Constructing Cross-Linked Nanofibrous Scaffold via Dual-Enzyme-Instructed Hierarchical Assembly

To explore the potential of step-by-step assembly in the fabrication of biological materials, we designed and synthesized two peptide-based molecules for enzyme-instructed hierarchical assembly. Upon the treatment of alkaline phosphatase, one molecule undergoes enzyme-instructed self-assembly forming uniformed nanofibers. The other one that can self-assemble into vesicles undergoes enzyme-induced transformation of self-assembly converting vesicles into irregular aggregates upon the treatment of carboxylesterase. Coadministration of two enzymes to a mixture of these two molecules in a stage-by-stage fashion leads to a physically knotted nanofibrous scaffold that is applicable as a nanostructured matrix for cell culture.

Fullerene Nanoarchitectonics with Shape-Shifting

This short review article introduces several examples of self-assembly-based structural formation and shape-shifting using very simple molecular units, fullerenes (C60, C70, and their derivatives), as fullerene nanoarchitectonics. Fullerene molecules are suitable units for the basic science of self-assembly because they are simple zero-dimensional objects with only a single elemental component, carbon, without any charged or interactive functional groups. In this review article, self-assembly of fullerene molecules and their shape-shifting are introduced as fullerene nanoarchitectonics. An outline and a background of fullerene nanoarchitectonics are first described, followed by various demonstrations, including fabrication of various fullerene nanostructures, such as rods on the cube, holes in the cube, interior channels in the cube, and fullerene micro-horns, and also a demonstration of a new concept, supramolecular differentiation.

2D Nanoarchitectonics: Soft Interfacial Media as Playgrounds for Microobjects, Molecular Machines, and Living Cells

Soft and flexible two-dimensional (2D) systems, such as liquid interfaces, would have much more potentials in dynamic regulation on nano-macro connected functions. In this Minireview article, we focus especially on dynamic motional functions at liquid dynamic interfaces as 2D material systems. Several recent examples are selected to be explained for overviewing features and importance of dynamic soft interfaces in a wide range of action systems. The exemplified research systems are mainly classified into three categories: (i) control of microobjects with motional regulations; (ii) control of molecular machines with functions of target discrimination and optical outputs; (iii) control of living cells including molecular machine functions at cell membranes and cell/biomolecular behaviors at liquid interface. Sciences on soft 2D media with motional freedom and their nanoarchitectonics constructions will have increased importance in future technology in addition to popular rigid solid 2D materials.

Nanoarchitectonics of Nanoporous Carbon Materials in Supercapacitors Applications

High surface area and large pore volume carbon materials having hierarchical nanoporous structure are required in high performance supercapacitors. Such nanoporous carbon materials can be fabricated from organic precursors with high carbon content, such as synthetic biomass or agricultural wastes containing cellulose, hemicellulose, and lignin. Using recently developed unique concept of materials nanoarchitectonics, high performance porous carbons with controllable surface area, pore size distribution, and hierarchy in nanoporous structure can be fabricated. In this review, we will overview the recent trends and advancements on the synthetic methods for the production of hierarchical porous carbons with one- to three-dimensional network structure with superior performance in supercapacitors applications. We highlight the promising scope of accessing nanoporous graphitic carbon materials from: (i) direct conversion of single crystalline self-assembled fullerene nanomaterials and metal organic frameworks, (ii) hard- and soft-templating routes, and (iii) the direct carbonization and/or activation of biomass or agricultural wastes as non-templating routes. We discuss the appealing points of the different synthetic carbon sources and natural precursor raw-materials derived nanoporous carbon materials in supercapacitors applications.

Facile synthesis of biodegradable flower-like hydroxyapatite for drug and gene delivery

Controlled synthesis of hierarchical hydroxyapatite materials is a hot research topic because of the excellent biocompatibility and bioactivity of the materials. In this study, flower-like hydroxyapatite spheres (FHAPS) were facile synthesized in one pot using Al(OH)₃ as a structure-directing agent. The prepared FHAPS comprised nanosheets possessing a uniform diameter of approximately 4 µm. Notably, the FHAPS can be degraded in solutions with a pH of 5.5 for 144 h or incubated with cells for 48 h. In addition, the FHAPS have rough surfaces, which exhibit high loading contents for the anticancer drug doxorubicin (DOX, 9.1%) and siRNA (2.0%). Thus, the FHAPS can effectively deliver DOX into drug-resistant breast cancer cells to exert an excellent killing effect compared with free DOX and transfect siRNA into tumor cells to interfere with the expression of the target protein. Taken together, this work successfully prepared FHAPS via a convenient synthesis route that shows high delivery efficiency for anticancer drugs and siRNA.

Nanoarchitectonics from Atom to Life

Functional materials with rational organization cannot be directly created only by nanotechnology-related top-down approaches. For this purpose, a novel research paradigm next to nanotechnology has to be established to create functional materials on the basis of deep nanotechnology knowledge. This task can be assigned to an emerging concept, nanoarchitectonics. In the nanoarchitectonics approaches, functional materials were architected through combination of atom/molecular manipulation, organic chemical synthesis, self-assembly and related spontaneous processes, field-applied assembly, micro/nano fabrications, and bio-related processes. In this short review article, nanoarchitectonics-related approaches on materials fabrications and functions are exemplified from atom-scale to living creature level. Based on their features, unsolved problems for future developments of the nanoarchitectonics concept are finally discussed.

