Direct electrochemical reduction of graphene oxide thin film for aptamer-based selective and highly sensitive detection of matrix metalloproteinase 2.

Simple and low-cost biosensing solutions are suitable for point-of-care applications aiming to overcome the gap between scientific concepts and technological production. To compete with sensitivity and selectivity of golden standards, such as liquid chromatography, the functionalization of biosensors is continuously optimized to enhance the signal and improve their performance, often leading to complex chemical assay development. In this research, the efforts are made on optimizing the methodology for electrochemical reduction of graphene oxide to produce thin film-modified gold electrodes. Under the employed specific conditions, 20 cycles of cyclic voltammetry (CV) are shown to be optimal for superior electrical activation of graphene oxide into electrochemically reduced graphene oxide (ERGO). This platform is further used to develop a matrix metalloproteinase 2 (MMP-2) biosensor, where specific anti-MMP2 aptamers are utilized as a biorecognition element. MMP-2 is a protein which is typically overexpressed in tumor tissues, with important roles in tumor invasion, metastasis as well as in tumor angiogenesis. Based on impedimetric measurements, we were able to detect as low as 3.32 pg mL-1 of MMP-2 in PBS with a dynamic range of 10 pg mL-1 - 10 ng mL-1. Further experiments with real blood samples revealed a promising potential of the developed sensor for direct measurement of MMP-2 in complex media. High specificity of detection is demonstrated - even to the closely related enzyme MMP-9. Finally, the potential of reuse was demonstrated by signal restoration after experimental detection of MMP-2.

One-Step Photochemical Immobilization of Aptamer on Graphene for Label-Free Detection of NT-proBNP.

A novel photochemical technological route for one-step functionalization of a graphene surface with an azide-modified DNA aptamer for biomarkers is developed. The methodology is demonstrated for the functionalization of a DNA aptamer for an N-terminal B-type natriuretic peptide (NT-proBNP) heart failure biomarker on the surface of a graphene channel within a system based on a liquid-gated graphene field effect transistor (GFET). The limit of detection (LOD) of the aptamer-functionalized sensor is 0.01 pg/mL with short response time (75 s) for clinically relevant concentrations of the cardiac biomarker, which could be of relevance for point-of-care (POC) applications. The novel methodology could be applicable for the development of different graphene-based biosensors for fast, stable, real-time, and highly sensitive detection of disease markers.

Advanced mesoporous silica nanocarriers in cancer theranostics and gene editing applications.

Targeted nanomaterials for cancer theranostics have been the subject of an expanding volume of research studies in recent years. Mesoporous silica nanoparticles (MSNs) are particularly attractive for such applications due to possibilities to synthesize nanoparticles (NPs) of different morphologies, pore diameters and pore arrangements, large surface areas and various options for surface functionalization. Functionalization of MSNs with different organic and inorganic molecules, polymers, surface-attachment of other NPs, loading and entrapping cargo molecules with on-desire release capabilities, lead to seemingly endless prospects for designing advanced nanoconstructs exerting multiple functions, such as simultaneous cancer-targeting, imaging and therapy. Describing composition and multifunctional capabilities of these advanced nanoassemblies for targeted therapy (passive, ligand-functionalized MSNs, stimuli-responsive therapy), including one or more modalities for imaging of tumors, is the subject of this review article, along with an overview of developments within a novel and attractive research trend, comprising the use of MSNs for CRISPR/Cas9 systems delivery and gene editing in cancer. Such advanced nanconstructs exhibit high potential for applications in image-guided therapies and the development of personalized cancer treatment.

Cultivating Multidisciplinarity: Manufacturing and Sensing Challenges in Cultured Meat Production.

