Ángel Maquieira

Bio: Ángel Maquieira is an academic researcher from Polytechnic University of Valencia. The author has contributed to research in topics: Medicine & Recombinase Polymerase Amplification. The author has an hindex of 35, co-authored 111 publications receiving 4852 citations. Previous affiliations of Ángel Maquieira include University of California & University of California, Davis.

Fast screening methods to detect antibiotic residues in food samples

Abstract: Antibiotic residues in edible animal products are of great concern to regulatory agencies and consumers, so reliable screening methods for rapid, selective and sensitive detection of these residues are necessary to ensure food safety. In recent years, great efforts have been made to simplify the treatment of solid food samples and also to introduce high-throughput methods, so different screening methods have been developed. This review presents a general overview on the progress of the three most important screening approaches to detect antibiotic residues in food samples (i.e. immunoassays, microbiological tests and biosensors). Their main advantages are short analysis time, high sensitivity and selectivity for immunoassays, simplicity and low cost for microbiological tests, and automation and the possibility of in situ analysis for biosensors. Moreover, it is important to note a great increase in the number of commercial kits. Regarding the detection mode employed, the lowest limits of detection were achieved using microbiological inhibition tests and immunoassays with time-resolved fluorometry detection, so antibiotic residues at levels lower than the maximum residue limits established by legislation were detected.

Controlled delivery using oligonucleotide-capped mesoporous silica nanoparticles.

Abstract: The design of delivery systems with “molecular locks” able to selectively release entrapped guests in the presence of target triggers has attracted great attention recently. As an alternative to traditional polymer-based delivery systems, mesoporous silica supports show unique properties such as a large load capacity, biocompatibility, and potential for the development of gated supports for on-command delivery applications. Recently, mesoporous-silica-based systems displaying controlled release have been reported relying on changes in pH, redox potential, and light for uncapping the pores. However, the use of mesoporous silica supports equipped with gatelike scaffoldings is still an incipient area of research. In particular, despite some recent reported gated mesoporous silica supports that can be uncapped using antigens or enzymes, there is an almost complete lack of mesoporous-silica-based devices designed to trigger cargo release involving biomolecules. Within this context, our interest in the development of gated materials motivated us to explore the possible design of new “bio-gates” able to respond selectively to “key” molecules. We focused our attention on the use of nucleotides. The proposed paradigm is represented in Scheme 1. In this work nanoparticles (ca. 100 nm) of mesoporous MCM-41 have been selected as the inorganic scaffold. The MCM-41 support is first loaded with a suitable guest (fluorescein), and then the external surface is functionalized with 3-aminopropyltriethoxysilane (APTS) to give the solid S1. Aminopropyl groups are partially charged at neutral pH in water and will interact with negatively charged oligonucleotides, resulting in the closing of the mesopores. The opening protocol will be expected to occur by a highly effective displacement reaction in the presence a target complementary strand; this will result in hybridization of the two oligonucleotides, the uncapping of the pores, and release of the entrapped cargo. The mesoporous solid S1 containing fluorescein in the pore voids and functionalized on the external surface with APTS groups was characterized following standard procedures (see the Supporting Information). The powder X-ray diffraction (XRD) pattern of siliceous MCM-41 nanoparticles as synthesized (Figure 1, curve a) shows four low-angle reflections typical of a hexagonal array which can be indexed as (100), (110), (200), and (210) Bragg peaks. A significant displacement of the (100) peak in the XRD pattern of the MCM-41 calcined nanoparticles is evident in curve b. Finally, curve c corresponds to the XRD pattern of S1. The (100), (110), and (200) peaks are clearly observed strongly suggesting that the dye loading and further functionalization with Scheme 1. Representation of the gated material S1 functionalized with 3-aminopropyltriethoxysilane and capped with a single-stranded oligonucleotide (O1). The delivery of the entrapped guest (fluorescein) is selectively accomplished in the presence of the complementary oligonucleotide (O2). The sequence of the oligonucleotides O1 and O2 is shown.

