TiC MXene is a new two-dimensional material exhibiting a variety of novel properties including good photothermal effect, and the capability of TiC for multimodal tumor therapy is in urgent need of development. Herein, ultrathin TiC MXene nanosheets (∼100 nm) have been synthesized by supplying additive Al to avoid Al loss and employed as a photothermal/photodynamic agent for cancer therapy. The as-obtained nanosheets exhibit outstanding mass extinction coefficient (28.6 Lg cm at 808 nm), superior photothermal conversion efficiency (∼58.3%), and effective singlet oxygen generation (O) upon 808 nm laser irradiation. Based on these TiC nanosheets, a multifunctional nanoplatform (TiC-DOX) is established via layer-by-layer surface modification with doxorubicin (DOX) and hyaluronic acid (HA). In vitro and in vivo experiments disclose that TiC-DOX shows enhanced biocompatibility, tumor specific accumulation, and stimuli-responsive drug release behavior and achieve effective cancer cell killing and tumor tissue destruction through photothermal/photodynamic/chemo synergistic therapy.

Herein, a donor-acceptor-donor (D-A-D) structured small molecule (DPP-TPA) is designed and synthesized for photoacoustic imaging (PAI) guided photodynamic/photothermal synergistic therapy. In the diketopyrrolopyrrole (DPP) molecule, a thiophene group is contained to increase the intersystem crossing (ISC) ability through the heavy atom effect. Simultaneously, triphenylamine (TPA) is introduced for bathochromic shift absorption as well as charge transport capacity enhancement. After formation of nanoparticles (NPs, ∼76 nm) by reprecipitation, the absorption of DPP-TPA NPs further displays obvious bathochromic-shift with the maximum absorption peak at 660 nm. What's more, the NPs architecture enhances the D-A-D structure, which greatly increases the charge transport capacity and impels the charge to generate heat by light. DPP-TPA NPs present high photothermal conversion efficiency (η = 34.5%) and excellent singlet oxygen (O) generation (Φ = 33.6%) under 660 nm laser irradiation. PAI, with high spatial resolution and deep biotissue penetration, indicates DPP-TPA NPs can rapidly target the tumor sites within 2 h by the enhanced permeability and retention (EPR) effect. Importantly, DPP-TPA NPs could effectively hinder the tumor growth by photodynamic/photothermal synergistic therapy in vivo even at a low dosage (0.2 mg/kg) upon laser irradiation (660 nm 1.0 W/cm). This study illuminates the photothermal conversion mechanism of small organic NPs and demonstrates the promising application of DPP-TPA NPs in PAI guided phototherapy.

Gold nanoparticles (GNPs) and modified GNPs having two kinds of functional molecules, cysteamine (AET) and thioglucose (Glu), are synthesized. Cell uptake and radiation cytotoxicity enhancement in a breast-cancer cell line (MCF-7) versus a nonmalignant breast-cell line (MCF-10A) are studied. Transmission electron microscopy (TEM) results show that cancer cells take up functional Glu-GNPs significantly more than naked GNPs. The TEM results also indicate that AET-capped GNPs are mostly bound to the MCF-7 cell membrane, while Glu-GNPs enter the cells and are distributed in the cytoplasm. After MCF-7 cell uptake of Glu-GNPs, or binding of AET-GNPs, the in vitro cytotoxicity effects are observed at 24, 48, and 72 hours. The results show that these functional GNPs have little or no toxicity to these cells. To validate the enhanced killing effect on cancer cells, various forms of radiation are applied such as 200 kVp X-rays and gamma-rays, to the cells, both with and without functional GNPs. By comparison with irradiation alone, the results show that GNPs significantly enhance cancer killing.

Tetrahedral units can transport oxide anions via interstitial or vacancy defects owing to their great deformation and rotation flexibility. Compared with interstitial defects, vacancy-mediated oxide-ion conduction in tetrahedra-based structures is more difficult and occurs rarely. The isolated tetrahedral anion Scheelite structure has showed the advantage of conducting oxygen interstitials but oxygen vacancies can hardly be introduced into Scheelite to promote the oxide ion migration. Here we demonstrate that oxygen vacancies can be stabilized in the BiVO4 Scheelite structure through Sr2+ for Bi3+ substitution, leading to corner-sharing V2O7 tetrahedral dimers, and migrate via a cooperative mechanism involving V2O7-dimer breaking and reforming assisted by synergic rotation and deformation of neighboring VO4 tetrahedra. This finding reveals the ability of Scheelite structure to transport oxide ion through vacancies or interstitials, emphasizing the possibility to develop oxide-ion conductors with parallel vacancy and interstitial doping strategies within the same tetrahedra-based structure type.

No abstract

In preclinical and clinical research, to destroy cancers, particularly those located in deep tissues, is still a great challenge. Photodynamic therapy and photothermal therapy are promising alternative approaches for tissue cancer curing. Black phosphorus (BP)-based nanomaterials, with broad UV-vis near-infrared absorbance and excellent photothermal effect, have shown great potential in biomedical applications. Herein, a biocompatible therapeutic platform, chlorin e6 (Ce6)-decorated BP nanosheets (NSs), has been developed for fluorescence and thermal imaging-guided photothermal and photodynamic synergistic cancer treatment. Taking advantage of the relatively high surface area of exfoliated BP NSs, the PEG-NH-modified BP NSs (BP@PEG) are loaded with a Ce6 photosensitizer. The resulted BP@PEG/Ce6 NSs not only have good biocompatibility, physiological stability, and tumor-targeting property but also exhibit enhanced photothermal conversion efficiency (43.6%) compared with BP@PEG NSs (28.7%). In addition, BP@PEG/Ce6 NSs could efficiently generate reactive oxygen species because of the release of the Ce6 photosensitizer, which is also verified by in vitro studies. In vivo fluorescence imaging suggests that BP@PEG/Ce6 NSs can accumulate in the tumor targetedly through the enhanced permeability and retention effect. Both in vitro and in vivo studies suggest that BP@PEG/Ce6 can be a promising nanotheranostic agent for synergetic photothermal/photodynamic cancer therapy.

It is of great difficulty to obtain deep-UV transparent materials with enhanced second harmonic generation (SHG), mainly limited by the theoretically poor transparency of these materials in the deep-UV spectral region. Here we report a new noncentrosymmetric, deep-UV transparent phosphate RbNaMgPO, which undergoes a thermo-induced reversible phase transition (at a high temperature of 723 K) and correspondingly an evident SHG enhancement up to ∼1.5 times. The phase transition is aroused by the twist of [PO] dimers with deviation from the P-O-P equilibrium positions. Theoretical analyses reveal that the enhanced SHG can be ascribed to the thermo-induced collective alignment of SHG-active [PO] dimers along the polar axis of high-temperature phase. This work provides an unprecedented physical routine (to SHG-enhanced materials) that is distinguished from the traditional one by chemical design and synthesis.

Proteins and peptides are widely indicated in many diseased states. Parenteral route is the most commonly employed method of administration for therapeutic proteins and peptides. However, requirement of frequent injections due to short in vivo half-life results in poor patient compliance. Non-invasive drug delivery routes such as nasal, transdermal, pulmonary, and oral offer several advantages over parenteral administration. Intrinsic physicochemical properties and low permeability across biological membrane limit protein delivery via non-invasive routes. One of the strategies to improve protein and peptide absorption is by delivering through nanostructured delivery carriers. Among nanocarriers, polymeric nanoparticles (NPs) have demonstrated significant advantages over other delivery systems. This article summarizes the application of polymeric NPs for protein and peptide drug delivery following oral, nasal, pulmonary, parenteral, transdermal, and ocular administrations.