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Various methods based on gold nanoparticles (AuNPs) have been applied to enhance the photothermal effect. Among these methods, combining gold nanoparticles and stem cells has been suggested as a new technique for elevating the efficiency of photothermal therapy (PT) in terms of enhancing tumor targeting effect. However, to elicit the efficiency of PT using gold nanoparticles and stem cells, delivering large amounts of AuNPs into stem cells without loss should be considered.AuNPs, AuNPs-decorated silica nanoparticles, and silica-capped and AuNPs-decorated silica nanoparticles (SGSs) were synthesized and used to treat human mesenchymal stem cells (hMSCs). After evaluating physical properties of each nanoparticle, the concentration of each nanoparticle was estimated based on its cytotoxicity to hMSCs. The amount of AuNPs loss from each nanoparticle by exogenous physical stress was evaluated after exposing particles to a gentle shaking. After these experiments, in vitro and in vivo photothermal effects were then evaluated.SGS showed no cytotoxicity when it was used to treat hMSCs at concentration up to 20 μg/mL. After intravenous injection to tumor-bearing mice, SGS-laden hMSCs group showed significantly higher heat generation than other groups following laser irradiation. Furthermore, in vivo photothermal effect in the hMSC-SGS group was significantly enhanced than those in other groups in terms of tumor volume decrement and histological outcome.Our results suggest that additional silica layer in SGSs could protect AuNPs from physical stress induced AuNPs loss. The strategy applied in SGS may offer a prospective method to improve PT.

Light has attracted significant attention as a promising tool in the biomedical and cosmetic industries. However, little is known about the cytotoxic effects of conventional light sources based on their physical effects such as temperature and luminance. Here, the cytotoxic effects of representative light sources, a light-emitting diode (LED) and an organic light-emitting diode (OLED), were studied with human adipose-derived stem cells (hADSCs). Regardless of the identical light energy conditions, LED group induced a higher apoptotic activity in hADSCs than the OLED group due to its significant heat generation compared to OLED as further demonstrated with heat shock protein family gene expression. Additionally, we further confirmed the effect of luminance by irradiating light from LED and OLED under the same temperature and energy conditions. Increased cell proliferation was confirmed in the OLED group, and a significant expression of intracellular reactive oxygen species was observed in the LED group without showing heat shock protein upregulation. Taken together, the differences in cytotoxicity and cellular response after LED irradiation compared with OLED irradiation can be varied with temperature and luminance control. This study suggests that OLED based device could be an alternative and promising light source for future biomedical and cosmetic applications.

Numerous heat-dependent chemical reactions are involved in organismal life, and temperature is an important factor that determines whether such reactions progress. To date, ultrasound and thermotherapy techniques have been established in high-end medical treatments and are proposed to monitor temperature changes on a nanoscale of localized areas such as single cells and to induce material synthesis due to local energy conversion. In this study, a nanoprobe that can measure the local temperature on the nanoscale is designed and developed using gold nanoparticles and thermo-sensitive fluorescent materials. To support this concept, a polymer capable of controlling the physical properties of gold nanorods (AuNRs) is manufactured using light-heat conversion synthesis.

Several nanostructures have been created with the advent of nanotechnology. DNA has been recognized as a new building block material in addition to its genetic coding role because of its unique features (e.g., intrinsic biocompatibility, precise tenability, specific selectivity). DNA can be organized into a variety of self-assembled nanomaterials including a sphere, a ball, and even an emoticon. In particular, a tree-shaped DNA structure possessing characteristic fractural patterns is easily controlled by size and functionality and can be exploited in various fields. Here, we report an empirical and theoretical evaluation of a Y-shaped tree DNA nanostructure with a looped arm (L-DNA). The synthesized L-DNAs were analyzed for thermal and structural stability. The melting temperature (Tm) of a Y-shaped DNA (Y-DNA) as a core unit and a model DNA nanostructure comprising of central Y-DNA and looped arm were measured individually. According to the complexity (e.g., increased length of the single stranded DNA (ssDNA) used), its yield suddenly decreased with the generation of ssDNAs with distinctive secondary structures. A complicated DNA product is predicted by considering the Tm of expected secondary structures, with increased Tm with respect to variation in salt concentrations. Therefore, the new DNA nanostructure may be utilized as a platform for various practical applications.

