Carbon nanoparticles (C-NPs) are novel and competitive luminescent materials both in academic research and practical applications owing to their environment-friendly behavior and high abundance on Earth. Despite the successes in preparing strongly luminescent C-NPs, preserving the luminescence in solid materials is still challenging. With the aim to produce C-NP-based white-light-emitting diodes (WLEDs), in this work, solvent-dispersible C-NPs are embedded into commercial silica gel via a dual solvent evaporation route. The basic idea is to lower the evaporation rate of the solvents, thus leading to a good dispersion of the C-NPs in the silica gel. This method avoids the aggregation-induced emission quenching of C-NPs in solid materials, and therefore preserves the strong luminescence in the C-NPs/silica gel composites. The composites are further blended with polydimethylsiloxane and act as the color conversion layer on InGaN UV-blue emitting chips, which produces LEDs with a bright white emission.

Iron oxide (Fe3O4), polydopamine (PDA), and in particular their composites are examples of the safest nanomaterials for developing multifunctional nanodevices to perform noninvasive tumor diagnosis and therapy. However, the structures and performances of Fe3O4–PDA nanocomposites should be further perfected to enhance the theranostic efficiency. In this work, we demonstrate the fabrication of PDA-capped Fe3O4 (Fe3O4@PDA) superparticles (SPs) employing preassembled Fe3O4 nanoparticles (NPs) as the cores. Owing to the collective effect of preassembled Fe3O4 NPs, the superparamagnetism and photothermal performance of Fe3O4@PDA SPs are greatly enhanced, thus producing nanodevices with improved magnetic resonance imaging (MRI)-guided photothermal efficiency. Systematical studies reveal that the molar extinction coefficient of the as-assembled Fe3O4 SPs is 3 orders of magnitude higher than that of individual Fe3O4 NPs. Also due to the high aggregation degree of Fe3O4 NPs, the T2-weighted MRI contrast is greatly enhanced for the SPs with r2 relaxivity of 230.5 mM–1 s–1, which is ∼2.5 times larger than that of individual Fe3O4 NPs. The photothermal stability, physiological stability, and biocompatibility, as well as the photothermal performance of Fe3O4 SPs, are further improved by enveloping with PDA shell.Keywords: Fe3O4 nanoparticle; polydopamine; self-assembly; superparticle; theranostics

A novel kind of flower-like Pd NPs with strong absorption in the near-infrared (NIR) region was successfully synthesized by using a seed-mediated method in aqueous solutions. The biocompatibilty of the prepared flower-like Pd NPs was improved by coating them with polypyrrole (PPy). In comparison to the pure NPs, the PPy-coated flower-like Pd NPs (Pd NPs@PPy) exhibited stronger NIR absorption, higher structural stability and lower cytotoxicity. Moreover, the photothermal conversion efficiency (η) of the Pd NPs@PPy was effectively tuned via controllably changing the thickness of the PPy shell. A η of 96.0% at 808 nm was reached when the Pd NPs@PPy with a shell of 7.0 nm was prepared. This η was higher than that of the bare flower-like Pd NPs due to the absorption of PPy in the NIR regions. In vitro photothermal heating of Pd NPs@PPy in the presence of HeLa cells led to cell destruction after 10 min of laser irradiation at a low power density of 3 W cm−2. The Pd NPs@PPy shows a potential application as a promising photothermal nanoplatform for cancer therapy.

Electron transition materials on the basis of transition metal ions usually possess higher photothermal transduction efficiency but lower extinction ability, which have not been considered as efficient photothermal agents for therapeutic applications. In this work, we demonstrate a facile and feasible approach for enhancing 808 nm photothermal conversion effect of d orbits transition Cu(II) ions by forming Cu-carboxylate complexes. The coordination with carboxylate groups greatly enlarges the splitting energy gap of Cu(II) and the capability of electron transition, thus enhancing the extinction ability in near-infrared region. The cupreous complexes are further loaded in biocompatible and biodegradable polymer nanoparticles (NPs) of chitosan to temporarily lower the toxicity, which allows the photothermal therapy of human oral epithelial carcinoma (KB) cells in vitro and KB tumors in vivo. Animal experiments indicate the photothermal tumor inhibition rate of 100%. In addition, the gradual degradation of chitosan NPs leads to the release of cupreous complexes, thus exhibiting additional chemotherapeutic behavior in KB tumor treatment. Onefold chemotherapy experiments indicate the tumor inhibition rate of 93.1%. The combination of photothermal therapy and chemotherapy of cupreous complex-loaded chitosan NPs indicates the possibility of inhibiting tumor recurrence.Keywords: chemotherapy; chitosan; cupreous complexes; nanocomposites; photothermal therapy

