Multifunctional Upconversion Nanoparticles for Dual‐Modal Imaging‐Guided Stem Cell Therapy under Remote Magnetic Control

Stem cells have generated a great deal of excitement in cell‐based therapies. Here, a unique class of multifunctional nanoparticles (MFNPs) with both upconversion luminescence (UCL) and superparamagnetic properties is used for stem cell research. It is discovered that after being labeled with MFNPs, mouse mesenchymal stem cells (mMSCs) are able to maintain their viability and differentiation ability. In vivo UCL imaging of MFNP‐labeled mMSCs transplanted into animals is carried out, achieving ultrahigh tracking sensitivity with a detection limit as low as ≈10 cells in a mouse. Using both UCL optical and magnetic resonance (MR) imaging approaches, MFNP‐labeled mMSCs are tracked after being intraperitoneally injected into wound‐bearing mice under a magnetic field. The translocation of mMSCs from the injection site to the wound nearby the magnet is observed and, intriguingly, a remarkably improved tissue repair effect is observed as the result of magnetically induced accumulation of stem cells in the wound site. The results demonstrate the use MFNPs as novel multifunctional probes for labeling, in vivo tracking, and manipulation of stem cells, which is promising for imaging guided cell therapies and tissue engineering.     

Tracking of Transplanted Human Mesenchymal Stem Cells in Living Mice using Near‐Infrared Ag2S Quantum Dots

Stem cell therapeutics has emerged as a novel regenerative therapy for tissue repair in the last decade. However, dynamically tracking the transplanted stem cells in vivo remains a grand challenge for stem cell‐based regeneration medicine in full understanding the function and the fate of the stem cells. Herein, Ag₂S quantum dots (QDs) in the second near‐infrared window (NIR‐II, 1.0–1.4 μm) are employed for dynamically tracking of human mesenchymal stem cells (hMSCs) in vivo with high sensitivity and high spatial and temporal resolution. As few as 1000 Ag₂S QDs‐labeled hMSCs are detectable in vivo and their fluorescence intensity can maintain up to 30 days. The in situ translocation and dynamic distribution of transplanted hMSCs in the lung and liver can be monitored up to 14 days with a temporal resolution of 100 ms. The in vivo high‐resolution imaging indicates the heparin‐facilitated translocation of hMSCs from lung to liver as well as the long‐term retention of hMSCs in the liver contribute to the treatment of liver failure. The novel NIR‐II imaging offers a possibility of tracking stem cells in living animals with both high spatial and temporal resolution, and encourages the future clinical applications in imaging‐guided cell therapies.     

In Vivo Micro‐CT Imaging of Human Mesenchymal Stem Cells Labeled with Gold‐Poly‐l‐Lysine Nanocomplexes

Developing in vivo cell tracking is an important prerequisite for further development of cell‐based therapy. So far, few computed tomography (CT) cell tracking studies have been described due to its notoriously low sensitivity and lack of efficient labeling protocols. A simple method is presented to render human mesenchymal stem cells (hMSCs) sufficiently radiopaque by complexing 40 nm citrate‐stabilized gold nanoparticles (AuNPs) with poly‐l ‐lysine (PLL) and rhodamine B isothiocyanate (RITC). AuNP‐PLL‐RITC labeling does not affect cellular viability, proliferation, or downstream cell differentiation into adipocytes and osteocytes. Labeled hMSCs can be clearly visualized in vitro and in vivo with a micro‐CT scanner, with a detection limit of ≈2 × 10⁴ cells per µL in vivo. Calculated Hounsfield unit values are 2.27 per pg of intracellular Au, as measured with inductively coupled plasma mass spectrophotometry, and are linear over a wide range of cell concentrations. This linear CT attenuation is observed for both naked AuNPs and those that were taken up by hMSCs, indicating that the number of labeled cells can be quantified similar to the use of radioactive or fluorine tracers. This approach for CT cell tracking may find applications in CT image‐guided interventions and fluoroscopic procedures commonly used for the injection of cellular therapeutics.     