With the advent of innovative genomic discovery toolkits such as RT-PCR, genetic information can be quickly decrypted, and this has resulted in significant progress in overcoming diseases. However, RT-PCR has the serious problem of frequent errors, and the demand for a new gene diagnostic system is emerging. Herein, we propose a universal coding system for the effective detection of short single-stranded DNA or RNA by using a topological transformation-based nano-barcoding technique (TNT). Our goal was to develop a dedicated diagnostic device that unifies the other gene groups, thus resulting in minimum testing. In a universal coding system consisting of two separate circulation structures, different gene groups become generalized into specific single genes with the same sequence by a strand-displacement reaction and are then amplified, eventually being quickly detected in one TNT system. Simple gene diagnostic systems like this make high-speed, point-of-care diagnostic technologies, and we are very confident that these will provide clinical gene detection in the near future.

Gold particles have been widely used in the treatment of prostate cancer due to their unique optical properties, such as their light-heat conversion in response to near-infrared radiation. Due to well-defined synthesis mechanisms and simple manufacturing methods, gold particles have been fabricated in various sizes and shapes. However, the low photothermal transduction efficiency in their present form is a major obstacle to practical and therapeutic uses of these particles. In the current work, we present a silica-coated gold nanoparticle cluster to address the therapeutic limit of single gold nanoparticles (AuNPs) and use its photothermal effect for treatment against PC-3, a typical prostate cancer. Due to its specific nanostructure, this gold nanocluster showed three times higher photothermal transduction efficiency than free single AuNPs. Moreover, while free single particles easily clump and lose optical properties, this silica-coated cluster form remained stable for a longer time in a given medium. In photothermal tests under near-infrared radiation, the excellent therapeutic efficacy of gold nanoclusters, referred to as AuNC@SiO2, was observed in a preclinical sample. Only the samples with both injected nanoclusters followed by photothermal treatment showed completely degraded tumors after 15 days. Due to the unique intrinsic biocompatibility and higher therapeutic effect of these silica-coated gold nanoclusters, they may contribute to enhancement of therapeutic efficacy against prostate cancer.

A variety of nanostructured diagnostic tools have been developed for the precise detection of known genetic variants. Molecular beacon systems are very promising tools due to their specific selectivity coupled with relatively lower cost and time requirements than existing molecular detection tools such as next generation sequencing or real-time PCR (polymerase chain reaction). However, they are prone to errors induced by secondary structure responses to environmental fluctuations, such as temperature and pH. Herein, we report a temperature-insensitive, bead-immobilized, molecular beacon-equipped novel DNA nanostructure for detection of cancer miRNA variants with the consideration of thermodynamics. This system consists of three parts: a molecular beacon for cancer-specific RNA capture, a stem body as a core template, and a single bead for solid-support. This DNA system was selectively bound to nanosized beads using avidin–biotin chemistry. Synthetic DNA nanostructures, designed based on the principle of fluorescence-resonance enhanced transfer, were effectively applied for in vitro cancer-specific RNA detection. Several parameters were optimized for higher performance, with a focus on thermodynamic stability. Theoretical issues regarding the secondary structure of a single molecular beacon and its combinatory forms were also studied. This study provides design guidelines for new sensing systems of miRNA variation for next-generation biotechnological applications.

Effective intermolecular interaction is required between probe and target molecules for successful detection of biomarkers. Here, we demonstrate that localization of probes on DNA nanostructures improves detection sensitivity and reaction rate. The structural flexibility of DNA nanostructures enabled frequent intramolecular interactions among the localized probes. The Smoluchowski coagulation method and the coarse-grained molecular dynamic software oxDNA were used for theoretical estimation of inter- and intramolecular behaviors of the DNA nanostructures as well as adequate experiments verifying the improvements in sensitivity with probe localization. Remarkably, the probe-localized DNA nanostructure had an increased sensitivity up to 274 times higher than that of the same probes without localization. We believe this achievement represents a wide applicability as a potential design strategy for robust, reliable, and sensitive biosensors.

