The incorporation of intensive light absorbing porphyrins macrocycles with biocompatible nanoparticles would lead to new nanomaterials with multiple imaging and therapeutic modalities. Herein, a facile synthetic strategy has been applied to prepare porphyrin-implanted carbon nanodots (PNDs) by partial and selective pyrolysis of 5,10,15,20-tetrakis­(4-aminophenyl)­porphyrin (TAPP) and citric acid (CA) at an appropriate temperature. As-prepared PNDs exhibit not only the excellent stability and biocompatibility characteristic of carbon nanodots but also the unique properties of porphyrin macrocycle such as strong UV–visible and near-infrared absorption, specifically, high photodynamic therapy efficiency. More importantly, the PNDs with near-infrared absorption could act as a contrast agent for photoacoustic molecular imaging with deep tissue penetration and fine spatial resolution. The Cetuximab-conjugated porphyrin-based carbon nanodots (C225-PNDs) have been further prepared to precisely target the cancer cells (HCC827 and MDA-MB-231 cells) with overexpression of EGFR, leading to highly efficient photodynamic therapy upon two-photo excitation at 800 nm. A complete ablation of tumor together with an enhanced photoacoustic contrast ability for C225-PNDs have been further validated in mice bearing MDA-MB-231 breast cancer.

N-rich metal-free and metal-doped carbon quantum dots (CQDs) have been prepared through one-step hydrothermal method using tetraphenylporphyrin or its transition metal (Pd or Pt) complex as precursor. The structures and morphology of the as-prepared nanoparticles were analyzed by X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra. Three kinds of nanocomposites show similar structures except for the presence of metal ions in Pd-CQDs and Pt-CQDs indicated by X-ray photoelectron spectroscopy. All of them display bright blue emission upon exposure to ultraviolet irradiation. The CQDs exhibit typical excitation-dependent emission behavior, with the emission quantum yield of 10.1%, 17.8%, and 15.2% for CQDs, Pd-CQDs, and Pt-CQDs, respectively. Moreover, the CQDs, Pd-CQDs, and Pt-CQDs could serve as fluorescent probes for the specific and sensitive detection of Fe 3+ ions in aqueous solution. The low cytotoxicity of CQDs is demonstrated by MTT assay against HeLa cells. Therefore, the CQDs can be used as efficient probes for cellular multicolor imaging and fluorescence sensors for the detection of Fe 3+ ions due to their low toxicity, excellent biocompatibility, and low detection limits. This work provides a new route to synthesize highly luminescent N-rich metal-free or metal-doped CQDs for multifunctional applications.

Near-infrared (NIR)-absorbing organic nanoparticles (ONPs) are emerging candidates for “one-for-all” theranostic nanomaterials with considerations of safety and formulation in mind. However, facile fabrication methods and improvements in the photothermal conversion efficiency (PCE) and photostability are likely needed before a clinically viable set of candidates emerges. Herein, a new organic compound, [porphyrin–diketopyrrolopyrrole (Por–DPP)] with the donor–acceptor structure was synthesized, where porphyrin was used as a donor unit while diketopyrrolopyrrole was used as an acceptor unit. Por–DPP exhibited efficient absorption extending from visible to NIR regions. After self-assembling into nanoparticles (NPs) (∼120 nm), the absorption spectrum of Por–DPP NPs broadened and red-shifted to some extent, relative to that of organic molecules. Furthermore, the architecture of NPs enhanced the acceptor–donor structure, leading to emission quenching and facilitating nonradiative thermal generation. The PCE of Por–DPP NPs was measured and calculated to be 62.5%, higher than most of ONPs. Under 808 nm laser irradiation, the Por–DPP NPs possessed a distinct photothermal therapy (PTT) effect in vitro and can damage cancer cells efficiently in vivo without significant side effects after phototherapy. Thus, the small-molecule porphyrin-based ONPs with high PCE demonstrated promising application in photoacoustic imaging-guided PTT.