Meat cultivation via cellular agriculture holds great promise as a method for future food production. In theory, it is an ideal way of meat production, humane to the animals and sustainable for the environment, while keeping the same taste and nutritional values as traditional meat and having additional benefits such as controlled fat content and absence of antibiotics and hormones used in the traditional meat industry. However, in practice, there is still a number of challenges, such as those associated with the upscale of cultured meat (CM). CM food safety monitoring is a necessary factor when envisioning both the regulatory compliance and consumer acceptance. To achieve this, a multidisciplinary approach is necessary. This includes extensive development of the sensitive and specific analytical devices i.e., sensors to enable reliable food safety monitoring throughout the whole future food supply chain. In addition, advanced monitoring options can help in the further optimization of the meat cultivation which may reduce the currently still high costs of production. This review presents an overview of the sensor monitoring options for the most relevant parameters of importance for meat cultivation. Examples of the various types of sensors that can potentially be used in CM production are provided and the options for their integration into bioreactors, as well as suggestions on further improvements and more advanced integration approaches. In favor of the multidisciplinary approach, we also include an overview of the bioreactor types, scaffolding options as well as imaging techniques relevant for CM research. Furthermore, we briefly present the current status of the CM research and related regulation, societal aspects and challenges to its upscaling and commercialization.

pH-Responsive Release of Ruthenium Metallotherapeutics from Mesoporous Silica-Based Nanocarriers.

Ruthenium complexes are attracting interest in cancer treatment due to their potent cytotoxic activity. However, as their high toxicity may also affect healthy tissues, efficient and selective drug delivery systems to tumour tissues are needed. Our study focuses on the construction of such drug delivery systems for the delivery of cytotoxic Ru(II) complexes upon exposure to a weakly acidic environment of tumours. As nanocarriers, mesoporous silica nanoparticles (MSN) are utilized, whose surface is functionalized with two types of ligands, (2-thienylmethyl)hydrazine hydrochloride (H1) and (5,6-dimethylthieno[2,3-d]pyrimidin-4-yl)hydrazine (H2), which were attached to MSN through a pH-responsive hydrazone linkage. Further coordination to ruthenium(II) center yielded two types of nanomaterials MSN-H1[Ru] and MSN-H2[Ru]. Spectrophotometric measurements of the drug release kinetics at different pH (5.0, 6.0 and 7.4) confirm the enhanced release of Ru(II) complexes at lower pH values, which is further supported by inductively coupled plasma optical emission spectrometry (ICP-OES) measurements. Furthermore, the cytotoxicity effect of the released metallotherapeutics is evaluated in vitro on metastatic B16F1 melanoma cells and enhanced cancer cell-killing efficacy is demonstrated upon exposure of the nanomaterials to weakly acidic conditions. The obtained results showcase the promising capabilities of the designed MSN nanocarriers for the pH-responsive delivery of metallotherapeutics and targeted treatment of cancer.

Antimicrobial nanoparticles and biodegradable polymer composites for active food packaging applications.

The food industry faces numerous challenges to assure provision of tasty and convenient food that possesses extended shelf life and shows long-term high-quality preservation. Research and development of antimicrobial materials for food applications have provided active antibacterial packaging technologies that are able to meet these challenges. Furthermore, consumers expect and demand sustainable packaging materials that would reduce environmental problems associated with plastic waste. In this review, we discuss antimicrobial composite materials for active food packaging applications that combine highly efficient antibacterial nanoparticles (i.e., metal, metal oxide, mesoporous silica and graphene-based nanomaterials) with biodegradable and environmentally friendly green polymers (i.e., gelatin, alginate, cellulose, and chitosan) obtained from plants, bacteria, and animals. In addition, innovative syntheses and processing techniques used to obtain active and safe packaging are showcased. Implementation of such green active packaging can significantly reduce the risk of foodborne pathogen outbreaks, improve food safety and quality, and minimize product losses, while reducing waste and maintaining sustainability.

Magnetic nanoarchitectures for cancer sensing, imaging and therapy.

The use of magnetic nanoparticles for sensing and theranostics of cancer has grown substantially in the last decade. Since the pioneering studies, which reported magnetic nanoparticles for bio-applications more than fifteen years ago, nanomaterials have increased in complexity with different shapes (nanoflowers, nanospheres, nanocubes, nanostars etc.) and compositions (e.g. core-shell) of nanoparticles for an increase in the sensitivity (imaging or sensing) and efficiency through synergistic treatments such as hyperthermia and drug delivery. In this review, we describe recent examples concerning the use of magnetic nanoparticles for bio-applications, from the surface functionalization methods to the development of cancer sensors and nanosystems for magnetic resonance and other imaging methodologies. Multifunctional nanosystems (nanocomposites, core shell nanomaterials) for theranostic applications involving treatments such as hyperthermia, photodynamic therapy, targeted drug delivery, and gene silencing are also described. These nanomaterials could be the future of medicine, although their complexity raises concerns about their safety.