Nanoparticles (NPs) of protein-based materials have become one of the most promising candidates for drug carriers in drug-delivery systems because of their in vivo nontoxicity, biodegradability, compatibility with hydrophilic drugs, and adaptability to the human body. Many studies have investigated the fabrication of protein NPs from human serum albumin (HSA) as a new drug carrier. It is important for these NPs to remain in the blood until they reach their therapeutic target to achieve the desired effect; the quicker the clearance of drugs from the body, the shorter is the residence time of drugs in the body, which eventually reduces drug efficacy. Macrophage uptake is a major mechanism for clearance of NPs from the body, so, reducing the degree of macrophage uptake is a major challenge in drug-delivery systems. Original studies of HSA NP uptake by macrophages showed that denatured HSA and HSA NPs synthesized with 80% (v/v) ethanol showed a high degree of macrophage uptake. We found that HSA NPs synthesized with lower ethanol content at pH 7 showed lower macrophage uptake in in vitro macrophage cellular uptake experiments. The effects of the preparation parameters of ethanol concentration, pH, and glutaraldehyde on the macrophage uptake of NPs were thoroughly studied. This newly developed protein NP with lower macrophage uptake has potential application as a drug carrier for many delivery systems.

Due to its unique physical and chemical characteristics, DNA, which is known only as genetic information, has been identified and utilized as a new material at an astonishing rate. The role of DNA has increased dramatically with the advent of various DNA derivatives such as DNA–RNA, DNA–metal hybrids, and PNA, which can be organized into 2D or 3D structures by exploiting their complementary recognition. Due to its intrinsic biocompatibility, self‐assembly, tunable immunogenicity, structural programmability, long stability, and electron‐rich nature, DNA has generated major interest in electronic and catalytic applications. Based on its advantages, DNA and its derivatives are utilized in several fields where the traditional methodologies are ineffective. Here, the present challenges and opportunities of DNA transformations are demonstrated, especially in biomedical applications that include diagnosis and therapy. Natural DNAs previously utilized and transformed into patterns are not found in nature due to lack of multiplexing, resulting in low sensitivity and high error frequency in multi‐targeted therapeutics. More recently, new platforms have advanced the diagnostic ability and therapeutic efficacy of DNA in biomedicine. There is confidence that DNA will play a strong role in next‐generation clinical technology and can be used in multifaceted applications., Newly discovered properties of DNA have triggered the transformation of DNA from its conventional use as a repository of genetic information. The sequence specificity, self‐assembling property, and ability of DNA to dynamically interact with other non‐nucleic acid materials contribute significantly to the advent of molecular diagnosis and therapeutics.

Nanoparticles are used extensively to detect nucleic acid biomarkers due to their analytical applicability and sensitivity. Systems employing the surface plasmon resonance of gold nanomaterials are overwhelmingly considered to be candidates. The aggregation of gold nanomaterials mediated by the hybridization of target DNA at the interface causes a change in the surface plasmon resonance inherent in gold nanomaterials. Such changes can be measured by spectroscopy or even visualized by the naked eye, enabling effective and positive detection. The optical properties of gold nanoparticles are affected by their shape. The geometric appearance of the nanoparticles also affects their colloidal stability and aggregation behavior. In this study, we examined the effect of the geometric appearance of gold nanomaterials on DNA-mediated aggregation behavior through comparative experiments. Experimental and theoretical methods were used concurrently to derive accurate results and to support the hypotheses. Coarse-grained molecular dynamics simulations were performed with a large-scale atomic/molecular massively parallel simulator to understand the aggregation of nanoparticles with the same surface area and various aspect ratios. As a result, we confirmed that the aggregation sensitivity of nanoparticles was affected by the shape of the contact point with the gold nanomaterials. This study demonstrates that the design of a detection system should be accompanied by an in-depth review of the morphology of the nanoparticle.

Room temperature electron mobility of >100 cm2 V–1 s–1 is achieved for a few-layer MoS2 transistor by use of a polyanionic proton conductor as the top-gate dielectric of the device. The use of a proton conductor that inherently exhibits a cationic transport number close to 1 yields unipolar electron transport in the MoS2 channel. The high mobility value is attributed to the effective formation of an electric double layer by the proton conductor, which facilitates electron injection into the MoS2 channel, and to the effective screening of the charged impurities in the vicinity of the device channel. Through careful temperature-dependent transistor and capacitor measurements, we also confirm quenching of the phonon modes in the proton-conductor-gated MoS2 channel, which should also contribute to the achieved high mobility. These devices are then used to assemble a simple resistive-load inverter logic circuit, which can be switched at high frequencies above 1 kHz.