Despite the success of galvanic replacement in preparing hollow nanostructures with diversified morphologies via the replacement reaction between sacrificial metal nanoparticles (NPs) seeds and less active metal ions, limited advances are made for producing branched alloy nanostructures. In this paper, we report an extended galvanic replacement for preparing branched Au–Ag NPs with Au-rich core and Ag branches using hydroquinone (HQ) as the reductant. In the presence of HQ, the preformed Ag seeds are replaceable by Au and, in turn, supply the growth of Ag branches. By altering the feed ratio of Ag seeds, HAuCl4, and HQ, the size and morphology of the NPs are tunable. Accordingly, the surface plasmon resonance absorption is tuned to near-infrared (NIR) region, making the branched NPs as potential materials in photothermal therapy. The branched NPs are further coated with polydopamine (PDA) shell via dopamine polymerization at room temperature. In comparison with bare NPs, PDA-coated branched Au–Ag (Au–Ag@PDA) NPs exhibit improved stability, biocompatibility, and photothermal performance. In vitro experiments indicate that the branched Au–Ag@PDA NPs are competitive agents for photothermal ablation of cancer cells.Keywords: hydroquinone; metal nanostructures; nanocomposites; photothermal therapy; polydopamine;

Photothermal nanoplatforms with small size, low cost, multifunctionality, good biocompatibility and in particular biodegradability are greatly desired in the exploration of novel diagnostic and therapeutic methodologies. Despite Fe3O4 nanoparticles (NPs) have been approved as safe clinical agents, the low molar extinction coefficient and subsequent poor photothermal performance shed the doubt as effective photothermal materials. In this paper, we demonstrate the fabrication of polypyrrole (PPy)-enveloped Fe3O4 NP superstructures with a spherical morphology, which leads to a 300-fold increase in the molar extinction coefficient. The basic idea is the optimization of Fe3O4 electronic structures. By controlling the self-assembly of Fe3O4 NPs, the diameters of the superstructures are tuned from 32 to 64 nm. This significantly enhances the indirect transition and magnetic coupling of Fe ions, thus increasing the molar extinction coefficient of Fe3O4 NPs from 3.65 × 106 to 1.31 × 108 M–1 cm–1 at 808 nm. The envelopment of Fe3O4 superstructures with conductive PPy shell introduces additional electrons in the Fe3O4 oscillation system, and therewith further enhances the molar extinction coefficient to 1.12 × 109 M–1 cm–1. As a result, the photothermal performance is greatly improved. Primary cell experiments indicate that PPy-enveloped Fe3O4 NP superstructures are low toxic, and capable to kill Hela cells under near-infrared laser irradiation. Owing to the low cost, good biocompatibility and biodegradability, the PPy-enveloped Fe3O4 NP superstructures are promising photothermal platform for establishing novel diagnostic and therapeutic methods.Keywords: Fe3O4; nanocomposites; photothermal platform; polypyrrole; self-assembly

The biocompatibility of biomaterials is essentially for its application. The aim of current study was to evaluate the biocompatibility of poly(lactic-co-glycolic acid) (PLGA)/gelatin/nanohydroxyapatite (n-HA) (PGH) nanofibers systemically to provide further rationales for the application of the composite electrospun fibers as a favorable platform for bone tissue engineering. The PGH composite scaffold with diameter ranging from nano- to micrometers was fabricated by using electrospinning technique. Subsequently, we utilized confocal laser scanning microscopy (CLSM) and MTT assay to evaluate its cyto-compatibility in vitro. Besides, real-time quantitative polymerase chain reaction (qPCR) analysis and alizarin red staining (ARS) were performed to assess the osteoinductive activity. To further test in vivo, we implanted either PLGA or PGH composite scaffold in a rat subcutaneous model. The results demonstrated that PGH scaffold could better support osteoblasts adhesion, spreading, and proliferation and show better cyto-compatibility than pure PLGA scaffold. Besides, qPCR analysis and ARS showed that PGH composite scaffold exhibited higher osteoinductive activity owing to higher phenotypic expression of typical osteogenic genes and calcium deposition. The histology evaluation indicated that the incorporation of Gelatin/nanohydroxyapatite (GH) biomimetics could significantly reduce local inflammation. Our data indicated that PGH composite electrospun nanofibers possessed excellent cyto-compatibility, good osteogenic activity, as well as good performance of host tissue response, which could be versatile biocompatible scaffolds for bone tissue engineering.Keywords: biocompatibility; bone biomimetics; bone tissue engineering; electrospun nanofibers; gelatin/nanohydroxyapatite; poly(lactic-co-glycolic acid);