Mesoporous Silica and Organosilica Nanomaterials as UV-Blocking Agents.

Mesoporous silica nanoparticles (MSN) and periodic mesoporous organosilica nanoparticles containing bridging benzene (PMOBTB) and ethane (PMOBTE) moieties are synthesized, characterized, and evaluated for application in skin protection from UVA/UVB sun irradiation. Furthermore, the influence of surface functionalization with chelating 3-(2-aminoethylamino)propylsilane and Zn2+ ions on the UV-blocking ability of MSN is evaluated, along with the photostability and capability of the synthesized nanomaterials to carry avobenzone, a known UV-absorbing agent. The obtained results reveal promising characteristics of MSN and PMO materials with regard to their potential for sunscreen applications, which could be beneficial in terms of alleviating concerns about health and environmental hazards of sunscreen ingredients.

Silicon-based nanotheranostics.

With the rapid expansion of nanoscience and nanotechnology in interdisciplinary fields, multifunctional nanomaterials have attracted particular attention. Recent advances in nanotherapeutics for cancer applications provided diverse groups of synthetic particles with defined cellular and biological functions. The advance of nanotechnology significantly increased the number of possibilities for the construction of diverse biological tools. Such materials are destined to be of great importance because of the opportunity to combine the biotechnological potential of nanoparticles together with the recognition, sensitivity and modulation of cellular pathways or genes when applied to living organisms. In this mini review three main types of Si-based nanomaterials are highlighted in the area of their application for therapy and imaging: porous silicon nanoparticles (pSiNPs), mesoporous silica nanoparticles (MSNs), focusing on their nanoconstructs containing coordination compounds, and periodic mesoporous silica nanoparticles (PMONPs). Moreover, a critical discussion on the research efforts in the construction of nanotheranostics is presented.

Magnetic Field-Induced Accentuation of Drug Release from Core/Shell Magnetic Mesoporous Silica Nanoparticles for Anticancer Treatment.

Drug (9-aminoacridine) loaded core/shell magnetic iron oxide-containing mesoporous silica nanoparticles (MMSN) were treated with HeLa cells and the drug carriers were agitated by expo- sure to magnetic field. Viability studies show the applicability of drug loaded magnetic material for anticancer treatment, which is enhanced upon stimulation with magnetic field. Confocal micrographs of fluorescein grafted MMSN-treated HeLa cells confirmed the ability of magnetic field to concentrate the synthesized material in the exposed area of the cells. The synthesized material and the applied drug delivery method may find application in magnetic field-responsive targeted treatment of cancer.

Ruthenium(ii) complex-photosensitized multifunctionalized porous silicon nanoparticles for two-photon near-infrared light responsive imaging and photodynamic cancer therapy.

Multifunctionalized porous silicon nanoparticles (pSiNPs), containing the novel Ru(ii) complex-photosensitizer, the polyethylene glycol moiety, and mannose molecules as cancer targeting ligands, are constructed and showcased for application in near infrared (NIR) light-responsive photodynamic therapy (PDT) and imaging of cancer. Exposure to NIR light leads to two-photon excitation of the Ru(ii)-complex which allows efficient simultaneous cancer-imaging and targeted PDT therapy with the functionalized biodegradable pSiNP nanocarriers.

Nanodiamond-PMO for two-photon PDT and drug delivery.

In this article, we highlight the properties of nanodiamonds (ND), which were encapsulated in periodic mesoporous organosilica nanoparticles (PMO) and were able to generate reactive oxygen species for photodynamic applications upon two-photon excitation (TPE). The ND@PMO nanoparticles were characterized by various techniques and were then loaded with the anti-cancer drug doxorubicin. The release of the drug was pH sensitive and a synergistic cancer cell killing effect was observed when cancer cells were incubated with doxorubicin-loaded ND@PMO and irradiated with two-photon excitation at 800 nm.