Various synthetic polymers based on poly(amino ester) (PAE) are suggested as candidates for gene and drug delivery owing to their pH-responsiveness, which contributes to efficient delivery performance. PAE-based pH-responsive polymers are more biodegradable and hydrophilic than other types of pH-responsive polymers. The functionality of PAE-based polymers can be reinforced by using different chemical modifications to improve the efficiency of gene and drug delivery. Additionally, PAE-based polymers are used in many ways in the biomedical field, such as in transdermal delivery and stem cell culture systems. Here, the recent novel PAE-based polymers designed for gene and drug delivery systems along with their further applications toward adult stem cell culture systems are reviewed. The synthetic tactics are contemplated and pros and cons of each type of polymer are analyzed, and detailed examples of the different types are analyzed.

Since the delivery kinetics of different cell types are different, the signal from the target cell is greatly affected by the noise signal of the diagnostic system. This is a major obstacle hindering the practical application of intracellular diagnostic systems, such as tumor heterogeneity. To address these issues, here we present a microRNA detection platform using fluorescence-encoded nanostructured DNA-based probes. The nanostructured DNA was designed to include molecular beacons for detecting cytosolic microRNA as well as additional fluorophores. When the intracellular diagnostic system is delivered, fluorescence signals are generated by the molecular beacons, depending on the concentration of the target microRNA. The fluorescence signals are then normalized to the intensity of the additional fluorophore. Through this simple calculation, the concentration of intracellular microRNA can be determined without interference from the diagnosis system itself. And also it enabled discrimination of microRNA expression heterogeneity in five different breast cancer cell lines.

Neural diseases, like Alzheimer’s (AD) and Parkinson’s (PD) are widely expanding portions of neurodegenerative diseases, are related to norepinephrine (NE) concentration with proportional correlation. However, quantification of NE is quite difficult because NE coexists with ascorbic acid (AA) and uric acid (UA), which interferes with detecting NE in biological fluid. We fabricated a multi-modified electrode with reduced graphene oxide sheets (GS) and gold nanoparticles (GNPs) for highly selective and sensitive detection of NE. Thus, GS-GNPs modified electrode could enhance the sensitivity for detection of NE, as well as highly sensitive manner with AA. Compared with recent studies, our newly developed sensor appears to have not only a wide detection range (0.2-10 μM), but also superior detection limit (200 nM) in presence of 2000 times higher concentration of AA.

A simple method that uses magnetic field induction for the disentanglement of bundled multiwall carbon nanotubes (MWCNTs) that are massively aggregated in a single and intact form was investigated. MWCNTs exposed to a 1 Tesla (T) field periodically switched on and off were separated into individual MWCNTs using 4,4′-azobis(4-cyanovaleric acid) as a radical initiator with iron oxide nanoparticles. The study results show that, in accordance with the dissipation working principle, MWCNT bundles under 40 nN achieved complete disentanglement within a few hours, and these results were theoretically verified by an Opera 3D simulation. We anticipate that single CNTs obtained using our method will have applications in several CNT research areas ranging from electronic devices to biocomputers.

Direct activation of CH4 to oxygenates and unsaturated light hydrocarbons was investigated using Fe-modified ZSM-5 and Ferrierite (FER) for a partial oxidation of CH4 with N2O oxidant. The amount of active α-oxygen sites and number of Bronsted acid sites on the Fe-modified zeolites were well correlated with CH4 conversion rate and product distributions. The amount of α-oxygen sites was largely changed according to preparation method such as wet impregnation or ion-exchange of iron precursor and types of zeolites. A large number of Bronsted acid sites and α-oxygen sites on the Fe-modified FER revealed a higher oxygenate formation such as methanol and dimethyl ether (DME) with COx, and a larger number of strong acid sites on Fe-modified ZSM-5 was also responsible for a higher selectivity to light hydrocarbons by a successive dehydration of oxygenates formed. The different catalytic performances were verified through proper measurements of the amount and type of acidic sites as well as the α-oxygen sites measured by N2O pulse chemisorption. The Fe-modified FER prepared by impregnation method possessed a larger amount of α-oxygen sites due to abundant Bronsted acid sites, which was responsible for a higher rate of CH4 conversion to oxygenates with the help of N2O decomposition on the α-oxygen sites originated from iron oxide nanoparticles.

