Recent advances in technologies such as nanomanufacturing and nanorobotics have opened new pathways for the design of active nanoparticles (NPs) capable of penetrating biolayers for biomedical applications, e.g., for drug delivery. The coupling and feedback between active NP motility (with large stochastic increments relative to passive NPs) and the induced nonequilibrium deformation and relaxation responses of the polymer network, spanning scales from the NP to the local structure of the network, remain to be clarified. Using molecular dynamics simulations, combined with a Rouse mode analysis of network chains and position and velocity autocorrelation functions of the NPs, we demonstrate that the mobility of active NPs within cross-linked, concentrated polymer networks is a monotonically increasing function of chain stiffness, contrary to passive NPs, for which chain stiffness suppresses mobility. In flexible networks, active NPs exhibit a behavior similar to passive NPs, with a boost in mobility proportional to the self-propulsion force. These results are suggestive of design strategies for active NP penetration of stiff biopolymer matrices.

中文翻译：

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链刚度增强了聚合物网络中活性纳米颗粒的运输

纳米制造和纳米机器人学等技术的最新进展为活性纳米颗粒（NP）的设计开辟了新途径，这些纳米颗粒能够穿透生物层用于生物医学应用，例如药物输送。主动NP运动性（相对于被动NP具有较大的随机增量）与聚合物网络的诱导的非平衡变形和弛豫响应之间的耦合和反馈，范围从NP到网络的局部结构，还有待澄清。使用分子动力学模拟，结合网络链的Rouse模式分析以及NP的位置和速度自相关函数，我们证明了活性NP在交联的浓缩聚合物网络内的迁移率是链刚度的单调递增函数，与被动NP相反，被动NP的链刚度会抑制移动性。在灵活的网络中，主动NP表现出与被动NP相似的行为，其移动性与自推进力成正比。这些结果暗示了刚性生物聚合物基质主动NP渗透的设计策略。