The development of multidrug resistance (MDR) has become an increasingly serious problem in cancer therapy. The cell-membrane overexpression of P-glycoprotein (P-gp), which can actively efflux various anticancer drugs from the cell, is a major mechanism of MDR. Nuclear-uptake nanodrug delivery systems, which enable intranuclear release of anticancer drugs, are expected to address this challenge by bypassing P-gp. However, before entering the nucleus, the nanocarrier must pass through the cell membrane, necessitating coordination between intracellular and intranuclear delivery. To accommodate this requirement, we have used DNA self-assembly to develop a nuclear-uptake nanodrug system carried by a cell-targeted near-infrared (NIR)-responsive nanotruck for drug-resistant cancer therapy. Via DNA hybridization, small drug-loaded gold nanoparticles (termed nanodrugs) can self-assemble onto the side face of a silver–gold nanorod (NR, termed nanotruck) whose end faces were modified with a cell type-specific internalizing aptamer. By using this size-photocontrollable nanodrug delivery system, anticancer drugs can be efficiently accumulated in the nuclei to effectively kill the cancer cells.

This study demonstrates the use of aptamer-conjugated graphene oxide as an affinity extraction and detection platform for analytes from complex biological media. We have shown that cocaine and adenosine can be selectively enriched from plasma samples and that direct mass spectrometric readout can be obtained without a matrix and with greatly improved signal-to-noise ratios. The aptamer conjugated graphene oxide has clear advantages in target enrichment and in generating highly efficient ionization of target molecules for mass spectrometry. These results demonstrate the utility of the approach for analysis of small molecules in real biological samples.

The development of nanomaterials that combine diagnostic and therapeutic functions within a single nanoplatform is extremely important for molecular medicine. Molecular imaging with simultaneous diagnosis and therapy will provide the multimodality needed for accurate diagnosis and targeted therapy. Here, we demonstrate gold-coated iron oxide (Fe3O4@Au) nanoroses with five distinct functions, which integrate aptamer-based targeting, magnetic resonance imaging (MRI), optical imaging, photothermal therapy and chemotherapy into one single probe. The inner Fe3O4 core functions as an MRI agent, while the photothermal effect is achieved through near-infrared absorption by the gold shell, causing a rapid rise in temperature and also resulting in a facilitated release of the anticancer drug doxorubicin carried by the nanoroses. Where the doxorubicin is released is monitored by its fluorescent. Aptamers immobilized on the surfaces of the nanoroses enable efficient and selective drug delivery, imaging and photothermal effect with high specificity. The five-function-embedded nanoroses show great advantages in multimodality.

In this paper, we have developed an interesting imaging method for intracellular ATP molecules with semi-quantitation. While there has been a lot of work in understanding intracellular events, very few can come close to quantitation or semi-quantitation in living cells. In this work, we made an effective use of nanomaterials, graphene oxides, both as a quencher and a carrier for intracellular delivery. In addition, this graphene oxide also serves as the carrier for reference probes for fluorescent imaging. An ATP aptamer molecular beacon (AAMB) is adsorbed on graphene oxide (GO) to form a double quenching platform. The AAMB/GO spontaneously enters cells, and then AAMB is released and opened by intracellular ATP. The resulting fluorescence recovery is used to perform ATP live-cell imaging with greatly improved background and signaling. Moreover, a control ssDNA, which is released non-specifically from GO by non-target cellular proteins, can serve as an internal reference for ATP semi-quantification inside living cells using the intensity ratio of the AAMB and control. This approach can serve as a way for intracellular delivery and quantitative analysis.

Rare protein enrichment and sensitive detection hold great potential in biomedical studies and clinical practice. This work describes the use of aptamer-conjugated gold nanorods for the efficient enrichment of rare proteins from buffer solutions and human plasma. Gold nanorod (AuNR) surfaces were modified with a long PEG chain and a 15-mer thrombin aptamer for protein enrichment and detection. Studies of the effect of surface modification on enrichment efficiency of thrombin showed that a change of only one EG 6 linker unit, i.e., from 2EG 6 to 3EG 6 , could increase thrombin protein capture efficiency by up to 47%. Furthermore, a 1 ppm sample of thrombin in buffer could be enriched with around 90% efficiency using a low concentration (0.19 nM) of gold nanorod probe modified with 3EG 6 spacer, and with the same probe, effective capture was achieved down to 10 ppb (1 ng) thrombin in plasma samples. In addition to α-thrombin enrichment, prothrombin was also efficiently captured from plasma samples via gold nanorods conjugated with 15-mer thrombin aptamer. Our work demonstrates efficient enrichment of rare proteins using aptamer-modified nanomaterials, which can be used in biomarker discovery studies.