Iron oxide nanoparticles (NPs) were encapsulated with polyaspartamide-based graft copolymers to bind and track the immune cells as imaging probes. Mono-disperse iron oxide NPs with a mean diameter of 10.7 nm were synthesized by the thermal decomposition method, and their shape and distribution were measured by electrophoretic light scattering and transmission electron microscopy. To enhance their biocompatibility, interfacial and hydrodynamic stability, and fluorescence detection, biodegradable polysuccinimide (PSI) grafted with several functional groups of octadecylamine (C18), ethanolamine (EA), ethylenediamine (EDA), 4-(N-maleimidomethyl) cyclohexane carboxylic acid N-hydroxysuccinimide ester (SMCC), and fluorescein isothiocyanate (FITC) was coated on the iron oxide NPs. The structure of the C18/EA/SMCC/FITC-g-PSI copolymer was confirmed using 1H-NMR and FTIR spectroscopy, and its cell binding ability was investigated by flow cytometry and confocal laser scanning microscopy. The synthesized C18/EA/SMCC/FITC-g-PSI copolymer showed an excellent binding affinity to CD4+ T cells, and was highly biocompatible as the cell viability at the highest polymer concentration of 0.4 mg mL−1 was greater than 85 and 75% after 24 and 48 h, respectively, from MTT assay.

In this study, we designed core/shell nanostructures (CSNs) of silicon dioxide (SiO2)/titanium dioxide (TiO2), which were decorated with gold (Au) nanoparticles (NPs), to activate the visible light-driven photocatalytic reaction that is not feasible with only the SiO2@TiO2 CSN because there is no absorption in the visible wavelengths. The CSNs were simply synthesized by hydrothermal method. In the core/shell structure, TiO2 covered the SiO2 core surface, which acts as a template. The attachment of additional Au NPs inside or outside the core/shell led to absorbance in visible wavelengths of light from the Sun, from which most radiation comes with a spectrum peak at yellow wavelength, owing to the localized surface plasmon resonance (LSPR) peak at approximately 550 nm. The SiO2@Au@TiO2@Au CSN (0.01 g) decomposed 1% of methyl orange (MO) solution in 15 mL deionized water in 1 h under the visible light. The visible light-driven photocatalytic reaction was ascribed to the LSPR around the Au NPs that were deposited inner or outer the mesoporous TiO2 shell.

A stem cell tracking system is in high demand for the determination of cell destinations and for the validation of cell therapeutic efficacy in regenerative transplantation. To date, near-infrared (NIR) imaging technology has received considerable attention in cell behavior monitoring, owing to its patient compatibility, easy accessibility and cost effectiveness. Conventionally, in vivo cell tracking has been visualized by direct in-cell staining with NIR, where it may be achieved by complicated genetic engineering. Such genetic amendment techniques have suffered from serious challenges, which can destroy a cell's metabolism and can accidentally incur unexpected carcinoma. Herein we demonstrate a novel cell nano-modulation method for noninvasive stem cell monitoring. It is simply achieved by conjugating stem cells with lipid-supported, NIR-tagged, polymeric nanoparticles. These engineered cells, which are designated as NIR-labeled light-emitting stem cells (LESCs), maintain their biochemical functionality (i.e., differentiation, quantum efficacy, etc.) even after conjugation. LESCs were used for in situ stem cell monitoring at inoculation sites. It is speculated that the LESC technique could provide a new preparative methodology for in vivo cell tracking in advanced diagnostic medicine, where cell behavior is a critical issue.

The low response rate of current cancer immunotherapy suggests the presence of few antigen-specific T cells and a high number of immunosuppressive factors in tumor microenvironment (TME). Here, we develop a syringeable immunomodulatory multidomain nanogel (iGel) that overcomes the limitation by reprogramming of the pro-tumoral TME to antitumoral immune niches. Local and extended release of immunomodulatory drugs from iGel deplete immunosuppressive cells, while inducing immunogenic cell death and increased immunogenicity. When iGel is applied as a local postsurgical treatment, both systemic antitumor immunity and a memory T cell response are generated, and the recurrence and metastasis of tumors to lungs and other organs are significantly inhibited. Reshaping of the TME using iGel also reverts non-responding groups to checkpoint blockade therapies into responding groups. The iGel is expected as an immunotherapeutic platform that can reshape immunosuppressive TMEs and synergize cancer immunotherapy with checkpoint therapies, with minimized systemic toxicity., The limited efficacy of current immunotherapy suggests low antigen-specific T cells and immunosuppressive factors in tumor microenvironment (TME). Here, the authors develop a syringeable immunomodulatory multi-domain nanogel that can reprogram the TME and induce enhanced cancer immunotherapy.

