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Herein, we develop a novel tripartite DNA probe to transport phosphorothioated substrate hairpins and an aptamer for the intramolecular CHA circuit, which achieves detection of a low amount of specific mRNA in living cells and mice. Our study provides an improved strategy to promote in vivo fluorescence imaging applications in early-stage clinical diagnosis.

Near-infrared (NIR, 700–1700 nm) bioimaging has gained considerable attention in recent years owing to its high imaging resolution and increasing penetration depth of tissues. NIR emissive lanthanide(III) complexes have emerged as alluring candidates for the design of NIR molecular probes in clinical imaging and diagnosis because of their desirable temporal–spatial resolution, negligible photobleaching effect, long lifetime and low biotoxicity. In this mini-review, we summarize our efforts in the molecular design of NIR luminescent lanthanide porphyrinoids and their biological applications in bioimaging and further clinical diagnosis and treatment. Remarkably, β-fluorinated porphyrin Yb3+ probes exhibit high luminescence (5–13% quantum yields in H2O), long decay lifetimes (>100 μs) and enable in vivo fluorescence intensity imaging and time-resolved fluorescence lifetime imaging (FLIM). Finally, the main concerns and challenges for NIR emissive Ln biolabels such as the diversity of the NIR Ln3+ optical toolbox and their biocompatibility and targeting capability in biological media are discussed so as to facilitate the long-term development of lanthanide chemical biology.

Personalized approaches for continuous monitoring of chloride levels are potentially valuable for evaluating the efficacy of new treatments of genetic disorders such as cystic fibrosis. In this report, we validated optode-based nanosensors for real-time chloride monitoring in the interstitial fluid of living animals. These nanosensors take advantage of a ratiometric sensing scheme which demonstrates reversible and selective chloride detection in the physiological range. We further investigate how skin pigmentation affects the sensor performance during in vivo fluorescence imaging. We successfully monitored endogenous chloride changes using nanosensors during pharmacological treatment in a cystic fibrosis mouse model. We believe this platform is a valuable tool for chloride detection which could assess the efficacy of new treatments for cystic fibrosis.

Current therapeutics for glioblastoma multiforme (GBM) treatment are unsatisfactory due to their limited ability to control the progression from tumour margins. In this work, organic nanoparticles (NPs) are synthesized by co-encapsulating a fluorogen with aggregation-induced emission to generate a bright red emission for imaging and a semiconducting polymer to offer NIR absorption for photothermal therapy. The NPs are further modified with different ratios of two targeting ligands, folate and cRGD peptide. The best ratio that performs specific and efficient GBM targeting is screened out through in vitro and ex vivo fluorescence imaging analysis. The NPs with an FA to cRGD ratio of 25 : 75 exhibit superior ability to target GBM cells in vitro and also show efficient accumulation at the GBM margin and in the tumour interior after in vivo administration. The progression of GBM can be greatly suppressed through photothermal therapy, which provides a simple but promising strategy for GBM treatment.

The aim of this paper is to develop a novel fluorescence/ultrasound dual-modal contrast agent. We prepared multicolor nanobubbles by doping with three fluorescent dyes for combined fluorescence and contrast enhanced ultrasound imaging. The nanobubbles based on fluorescence resonance energy transfer (FRET) with different doping dye ratio combinations exhibited multiple colors under single wavelength excitation, allowing multiplexed assays for various biomedical applications. In vitro and in vivo ultrasound imaging indicated that nanobubbles have great contrast enhancement capability. In vivo fluorescence imaging showed the excellent ability to provide simultaneous multicolor imaging. The novel multicolor nanobubbles may have great potential for a variety of applications in the study of life science and clinical medicine.

Near-infrared (NIR)-responsive drug delivery systems have received enormous attention because of their good biocompatibility and high biological penetration. In this work, we report a novel 1-tetradecanol (TD)-controlled and indocyanine green (ICG)-loaded CuS@mSiO2 phototherapy nanoplatform (CuS@mSiO2-TD/ICG). The CuS@mSiO2 nanoparticles prepared by a facile one-pot approach can serve as drug-delivery vehicles to transport the NIR absorbing phototherapeutic agent (ICG) within the mesoporous cavities. Meanwhile a phase-change molecule (PCM), TD, is introduced as a thermosensitive gatekeeper to avoid the premature release of loaded ICG. Noticeably, the combined therapy is irradiated at an 808 nm single-light wavelength, thus performing the photothermal therapy (PTT) based on CuS@mSiO2 as well as simultaneously triggering the photodynamic (PDT)/PTT effect based on ICG. Furthermore, ICG also has the function of dual in vivo fluorescence imaging and photoacoustic (PA) imaging. This dual imaging-guided and gatekeeper-controlled nanoplatform for the single-light triggered PTT/PDT treatment holds significant promise for future cancer therapy due to their markedly improved therapeutic efficacy and decreased systemic toxicity.