Labeling of Adipose‐Derived Stem Cells by Oleic‐Acid‐Modified Magnetic Nanoparticles

The in vivo tracking of adipose derived stem cells (ASCs) is of essential concern when they are used as seed cells in tissue engineering. This study explores the feasibility of using magnetic nanoparticles (MNs), a type of contrast agents in magnetic resonance imaging (MRI), to label ASCs such that the labeled ASCs could be tracked in vivo by MRI non‐invasively and repeatedly. To do this, MNs of <10 nm surface‐coated with oleic acid are synthesized via a high‐temperature solution‐phase reaction. Cytotoxicity of the as‐synthesized MNs at concentrations up to 0.1 mg mL^?1 on 10⁴ cells mL^?1 ASCs is evaluated by LDH release. Since only minor cytotoxicity is detected, the effects of the labeling technique on cellular behaviors and uptake by labeled cells are investigated. Cell proliferation and differentiation with and without MNs are compared. The results show that proliferation of ASCs (10⁴ cells mL^?1) labeled by MNs (0.05 mg mL^?1) is significantly enhanced and dependent on the labeling time. The MNs are located in the vesicles within cytoplasm of ASCs. The cellular uptake reaches as high as ～180 pg/cell. Nevertheless, the labeled ASCs still maintained adipogenic and osteogenic differentiation. Hence, the feasibility of labeling ASCs by oleic acid coated MNs is ascertained and it was better to label the cells during their quiescent stage. The labeled ASCs can also be in vivo detected by MRI in a subcutaneous model in vivo. Further MRI tracking of the labeled ASCs in long‐term follow‐up would thus follow this current study.     

Multimodal Magnetic Nanoclusters for Gene Delivery,Directed Migration,and Tracking of Stem Cells

This study develops multimodal magnetic nanoclusters (M‐MNCs) for gene transfer, directed migration, and tracking of human mesenchymal stem cells (hMSCs). The M‐MNCs are designed with 5 nm iron oxide nanoparticles and a fluorescent dye (i.e., Rhodamine B) in the matrix of the Food and Drug Administration approved polymer poly(lactide‐co‐glycolide) using a nanoemulsion method. The synthesized M‐MNCs have a hydrodynamic diameter of ≈150 nm, are internalized by stem cells via endocytosis, and deliver genes with high efficiency. The cellular internalization and gene expression efficiency of the clustered nanoparticles are significantly higher than that of single nanoparticles. The M‐MNC‐labeled hMSCs migrate upon application of a magnetic force and can be visualized by both optical and magnetic resonance (MR) imaging. In animal models, the M‐MNC‐labeled hMSCs are also successfully tracked using optical and MR imaging. Thus, the M‐MNCs not only allow the efficient delivery of genes to stem cells but also the tracking of cells in animal models. Taken together, the results show that this new type of nanocomposite can be of great help in future stem cell research and in the development of cell‐based therapeutic agents.     

Mesoporous Silica Coated Single‐Walled Carbon Nanotubes as a Multifunctional Light‐Responsive Platform for Cancer Combination Therapy

The development of cancer combination therapies, many of which rely on nanoscale theranostic agents, has received increasing attention in recent years. In this work, polyethylene glycol (PEG) modified mesoporous silica (MS) coated single‐walled carbon nanotubes (SWNTs) are fabricated and utilized as a multifunctional platform for imaging guided combination therapy of cancer. A model chemotherapy drug, doxorubicin (DOX), could be loaded into the mesoporous structure of the obtained SWNT@MS‐PEG nano‐carriers with high efficiency. Upon stimulation under near‐infrared (NIR) light, photothermally triggered drug release from DOX loaded SWNT@MS‐PEG is observed inside cells, resulting in a synergistic cancer cell killing effect. As revealed by both photoacoustic (PA) and magnetic resonance (MR) imaging, we further uncover efficient tumor accumulation of SWNT@MS‐PEG/DOX after intravenous injection into mice. In vivo combination therapy using this agent is further demonstrated in a mouse tumor model, achieving a remarkable synergistic anti‐tumor effect superior to that obtained by mono‐therapy. Our work presents a new type of theranostic nano‐platform, which could load therapeutic molecules with high efficiency, be responsive to external NIR stimulation, and at the same time serve as a diagnostic imaging agent.     