Photosensitizers are light-sensitive molecules that are highly hydrophobic, which poses a challenge to their use for photodynamic therapy. Hence, considerable efforts have been made to develop carriers for the delivery of PSs. Herein, we synthesized a new theranostic nanoagent (CQDs@PtPor) through the electrostatic interaction between the tetraplatinated porphyrin complex (PtPor) and the negatively charged CQDs. The size and morphology of as-prepared CQDs and CQDs@PtPor were characterized by a series of methods, such as XRD, TEM, XPS, and FTIR spectroscopy. The CQDs@PtPor composite integrates the optical properties of CQDs and the anticancer function of porphyrin into a single unit. The spectral results suggested the effective resonance energy transfer from CQDs to PtPor in the CQDs@PtPor composite. Impressively, the CQDs@PtPor composite showed the stronger PDT effect than that of organic molecular PtPor, suggesting that CQDs@PtPor is advantageous over the conventional formulation, attributable to the enhanced efficiency of 1O2 production of PtPor by CQDs. Thus, this CQDs-based drug nanocarrier exhibited enhanced tumor-inhibition efficacy as well as low side effects in vitro, showing significant application potential in the cancer therapy.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2761-5) contains supplementary material, which is available to authorized users.

A mesoporous silica (SBA-15)-supported bipyridine iridium complex is prepared by grafting of bipyridine onto the silica support, followed by complexation of an iridium(I) precursor in the presence of HBpin and cyclooctene. Structural analyses by X-ray powder diffraction, nitrogen physisorption, FT-IR, and solid-state NMR spectroscopy demonstrate that the 3-dimensional, hexagonal pore structure of SBA-15 is maintained after the immobilization. In particular, as a heterogeneous catalyst, this silica-supported iridium complex shows moderate to good catalytic activity in the aromatic C−H borylation of a variety of substrates. More importantly, the heterogeneous catalyst is recovered easily and reused repeatedly by simple washing without chemical treatment and exhibits good recycling performance with a modest decrease in the catalytic rate, showing good potential for increasing the overall turnover number of this synthetically useful catalyst.

No abstract

Carbon dots (CDs) as an emerging type of carbon nanomaterials exhibit great potential in bioimaging applications owing to their superior optical properties and excellent biocompatibility. However, it is still challenging to fabricate sole carbon dots with integrated functionalities of diagnostic and therapeutic modalities. Herein, we developed a facile strategy to prepare the ruthenium-containing carbon dots (Ru-CDs) via a hydrothermal method using the 5-amino-1,10-phenanthroline ruthenium­(II) complex (Ru-Aphen) and citric acid as starting materials. The structure and morphology of Ru-CDs were verified by transmission electron spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier transform infrared spectra. The Ru-CDs exhibited good water solubility, intense red emission, and efficient reactive oxygen species (ROS) generation. The MTT assay against HeLa cells demonstrated favorable biocompatibility and distinct photodynamic effect of Ru-CDs. Owing to strong luminescence in water (QY = 20.79%) and efficient ROS generation, Ru-CDs were not only applied as bioimaging agents for tumor cells and zebrafish embryos, but also as photodynamic nanoagents for cancer therapy. Finally, the DNA photocleavage of Ru-CDs was verified through the experiment of gel electrophoresis. The results suggested that the plasmid DNA could only be damaged in the presence of Ru-CDs and light. Thus, the as-prepared Ru-CDs showed good prospects and a wide range of biological applications.

Light-activated phototherapy, including photothermal and photodynamic therapy, has become a new way for spatiotemporal control and noninvasive treatment of cancer. In this study, two new organic porphyrin molecules (NI-Por and NI-ZnPor) with donor (D)−acceptor (A) structure were designed and synthesized. The donor−acceptor pairs facilitated the intermolecular electron transfer, resulting in the enhancement of near-infrared (NIR) absorbance and nonradiative heat generation. After self-assembling, the nanoparticles were formed with the size around 60 nm. Relative to that of organic molecules, the absorption of NI-Por NPs and NI-ZnPor NPs broadened and red-shifted to the near-infrared region. Moreover, the porphyrin-containing nanoparticles can generate heat and reactive oxygen species (ROS) simultaneously induced by a single laser (635 nm). The intracellular reactive oxygen species production of NI-Por NPs and NI-ZnPor NPs was confirmed using DCFH-DA as an indicator. Furthermore, the localization of NI-Por NP and NI-ZnPor NP in HeLa cells was verified by fluorescence confocal laser microscopy. The photocytoxicity of two nanoparticles against HeLa cells was evaluated through the CCK-8 method. The IC 50 of NI-Por NPs and NI-ZnPor NPs upon 635 nm laser irradiation was calculated to be 6.92 μg/mL and 5.86 μg/mL, respectively. Furthermore, the PDT/PTT synergistic effect of NPs under a 635 nm laser was verified through different treatment groups in vitro. All these results demonstrated that the as-prepared porphyrin-based nanoparticles are promising nanoagents for PDT/PTT in clinic.