A novel strategy to fabricate bovine serum albumin and styrene-terminated porous silicon nanocomposites with stable near-infrared fluorescence under physiological conditions was described. And these resultant nontoxic porous silicon-based nanocomposites were administrated into nude mice via subcutaneous injection, which exhibited a potential application for in vivo fluorescence imaging.

The performance of two field probes (YSI 6600 and TriOS), used for the measurement of in vivo phycocyanin fluorescence, was compared and validated in the laboratory in 2008 and 2009 with cultures of Microcystis aeruginosa and field samples. The background noise of the two probes was low and the detection limits were estimated at 1500 cells mL(-1) for the YSI and 0.69 µg PC L(-1) for the TriOS. The linearity and repeatability of both probes have been excellent. Strong relationships were observed between the in vivo fluorescence and the total cyanobacterial biovolume (R(2) = 0.82 YSI; 0.83 TriOS) or the abundance (R(2) = 0.71 YSI; 0.75 TriOS) of cyanobacteria. However, the difference between cell densities determined by microscopy and measured by the YSI can be very large and has been associated to the variability of cell volume among cyanobacteria. This last observation makes the YSI a qualitative tool if a post-calibration is not done. The analysis of filtrated samples showed that dissolved phycocyanin (extracellular) may represent a significant fluorescence signal. No relationship could be established between the abundance, the total cyanobacterial biovolume or the in vivo fluorescence of phycocyanin and the concentrations of cyanotoxins (R(2) ≤ 0.22).

Oral submucous fibrosis (OSF) is a precancerous condition which leads to the development of fibrous band and loss of oral mucosa elasticity. In the absence of medical treatment OSF can also lead to oral cancer. In the present work, in vivo fluorescence data obtained from the oral tissues of the pre-treated OSF subjects, post-treated OSF subjects, and the normal healthy volunteers were subjected to principal component analysis (PCA) and partial least square discriminate analysis (PLS-DA). PCA and PLS-DA are unsupervised and supervised pattern recognition methods, respectively. PCA and PLS-DA models were found to be highly sensitive and specific. The receiver operating characteristic (ROC) curve of the PLS-DA models mainly consisted of horizontal and vertical lines with an area under the curve of greater than 0.9 which shows that PLS-DA models are genuine classifier. Outcomes of the present work clearly illustrate that by combining the in vivo fluorescence spectroscopy with PCA and PLS-DA, a fast, sensitive, and non-invasive procedure could be obtained for the diagnosis of OSF affected subjects. The developed diagnosis procedure could be of significant importance in rural areas where access to clinical diagnosis is relatively difficult and costly. � 2013 The Royal Society of Chemistry.

β-NaYF(4) : Yb,Er upconversion nanoparticles (UCNPs) can emit bright green fluorescence under near-infrared (NIR) light excitation which is safe to the body and can penetrate deeply into tissues. The application of UCNPs in biolabeling and imaging has received great attention recently. In this work, β-NaYF(4) : Yb,Er UCNPs with an average size of 35 nm, uniformly spherical shape, and surface modified with amino groups were synthesized by a one-step green solvothermal approach through the use of room-temperature ionic liquids as the reactant, co-solvent and template. The as-prepared UCNPs were introduced into Caenorhabditis elegans (C. elegans) to achieve successful in vivo imaging. We found that longer incubation time, higher UCNP concentration and smaller UCNP size can make the in vivo fluorescence of C. elegans much brighter and more continuous along their body. The worms have no apparent selectivity on ingestion of the UCNPs capped with different capping ligands while having similar size and shape. The next generation of worms did not show fluorescence under excitation. In addition, low toxicity of the nanoparticles was demonstrated by investigating the survival rates of the worms in the presence of the UCNPs. Our work demonstrates the potential application of the UCNPs in studying the biological behavior of organisms, and lays the foundation for further development of the UCNPs in the detection and diagnosis of diseases.