Polymer actuators are important components in lab-on-a-chip and micromechanical systems because of the inherent properties that result from their large and fast mechanical responses induced by molecular-level deformations (e.g., isomerization). They typically exhibit bending movements via asymmetric contraction or expansion with respect to changes in environmental conditions. To enhance the mechanical properties of actuators, a strain gradient should be introduced by regulating the molecular alignment, however, the miniaturization of polymer actuators for microscale systems has raised concerns regarding the complexity of such molecular control. Herein, a novel method for the fabrication of micro-actuators using a simple molecular self-alignment method is presented. Amphiphilic molecules that consist of azobenzene mesogens were located between the hydrophilic and hydrophobic surfaces, which resulted in a splayed alignment. Thereafter, molecular isomerization on the surface induced a large strain gradient and bending movement of the actuator under ultraviolet-light irradiation. Moreover, the microelectromechanical systems allowed for the variation of the actuator size below the micron scale. The mechanical properties of the fabricated actuators such as the bending direction, maximum angle, and response time were evaluated with respect to their thicknesses and lengths. The derivatives of the polymer actuator microstructure may contribute to the development of novel applications in the micro-robotics field.

Motion capture systems are gaining much attention in various fields, including entertainment, medical and sports fields. Although many types of motion capture sensor have been emerging, they have limitations and disadvantages such as occlusion, drift and interference by electromagnetic fields. Here, we introduce the novel wearable motion capture system using fiber Bragg gratings (FBGs) sensors. Since the human joints have different degrees of freedom (DOF), we developed three types of sensors to reconstruct the human body motion from the strains induced on the FBGs. First, a shape sensor using three fibers provides the position and orientation of joints in three dimensional space. Second, we introduce the angle sensor which is capable of measuring bending angle with high curvature using single fiber. Lastly, to detect the twisting of joints, a sensor with fiber attached on a soft material spirally is used. With the optical fiber based motion capture sensors, we reconstruct the motion of arm in realtime. In detail, the joints of the arm include the sternoclavicular, acromioclavicular, shoulder and elbow. By arranging the three types of sensors on the joints in accordance with the DOF, the accuracy of the reconstructed motion is evaluated, resulting in an average error below 2.42°. Finally, to prove the feasibility of applying in virtual reality, we successfully manipulate the virtual avatar in real-time.

Measuring high curvatures is essential in various applications such as structural engineering, medical treatment, and robotics. Herein, we present a novel ultra-high curvature sensor with an ultra-thin and highly flexible structure incorporating fiber Bragg gratings (FBGs). The sensor can measure curvature of bidirectional bending up to 200 m-1. In addition, the multi-bend curvature sensor in conjunction with the proposed calibration scheme enables the accurate reconstruction of a curve with varying curvature. The sensitivity and the accuracy of the curvature sensor are investigated for different sensor designs. Finally, we demonstrate the accurate shape sensing of various 2-D patterns using the multi-bend curvatures sensor.

In biological systems, a few sequence differences diversify the hybridization profile of nucleotides and enable the quantitative control of cellular metabolism in a cooperative manner. In this respect, the information required for a better understanding may not be in each nucleotide sequence, but representative information contained among them. Existing methodologies for nucleotide sequence design have been optimized to track the function of the genetic molecule and predict interaction with others. However, there has been no attempt to extract new sequence information to represent their inheritance function. Here, we tried to conceptually reveal the presence of a representative sequence from groups of nucleotides. The combined application of the K-means clustering algorithm and the social network analysis theorem enabled the effective calculation of the representative sequence. First, a “common sequence” is made that has the highest hybridization property to analog sequences. Next, the sequence complementary to the common sequence is designated as a ‘representative sequence’. Based on this, we obtained a representative sequence from multiple analog sequences that are 8–10-bases long. Their hybridization was empirically tested, which confirmed that the common sequence had the highest hybridization tendency, and the representative sequence better alignment with the analogs compared to a mere complementary.

