Phototheranostic DNA micelles from the self-assembly of DNA-BODIPY amphiphiles for the thermal ablation of cancer cells.

Design of phototheranostic agents in a single step approach is one of the challenges in cancer therapy. Herein, a one-step strategy based on amphiphilicity-driven self-assembly of DNA-BODIPY amphiphiles for the design of a new class of micelles, which offer all three phototheranostic functions, is reported. These include (i) strong emission at NIR (φf = 30%) for imaging, (ii) high photothermal conversion (η = 52%) for PTT and (iii) an ssDNA-based shell for the integration of cell targeting moieties. Selective uptake of DNA micelles into a target cancer cell and its killing by laser irradiation (635 nm) are also demonstrated. Furthermore, the excellent biocompatibility, ultrasmall nanosize and high stability of DNA micelles are promising for in vivo applications.

Efficient Capturing of Polycyclic Aromatic Micropollutants From Water Using Physically Crosslinked DNA Nanoparticles.

Design and synthesis of physically (non-covalently) cross-linked nanoparticles through host-guest interaction between ß-CD and adamantane is reported. Specific molecular recognition between ß-CD functionalized branched DNA nanostructures (host) and a star-shaped adamantyl-terminated 8-arm poly(ethylene glycol) polymer (guest) is explored for the design of the nanoparticles. The most remarkable structural features of DNA nanoparticles include their excellent biocompatibility and the possibility of various non-covalent interactions with both hydrophobic and hydrophilic organic molecules. Potential of DNA nanoparticles for the rapid and efficient capture of various micropollutants typically present in water including carcinogens (hydrophobic micropollutants), organic dyes (hydrophilic), and pharmaceutical molecules (hydrophilic) is also demonstrated. The capture of micropollutants by DNA nanoparticles is attributed to the various non-covalent interactions between DNA nanoparticles and the micropollutants. Our results clearly suggest that DNA based nanomaterials would be an ideal candidate for the capturing and removal of both hydrophilic and hydrophobic micropollutants typically present in water.

Self-Assembly of an Aptamer-Decorated, DNA-Protein Hybrid Nanogel: A Biocompatible Nanocarrier for Targeted Cancer Therapy.

Nanocarrier-based chemotherapy is one of the most efficient approaches for the treatment of cancer, and hence, the design of new nanocarriers is very important. Herein, the design of a new class of physically cross-linked nanoparticles (nanogel) solely made of biomolecules including DNA, protein, and biotin as a nanocarrier for the targeted cancer therapy is reported. A specific molecular recognition interaction between biotin and streptavidin is explored for the cross-linking of a DNA nanostructure for the crafting of a nanogel. The most unique structural features of nanogels include the following: (i) excellent biocompatibility, (ii) decoration of the nanogel surface with biotin and streptavidin randomly that allowed the integration of aptamer DNA onto the surface of the nanostructure through the biotin-streptavidin interaction, (iii) high doxorubicin encapsulation efficacy through the intercalation of doxorubicin inside the DNA duplex, and (iv) stimuli responsiveness. The selective uptake of a doxorubicin-loaded nanogel by aptamer-receptor-positive cell lines (CCRF-CEM and HeLa) and its delivery inside the target cells are demonstrated. The selective uptake of the nanogel by CCRF-CEM and HeLa cells is attributed to the specific interaction between the aptamer DNA decorated on the surface of the nanogel with the PTK7 receptor overexpressed on CCRF-CEM and HeLa cell lines. These results imply that the nanogel obtained from the self-assembly of biomolecules would be ideal for the crafting of nanocarriers for targeted cargo delivery applications.

Self-assembly of DNA-tetraphenylethylene amphiphiles into DNA-grafted nanosheets as a support for the immobilization of gold nanoparticles: a recyclable catalyst with enhanced activity.

Preventing the aggregation of NPs and their recovery are the two major hurdles in NP based catalysis. Immobilization of NPs on a support has proven to be a promising strategy to overcome these difficulties. Herein we report the design of high aspect ratio two-dimensional (2D) crystalline DNA nanosheets formed from the amphiphilicity-driven self-assembly of DNA-tetraphenylethylene amphiphiles and also demonstrate the potential of DNA nanosheets for the immobilization of catalytically active NPs. The most remarkable feature of this approach is the high loading of NPs in a non-aggregated manner, and hence exhibiting enhanced catalytic activity. Recycling of NP loaded nanosheets for several cycles without reduction in catalytic efficiency by simple ultrafiltration is also demonstrated.

DNA-Decorated Two-Dimensional Crystalline Nanosheets.

