The loop-mediated isothermal amplification (LAMP) technique has the potential to revolutionize molecular biology because it allows DNA amplification under isothermal conditions and is highly ...compatible with point-of-care analysis. To achieve efficient genetic analysis of samples, the method of real-time or endpoint determination selected to monitor the biochemical reaction is of great importance. In this paper we briefly review progress in the development of monitoring methods for LAMP.
•The loop-mediated isothermal amplification (LAMP) technique has the potential to revolutionize molecular biology.•Methods for determining the result of LAMP is of great importance.•We review progress in the development of monitoring methods for LAMP.
Concerns over possible toxicities of conventional metal-containing quantum dots have inspired growing research interests in colloidal silicon nanocrystals (SiNCs), or silicon quantum dots (SiQDs). ...This is related to their potential applications in a number of fields such as solar cells, optoelectronic devices and fluorescent bio-labelling agents. The past decade has seen significant progress in the understanding of fundamental physics and surface properties of silicon nanocrystals. Such understanding is based on the advances in the preparation and characterization of surface passivated colloidal silicon nanocrystals. In this critical review, we summarize recent advances in the methods of preparing high quality silicon nanocrystals and strategies for forming self-assembled monolayers (SAMs), with a focus on their bio-applications. We highlight some of the major challenges that remain, as well as lessons learnt when working with silicon nanocrystals (239 references).
Cancer accounted for 13% of all deaths worldwide in 2005. Although early detection is critical for the successful treatment of many cancers, there are sensitivity limitations associated with current ...detection methodologies. Furthermore, many traditional anticancer drug treatments exhibit limited efficacy and cause high morbidity. The unique physical properties of nanoscale materials can be utilized to produce novel and effective sensors for cancer diagnosis, agents for tumor imaging, and therapeutics for cancer treatment. Functionalizing inorganic nanoparticles with biocompatible polymers and natural or rationally designed biomolecules offers a route towards engineering responsive and multifunctional composite systems. Although only a few such innovations have reached human clinical trial to date, nanocomposite materials based on functionalized metal and semiconductor nanoparticles promise to transform the way cancer is diagnosed and treated. This review summarizes the current state‐of‐the‐art in the development of inorganic nanocomposites for cancer‐related applications.
Inorganic nanoscale particles possess novel and unique physical properties. Surface functionalization with biocompatible polymers and biomolecules can improve current technologies and holds great promise for cancer diagnosis, imaging, and therapy. This review highlights the state‐of‐the‐art developments in inorganic nanocomposites for cancer‐related applications.
Nanoparticle-based labels are emerging as simpler and more sensitive alternatives to traditional fluorescent small molecules and radioactive reporters in biomarker assays. The determination of ...biomarker levels is a recommended clinical practice for the assessment of many diseases, and detection of multiple analytes in a single assay, known as multiplexing, can increase predictive accuracy. While multiplexed detection can also simplify assay procedures and reduce systematic variability, combining multiple assays into a single procedure can lead to complications such as substrate cross-reactivity, signal overlap, and loss of sensitivity. By combining the specificity of biomolecular interactions with the tunability of quantum dot optical properties, we have developed a detection system capable of simultaneous evaluation of the activity of two critical enzyme classes, proteases and kinases. We avoid cross-reactivity and signal overlap by synthesizing enzyme-specific peptide sequences with orthogonal terminal functionalization for attachment to quantum dots with distinct emission spectra. Enzyme activity is reported via binding of either gold nanoparticle–peptide conjugates or FRET acceptor dye-labeled antibodies, which mediate changes in quantum dot emission spectra. To the best of our knowledge, this is the first demonstration of the multiplexed sensing of the activity of two different classes of enzymes via a nanoparticle-based activity assay. Using the quantum dot-based assay described herein, we were able to detect the protease activity of urokinase-type plasminogen activator at concentrations ≥ 50 ng/mL and the kinase activity of human epidermal growth factor receptor 2 at concentrations ≥ 7.5 nM, levels that are clinically relevant for determination of breast cancer prognosis. The modular nature of this assay design allows for the detection of different classes of enzymes simultaneously and represents a generic platform for high-throughput enzyme screening in rapid disease diagnosis and drug discovery.
Fluorescence lifetime imaging microscopy is successfully demonstrated in both one‐ and two‐photon cases with surface modified, nanocrystalline silicon quantum dots in the context of bioimaging. The ...technique is further demonstrated in combination with Förster resonance energy transfer studies where the color of the nanoparticles is tuned by using organic dye acceptors directly conjugated onto the nanoparticle surface.