Aptamer-conjugated gold nanorods (AuNRs) are excellent candidates for targeted hyperthermia therapy of cancer cells. However, in high concentrations of AuNRs, aptamer conjugation alone fails to result in highly cell-specific AuNRs due to the presence of positively charged cetyltrimethylammonium bromide (CTAB) as a templating surfactant. Besides causing nonspecific electrostatic interactions with the cell surfaces, CTAB can also be cytotoxic, leading to uncontrolled cell death. To avoid the nonspecific interactions and cytotoxicity triggered by CTAB, we report the further biologically inspired modification of aptamer-conjugated AuNRs with bovine serum albumin (BSA) protein. Following this modification, interaction between CTAB and the cell surface was efficiently blocked, thereby dramatically reducing the side effects of CTAB. This approach may provide a general and simple method to avoid one of the most serious issues in biomedical applications of nanomaterials: nonspecific binding of the nanomaterials with biological cells.

Through the developments in controlling the shape of gold nanoparticles, synthesis of gold nanorods (AuNRs) can be considered as a milestone discovery in the area of nanomaterial-based cancer treatments. Besides having tuneable absorption maxima at near infrared (NIR) range, AuNRs have superior absorption cross section at NIR frequencies compared with other gold nanoparticles. When this unique optical property is combined with the specificity against cancer cells used by affinity tag conjugations, AuNRs become one of the most important nanoparticles used in both cancer cell sensing and in therapy. In this review, the impact of size and shape control of nanoparticles, especially AuNRs, on cancer cell treatments and a range of aptamer-conjugated AuNR applications in this regard are reviewed.

Plasmonic near-field coupling can induce the enhancement of photoresponsive processes by metal nanoparticles. Advances in nanostructured metal synthesis and theoretical modeling have kept surface plasmons in the spotlight. Previous efforts have resulted in significant intensity enhancement of organic dyes and quantum dots and increased absorption efficiency of optical materials used in solar cells. Here, we report that silver nanostructures can enhance the conversion efficiency of an interesting type of photosensitive DNA nanomotor through coupling with incorporated azobenzene moieties. Spectral overlap between the azobenzene absorption band and plasmonic resonances of silver nanowires increases light absorption of photon-sensitive DNA motor molecules, leading to 85% close-open conversion efficiency. The experimental results are consistent with our theoretical calculations of the electric field distribution. This enhanced conversion of DNA nanomotors holds promise for the development of new types of molecular nanodevices for light manipulative processes and solar energy harvesting.energy conversion | localized surface plasmon | photo-driven nanomotor P lants harvest solar energy by photosynthesis, in which photosensitive biomolecules absorb energy from sunlight and convert it into chemical energy. Human beings utilize solar energy by fossil fuels, solar thermal systems, and, most frequently nowadays, by photovoltaic systems based on optoelectric materials (1). The design of new synthetic materials coupled with a mechanism to capture, convert, and store photon energy will provide new ways to utilize solar energy (2, 3). However, achieving high conversion efficiency remains a challenge in such energy conversion systems.Recently, DNA has received attention in material sciences, especially for the fabrication of nanomachines able to perform nanoscale movements in response to external stimuli (4-11). Experimental and theoretical studies on single DNA nanomachines have led to the development of new energy conversion strategies (12, 13). As one of the most popular phototransformable molecules, azobenzene and its derivatives can change the overall structure by cis-trans isomerisation mechanism. Using the photoisomerization of azobenzene to photo-regulate DNA hybridization, (14) we have designed a single-molecule light-driven DNA nanomotor (15) for the continuous production of energy in the form of mechanical work. This photon-fueled nanomotor is simple and easy to operate, promising a unique approach to harvest photonic energy. Herein, azobenzene derivatives act as element for energy absorption and DNA molecules movement act for mechanical energy export. As we know, solar thermal technology is a technology to harvest solar thermal energy that converts solar energy to movement of molecules and then produces heat caused by molecule thermal moving. In our design, solar energy is converted to close-open movement of DNA molecules. However, few DNA motor molecules can undergo the close-open conversion as a result of the low p...