Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA.
J Chem Phys. 2013 Jul 28;139(4):044908. doi: 10.1063/1.4813921.
We present theoretical results on kinetics for the passive wrapping of a single, rigid particle by a flexible membrane. Using a simple geometric ansatz for the shape of the membrane/particle complex we first compute free energy profiles as a function of the particle size, attraction strength between the particle and vesicle, and material properties of the vesicle--bending stiffness and stretching modulus. The free energy profiles thus computed are taken as input to a stochastic model of the wrapping process, described by a Fokker-Planck equation. We compute average uptake rates of the particle into the vesicle. We find that the rate of particle uptake falls to zero outside of a thermodynamically allowed range of particle sizes. Within the thermodynamically allowed range of particle size, the rate of uptake is variable and we compute the optimal particle size and maximal uptake rate as a function of the attraction strength, the vesicle size, and vesicle material properties.
我们提出了关于单个刚性粒子被柔性膜被动包裹的动力学理论结果。使用膜/粒子复合物形状的简单几何假设，我们首先计算了自由能曲线作为粒子尺寸、粒子与囊泡之间的吸引力强度以及囊泡的材料性质（弯曲刚度和拉伸模量）的函数。由此计算出的自由能曲线被用作包裹过程的随机模型的输入，该模型由福克-普朗克方程描述。我们计算了粒子进入囊泡的平均摄取率。我们发现，在粒子尺寸的热力学允许范围内，摄取率降至零。在热力学允许的粒子尺寸范围内，摄取率是可变的，我们计算了最佳粒子尺寸和最大摄取率作为吸引力强度、囊泡尺寸和囊泡材料性质的函数。