In this study, we describe a solution procedure for the preparation and surface modification of photostable colloidal silicon quantum dots (SiQDs) for imaging of cancer cells. Photoluminescent SiQDs ...were synthesized by reduction of halogenated silane precursors using a microemulsion process. It was shown that 1,8-nonadiyne molecules could be grafted onto the surface of hydrogen-terminated SiQDs via ultraviolet (UV)-promoted hydrosilylation, demonstrated by Fourier transform infrared spectroscopy (FTIR) measurements. In addition, various azide molecules were coupled onto nonadiyne-functionalized particles, rendering particles dispersible in selected polar and nonpolar solvents. The photoluminescence of functionalized SiQDs was stable against photobleaching and did not vary appreciably within biologically applicable pH and temperature ranges. To demonstrate compatibility with biological systems, water-soluble SiQDs were used for fluorescent imaging of HeLa cells. In addition, the SiQDs were shown to be non-cytotoxic at concentrations up to 240 μg/mL. The results presented herein provide good evidence for the versatility of functionalized SiQDs for fluorescent bioimaging application.
Straightforward and label‐free: A simple method for the detection of histone‐modifying enzymes is based on quantum dot (QD) Förster resonance energy transfer (FRET) donors. Histone acetyltransferase ...activity can be measured via the enzyme‐dependent assembly of a quantum dot/peptide immunocomplex (see picture; His=histidine), which can be conducted in a homogeneous reaction without the need for complicated surface derivatization procedures.
Herein is presented a microsensor technology as a diagnostic tool for detecting specific matrix metalloproteinases (MMPs) at very low concentrations. MMP-2 and MMP-9 are detected using label free ...porous silicon (PSi) photonic crystals that have been made selective for a given MMP by filling the nanopores with synthetic polymeric substrates containing a peptide sequence for that MMP. Proteolytic cleavage of the peptide sequence results in a shift in wavelength of the main peak in the reflectivity spectrum of the PSi device, which is dependent on the amount of MMP present. The ability to detect picogram amounts of MMP-2 and MMP-9 released by primary retinal pigment epithelial (RPE) cells and iris pigment epithelial (IPE) cells stimulated with lipopolysaccharide (LPS) is demonstrated. It was found that both cell types secrete higher amounts of MMP-2 than MMP-9 in their stimulated state, with RPE cells producing higher amounts of MMPs than IPE cells. The microsensor performance was compared to conventional protease detection systems, including gelatin zymography and enzyme linked immunosorbent assay (ELISA). It was found that the PSi microsensors were more sensitive than gelatin zymography; PSi microsensors detected the presence of both MMP-2 and MMP-9 while zymography could only detect MMP-2. The MMP-2 and MMP-9 quantification correlated well with the ELISA. This new method of detecting protease activity shows superior performance to conventional protease assays and has the potential for translation to high-throughput multiplexed analysis.
The privately rented housing market has largely catered for young, mobile people and students since it was deregulated in the UK. In this volume, key writers provide timely insights into this rapidly ...evolving market. This volume is based on new, original research which brings together specialists in housing policy and legal studies, with their common and increasingly interdependent knowledge base about the privately rented sector and its future direction. The collection opens with an overview of the historical context and recent changes to the sector, such as the rapid and continued expansion of the buy-to-let market, followed by a discussion of the factors shaping the contemporary market. The contributors show how the new regulatory environment is opening a series of issues with significant potential to affect (and potentially damage) the market. The volume will interest academics and students in social and public policy, law and housing studies, as well as law practices and housing authorities.
3D cell cultures have drawn a large amount of interest in the scientific community with their ability to closely mimic physiological conditions. Hydrogels have been used extensively in the ...development of extracellular matrix (ECM) mimics for 3D cell culture. Compounds such as collagen and fibrin are commonly used to synthesize natural ECM mimics; however they suffer from batch-to-batch variation. In this Review we explore the synthesis route of hydrogels; how they can be altered to give different chemical and physical properties; how different biomolecules such as arginylglycylaspartic acid (RGD) or vascular endothelial growth factor (VEGF) can be incorporated to give different biological cues; and how to create concentration gradients with UV light. There will also be emphasis on the types of techniques available in high-throughput processing such as nozzle and droplet-based biofabrication, photoenabled biofabrication, and microfluidics. The combination of these approaches and techniques allow the preparation of hydrogels which are capable of mimicking the ECM.
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