An NIR‐II Fluorescence/Dual Bioluminescence Multiplexed Imaging for In Vivo Visualizing the Location,Survival, and Differentiation of Transplanted Stem Cells

The in vivo distribution, viability, and differentiation capability of transplanted stem cells are vital for the therapeutic efficacy of stem cell–based therapy. Herein, an NIR‐II fluorescence/dual bioluminescence multiplexed imaging method covering the visible and the second near‐infrared window from 400 to 1700 nm is successfully developed for in vivo monitoring the location, survival, and osteogenic differentiation of transplanted human mesenchymal stem cells (hMSCs) in a calvarial defect mouse model. The exogenous Ag₂S quantum dot–based fluorescence imaging in the second near‐infrared window is applied for visualizing the long‐term biodistribution of transplanted hMSCs. Endogenous red firefly luciferase (RFLuc)‐based bioluminescence imaging (BLI) and the collagen type 1 promoter–driven Gaussia luciferase (GLuc)‐based BLI are employed to report the survival and osteogenic differentiation statuses of the transplanted hMSCs. Meanwhile, by integrating the three imaging channels, multiple dynamic biological behaviors of transplanted hMSCs and the promotion effects of immunosuppression and the bone morphogenetic protein 2 on the survival and osteogenic differentiation of transplanted hMSCs are directly observed. The novel multiplexed imaging method can greatly expand the capability for multifunctional analysis of the fates and therapeutic capabilities of the transplanted stem cells, and aid in the improvement of stem cell–based regeneration therapies and their clinical translation.     

Nanocarrier‐Mediated Codelivery of Small Molecular Drugs and siRNA to Enhance Chondrogenic Differentiation and Suppress Hypertrophy of Human Mesenchymal Stem Cells

Cartilage loss is a leading cause of disability among adults, and effective therapy remains elusive. Human mesenchymal stem cells (hMSCs), which have demonstrated self‐renewal and multipotential differentiation, are a promising cell source for cartilage repair. However, the hypertrophic differentiation of the chondrogenically induced MSCs and resulting tissue calcification hinders the clinical translation of MSCs for cartilage repair. Here, a multifunctional nanocarrier based on quantum dots (QDs) is developed to enhance chondrogenic differentiation and suppress hypertrophy of hMSCs simultaneously. Briefly, the QDs are modified with β‐cyclodextrin (β‐CD) and RGD peptide. The resulting nanocarrier is capable of carrying hydrophobic small molecules such as kartogenin in the hydrophobic pockets of conjugated β‐CD to induce chondrogenic differentiation of hMSCs. Meanwhile, via electrostatic interaction the conjugated RGD peptides bind the cargo siRNA targeting Runx2, which is a key regulator of hMSC hypertrophy. Furthermore, due to the excellent photostability of QDs, hMSCs labeled with the nanocarrier can be tracked for up to 14 d after implantation in nude mice. Overall, this work demonstrates the potential of our nanocarrier for inducing and maintaining the chondrogenic phenotype and tracking hMSCs in vivo.     

N‐Type Conjugated Polymer‐Enabled Selective Dispersion of Semiconducting Carbon Nanotubes for Flexible CMOS‐Like Circuits

Sorting of semiconducting single‐walled carbon nanotubes (SWNTs) by conjugated polymers has attracted considerable attention recently because of its simplicity, high selectivity, and high yield. However, up to now, all the conjugated polymers used for SWNT sorting are electron‐donating (p‐type). Here, a high‐mobility electron‐accepting (n‐type) polymer poly([N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)) (P(NDI2OD‐T2)) is utilized for the sorting of high‐purity semiconducting SWNTs, as characterized by Raman spectroscopy, dielectric force spectroscopy and transistor measurements. In addition, the SWNTs sorted by P(NDI2OD‐T2) have larger diameters than poly(3‐dodecylthiophene) (P3DDT)‐sorted SWNTs. Molecular dynamics simulations in explicit toluene demonstrate distinct linear or helical wrapping geometry between P(NDI2OD‐T2) and different types of SWNTs, likely as a result of the strong interactions between the large aromatic core of the P(NDI2OD‐T2) backbone and the hexagon path of SWNTs. By using high‐mobility n‐type P(NDI2OD‐T2) as the sorting polymer, ambipolar SWNT transistors with better electron transport than that attained by P3DDT‐sorted SWNTs are achieved. As a result, flexible negated AND and negated OR logic circuits from the same set of ambipolar transistors are fabricated, without the need for doping. The use of n‐type polymers for sorting semiconducting SWNTs and achieving ambipolar SWNT transistor characteristics greatly simplifies the fabrication of flexible complementary metal‐oxide‐semiconductor‐like SWNT logic circuits.     