Large pore mesoporous silica nanomaterials for application in delivery of biomolecules.

Various approaches for the synthesis of mesoporous silicate nanoparticles (MSN) with large pore (LP) diameters (in the range of 3-50 nm) are reviewed in this article. The work also covers the construction of magnetic analogues of large pore-mesoporous silica nanoparticles (LPMMSN) and their biomedical applications. The constructed materials exhibit vast potential for application in the loading and delivery of large drug molecules and biomolecules. Literature reports on the application of LPMSN and LPMMSN materials for the adsorption and delivery of proteins, enzymes, antibodies, and nucleic acids are covered in depth, which exemplify their highly potent characteristics for use in drug and biomolecule delivery to diseased tissues.

Monomolecular sheets of propeller-shaped triethyl 4,4',4''-[benzene-1,3,5-triyltris(ethyne-2,1-diyl)]tribenzoate deuterochloroform monosolvate.

The title compound, C39H30O6·CDCl3, has a chemical threefold axis and an approximately planar structure, with an ethoxycarbonyl substituent on each of the terminal benzenes oriented in the same direction, thus forming a propeller-shaped molecule. This molecule is of particular interest in the field of metal-organic frameworks (MOFs), where its hydrolyzed analogue forms MOF structures with high surface areas. The benzene ring which occupies the centre of the molecule forms π-π interactions to the equivalent benzene ring at a perpendicular distance of 3.32 (1) Å. Centrosymmetric dimers formed in this way are interconnected by intermolecular C-H···π interactions with a rather short H···CgA distance of 2.51 Š(CgA is the centroid of the central benzene ring). The molecules are arranged in regular parallel sheets. Within a sheet, molecules are interconnected via C-H···O interactions where all carbonyl O atoms participate in weak hydrogen bonds as hydrogen-bond acceptors. Neighbouring sheets are connected through the above-mentioned π-π and C-H···π interactions.

A magnetic mesoporous silica nanoparticle-based drug delivery system for photosensitive cooperative treatment of cancer with a mesopore-capping agent and mesopore-loaded drug.

Lately, there has been a growing interest in anticancer therapy with a combination of different drugs that work by different mechanisms of action, which decreases the possibility that resistant cancer cells will develop. Herein we report on the development of a drug delivery system for photosensitive delivery of a known anticancer drug camptothecin along with cytotoxic cadmium sulfide nanoparticles from a magnetic drug nanocarrier. Core-shell nanoparticles consisting of magnetic iron-oxide-cores and mesoporous silica shells are synthesized with a high surface area (859 m(2) g(-1)) and hexagonal packing of mesopores, which are 2.6 nm in diameter. The mesopores are loaded with anticancer drug camptothecin while entrances of the mesopores are blocked with 2-nitro-5-mercaptobenzyl alcohol functionalized CdS nanoparticles through a photocleavable carbamate linkage. Camptothecin release from this magnetic drug delivery system is successfully triggered upon irradiation with UV light, as measured by fluorescence spectroscopy. Photosensitive anticancer activity of the drug delivery system is monitored by viability studies on Chinese hamster ovarian cells. The treatment of cancer cells with drug loaded magnetic material leads to a decrease in viability of the cells due to the activity of capping CdS nanoparticles. Upon exposure to low power UV light (365 nm) the loaded camptothecin is released which induces additional decrease in viability of CHO cells. Hence, the capping CdS nanoparticles and loaded camptothecin exert a cooperative anticancer activity. Responsiveness to light irradiation and magnetic activity of the nanocarrier enable its potential application for selective targeted treatment of cancer.

Functionalized mesoporous silica nanoparticle-based visible light responsive controlled release delivery system.

A supramolecular assembly for visible light responsive release of cargo molecules is presented. Sulforhodamine 101 was loaded inside the mesopores of mercaptopropyl-functionalized mesoporous silica nanoparticles (MP-MSN) and entrapped by mercaptopropyl-coordinated Ru(bpy)(2)(PPh(3))-moieties. Irradiation with visible light triggers the release of capping species and loaded molecules.