Label-free optical biosensing with slot-waveguides

Abstract: We demonstrate label-free molecule detection by using an integrated biosensor based on a Si3N4/SiO2 Slot-waveguide microring resonator. Bovine serum albumin (BSA) and anti-BSA molecular binding eve ...

Controlled delivery systems using antibody-capped mesoporous nanocontainers.

Abstract: This paper describes the design of new controlled delivery systems consisting of a mesoporous support functionalized on the pore outlets with a certain hapten able to interact with an antibody that acts as a nanoscopic cap. The opening protocol and delivery of the entrapped guest is related by a displacement reaction involving the presence in the solution of the antigen to which the antibody is selective. As a proof-of-the-concept, the solid MCM-41 was selected as support and was loaded with the dye [Ru(bipy)3]Cl2. Then a suitable derivative of the hapten 4-(4-aminobenzenesulfonylamino)benzoic acid was anchored on the outer surface of the mesoporous support (solid S1). Finally the pores were capped with a polyclonal antibody for sulfathiazole (solid S1-AB). Delivery of the dye in the presence of a family of sulfonamides was studied in phosphate-buffered saline (PBS; pH 7.5). A selective uncapping of the pores and dye delivery was observed for sulfathiazole. This delivery behavior was compared with that sh...

Mesoporous Silica Nanoparticles: Synthesis, Biocompatibility and Drug Delivery

Abstract: In the past decade, mesoporous silica nanoparticles (MSNs) have attracted more and more attention for their potential biomedical applications. With their tailored mesoporous structure and high surface area, MSNs as drug delivery systems (DDSs) show significant advantages over traditional drug nanocarriers. In this review, we overview the recent progress in the synthesis of MSNs for drug delivery applications. First, we provide an overview of synthesis strategies for fabricating ordered MSNs and hollow/rattle-type MSNs. Then, the in vitro and in vivo biocompatibility and biotranslocation of MSNs are discussed in relation to their chemophysical properties including particle size, surface properties, shape, and structure. The review also highlights the significant achievements in drug delivery using mesoporous silica nanoparticles and their multifunctional counterparts as drug carriers. In particular, the biological barriers for nano-based targeted cancer therapy and MSN-based targeting strategies are discussed. We conclude with our personal perspectives on the directions in which future work in this field might be focused.

Inkjet Printing for Materials and Devices

Abstract: Inkjet printing is familiar as a method of printing text and images onto porous surfaces. In the last few years it has been used as a free-form fabrication method for building three-dimensional parts and is being explored as a way of printing electrical and optical devices, especially where these involve organic components. Inkjet printers are also being used to produce arrays of proteins and nucleic acids. The need for a versatile inkjet technology for free-forming materials and for multilayer devices raises a number of materials problems that do not apply to conventional printing of images. Higher resolutions will be needed if organic transistors are to be printed. Also, it must be possible to print pinhole-free layers to avoid shorting of devices. Multiple layers must be printed such that they mix and react to form a single material or such that they form discrete unmixed layers. Printing on dense rather than porous substrates will be the norm. This article reviews the range of materials that has been ...

Functionalized mesoporous silica materials for controlled drug delivery

Abstract: In the past decade, non-invasive and biocompatible mesoporous silica materials as efficient drug delivery systems have attracted special attention. Great progress in structure control and functionalization (magnetism and luminescence) design has been achieved for biotechnological and biomedical applications. This review highlights the most recent research progress on silica-based controlled drug delivery systems, including: (i) pure mesoporous silica sustained-release systems, (ii) magnetism and/or luminescence functionalized mesoporous silica systems which integrate targeting and tracking abilities of drug molecules, and (iii) stimuli-responsive controlled release systems which are able to respond to environmental changes, such as pH, redox potential, temperature, photoirradiation, and biomolecules. Although encouraging and potential developments have been achieved, design and mass production of novel multifunctional carriers, some practical biological application, such as biodistribution, the acute and chronic toxicities, long-term stability, circulation properties and targeting efficacy in vivo are still challenging.