Conjugated Polymer Nanodots as Ultrastable Long‐Term Trackers to Understand Mesenchymal Stem Cell Therapy in Skin Regeneration

Stem cell–based therapies hold great promise in providing desirable solutions for diseases that cannot be effectively cured by conventional therapies. To maximize the therapeutic potentials, advanced cell tracking probes are essential to understand the fate of transplanted stem cells without impairing their properties. Herein, conjugated polymer (CP) nanodots are introduced as noninvasive fluorescent trackers with high brightness and low cytotoxicity for tracking of mesenchymal stem cells (MSCs) to reveal their in vivo behaviors. As compared to the most widely used commercial quantum dot tracker, CP nanodots show significantly better long‐term tracking ability without compromising the features of MSCs in terms of proliferation, migration, differentiation, and secretome. Fluorescence imaging of tissue sections from full‐thickness skin wound–bearing mice transplanted with CP nanodot‐labeled MSCs suggests that paracrine signaling of the MSCs residing in the regenerated dermis is the predominant contribution to promote skin regeneration, accompanied with a small fraction of endothelial differentiation. The promising results indicate that CP nanodots could be used as next generation of fluorescent trackers to reveal the currently ambiguous mechanisms in stem cell therapies through a facile and effective approach.     

Single‐Walled Carbon Nanotube Dispersions in Poly(ethylene oxide)

Dispersions of single‐walled carbon nanotubes (SWNTs) in poly(ethylene oxide) (PEO) assisted by a lithium‐based anionic surfactant demonstrate an electrical percolation of 0.03 wt.‐% and a geometrical percolation, inferred from melt rheometry, of 0.09 wt.‐%. Both the melting temperature and the extent of crystallinity of the PEO crystals decrease with increasing SWNT loading. Raman spectroscopy of the nanocomposites indicates a down‐shift of the SWNT G‐modes and suggests that the nanotubes are subjected to tensile stress transfer from the polymer at room temperature.     

Simultaneous Deep Tracking of Stem Cells by Surface Enhanced Raman Imaging Combined with Single-Cell Tracking by NIR-II Imaging in Myocardial Infarction

Stem cell therapy has been used as a potential approach for the treatment of myocardial infarction (MI) over the last two decades. Imaging cellular behaviors of the transplanted stem cells with deep tissue penetration and high precision imaging modalities is crucial for the clinical translation of stem cell therapy approaches for MI. Herein, a gold nanostar (Au-Star) based second near-infrared window (NIR-II) fluorescence/surface enhanced Raman scattering dual-modal imaging probe (gold nanostar-3.3′-diethylthiatricarbocyanine iodide-silver sulfide nanoparticles, Au-Star-DTTC-Ag₂S NPs, GDS NPs) is designed for labeling and precise tracking of the stem cells. The Ag₂S compartment generates strong NIR-II emission, which compensates for the deficiencies of bioluminescent imaging and enables the dynamic observation of in vivo cellular behavior. Subsequently, the specific Raman signal of Au-Star-DTTC compartment enables high-resolution imaging, which could effectively delineate stem cells from the surrounding normal tissues, even at a single-cell resolution. Using this imaging and tracking approach, it is able to track stem cells in hypodermic and MI models, with high resolution and depth-independent imaging capabilities, which have not been reported in any other cell tracking platform. This two-armed imaging toolkit offers new opportunities for a wide range of mechanistic stem cell therapy investigations in different organs.     

New Opportunities: Second Harmonic Generation of Boron‐Doped Graphene Quantum Dots for Stem Cells Imaging and Ultraprecise Tracking in Wound Healing

Second harmonic generation (SHG) has recently emerged, having the advantages of no bleaching, no blinking, and no signal saturation, as well as a high signal to‐noise ratio compared to fluorescence. Existing SHG probes are based on heavy metal or organic dye molecules, which have the shortcomings of toxicity, a large size, or photoinstability. To address the urgent need for long‐term tracking and imaging in organisms, boron‐doped graphene quantum dots (B‐GQDs), a highly biocompatible graphene based with a strong and photostable SHG signal is first synthesized and is further applied for stem cell imaging and tracking in wounds. The results demonstrate the possibility of stem cell internalization of B‐GQDs as a SHG probe and show no hindering of the stem cell's central physiological activities such as differentiation. Most importantly, B‐GQDs are successfully tracked in skin tissue in vivo after the labeled mouse mesenchymal stem cells being implanted over 35 days. This work will inspire the development of doped graphene quantum dot materials and promote the broad use of B‐GQDs in future molecular imaging, drug delivery, and stem cell therapy.     

