Gold nanoparticles functionalized with thiol-oligonucleotides are ideal platforms for detection of specific DNA sequences. Here we evaluate the effect of single base mismatches in hybridization efficiency according to the position of the mismatch, base pairing combination and thiol-oligonucleotide density in terms of specificity and efficiency of target recognition. Hybridization efficiency and single-nucleotide polymorphism discrimination at room temperature is maximized at a density of 83 +/- 4 thiol-oligonucleotides per 13.5 nm gold nanoparticle (24 pmol/cm(2)), and when the mismatch is localized at the 3'-end of the Au-nanoprobe, i.e. away from the gold nanoparticle surface. (C) 2010 Elsevier B.V. All rights reserved.

Pulmonary hypertension is a significant problem to take into account in the post-operative management of cardiac patients, especially valvular patients. Inhaled nitric oxide allows more effective control of pulmonary pressure and other hemodynamic parameters, with better post-operative results. We present a clinical case of a patient with mitral stenosis and severe pulmonary hypertension, with post-operative hemodynamic instability, in which we used inhaled nitric oxide for better control of pulmonary pressures and to help ventilator weaning.

Throughout the last decade, the expansion of food testing has been gradually moving towards ordinary high throughput screening methods performed on-site. The demand for point-of-care testing, able to distinguish molecular signatures with high accuracy, sensitivity and specificity has been significantly increasing. This new requirement relies on the on-site detection and monitorization of molecular signatures suitable for the surveillance of food production and processing. The widespread use of antibiotics has contributed to disease control of livestock but has also created problems for the dairy industry and consumers. Its therapeutic and subtherapeutic use has increased the risk of contamination in milk in enough concentrations to cause economic losses to the dairy industry and have a health impact in highly sensitive individuals. This study focuses on the development of a simple Surface-Enhanced Raman Spectroscopy (SERS) method for fast high throughput screening of tetracycline (TET) in milk. For this, we integrate a paper-based low-cost, fully recyclable and highly stable SERS platform, with a minimal sample preparation protocol. A two-microliter sample of milk solutions spiked with TET (from 0.01 to 1000 ppm) is dried on a silver nanoparticle coated cardboard substrate and measured via a Raman spectrophotometer. The SERS substrate showed to be extremely stable with a shelf life of several months. A global spectrum principal component analysis approach was used to test all the detected vibrational modes and their correlation with TET concentration. Peak intensity ratios (455 cm−1/1280 cm−1 and 874 cm−1/1397 cm−1) were found to be correlated with TET concentrations in milk, achieving a sensitivity as low as 0.1 ppm. Results indicate that this SERS method combined with portable Raman spectrometer is a potential tool that can be used on-site for the monitoring of TET residues and other antibiotics.

Poly(p-xylylene) derivatives, widely known as Parylenes, have been considerably adopted by the scientific community for several applications, ranging from simple passive coatings to active device components. Here, we explore the thermal, structural, and electrical properties of Parylene C, and further present a variety of electronic devices featuring this polymer: transistors, capacitors, and digital microfluidic (DMF) devices. We evaluate transistors produced with Parylene C as a dielectric, substrate, and encapsulation layer, either semitransparent or fully transparent. Such transistors exhibit steep transfer curves and subthreshold slopes of 0.26 V/dec, negligible gate leak currents, and fair mobilities. Furthermore, we characterize MIM (metal–insulator–metal) structures with Parylene C as a dielectric and demonstrate the functionality of the polymer deposited in single and double layers under temperature and AC signal stimuli, mimicking the DMF stimuli. Applying temperature generally leads to a decrease in the capacitance of the dielectric layer, whereas applying an AC signal leads to an increase in said capacitance for double-layered Parylene C only. By applying the two stimuli, the capacitance seems to suffer from a balanced influence of both the separated stimuli. Lastly, we demonstrate that DMF devices with double-layered Parylene C allow for faster droplet motion and enable long nucleic acid amplification reactions.

