磁性颗粒形成细胞膜孔的能量限制。
Energetic constraints on the creation of cell membrane pores by magnetic particles.
作者信息
Vaughan T E, Weaver J C
机构信息
Harvard-M.I.T. Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, USA.
出版信息
Biophys J. 1996 Aug;71(2):616-22. doi: 10.1016/S0006-3495(96)79262-7.
Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores"). We show that this possibility is significantly constrained by the maximum rotational energy that can be transferred to the cell membrane. For single biologically synthesized magnetosomes (radius rmag approximately 10(-7) m, magnetic moment mu approximately 2 x 10(-15) A m2) and typical cell membranes, the estimated pulse magnitude must exceed Bo approximately 6 x 10(-3) to 7 x 10(-2) T, and the optimal pulse durations are in the range 10(-5) s < tpulse < 10(-1) s. For larger contaminant particles with larger net magnetic moments, the pulse magnitudes could be only somewhat smaller, and the optimal durations are about the same. Very large pulses that exceed the coercive force of a particle are predicted to have a smaller effective magnitude and shorter effective duration.
在细胞内部或其附近发现了天然存在的以及作为污染物的铁磁性和亚铁磁性颗粒，这些颗粒可能使脉冲磁场导致细胞膜瞬间打开（“形成孔道”）。我们发现，这种可能性受到能够传递至细胞膜的最大旋转能量的显著限制。对于单个生物合成的磁小体（半径rmag约为10^(-7)米，磁矩μ约为2×10^(-15)安·米²）和典型的细胞膜而言，估计脉冲强度必须超过Bo约6×10^(-3)至7×10^(-2)特斯拉，并且最佳脉冲持续时间在10^(-5)秒 < tpulse < 10^(-1)秒范围内。对于具有更大净磁矩的较大污染物颗粒，脉冲强度可能仅略小一些，而最佳持续时间大致相同。预计超过颗粒矫顽力的非常大的脉冲具有较小的有效强度和较短的有效持续时间。
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