Selective Electrochemical Etching of Single‐Walled Carbon Nanotubes

Single‐walled carbon nanotubes (SWNTs) are a promising material for future nanotechnology. However, their applications are still limited in success because of the co‐existence of metallic SWNTs and semiconducting SWNTs produced samples. Here, electrochemical etching, which shows both diameter and electrical selectivity, is demonstrated to remove SWNTs. With the aid of a back‐gate electric field, selective removal of metallic SWNTs is realized, resulting in high‐performance SWNT field‐effect transistors with pure semiconducting SWNT channels. Moreover, electrochemical etching is realized on a selective area. These findings would be valuable for research and the application of SWNTs in electrochemistry and in electronic devices.     

A Versatile,Molecular Engineering Approach to Simultaneously Enhanced,Multifunctional Carbon‐Nanotube– Polymer Composites

Single‐walled carbon nanotubes (SWNTs) are recognized as the ultimate carbon fibers for high‐performance, multifunctional composites. The remarkable multifunctional properties of pristine SWNTs have proven, however, difficult to harness simultaneously in polymer composites, a problem that arises largely because of the smooth surface of the carbon nanotubes (i.e., sidewalls), which is incompatible with most solvents and polymers, and leads to a poor dispersion of SWNTs in polymer matrices, and weak SWNT–polymer adhesion. Although covalently functionalized carbon nanotubes are excellent reinforcements for mechanically strong composites, they are usually less attractive fillers for multifunctional composites, because the covalent functionalization of nanotube sidewalls can considerably alter, or even destroy, the nanotubes' desirable intrinsic properties. We report for the first time that the molecular engineering of the interface between non‐covalently functionalized SWNTs and the surrounding polymer matrix is crucial for achieving the dramatic and simultaneous enhancement in mechanical and electrical properties of SWNT–polymer composites. We demonstrate that the molecularly designed interface of SWNT–matrix polymer leads to multifunctional SWNT–polymer composite films stronger than pure aluminum, but with only half the density of aluminum, while concurrently providing electroconductivity and room‐temperature solution processability.     

Interactions Between Amino Acid‐Tagged Naphthalenediimide and Single Walled Carbon Nanotubes for the Design and Construction of New Bioimaging Probes

A new synthetic route to functionalized single walled carbon nanotubes (SWNTs) via supramolecular interactions using a specifically designed naphthalenediimide (NDI) nanoreceptor is demonstrated. The tendency of the NDI to spontaneously form composites with carbon nanomaterials leads to fluorescent amino acid tagged SWNTs, which are dispersible in widely accessible organic solvents (CHCl₃, DMSO) as well as in biocompatible cell medium (EMEM, Eagle's modified essential medium). The X‐ray crystal structure of the first iodine‐tagged and amino acid‐functionalized NDI molecule, designed especially to facilitate the high resolution transmission electron microscopy (HR TEM) imaging whilst retaining its ability to self‐assemble into a nanodimensional receptor in weakly polar solvents, is also described. A new hybrid material, NDI@SWNT, was prepared and characterized as dispersed in organic solvents and aqueous media and in the solid state by HR TEM, tapping mode atomic force microscopy (TM AFM), scanning electron microscopy (SEM), circular dichroism, Raman and fluorescence spectroscopies (steady‐state single and two‐photon techniques). Combined microscopy techniques, density functional theory (DFT) calculations using the Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) program and spectroscopic measurements in solution indicate that amino acid‐functionalized NDI interacts strongly with SWNTs and forms a donor‐acceptor complex. Density functional theory (DFT) calculations predicted the geometry and the binding energies of an NDI molecule loaded onto a SWNT strand and the possibility of charge transfer interactions within the hybrid. The NDI@SWNT composite translocates into cells (e.g. FEK‐4, HeLa, MCF‐7) as an intact object and localizes in the cells' cytoplasm and partially in the nucleus. The NDI coating enhances the biocompatibility of SWNTs and mediates its intracellular localization as shown by confocal fluorescence imaging and fluorescence lifetime imaging (FLIM) techniques. The excited state fluorescence lifetime of the probes in cells versus solution phase indicates that the probes remain unaffected by the change in their chemical environment within the experimental timescale (2 h).     