In this work, peptides designed to selectively interact with cellular receptors involved in the regulation of angiogenesis were anchored to oligo-ethylene glycol-capped gold nanoparticles (AuNPs) and used to evaluate the modulation of vascular development using an ex ovo chick chorioallantoic membrane assay. These nanoparticles alter the balance between naturally secreted pro- and antiangiogenic factors, under various biological conditions, without causing toxicity. Exposure of chorioallantoic membranes to AuNP-peptide activators of angiogenesis accelerated the formation of new arterioles when compared to scrambled peptide-coated nanoparticles. On the other hand, antiangiogenic AuNP-peptide conjugates were able to selectively inhibit angiogenesis in vivo. We demonstrated that AuNP vectorization is crucial for enhancing the effect of active peptides. Our data showed for the first time the effective control of activation or inhibition of blood vessel formation in chick embryo via AuNP-based formulations suitable for the selective modulation of angiogenesis, which is of paramount importance in applications where promotion of vascular growth is desirable (eg, wound healing) or ought to be contravened, as in cancer development.

There are numerous reports of coumarin ester derivatives, in particular phosphate esters, as photocleavable cages in biological systems. Despite the comprehensive analysis of the photocleavage mechanism, studies of 4-methylcoumarin caged phosphates and/or nucleotides were always performed at constant pH. In this work, we present the study of the pH effect on the photochemistry of (7-diethylaminocoumarin-4-yl)methyl phosphate (DEACM-P). Fluorescence and photocleavage quantum yields, as well as the fluorescence decay times were measured as a function of the pH. It was found that the pH produces significant changes in the overall photochemical quantum yield of DEACM-P, and the observed changes are complementary to those obtained from the fluorescence quantum yield. Deprotonation of DEACM-HPO4 - to yield DEACM-PO4 2-, produces a decrease in the photochemical quantum yield (from 0.0045 to 0.0003) and an increase in the fluorescence quantum yield (from 0.072 to 0.092). Moreover, from the analysis of the decay times, we have also found that hydroxyl ion is not only relevant, but it is mechanistically involved in the photoreaction of DEACM-HPO4 -.

Photothermal Therapy (PTT) impact in cancer therapy has been increasing due to the enhanced photothermal capabilities of a new generation of nanoscale photothermal agents. Among these nanoscale agents, gold nanoshells and nanorods have demonstrated optimal properties for translation of near infra-red radiation into heat at the site of interest. However, smaller spherical gold nanoparticles (AuNPs) are easier to produce, less toxic and show improved photoconversion capability that may profit from the irradiation in the visible via standard surgical green lasers. Here we show the efficient light-to-heat conversion of spherical 14 nm AuNPs irradiated in the visible region (at the surface plasmons resonance peak) and its application to selectively obliterate cancer cells. Using breast cancer as model, we show a synergistic interaction between heat (photoconversion at 530 nm) and cytotoxic action by doxorubicin with clear advantages to those of the individual therapy approaches.

The effect of post-deposition annealing temperature on the pH sensitivity of room temperature RF sputtered Ta2O5 was investigated. Structural and morphological features of these films were analyzed before and after annealing at various temperatures. The deposited films are amorphous up to 600 degrees C and crystallize at 700 degrees C in an orthorhombic phase. Electrolyte-insulator-semiconductor (EIS) field effect based sensors with an amorphous Ta2O5 sensing layer showed pH sensitivity above 50 mV/pH. For sensors annealed above 200 degrees C pH sensitivity decreased with increasing temperature. Stabilized sensor response and maximum pH sensitivity was achieved after low temperature annealing at 200 degrees C, which is compatible with the use of polymeric substrates and application as sensitive layer in oxides TFT-based sensors.

