢弗。

Abstract Cell therapies have been held back by serious challenges in achieving specific delivery to the damaged organ, realizing treatment efficacy, and safety concerns. A noninvasive imaging technique that could follow a sub-therapeutic dose (say 10 cells) anywhere in the body, and report back on the cells' viability, could greatly expedite protocol optimization and hasten cellular therapy clinical adoption. Today's whole-animal cell tracking imaging methods (e.g., MRI, optical, ultrasound, nuclear medicine) all have their strengths and technical limitations. A new noninvasive imaging method called Magnetic Particle Imaging (MPI) uses zero radiation. MPI shows extraordinary promise as a complementary cell tracking and reporting method. Just to be clear, MPI images cannot be obtained in an MRI scanner. This year, our group at Berkeley showed MPI tracking of stem cells for the first time in live animals, with quantitative 200-cell “positive contrast” sensitivity. MPI shows ideal, quantitative contrast with no confounds near air or bone as in other modalities. MPI is already 100-times more sensitive than today's noninvasive cell imaging methods, and here we aim to make it even more sensitive. Both the 200-cell sensitivity and MPI's spatial resolution can still be greatly improved. Our overall aim is to improve MPI to reach the true physics limits of MPI, specifically 20-cell detection and 280-micron spatial resolution. Finally, we plan to validate these innovations by tracking an in vivo model of stem cell treatment for demyelinating disease with stem cell expert, UC Berkeley Professor David Schaffer.