Controlled assembly of filamentous viruses into hierarchical nano- to microstructures at liquid/liquid interfaces

Recently, viruses have been regarded as useful molecular assemblies for materials applications rather than as disease-causing agents. The orderly assembled structures of the viruses are highly related to the resultant properties and functions of the assemblies; however, methods to control the assembly are still limited. Here, we demonstrated the assembly of filamentous viruses into hierarchical nano- to microstructures at liquid/liquid interfaces through emulsification in a controlled manner. The viruses form fibrous nanostructures of several micrometers length, which are much longer than the original virus. Subsequently, the fibers self-assemble into well-packed ordered microstructures. Furthermore, the resultant hierarchically assembled structures showed long-term stability and potential applicability through the desired functionalization.

Assembly of filamentous viruses into hierarchical nano- to microstructures in a controlled manner was demonstrated using the liquid/liquid interface.

Sono-Polymerization of Poly(ethylene glycol)-Based Nanoparticles for Targeted Drug Delivery

Engineering functional nanoparticles (NPs) with low nonspecific interactions and a high specific targeting property is highly desired for improved drug delivery. Herein, we report a targeted poly(ethylene glycol) (PEG)-based chemotherapy system synthesized via a catalyst-free sono-polymerization process for drug delivery. The polymerization process was fast (20 min), and different monomers were able to be polymerized to form NPs in a one-pot process. Glutathione (GSH)-responsive platinum prodrugs and fluorescent dyes could be encapsulated in NPs by amidation formation. Cyclic peptides containing Arg-Gly-Asp (RGD)-modified PEG-based NPs possessed a much higher cell targeting (∼90%) than the unmodified PEG-based NPs (∼10%) after a 12 h incubation with U87 MG cells, which could improve drug delivery efficacy. The IC₅₀ (50% inhibitory concentration) could also be reduced more than 50% compared to the nontargeted PEG-based NPs. Importantly, these PEG-based NPs can be freeze-dried into a powder form and redispersed in an aqueous solution without aggregation, which may facilitate the storage and transportation of nanomedicine. This study establishes a green and efficient method to engineer targeted drug carriers for drug delivery.

Designer Peptide Amphiphiles: Self-Assembly to Applications

Peptide amphiphiles (PAs) are extremely attractive as molecular building blocks, especially in the bottom-up fabrication of supramolecular soft materials, and have potential in many important applications across various fields of science and technology. In recent years, we have designed and synthesized a large group of peptide amphiphiles. This library of PAs has the ability to self-assemble into a variety of aggregates such as fibers, nanosphere, vesicles, nanosheet, nanocups, nanorings, hydrogels, and so on. The mechanism behind the formation of such a wide range of structures is intriguing. Each system has its individual method of aggregation and results in assemblies with important applications in areas including chemistry, biology, and materials science. The aim of this feature article is to bring together our recent achievements with designer PAs with respect to their self-assembly processes and applications. Emphasis is placed on rational design, mechanistic aspects of the self-assembly processes, and the applications of these PAs. We hope that this article will provide a conceptual demonstration of the different approaches taken toward the construction of these task-specific PAs.

Using Self-Assembling Peptides to Integrate Biomolecules into Functional Supramolecular Biomaterials

Throughout nature, self-assembly gives rise to functional supramolecular biomaterials that can perform complex tasks with extraordinary efficiency and specificity. Inspired by these examples, self-assembly is increasingly used to fabricate synthetic supramolecular biomaterials for diverse applications in biomedicine and biotechnology. Peptides are particularly attractive as building blocks for these materials because they are based on naturally derived amino acids that are biocompatible and biodegradable; they can be synthesized using scalable and cost-effective methods, and their sequence can be tailored to encode formation of diverse architectures. To endow synthetic supramolecular biomaterials with functional capabilities, it is now commonplace to conjugate self-assembling building blocks to molecules having a desired functional property, such as selective recognition of a cell surface receptor or soluble protein, antigenicity, or enzymatic activity. This review surveys recent advances in using self-assembling peptides as handles to incorporate biologically active molecules into supramolecular biomaterials. Particular emphasis is placed on examples of functional nanofibers, nanovesicles, and other nano-scale structures that are fabricated by linking self-assembling peptides to proteins and carbohydrates. Collectively, this review highlights the enormous potential of these approaches to create supramolecular biomaterials with sophisticated functional capabilities that can be finely tuned to meet the needs of downstream applications.

Solvent-tunable dipeptide-based nanostructures with enhanced optical-to-electrical transduction

We explore a facile approach to construct solvent-tunable dipeptide-based nanostructures, which exhibit a structure-dependent and remarkably enhanced optoelectronic response.

An injectable molecular hydrogel assembled by antimicrobial peptide PAF26 for antimicrobial application

Wound infection is a crucial factor that inhibits wound recovery. A feasible measure to solve this problem is using antimicrobial biomaterials to suppress the microbial growth. In this work, an amphipathic antimicrobial peptide (Ac-RKKWFW-NH₂, PAF26) was investigated to form the antimicrobial hydrogel. Triggered by pH, PAF26 peptide could self-assemble into a hydrogel, and the hydrogel formed was injectable and exhibited shear-thinning ability. Antimicrobial experiments demonstrated that the self-assembled hydrogel had an outstanding antimicrobial ability against pathogenic microbes such as Candida albicans, Staphylococcus aureus, and Escherichia coli via destroying the cell membrane structure. Thus, this study provides a novel method for preparing an injectable antimicrobial peptide hydrogel for antimicrobial therapies.

A hexa-antimicrobial PAF26 peptide was investigated to form a self-assembled hydrogel. The hydrogel was injectable and had an outstanding antimicrobial ability.