The design of small interfering RNA (siRNA) delivery materials showing efficacy in vivo is at the forefront of nanotherapeutics research. Polyurea (PURE-type) dendrimers are 'smart' biocompatible 3D polymers that unveil a dynamic and elegant back-folding mechanism involving hydrogen bonding between primary amines at the surface and tertiary amines and ureas at the core. Similarly, to a biological proton pump, they are able to automatically and reversibly transform their conformation in response to pH stimulus. Here, we show that PURE-G4 is a useful gene silencing platform showing no cellular toxicity. As a proof of concept we investigated the PURE-G4-siRNA dendriplex, which was shown to be an attractive platform with high transfection efficacy. The simplicity associated with the complexation of siRNA with polyurea dendrimers makes them a powerful tool for efficient cytosolic siRNA delivery.

In this paper we report on the fabrication and performance of a portable and low cost optoelectronic platform integrating a double color tuned light emitting diode as light source, an amorphous/nanocrystalline silicon photodetector with a flat spectral response in the wavelength range from 520. nm to 630. nm and integrated electronic for signal acquisition and conditioning constituted by current to voltage converter, a filter and an amplification stage, followed by an analog to digital converter, with appropriate software for full automation to minimize human error. Incorporation of the double color tuned light emitting diode provides for a simple yet innovative solution to signal acquisition independently from the light intensity and/or solution concentration, while considerably decreasing production costs. Detection based on Au-nanoprobes constitutes the biorecognition step and allowed identification of specific sequences of Mycobacterium tuberculosis complex, namely Mycobacterium bovis and M. tuberculosis in biological samples.

Background: Anti-angiogenic therapy has great potential for cancer therapy with several FDA approved formulations but there are considerable side effects upon the normal blood vessels that decrease the potential application of such therapeutics. Chicken chorioallantoic membrane (CAM) has been used as a model to study angiogenesis in vivo. Using a CAM model, it had been previously shown that spherical gold nanoparticles functionalised with an anti-angiogenic peptide can humper neo-angiogenesis. Results: Our results show that gold nanoparticles conjugated with an anti-angiogenic peptide can be combined with visible laser irradiation to enhance angiogenesis arrest in vivo. We show that a green laser coupled to gold nanoparticles can achieve high localized temperatures able to precisely cauterize blood vessels. This combined therapy acts via VEGFR pathway inhibition, leading to a fourfold reduction in FLT-1 expression. Conclusions: The proposed phototherapy extends the use of visible lasers in clinics, combining it with chemotherapy to potentiate cancer treatment. This approach allows the reduction of dose of anti-angiogenic peptide, thus reducing possible side effects, while destroying blood vessels supply critical for tumour progression.

POxylated polyurea dendrimer (PUREG4OOx48)-based nanoparticles were loaded with paclitaxel (PTX) and doxorubicin (DOX) and micronized with chitosan (CHT) by using supercritical CO2-assisted spray drying (SASD). Respirable, biocompatible, and biodegradable dry powder formulations (DPFs) were produced to effectively transport and deliver the chemotherapeutics with a controlled rate to the deep lung. In vitro studies performed with the use of the lung adenocarcinoma cell line showed that DOX@PUREG4OOx48 nanoparticles were much more cytotoxic than the free drug. Additionally, the DPFs did not show higher cytotoxicity than the respective nanoparticles, and DOX-DPFs showed a higher chemotherapeutic effect than PTX formulations in adenocarcinoma cells.

The design and preparation of highly efficient drug delivery platforms using green methodologies is at the forefront of nanotherapeutics research. POxylated polyurea dendrimers are efficiently synthesized using a supercritical-assisted polymerization in carbon dioxide. These fluorescent, pH-responsive and water-soluble core-shell smart nanocarriers show low toxicity in terms of cell viability and absence of glutathione depletion, two of the major side effect limitations of current vectors. The materials are also found to act as good transfection agents, through a mechanism involving an endosomal pathway, being able to reduce 100-fold the IC50 of paclitaxel.

