The photothermal response of plasmonic nanomaterials can be exploited for a number of biomedical applications in diagnostics (biosensing and optoacoustic imaging) and therapy (drug delivery and ...photothermal therapy). The most common cellular response to photothermal cancer treatment (ablation of solid tumors) using plasmonic nanomaterials is necrosis, a process that releases intracellular constituents into the extracellular milieu producing detrimental inflammatory responses. Here we report the use of laser-induced photothermal therapy employing gold nanoprisms (NPRs) to specifically induce apoptosis in mouse embryonic fibroblast cells transformed with the SV40 virus. Laser-irradiated “hot” NPRs activate the intrinsic/mitochondrial pathway of apoptosis (programmed cell death), which is mediated by the nuclear-encoded proteins Bak and Bax through the activation of the BH3-only protein Bid. We confirm that an apoptosis mechanism is responsible by showing how the NPR-mediated cell death is dependent on the presence of caspase-9 and caspase-3 proteins. The ability to selectively induce apoptotic cell death and to understand the subsequent mechanisms provides the foundations to predict and optimize NP-based photothermal therapy to treat cancer patients suffering from chemo- and radioresistance.
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IJS, KILJ, NUK, PNG, UL, UM
Corrosion of stone by acid rain and deterioration from biofilms are global problems for industrial and residential buildings as well as cultural heritage, such as statues or historic buildings. ...Herein we show how typical building stones can be protected from corrosion (“weathering”) and biofilm formation (“biodeterioration”) by application of thin films of polyoxometalate‐based ionic liquids (POM‐ILs). Stone samples are coated with hydrophobic, acid resistant POM‐ILs featuring biocidal properties. Exposure of the samples to simulated acid rain showed negligible corrosion compared to the significant deterioration of unprotected samples; in addition the biocidal properties of the POM‐ILs suppress the formation of biofilms on coated stone slabs. A new class of modular molecular materials for protecting stones can now be developed for use in construction, environmental protection, and cultural heritage preservation.
Brush‐on protection: Polyoxometalate ionic liquids (POM‐ILs) are used as brush‐on coatings to protect natural building stones from acid corrosion and the growth of biofilms. Tuning of their physical, chemical and rheological properties opens new opportunities for deploying POM‐ILs on construction stones or outdoor cultural heritage objects.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The simultaneous removal of organic, inorganic, and microbial contaminants from water by one material offers significant advantages when fast, facile, and robust water purification is required. ...Herein, we present a supported ionic liquid phase (SILP) composite where each component targets a specific type of water contaminant: a polyoxometalate‐ionic liquid (POM‐IL) is immobilized on porous silica, giving the heterogeneous SILP. The water‐insoluble POM‐IL is composed of antimicrobial alkylammonium cations and lacunary polyoxometalate anions with heavy‐metal binding sites. The lipophilicity of the POM‐IL enables adsorption of organic contaminants. The silica support can bind radionuclides. Using the POM‐SILP in filtration columns enables one‐step multi‐contaminant water purification. The results show how multi‐functional POM‐SILPs can be designed for advanced purification applications.
Pure and simple: Multi‐functional polyoxometalate supported ionic liquid phases (POM‐SILPs) can remove organic, inorganic, and microbial contaminants from water. Each POM‐SILP component targets one specific contaminant so that toxic heavy metals, radionuclides, organic dyes, and bacteria can be removed from water simultaneously.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Nanotechnology has brought a variety of new possibilities into biological discovery and clinical practice. In particular, nano-scaled carriers have revolutionalized drug delivery, allowing for ...therapeutic agents to be selectively targeted on an organ, tissue and cell specific level, also minimizing exposure of healthy tissue to drugs. In this review we discuss and analyze three issues, which are considered to be at the core of nano-scaled drug delivery systems, namely functionalization of nanocarriers, delivery to target organs and in vivo imaging. The latest developments on highly specific conjugation strategies that are used to attach biomolecules to the surface of nanoparticles (NP) are first reviewed. Besides drug carrying capabilities, the functionalization of nanocarriers also facilitate their transport to primary target organs. We highlight the leading advantage of nanocarriers, i.e. their ability to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells surrounding the brain that prevents high-molecular weight molecules from entering the brain. The BBB has several transport molecules such as growth factors, insulin and transferrin that can potentially increase the efficiency and kinetics of brain-targeting nanocarriers. Potential treatments for common neurological disorders, such as stroke, tumours and Alzheimer's, are therefore a much sought-after application of nanomedicine. Likewise any other drug delivery system, a number of parameters need to be registered once functionalized NPs are administered, for instance their efficiency in organ-selective targeting, bioaccumulation and excretion. Finally, direct in vivo imaging of nanomaterials is an exciting recent field that can provide real-time tracking of those nanocarriers. We review a range of systems suitable for in vivo imaging and monitoring of drug delivery, with an emphasis on most recently introduced molecular imaging modalities based on optical and hybrid contrast, such as fluorescent protein tomography and multispectral optoacoustic tomography. Overall, great potential is foreseen for nanocarriers in medical diagnostics, therapeutics and molecular targeting. A proposed roadmap for ongoing and future research directions is therefore discussed in detail with emphasis on the development of novel approaches for functionalization, targeting and imaging of nano-based drug delivery systems, a cutting-edge technology poised to change the ways medicine is administered.