To overcome treatment limitations of adenoid cystic carcinoma, we developed a novel treatment combining gene therapy and nanotechnology. In this study, we created a plasmid, pACTERT-TRAIL, which used the human telomerase reverse transcriptase promoter, a tumor-specific promoter, to drive tumor necrosis factor–related apoptosis-inducing ligand (TRAIL). A Fe3O4-PEI-plasmid complex (FPP) was generated, in which the iron oxide nanoparticles were modified by positively charged polyethylenimine (PEI) to enable them to carry the negatively charged plasmid. In vitro transfection assays showed that efficiency of magnetofection (i.e., FPP transfection) was sixfold higher compared to PEI alone or Lipofectamine 2000 (hereafter referred to as lipofectin) (P < 0.05). Importantly, apoptotic assays demonstrated that FPP-mediated TRAIL gene transfer could efficiently induce apoptosis of SACC-83 cells in vitro and in vivo. These results demonstrate that magnetofection of the plasmids driven by the tumor-specific promoter hTERT provides an effective way to deliver therapeutic genes for the treatment of adenoid cystic carcinoma in the future.From the Clinical EditorIn this novel study addressing adenoid cystic carcinoma, the authors created a plasmid to drive tumor necrosis factor–related apoptosis-inducing ligand (TRAIL). Following that, a Fe3O4-PEI-plasmid complex (FPP) was generated, in which the iron oxide nanoparticles were modified by positively charged polyethylenimine (PEI) enabling them to carry the negatively charged plasmid, giving rise to sixfold higher transfection rates compared to standard technology.This image shows SACC-83 cells transfected by the PEI modified Fe3O4 nanoparticles after 24 hours. The magnetic particle-DNA complexes are on the cell surface and in cytoplasm. The magnetic particle-DNA complex in the cytoplasm appears to have membrane-surrounded. This indicates that the PEI modified Fe3O4 nanoparticles can efficiently transfect the target cells.

High quality CdHgTe quasi core/shell nanocrystals (NCs) were prepared via the one-step method. The relationship between the composition, structure, and property was systematically investigated by the combination of X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission (ICP), and the photoluminescence (PL) measurements. The quantum yield (QY) was ∼50% when the feed ratio of Cd2+ to Hg2+ was equal to 1. The PL property was further polished, and the QY was improved to ∼80% through the variance of the prepared conditions such as the ratio of ligand to metal ion and HTe– to metal ion, pH value, and temperature. In addition, the cytotoxic effects of CdHgTe NCs were systematically studied. The results showed that, for Cd0.21Hg0.79Te NCs, its quasi core/shell structure was very stable and little cadmium ions were released. As a result, such NCs showed little cytotoxicity and would find applications in tissue imaging or detection.

Photothermal therapy using inorganic nanoparticles (NPs) is a promising technique for the selective treatment of tumor cells because of their capability to convert the absorbed radiation into heat energy. Although anisotropic gold (Au) NPs present an excellent photothermal effect, the poor structural stability during storage and/or upon laser irradiation still limits their practical application as efficient photothermal agents. With the aim of improving the stability, in this work we adopted biocompatible polypyrrole (PPy) as the shell material for coating urchinlike Au NPs. The experimental results indicate that a several nanometer PPy shell is enough to maintain the structural stability of NPs. In comparison to the bare NPs, PPy-coated NPs exhibit improved structural stability toward storage, heat, pH, and laser irradiation. In addition, the thin shell of PPy also enhances the photothermal transduction efficiency (η) of PPy-coated Au NPs, resulting from the absorption of PPy in the red and near-infrared (NIR) regions. For example, the PPy-coated Au NPs with an Au core diameter of 120 nm and a PPy shell of 6.0 nm exhibit an η of 24.0% at 808 nm, which is much higher than that of bare Au NPs (η = 11.0%). As a primary attempt at photothermal therapy, the PPy-coated Au NPs with a 6.0 nm PPy shell exhibit an 80% death rate of Hela cells under 808 nm NIR laser irradiation.

Nanodevices for multimodal tumor theranostics have shown great potentials for noninvasive tumor diagnosis and therapy, but the libraries of multimodal theranostic building blocks should be further stretched. In this work, Cu(II) ions are doped into polyaniline (Pani) nanoshuttles (NSs) to produce Cu-doped Pani (CuPani) NSs, which are demonstrated as new multimodal building blocks to perform tumor theranostics. The CuPani NSs are capable of shortening the longitudinal relaxation (T1) of protons under magnetic fields and can help light up tumors in T1-weighted magnetic resonance imaging. In addition, the released Cu(II) ions from CuPani NSs lead to cytotoxicity, showing the behavior of chemotherapeutic agent. The good photothermal performance of CuPani NSs also makes them as photothermal agents to perform thermochemotherapy. By combining near-infrared laser irradiation, a complete tumor ablation is achieved and no tumor recurrence is observed.CuPani NSs perform noninvasive tumor diagnosis and therapy with enhanced properties including electrostatic attraction to Hela cells, contrast agents for MRI, and photothermal combined chemotherapy.

Carbon nanoparticles (C-NPs) are novel and competitive luminescent materials both in academic research and practical applications owing to their environment-friendly behavior and high abundance on Earth. Despite the successes in preparing strongly luminescent C-NPs, preserving the luminescence in solid materials is still challenging. With the aim to produce C-NP-based white-light-emitting diodes (WLEDs), in this work, solvent-dispersible C-NPs are embedded into commercial silica gel via a dual solvent evaporation route. The basic idea is to lower the evaporation rate of the solvents, thus leading to a good dispersion of the C-NPs in the silica gel. This method avoids the aggregation-induced emission quenching of C-NPs in solid materials, and therefore preserves the strong luminescence in the C-NPs/silica gel composites. The composites are further blended with polydimethylsiloxane and act as the color conversion layer on InGaN UV-blue emitting chips, which produces LEDs with a bright white emission.