Molecular Self‐Assembly of Multifunctional Nanoparticle Composites with Arbitrary Shapes and Functions: Challenges and Strategies

Abstract

The assembly of nanoparticles into complicated, anisotropic shapes has much promise for advanced materials and devices. Developing effective and efficient anisotropic mono‐functionalization strategies is an imperative step in realizing this potential. By functionalizing DNA one at a time to the nanoparticle, a DNA‐nanoparticle building block could have distinct DNA sequences at different locations on the surface of the particle. Since this technology could incorporate nanoparticles of different composition, generating toolboxes of various nanoparticle building blocks (“nano‐toolboxes”) with DNA at defined locations and in defined 3D orientations on a nanoparticle, it promises not only complicated shapes, but also the ability to tune the function of the assembly. The challenges of programmable and scalable multifunctional nanostructure self‐assembly with DNA conjugated to nanoparticles are reviewed. The first difficulty is to control the assembly process so that designed products are formed, and unwanted products are minimized. The design problem for nanostructure construction is both physically and computationally complex. Thus, the other major challenge is to devise design methodologies that move nanostructure construction from trial and error to principled approaches. Strategies to overcome these challenges are also presented by realizing greater control over the final shapes and functions of the self‐assembled nanostructures. Finally, the future perspectives of nano‐toolboxes and their promise in applications such as multifunctional, multicolor, and multimodal contrast nanoagents for medical therapy and diagnostics (theranostics) are described.

Cellulose Nanocrystals as Advanced "Green" Materials for Biological and Biomedical Engineering

“…In tissue engineering, it is important for any implanted scaffold to mimic the ECM, which displays properties that can actively promote the natural healing and self-repair capacity of the body (Place et al, 2005). The hierarchical arrangement of the ECM varies from nano to macro scale; because it is based on tissue type and functions the matrix differs in composition and spatial organization of their respective components, making development of artificial scaffolds more challenging (Kim and Deaton, 2013;Kim et al, 2014). The surface characteristics of scaffolds, such as roughness, topography, porosity, pore size, pore interconnectivity, surface area to volume ratio, and chemistry, all play a pivotal role in tissue engineering (Domingues et al, 2014).…”

“…By modifying the cellulose nanocrystals with 2,2′:6′,2″-terpyridine, followed by supramolecular assembly of terpyridine-modified perylene dye into the terpyridine-modified cellulose nanocrystals, a highly fluorescent nanocellulosic composite was prepared via RuIII/RuII reduction for potential bioimaging (Hassan et al, 2012). Recently, for imaging purposes, most of the studies have been focused on functionalization of various gold and magnetic nanoparticles, carbon nanotubes (CNTs), graphene, silica or quantum dots with glucose (molecular unit of CNCs) (Zharov et al, 2005;de la Zerda, 2011;Kim and Deaton, 2013;Kim et al, , 2014bKotagiri and Kim, 2014;Hao et al, 2015). Glucose-coated gold nanoparticles with blood-brain barrier-permeable (BBB) neuropeptides have displayed interesting BBB permeability and bio-distribution, increasing the candidacy as a good positron emission tomography (PET) contrast agent for in vivo imaging of brain (Frigell et al, 2014).…”

“…However, overall control of the integrity of the final structure and manipulation of functionality need further research and evaluation. The nanotoolbox technology Kim et al, 2012;Kim and Deaton, 2013;Kim and Tung, 2015) is one of the promising methods. It allows different nanoparticles and nano-building blocks to assemble in predefined spatial arrangements.…”

Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution

“…Innovative approaches have been proposed to design and construct NPs and their architectures with desirable size, shape and functionality, including those based on the programmable self-assembly approach. 2,3 Such…”

“…Some novel approaches have been reported to engineer NPs and their architectures with desirable size, shape, and functionality, including those based on the "nanotoolbox"-based programmable self-assembly approach developed by our group. 2,3,156,157 The capability of modulating the geometric configurations and surface characteristics suggests opportunities to overcome the hurdle, while considerably increasing blood circulation times as well as biocompatibility. 128,129 There exist many biological particles, such as blood cells and pathogenic bacteria, that have evolved to evade macrophages by being transparent to the blood opsonins.…”