Nanoenabled technology holds great potential for health issues and biological research. Among the numerous inorganic nanoparticles that are available today, gold nanoparticles are fully developed as therapeutic and diagnostic agents both in vitro and in vivo due to their physicochemical properties. Owing to this, substantial work has been conducted in terms of developing biosensors for noninvasive and targeted tumor diagnosis and treatment. Some studies have even expanded into clinical trials. This article focuses on the fundamentals and synthesis of gold nanoparticles, as well as the latest, most promising applications in cancer research, such as molecular diagnostics, immunosensors, surface-enhanced Raman spectroscopy and bioimaging. Challenges to their further translational development are also discussed.

Ion sensitive field-effect transistors (ISFET) are the basis of radical new sensing approaches. Reliable molecular characterization of specific detection of DNA and/or RNA is vital for disease diagnostics and to follow up alterations in gene expression profiles. Devices and strategies for biomolecular recognition and detection should be developed into reliable and inexpensive platforms. Here, we describe the development of a flexible thin-film sensor for label free gene expression analysis. A charge modulated ISFET based sensor was integrated with real-time DNA/RNA isothermal nucleic acid amplification: Loop-mediated isothermal amplification (LAMP) and Rolling Circle Amplification (RCA) techniques for c-MYC and BCR-ABL1 genes, allowing for the real-time quantification of template. Also, RCA allowed the direct quantification of RNA targets at room temperature, eliminating the requirement for external temperature controllers and overall complexity of the molecular diagnostic approach. This integration between the biological and the sensor/electronic approaches enabled the development of an inexpensive and direct gene expression-profiling platform.

Ischemia and reperfusion injury (IRI) is a common complication caused by inflammation and oxidative stress resulting from liver surgery. Current therapeutic strategies do not present the desirable efficacy, and severe side effects can occur. To overcome these drawbacks, new therapeutic alternatives are necessary. Drug delivery nanosystems have been explored due to their capacity to improve the therapeutic index of conventional drugs. Within nanocarriers, liposomes are one of the most successful, with several formulations currently in the market. As improved therapeutic outcomes have been demonstrated by using liposomes as drug carriers, this nanosystem was used to deliver quercetin, a flavonoid with anti-inflammatory and antioxidant properties, in hepatic IRI treatment. In the present work, a stable quercetin liposomal formulation was developed and characterized. Additionally, an in vitro model of ischemia and reperfusion was developed with a hypoxia chamber, where the anti-inflammatory potential of liposomal quercetin was evaluated, revealing the downregulation of pro-inflammatory markers. The anti-inflammatory effect of quercetin liposomes was also assessed in vivo in a rat model of hepatic IRI, in which a decrease in inflammation markers and enhanced recovery were observed. These results demonstrate that quercetin liposomes may provide a significant tool for addressing the current bottlenecks in hepatic IRI treatment.

We present a new approach for real-time monitoring of PCR amplification of a specific sequence from the human c-MYC proto-oncogene using a Ta(2)O(5) electrolyte-insulator-semiconductor (EIS) sensor. The response of the fabricated EIS sensor to cycle DNA amplification was evaluated and compared to standard SYBR-green fluorescence incorporation, showing it was possible to detect DNA concentration variations with 30 mV/μM sensitivity. The sensor's response was then optimized to follow in real-time the PCR amplification of c-MYC sequence from a genomic DNA sample attaining an amplification profile comparable to that of a standard real-time PCR. Owing to the small size, ease of fabrication and low-cost, the developed Ta(2)O(5) sensor may be incorporated onto a microfluidic device and then used for real-time PCR. Our approach may circumvent the practical and economical obstacles posed by current platforms that require an external fluorescence detector difficult to miniaturize and incorporate into a lab-on-chip system.

