As a noninvasive treatment, photodynamic therapy (PDT) is a promising strategy against tumors. It is based on photosensitizer (PS)-induced phototoxicity after irradiation. However, most clinically approved PSs will be widely distributed in normal tissues, especially in the skin, where they will induce phototoxicity on exposure to light. Therefore, patients must remain in a dark room for up to several weeks during or after a PDT. Herein, we proposed a strategy of aggregation-induced emission PSs (AIE-PSs) entrapped in liposomes with controlled photosensitization. The AIE-PSs begin to lose their photosensitivity when entrapped in liposomes. After liposomes have carried AIE-PSs into tumor tissues, the AIE-PSs will be released and immediately reaggregate in a targeted area as the liposomes are decomposed. Their photosensitivity can be triggered at turn-on state and induce cytotoxicity. Two different types of AIE molecules were synthesized and entrapped by liposomes, respectively, to verify the PDT features against tumors in vitro and in vivo. The results indicate that, using this strategy, the photosensitivity of AIE-PS can be controlled and PDT can be treated under normal working conditions, not necessarily in a dark room.

Photodynamic therapy (PDT) shows unique selectivity and irreversible destruction toward treated tissues or cells, but still has several problems in clinical practice. One is limited therapeutic efficiency, which is attributed to hypoxia in tumor sites. Another is the limited treatment depth because traditional photosensitizes are excited by short wavelength light (<700 nm). An assembled nano-complex system composed of oxygen donor, two-photon absorption (TPA) species, and photosensitizer (PS) was synthesized to address both problems. The photosensitizer is excited indirectly by two-photon laser through intraparticle FRET mechanism for improving treatment depth. The oxygen donor, hemoglobin, can supply extra oxygen into tumor location through targeting effect for enhanced PDT efficiency. The mechanism and PDT effect were verified through both in vitro and in vivo experiments. The simple system is promising to promote two-photon PDT for clinical applications.

Polydopamine nanoparticles were used to stabilize nano-Pt catalyst for relieving the tumour hypoxia in photodynamic therapy (PDT). Polydopamine not only provide a platform for carrying nano-Pt and photosensitizers but also...

BackgroundIn epidemic regions of the world, brucellosis is a reemerging zoonosis with minimal mortality but is a serious public hygiene problem. Currently, there are various methods for brucellosis diagnosis, however few of them are available to be used to diagnose, especially for serious cross-reaction with other bacteria.MethodTo overcome this disadvantage, we explored a novel multi-epitope recombinant protein as human brucellosis diagnostic antigen. We established an indirect enzyme-linked immunosorbent assay (ELISA) based on this recombinant protein. 248 sera obtained from three different groups including patients with brucellosis (146 samples), non-brucellosis patients (82 samples), and healthy individuals (20 samples) were tested by indirect ELISA. To evaluate the assay, a receiver-operating characteristic (ROC) analysis and immunoblotting were carried out using these characterized serum samples.ResultsFor this test, the area under the ROC curve was 0.9409 (95 % confidence interval, 0.9108 to 0.9709), and a sensitivity of 88.89 % and a specificity of 85.54 % was given with a cutoff value of 0.3865 from this ROC analysis. The Western blot results indicate that it is feasible to differentiate human brucellosis and non-brucellosis with the newly established method based on this recombinant protein.ConclusionOur results obtained high diagnostic accuracy of the ELISA assay which encourage the use of this novel recombinant protein as diagnostic antigen to implement serological diagnosis of brucellosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1552-9) contains supplementary material, which is available to authorized users.

Aggregation‐induced emission (AIE) molecules possess notable advantages outperforming traditional aggregation caused quenching (ACQ) materials on various aspects. They are rapidly developed these years. More and more AIE luminogens (AIEgens) are designed to possess multifunctions such as the abilities of near‐infrared two‐photon absorption and reactive oxygen species (ROS) generation, which could be used for deep tissue imaging and photodynamic therapy. The AIEgens exhibit great potential in biological application field. However, despite the photophysics stability and ROS generation ability in aggregated states are favorable conditions, their applications in biological field are retarded by uncontrolled size, single imaging mode, low targeting efficiency, and also poor biocompatibility and dispersibility in physiological environment. The combination of AIEgen and lipid is a straightforward, promising, and intensively used way to solve the above problems. Due to the special amphipathic property of lipid, which results from a hydrophilic head and hydrophobic tail structure, there are various possibilities of combination modes between lipid and AIEgen. Even a little procedure or condition change during the synthesis process will impact the structure of obtained product, which can further influence its application. Herein, we summarize the synthesis methods of different AIEgen–lipid compounds with diverse structures and properties, as well as their biological applications in this contribution, which has not been presented before, being aimed at serving as a synthesis and application reference for these promising AIEgen–lipid compounds applied in biological region.

Photodynamic therapy( PDT) shows unique selectivity and irreversible destruction towardtreated tissues or cells, but still has several problems in clinical practice.One is limited therapeutic efficiency,w hich is attributed to hypoxia in tumor sites.Another is the limited treatment depth because traditional photosensitizes are excited by short wavelength light (< 700 nm). An assembled nano-complex system composed of oxygen donor,t wo-photon absorption (TPA) species,a nd photosensitizer (PS) was synthesized to address both problems. The photosensitizer is excited indirectly by two-photon laser through intraparticle FRET mechanism for improvingt reatment depth. The oxygen donor,h emoglobin, can supply extra oxygen into tumor location through targeting effect for enhanced PDT efficiency.T he mechanism and PDT effect were verified through both in vitro and in vivo experiments. The simple system is promising to promote two-photon PDT for clinical applications.

Polyoxometalates (POMs) have shown the potential anti-bacterial, anti-viral and anti-tumor activities. In order to improve their physiological stability and antitumour activity for medical application, K2Na[AsIIIMo6O21(O2CCH2NH3)3]·6H2O doped silica nanospheres (POM@SiO2) with diameters of ~40 nm have been synthesized by the water-in-oil microemulsion method in this study. The obtained spheres were morphologically uniform nanosized and nearly monodispersed in solution. The nanoparticles had high entrapment efficiency, which was upto 46.2% by the inductively coupled plasma mass spectrometry (ICP-MS) analysis and POMs slowly released from the nanospheres both in the PH 7.4 and 5.5 phosphate buffer saline (PBS) solutions in 60 h. The in vitro MTT assays of particles on MCF-7 cell line (a human breast adenocarcinoma cell line) exhibited enhanced antitumor activity compared to that of plain polyoxometalate. The IC50 value of the POM@SiO2 nanoparticles was 40.0 μg/mL at 24 h calculated by the encapsulated POM concentration, which was much lower comparing to that of 2.0 × 104 μg/mL according to the pure POM. And the SiO2 shells showed low inhibitory effect at the corresponding concentration. Confocal images further indicated the cell morphology changes and necrosis. Flow cytometric analysis showed nanoparticles induced the apoptosis by arresting the cells in S phase and western blot analysis indicated they promoted apoptosis by inhibiting the Bcl-2 protein. Moreover, the study of interactions between human serum albumin (HSA) and the nanoparticles indicated the fluorescence quenching was static, and the nanoparticles were likely to bind to HSA and changed its conformation.

A novel material with a large two-photon absorption cross-section was conjugated with a typical photosensitizer for inducing a FRET process. The photosensitizer can be excited by a one-/two-photon laser and then induced photo-toxicity in vitro and in vivo. The system presents great potential for improving treatment depth and the precision of traditional photodynamic therapy.