Bini Margherita, Brancolini Giorgia, Tozzini Valentina
Istituto Nanoscienze-CNR, Lab NEST SNS, Pisa, Italy.
Istituto Nanoscienze-CNR, Center S3, Modena, Italy.
Front Mol Biosci. 2022 Sep 19;9:986223. doi: 10.3389/fmolb.2022.986223. eCollection 2022.
Surface functionalization of metal nanoparticles (NPs), e.g., using peptides and proteins, has recently attracted a considerable attention in the field of design of therapeutics and diagnostics. The possibility of diverse functionalization allows them to selectively interact with proteins, while the metal core ensures solubility, making them tunable therapeutic agents against diseases due to mis-folding or aggregation. On the other hand, their action is limited by possible self-aggregation, which could be, however, prevented based on the full understanding of their phase diagram as a function of the environmental variables (temperature, ionic strength of the solution, concentration) and intrinsic characteristics (size, charge, amount, and type of functional groups). A common modeling strategy to study the phase behavior is to represent the NPs as spheres interacting via effective potentials implicitly accounting for the solvation effects. Their size put the NPs into the class of colloids, albeit with particularly complex interactions including both attractive and repulsive features, and a consequently complex phase diagram. In this work, we review the studies exploring the phases of these systems starting from those with only attractive or repulsive interactions, displaying a simpler disperse-clustered-aggregated transitions. The phase diagram is here interpreted focusing on the universal aspects, i.e., those dependent on the general feature of the potentials, and available data are organized in a parametric phase diagram. We then consider the potentials with competing attractive short range well and average-long-range repulsive tail, better representing the NPs. Through the proper combination of the attractive only and repulsive only potentials, we are able to interpret the appearance of novel phases, characterized by aggregates with different structural characteristics. We identify the essential parameters that stabilize the disperse phase potentially useful to optimize NP therapeutic activity and indicate how to tune the phase behavior by changing environmental conditions or the NP chemical-physical properties.
金属纳米颗粒（NPs）的表面功能化，例如使用肽和蛋白质进行功能化，最近在治疗和诊断设计领域引起了相当大的关注。多样化功能化的可能性使它们能够与蛋白质选择性相互作用，而金属核心确保了溶解性，使其成为针对因错误折叠或聚集导致的疾病的可调谐治疗剂。另一方面，它们的作用受到可能的自聚集的限制，然而，基于对其作为环境变量（温度、溶液离子强度、浓度）和内在特性（尺寸、电荷、数量和官能团类型）的函数的相图的全面理解，可以防止这种自聚集。研究相行为的一种常见建模策略是将纳米颗粒表示为通过有效势相互作用的球体，该有效势隐含地考虑了溶剂化效应。它们的尺寸将纳米颗粒归类为胶体，尽管具有特别复杂的相互作用，包括吸引和排斥特征，因此具有复杂的相图。在这项工作中，我们回顾了从仅具有吸引或排斥相互作用的系统开始探索这些系统相的研究，这些系统显示出更简单的分散 - 聚集 - 团聚转变。这里将相图解释聚焦于普遍方面，即那些取决于势的一般特征的方面，并将可用数据整理在参数化相图中。然后我们考虑具有竞争吸引短程阱和平均 - 长程排斥尾的势，这能更好地代表纳米颗粒。通过仅吸引势和仅排斥势的适当组合，我们能够解释具有不同结构特征聚集体所表征的新相的出现。我们确定了稳定分散相对优化纳米颗粒治疗活性可能有用的基本参数，并指出如何通过改变环境条件或纳米颗粒的化学物理性质来调节相行为。