In the last 30 years we have assisted to a massive advance of nanomaterials in material science. Nanomaterials and structures, in addition to their small size, have properties that differ from those of larger bulk materials, making them ideal for a host of novel applications. The spread of nanotechnology in the last years has been due to the improvement of synthesis and characterization methods on the nanoscale, a field rich in new physical phenomena and synthetic opportunities. In fact, the development of functional nanoparticles has progressed exponentially over the past two decades. This work aims to extensively review 30 years of different strategies of surface modification and functionalization of noble metal (gold) nanoparticles, magnetic nanocrystals and semiconductor nanoparticles, such as quantum dots. The aim of this review is not only to provide in-depth insights into the different biofunctionalization and characterization methods, but also to give an overview of possibilities and limitations of the available nanoparticles.

Molecular nanodiagnostics applied to cancer may provide rapid and sensitive detection of cancer related molecular alterations, which would enable early detection even when those alterations occur only in a small percentage of cells. The use of gold nanoparticles derivatized with thiol modified oligonucleotides (Au-nanoprobes) for the detection of specific nucleic acid targets has been gaining momentum as an alternative to more traditional methodologies. Here, we present an Au-nanoparticles based approach for the molecular recognition and quantification of the BCR-ABL usion transcript (mRNA), which is responsible for chronic myeloid leukemia (CML), and to the best of our knowledge it is the first time quantification of a specific mRNA directly in cancer cells is reported. This inexpensive and very easy to perform Au-nanoprobe based method allows quantification of unamplified total human RNA and specific detection of the oncogene transcript. The sensitivity settled by the Au-nanoprobes allows differential gene expression from 10 ng/μl of total RNA and takes less than 30 min to complete after total RNA extraction, minimizing RNA degradation. Also, at later stages, accumulation of malignant mutations may lead to resistance to chemotherapy and consequently poor outcome. Such a method, allowing for fast and direct detection and quantification of the chimeric BCR-ABL mRNA, could speed up diagnostics and, if appropriate, revision of therapy. This assay may constitute a promising tool in early diagnosis of CML and could easily be extended to further target genes with proven involvement in cancer development.

Gold glyconanoparticles (GlycoNPs) are full of promise in areas like biomedicine, biotechnology and materials science due to their amazing physical, chemical and biological properties. Here, siRNA GlycoNPs (AuNP@PEG@Glucose@siRNA) in comparison with PEGylated GlycoNPs (AuNP@PEG@Glucose) were applied in vitro to a luciferase-CMT/167 adenocarcinoma cancer cell line and in vivo via intratracheal instillation directly into the lungs of B6 albino mice grafted with luciferase-CMT/167 adenocarcinoma cells. siRNA GlycoNPs but not PEGylated GlycoNPs induced the expression of pro-apoptotic proteins such as Fas/CD95 and caspases 3 and 9 in CMT/167 adenocarcinoma cells in a dose dependent manner, independent of the inflammatory response, evaluated by bronchoalveolar lavage cell counting. Moreover, in vivo pulmonary delivered siRNA GlycoNPs were capable of targeting c-Myc gene expression (a crucial regulator of cell proliferation and apoptosis) via in vivo RNAi in tumour tissue, leading to an similar to 80% reduction in tumour size without associated inflammation.

Edible flowers are being used as a new ingredient in modern gastronomy. Recently, these products have also gained interest as an important source of phenolic compounds with potential for biomedical applications. The present work studied a methanolic extract of Rosa x hybrida in which 35 individual phenolic compounds were identified. The extract has been evaluated for its antiproliferative properties in ovarian carcinoma cells. Results showed that the antiproliferative effect was associated with the induction of autophagy and apoptosis with the concomitant ROS increase probably related to mitochondria dysfunction. These antiproliferative effects might be associated with some components of the extract such as quercetin. The extract did not induce damage in healthy cells and that it was able to improve the wound healing activity. The present study also evaluated the properties of the mentioned extract in vivo in C. elegans. Tests demonstrated a lack of toxicity in the worm model. Promising results have been obtained in transgenic strains of C. elegans that produce human beta amyloid peptide, suggesting the possible utility of the extract from the point of view of Alzheimer disease. Altogether, results suggest that Rosa x hybrida extracts could be a new tool for the development of functional foods.