Colloidal nanoparticle assembly methods can produce intricate superlattice structures and often use knowledge of atomic crystallization behaviors to guide their design. While this analogy has enabled multiple routes to programming colloidal crystallization thermodynamics, fewer tools or strategies exist to manipulate nanoparticle superlattice growth kinetics in a controlled manner. Here we investigate how small molecule additives can be used to modulate the thermodynamics and kinetics of supramolecular-chemistry-driven nanoparticle assembly. Specifically, we introduce monovalent binding agents into the superlattice growth solution that compete with the multivalent interparticle bonding interactions driving particle assembly, thereby altering interparticle bond strength by reducing the number of bridging complexes formed between particles. In this manner, the assemblies can be steered to avoid kinetic traps and crystallize into faceted single crystals under isothermal conditions, alleviating the need for precise thermal control that has conventionally been required to produce large, faceted crystals in prior assembly methods.
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Quantifying and controlling bond multivalency for advanced nanoparticle targeting to cells
Abstract Nanoparticles have drawn intense interest as delivery agents for diagnosing and treating various cancers. Much of the early success was driven by passive targeting mechanisms such as the enhanced permeability and retention (EPR) effect, but this has failed to lead to the expected clinical successes. Active targeting involves binding interactions between the nanoparticle and cancer cells, which promotes tumor cell-specific accumulation and internalization. Furthermore, nanoparticles are large enough to facilitate multiple bond formation, which can improve adhesive properties substantially in comparison to the single bond case. While multivalent binding is universally believed to be an attribute of nanoparticles, it is a complex process that is still poorly understood and difficult to control. In this review, we will first discuss experimental studies that have elucidated roles for parameters such as nanoparticle size and shape, targeting ligand and target receptor densities, and monovalent binding kinetics on multivalent nanoparticle adhesion efficiency and cellular internalization. Although such experimental studies are very insightful, information is limited and confounded by numerous differences across experimental systems. Thus, we focus the second part of the review on theoretical aspects of binding, including kinetics, biomechanics, and transport physics. Finally, we discuss various computational and simulation studies of nanoparticle adhesion, including advanced treatments that compare directly to experimental results. Future work will ideally continue to combine experimental data and advanced computational studies to extend our knowledge of multivalent adhesion, as well as design the most powerful nanoparticle-based agents to treat cancer.
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- Award ID(s):
- 1929565
- PAR ID:
- 10394457
- Date Published:
- Journal Name:
- Nano Convergence
- Volume:
- 8
- Issue:
- 1
- ISSN:
- 2196-5404
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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