Design and synthesis of high aspect ratio 2D nanosheets with surface having ultradense array of information-rich molecule such as DNA is extremely challenging. Herein, we report a universal strategy based on amphiphilicity-driven self-assembly for the crafting of high aspect ratio, 2D sheets that are densely surface-decorated with DNA. Microscopy and X-ray analyses have shown that the sheets are crystalline. The most unique feature of the sheets is DNA-directed surface addressability, which is demonstrated through the decoration of either faces of the sheet with gold nanoparticles through sequence-specific DNA hybridization. Our results suggest that this design strategy can be applied as a general approach for the synthesis of DNA decorated high aspect ratio sheets, which may find potential applications in materials science, drug delivery, and nanoelectronics.

Size controllable DNA nanogels from the self-assembly of DNA nanostructures through multivalent host-guest interactions.

Nanogels made of biomolecules are one of the potential candidates as a nanocarrier for drug delivery applications. The unique structural characteristics and excellent biocompatibility of DNA suggest that DNA nanogels would be an ideal candidate. Herein, a general design strategy for the crafting of DNA nanogels with controllable size using the multivalent host-guest interaction between ß-CD functionalized branched DNA nanostructures as the host and a star-shaped adamantyl-terminated 8-arm poly(ethylene glycol) polymer as the guest is reported. Our results reveal that multivalent host-guest interactions are necessary for the nanogel formation. Nanogels exhibit excellent biocompatibility, good cell permeability and high drug encapsulation ability, which are promising features for their application as a drug carrier. The encapsulation of doxorubicin, an anticancer drug, inside the hydrophobic network of the nanogel and its delivery into cancer cells are also reported. We hope that the general design strategy demonstrated for the creation of DNA nanogels may encourage other researchers to use this approach for the design of DNA nanogels of other DNA nanostructures, and explore the potential of DNA nanogels in drug delivery applications.

A pH-Responsive DNAsome from the Self-Assembly of DNA-Phenyleneethynylene Hybrid Amphiphile.

A pH-responsive DNAsome derived from the amphiphilicity-driven self-assembly of DNA amphiphile containing C-rich DNA sequence is reported. The acidification of DNAsome induces a structural change of C-rich DNA from random coil to an i-motif structure that triggers the disassembly of DNAsome and its subsequent morphological transformation into an open entangled network. The encapsulation of a hydrophobic guest into the membrane of DNAsome and its pH-triggered release upon acidification of DNAsome is also demonstrated.

Modular synthesis of supramolecular DNA amphiphiles through host-guest interactions and their self-assembly into DNA-decorated nanovesicles.

DNA nanostructures have found potential applications in various fields including nanotechnology, materials science and nanomedicine, hence the design and synthesis of DNA nanostructures is extremely important. Self-assembly of DNA amphiphiles provides an efficient strategy for the crafting of soft DNA nanostructures. However, the synthesis of DNA amphiphiles is always challenging. Herein, we show a non-covalent approach based on the host-guest interaction between ß-CD and adamantane for the synthesis of DNA amphiphiles, and report their amphiphilicity-driven self-assembly into DNA decorated vesicles. The DNA-directed surface addressability of the vesicles is demonstrated through their surface decoration with Au-NPs through DNA hybridization. Our results suggest that the non-covalent approach represents a simple, efficient and universal method for the synthesis of DNA amphiphiles, and provides an excellent strategy for the creation of smart DNA nanostructures.

Synthesis and self-assembly of DNA-chromophore hybrid amphiphiles.

DNA based spherical nanostructures are one of the promising nanostructures for several biomedical and biotechnological applications due to their excellent biocompatibility and DNA-directed surface addressability. Herein, we report the synthesis and amphiphilicity-driven self-assembly of two classes of DNA (hydrophilic)-chromophore (hydrophobic) hybrid amphiphiles into spherical nanostructures. A solid-phase "click" chemistry based modular approach is demonstrated for the synthesis of DNA-chromophore amphiphiles. Various spectroscopic and microscopic analyses reveal the self-assembly of the amphiphiles into vesicular and micellar assemblies with the corona made of hydrophilic DNA and the hydrophobic chromophoric unit as the core of the spherical nanostructures.

Self-assembly of DNA-oligo(p-phenylene-ethynylene) hybrid amphiphiles into surface-engineered vesicles with enhanced emission.

Surface-addressable nanostructures of linearly π-conjugated molecules play a crucial role in the emerging field of nanoelectronics. Herein, by using DNA as the hydrophilic segment, we demonstrate a solid-phase "click" chemistry approach for the synthesis of a series of DNA-chromophore hybrid amphiphiles and report their reversible self-assembly into surface-engineered vesicles with enhanced emission. DNA-directed surface addressability of the vesicles was demonstrated through the integration of gold nanoparticles onto the surface of the vesicles by sequence-specific DNA hybridization. This system could be converted to a supramolecular light-harvesting antenna by integrating suitable FRET acceptors onto the surface of the nanostructures. The general nature of the synthesis, surface addressability, and biocompatibility of the resulting nanostructures offer great promises for nanoelectronics, energy, and biomedical applications.