Natural polysaccharides are frequently used in the design of drug delivery systems due to their biocompatibility, biodegradability, and low toxicity. Moreover, they are diverse in structure, size, ...and charge, and their chemical functional groups can be easily modified to match the needs of the final application and mode of administration. This review focuses on polysaccharidic nanocarriers based on chitosan and hyaluronic acid for small interfering RNA (siRNA) delivery, which are highly positively and negatively charged, respectively. The key properties, strengths, and drawbacks of each polysaccharide are discussed. In addition, their use as efficient nanodelivery systems for gene silencing applications is put into context using the most recent examples from the literature. The latest advances in this field illustrate effectively how chitosan and hyaluronic acid can be modified or associated with other molecules in order to overcome their limitations to produce optimized siRNA delivery systems with promising
and
results.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Fourteen volatile organic compound (VOC) biomarkers in the breath have been identified to distinguish early gastric cancer (EGC) and advanced gastric cancer (AGC) patients from healthy persons by gas ...chromatography–mass spectrometry coupled with solid phase microextraction (SPME). Then, a breath analysis approach based on a surface-enhanced Raman scattering (SERS) sensor was developed to detect these biomarkers. Utilizing hydrazine vapor adsorbed in graphene oxide (GO) film, the clean SERS sensor is facilely prepared by in situ formation of gold nanoparticles (AuNPs) on reduced graphene oxide (RGO) without any organic stabilizer. In the SERS sensor, RGO can selectively adsorb and enrich the identified biomarkers from breath as an SPME fiber, and AuNPs well dispersed on RGO endow the SERS sensor with an effective detection of adsorbed biomarkers. Fourteen Raman bands associated with the biomarkers are selected as the fingerprints of biomarker patterns to distinguish persons in different states. The approach has successfully analyzed and distinguished different simulated breath samples and 200 breath samples of clinical patients with a sensitivity of higher than 83% and a specificity of more than 92%. In conclusion, the VOC biomarkers and breath analysis approach in this study can not only diagnose gastric cancer but also distinguish EGC and AGC. This work has great potential for clinical translation in primary screening diagnosis and stage determination of stomach cancer in the near future.
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IJS, KILJ, NUK, PNG, UL, UM
Magnetic nanoparticles (MNPs), and in particular iron oxide nanoparticles (mainly magnetite and maghemite), are being widely used in the form of aqueous colloids for biomedical applications. In such ...colloids, nanoparticles tend to form assemblies, either aggregates, if the union is permanent, or agglomerates, if it is reversible. These clustering processes have a strong impact on the MNPs' properties that are often not well understood. In this review, the causes and consequences of MNPs aggregation/agglomeration are reviewed and discussed. Special attention has been paid to the impact of the MNPs aggregation/agglomeration on their magnetic properties and heating properties, when exposed to an alternating magnetic field in the frame of magnetic hyperthermia. In addition, a model system with MNPs of two different sizes coated with three different molecules oleic acid, meso-2, 3-dimercaptosuccinic acid and poly(maleic anhydride-alt-1-octadecene) has been characterized and the results used to support the ideas reviewed.
In this study, we present an innovation in the tumor treatment in vivo mediated by magnetic mesoporous silica nanoparticles. This device was built with iron oxide magnetic nanoparticles embedded in a ...mesoporous silica matrix and coated with an engineered thermoresponsive polymer. The magnetic nanoparticles act as internal heating sources under an alternating magnetic field (AMF) that increase the temperature of the surroundings, provoking the polymer transition and consequently the release of a drug trapped inside the silica pores. By a synergic effect between the intracellular hyperthermia and chemotherapy triggered by AMF application, significant tumor growth inhibition was achieved in 48 h after treatment. Furthermore, the small magnetic loading used in the experiments indicates that the treatment is carried out without a global temperature rise of the tissue, which avoids the problem of the necessity to employ large amounts of magnetic cores, as is common in current magnetic hyperthermia.
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The ring‐opening polymerisation of α‐amino acid N‐carboxyanhydrides (NCAs) offers a simple and scalable route to polypeptides with predicted and narrow molecular weight distributions. Here we show ...how polyoxometalates (POMs)—redox‐active molecular metal‐oxide anions—can serve as inorganic scaffold initiators for such NCA polymerisations. This “On‐POM polymerisation” strategy serves as an innovative platform to design hybrid materials with additive or synergistic properties stemming from the inorganic and polypeptide component parts. We have used this synthetic approach to synthesise a library of bactericidal poly(lysine)–POM hybrid derivatives that can be used to prevent biofilm formation. This versatile “On‐POM polymerisation” method provides a flexible synthetic approach for combining inorganic scaffolds with amino acids, and the potential to tailor and improve the specificity and performance of hybrid antimicrobial materials.
On‐POM polymerisation: An amino‐functionalised polyoxometalate (POM) acts as initiator for the ring‐opening polymerisation (ROP) of α‐amino acid N‐carboxyanhydrides (NCAs) under living polymerisation conditions. The resulting POM–peptide materials (POMlymers) possess bactericidal properties and prevent biofilm formation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The field of nanotechnology applied to medicine (nanomedicine) is developing at a fast pace and is expected to provide solutions for early diagnosis, targeted therapy, and personalized medicine. ...However, designing nanomaterials for biomedical applications is not a trivial task. Avoidance of the immune system, stability in physiological media, control over the interaction of a nanomaterial with biological entities such as proteins and cell membranes, low toxicity, and optimal bioperformance are critical for the success of the designed nanomaterial. In this Feature Article we provide a concise overview of some of the most recent advances concerning the derivatization of gold and iron oxide nanoparticles for bioapplications. The most important aspects relating to the functionalization of gold and iron oxide nanoparticles with carbohydrates, peptides, nucleic acids, and antibodies are covered, highlighting the recent contributions from our research group. We suggest tips for the appropriate (bio)functionalization of these inorganic nanoparticles in order to preserve the biological activity of the attached biomolecules and ensure their subsequent stability in physiological media.
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