Synthesis and Properties of a Water‐Soluble Single‐Walled Carbon Nanotube–Poly(m‐aminobenzene sulfonic acid) Graft Copolymer

Poly(m‐aminobenzene sulfonic acid) (PABS), was covalently bonded to single‐walled carbon nanotubes (SWNTs) to form a water‐soluble nanotube–polymer compound (SWNT–PABS). The conductivity of the SWNT–PABS graft copolymer was about 5.6 × 10^–3 S cm^–1, which is much higher than that of neat PABS (5.4 × 10^–7 S cm^–1). The mid‐IR spectrum confirmed the formation of an amide bond between the SWNTs and PABS. The ¹H NMR spectrum of SWNT–PABS showed the absence of free PABS, while the UV/VIS/NIR spectrum of SWNT–PABS showed the presence of the interband transitions of the semiconducting SWNTs and an absorption at 17 750 cm^–1 due to the PABS addend.     

Hierarchical Inorganic–Organic Nanocomposites Possessing Amphiphilic and Morphological Complexities: Influence of Nanofiller Dispersion on Mechanical Performance

Novel nanocomposites possessing ternary compositions and complex morphologies have been prepared from amphiphilic crosslinked hyperbranched fluoropolymer–poly(ethylene glycol) (HBFP–PEG) in the presence of pristine and chemically functionalized nanoscopic fillers, single‐walled carbon nanotubes (SWNTs) and silica nanoparticles (SiO₂). Both SWNTs and SiO₂ were engineered specifically to become phase‐designated reinforcing functional materials, SWNT‐g‐PEG and SiO₂‐g‐HBFP, which (1) improved the dispersion of fillers, nanotubes, or spherical nanoparticles in the amphiphilic matrices, (2) enhanced the non‐covalent interactions between nanofillers and polymers, and more importantly, (3) maintained reactive functionalities to be further covalently integrated into the complex networks. Tensile moduli (E_dry) for these as‐prepared SWNT‐containing composites increased by up to 430% relative to the unfilled material, while those incorporated with SiO₂ had a 420% increase of E_dry. After swelling in water, the water absorption within the micro‐ and nanochannels of PEG‐rich domains rigidified or softened the entire crosslinked network, as determined by the amount of PEG.     

Bottom‐Up Preparation of Uniform Ultrathin Rhenium Disulfide Nanosheets for Image‐Guided Photothermal Radiotherapy

Facile preparation of multifunctional theranostic nanoplatforms with well‐controlled morphology and sizes remains an attractive in the area of nanomedicine. Here, a new kind of 2D transition metal dichalcogenide, rhenium disulfide (ReS₂) nanosheets, with uniform sizes, strong near‐infrared (NIR) light, and strong X‐ray attenuation, is successfully synthesized. After surface modification with poly(ethylene glycol) (PEG), the synthesized ReS₂‐PEG nanosheets are stable in various physiological solutions. In addition to their contrasts in photoacoustic imaging and X‐ray computed tomography imaging because of their strong NIR light and X‐ray absorptions, respectively, such ReS₂‐PEG nanosheets can also be tracked under nuclear imaging after chelator‐free labeling with radioisotope ions, ^99mTc⁴⁺. Efficient tumor accumulation of ReS₂‐PEG nanosheets is then observed after intravenous injection into tumor‐bearing mice under triple‐modal imaging. The combined in vivo photothermal radiotherapy is further conducted, achieving a remarkable synergistic tumor destruction effect. Finally, no obvious toxicity of ReS₂‐PEG nanosheets is observed from the treated mice within 30 d. This work suggests that such ultrathin ReS₂ nanosheets with well‐controlled morphology and uniform sizes may be a promising type of multifunctional theranostic agent for remotely triggered cancer combination therapy.     

Single‐Walled Carbon Nanotube/Phase Change Material Composites: Sunlight‐Driven,Reversible, Form‐Stable Phase Transitions for Solar Thermal Energy Storage

The development of solar energy conversion materials is critical to the growth of a sustainable energy infrastructure in the coming years. A novel hybrid material based on single‐walled carbon nanotubes (SWNTs) and form‐stable polymer phase change materials (PCMs) is reported. The obtained materials have UV‐vis sunlight harvesting, light‐thermal conversion, thermal energy storage, and form‐stable effects. Judicious application of this efficient photothermal conversion to SWNTs has opened up a rich field of energy materials based on novel SWNT/PCM composits with enhanced performance in energy conversion and storage.