The novel Mn-modified ordered mesoporous Co 3 O 4 catalysts were investigated for water gas shift reaction (WGSR), which was synthesized through a nano-casting method using a hard template of KIT-6. An incipient wetness impregnation of Mn precursor with different concentrations was applied for preparing Mn-modified mesoporous Co 3 O 4 . On 15 wt%Mn impregnated mesoporous Co 3 O 4 (denoted as Mn(15)/meso-Co 3 O 4 ), WGSR activity was found to be higher among the tested catalysts due to a higher structural stability of the Co 3 O 4 mesopores with a larger surface area. The Mn(15)/meso-Co 3 O 4 also showed stable ordered mesopore structures with an exposed larger number of active metallic cobalt sites on the surfaces even after WGSR. The structural stability was mainly attributed to the strong and stable interactions between cobalt oxides and manganese oxides. With an optimum amount of Mn promoter, Mn plays an important role as a structural stabilizer of the mesoporous Co 3 O 4 as well as an electron modifier by enhancing redox cycle properties of cobalt species and fast mass transport in mesopores.

Shape memory polymers (SMPs) that can be actuated by a near-infrared (NIR) light are of high interest due to their potential applications in biomedical field. In this work, SMPs that could be actuated by an NIR light without using any NIR photothermal filler was introduced for the first time. Benzoxazine/epoxy (V-fa/ECO) copolymers with a shape memory property were synthesized from bio-based raw materials, which were vanillin, furfurylamine, paraformaldehyde, and epoxidized castor oil. The glass transition temperature of the copolymers could be tuned from 144 to 14 °C, by increasing the ECO content from 40 to 60% by weight. The V-fa/ECO copolymers were found to exhibit a shape memory property that could be remotely actuated by an NIR laser with a wavelength of 808 nm. A high recovery ratio of 100% within a 30 s of NIR irradiation was achieved when the percent weight of ECO in the copolymers was at least 50. We found that the shape memory property of V-fa/ECO copolymers was due to their photothermal effect in the NIR region that could induce the shape recovery process. The temperature of V-fa/ECO copolymers rose from room temperature to 100 °C within a 30 s of NIR irradiation (laser power density of 2.5 W/cm2). It was proposed that the π-conjugation in benzene rings of copolymers might play role on their NIR photothermal effect, due to the π-π interactions between polymer chains. The findings of this study suggested a new way to produce NIR light responsive SMPs without using any NIR photothemal filler.

The magnetic properties of nanoparticles make them ideal for using in various applications, especially in biomedical applications. However, the magnetic force generated by a single nanoparticle is low. Herein, we describe the development of nanocomplexes (size of 100 nm) of many iron oxide nanoparticles (IONPs) encapsulated in poly(lactic- co-glycolic acid) (PLGA) using the simple method of emulsion solvent evaporation. The response of the IONP-encapsulated PLGA nanocomplexes (IPNs) to an external magnetic field could be controlled by modifying the amount of IONPs loaded into each nanocomplex. In a constant size of IPNs, larger loading numbers of IONPs resulted in more rapid responses to a magnetic field. In addition, nanocomplexes were coated with a silica layer to facilitate the addition of fluorescent dyes. This allowed visualization of the responses of the IPNs to an applied magnetic field corresponding to the IONP loading amount. We envision that these versatile, easy-to-fabricate IPNs with controllable magnetism will have important potential applications in diverse fields.

A novel and simple method for the fabrication of gold nanoparticle (AuNP) clusters was introduced for use as an efficient near-infrared (NIR) photothermal agent. Cationic surfactants were employed to assemble AuNPs into clusters, during which polyvinylpyrrolidone (PVP) was used to stabilize the AuNP clusters. Through this manner, AuNP clusters with a uniform shape and a narrow size distribution (55.4 ± 5.0 nm by electron microscope) were successfully obtained. A mechanism for the formation of AuNP clusters was studied and proposed. Electrostatic interactions between AuNPs and cationic surfactants, hydrophobic interactions between hydrocarbon chains of cationic surfactants, and repulsive steric interactions of PVP were found to play an important role with regard to the formation mechanism. Photothermal effect in the NIR range of the AuNP clusters was demonstrated; results presented a highly efficient photothermal conversion (with a maximum η of 65%) of the AuNP clusters. The clusters could be easily coated by a silica layer, enabling their biocompatibility and colloidal stability in physiological fluids. The easy-to-fabricate AuNP clusters showed high potential of use as an NIR photothermal agent for cancer therapy.