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The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2.− produced by the PDT is converted to H2O2 by superoxide dismutase, followed by the transformation of H2O2 to the highly toxic.OH via Fenton reactions by Fe2+ originating from the dissolution of co‐loaded Fe3O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular delivery to the nucleus—even for drug‐resistant cells. Cisplatin generates O2.− in the presence of nicotinamide adenine dinucleotide phosphate oxidase and thereby improves the treatment efficiency by serving as an additional O2.− source for production of.OH radicals. Improved anticancer efficiency is achieved under both hypoxic and normoxic conditions. [ABSTRACT FROM AUTHOR]

Corrosion is still globally a major financial challenge and requires new materials development so that energy and resources can be saved more effectively. Suitable advanced coatings for metals shall first hinder corrosion. When corrosion still occurs, the coating shall emit a signal to allow timely maintenance before metallic structure is too much damaged. We prepared copolymers that can release corrosion inhibitors, 5-(aminomethyl)-8-hydroxyquinoline (AM8HQ) and benzotriazole (BTA), upon acidic hydrolysis of imine and hemiaminal ether linkages. Furthermore, a fluorescent molecule is attached to the copolymer via thiopropionate groups. Hydrolysis of the latter group and release of the fluorescent sensor occurs after release of the inhibitors. Corrosion rates of steel substrates coated with the pH-responsive polymers are dramatically reduced and fluorescence are detected upon onset of corrosion. Image 1 • pH-responsive polymers containing corrosion inhibitor and sensing agent in their structures were synthesized. • Coatings from these polymer conjugates dramatically reduced corrosion rates of steel substrates. • Corrosion could be simultaneously detected by fluorescence of the polymer sensor. [ABSTRACT FROM AUTHOR]

Herein, we design inflammation-responsive nanocapsules containing two antibiotics. The releases are programmed to be triggered under conditions occurring at the different stages of wound healing. The nanocapsules exhibit excellent antibacterial activities against Gram-positive, Gram-negative, and antibiotic-resistant bacteria. Incorporation of small amounts of nanocapsules in hydrogels leads to efficient antibacterial wound dressings. [ABSTRACT FROM AUTHOR]

Emulsions are metastable and can be destabilized by coalescence and Ostwald ripening, which lead to phase separation. Immobilizing emulsion droplets in a solid material shall improve their stability during storage. Miniemulsions and dispersions of nanocapsules are electrospun to immobilize colloids in polymer nanofibers. The nanofibers are dissolved after various period of time to re-disperse nanodroplets and nanocapsules. The size of nanodroplets and nanocapsules are close to the size of the original colloids before electrospinning, meaning that the emulsion droplets are efficiently stored overtime in nanofibers. Entrapping droplets in nanofibers by electrospinning allows a reduction of weight and volume of the emulsion of up to 82%. This method is therefore beneficial for improving shelf-life of emulsions, decreasing storage volume, and decreasing energy consumption for transportation of emulsions. [ABSTRACT FROM AUTHOR]

Core–shell nanocapsules are receiving increasing interest for drug delivery applications. Silica nanocapsules have been the focus of intensive studies due to their biocompatibility, versatile silica chemistry, and tunable porosity. However, a versatile one‐step preparation of silica nanocapsules with well‐defined core–shell structure, tunable size, flexible interior loading, and tailored shell composition, permeability, and surface functionalization for site‐specific drug release and therapeutic tracking remains a challenge. Herein, an interfacially confined sol–gel process in miniemulsion for the one‐step versatile preparation of functional silica nanocapsules is developed. Uniform nanocapsules with diameters from 60 to 400 nm are obtained and a large variety of hydrophobic liquids are encapsulated in the core. When solvents with low boiling point are loaded, subsequent solvent evaporation converts the initially hydrophobic cavity into an aqueous environment. Stimuli‐responsive permeability of nanocapsules is programmed by introducing disulfide or tetrasulfide bonds in the shell. Selective and sustained release of dexamethasone in response to glutathione tripeptide for over 10 d is achieved. Fluorescence labeling of the silica shell and magnetic loading in the internal cavity enable therapeutic tracking of nanocapsules by fluorescence and electron microscopies. Thus, silica nanocapsules represent a promising theranostic nanoplatform for targeted drug delivery applications. [ABSTRACT FROM AUTHOR]

Drug delivery from polymer nanocarriers is usually achieved by designing polymers so that they release drugs by cleavage of labile bonds, or by preparing nanoparticles that swell or collapse in response to external stimuli. Herein, we unravel the importance of polymer crystallinity in release profiles of drugs encapsulated in polymer nanoparticles. Polycaprolactone, as a model biocompatible and biodegradable semi-crystalline polymer, was processed into nanoparticles by the miniemulsion-solvent evaporation technique. The crystallinity of the nanoparticles was controlled by the polymer concentration, size of nanoparticles, and the composition of mixtures with amorphous polymers such as poly(vinyl formal) and polystyrene. Crystallinity decreased significantly with decreasing nanoparticle diameter. Release profiles of drugs were found to be dependent on an interplay of nanoparticle size and crystallinity. Therefore, crystallinity can be used for tuning the release profiles of nanoparticles. [ABSTRACT FROM AUTHOR]

• Dextran carbamate derivatives were synthesized as building blocks for preparing nanocapsules. • Corrosion inhibitors were loaded in dextran and dextran carbamate nanocapsules by the inverse miniemulsion process. • Release profiles depended on the chemical structure of the dextran derivatives, solubility of payload, and pH values. Controlled release of payloads such as drugs or corrosion inhibitors from nanocapsules is a prerequisite for their utilization. Indeed, premature leaching and contamination of the environment can be avoided. Herein, we investigate the pH-dependence of release kinetics of corrosion inhibitors from nanocapsules. Nanocapsules are formed by interfacial crosslinking of dextran derivatives in inverse miniemulsion and subsequently re-dispersed in aqueous solutions. Release kinetics are highly dependent on pH value and can be explained by a complex interplay involving swelling of nanocapsules shell, solubility of corrosion inhibitors, and electrostatic interactions between payloads and the shell. [ABSTRACT FROM AUTHOR]

Modern requirements for designing efficient nanocarriers against diseases such as cancer are very complex. A suitable nanocarrier should indeed remain colloidally stable in the body, be biodegradable, target specific tumor cells, and release efficiently drugs. These challenging tasks can be overcome by using the chemistry of saccharides and polysaccharides. We discuss here recent applications of carbohydrates-based materials for providing biodegradability, enhancing contrast in bioimaging, a stealth effect for controlling the composition of protein corona, and targeting ability. [ABSTRACT FROM AUTHOR]

Nanocapsules with a hydrophilic core are particularly interesting for biomedical and anticorrosion applications since these nanocontainers allow encapsulating a wide range of hydrophilic payloads and controlling their release profiles. However, a major challenge associated with the preparation of these nanocapsules is the non-controlled leakage of hydrophilic payloads from the core due to osmotic pressure. Herein, we present an approach for the preparation of polymer nanocapsules that suppress the non-controlled leakage of payloads and respond to chemical reduction that triggers release of encapsulated payloads. The non-controlled leakage of hydrophilic payloads from the nanocapsules is hindered by increasing the shell thickness. These nanocapsules consisting of reduction-responsive units possess a remarkable release property only under reductive condition while cease non-controlled leakage of the payload in the aqueous release medium. The described nanocapsules can be applied for biomedical and anticorrosion applications in which triggered release of hydrophilic payloads is suitable. [ABSTRACT FROM AUTHOR]

Orthovanadate (GdVO 4) nano- and microparticles doped with lanthanide ions are of interest for anti-counterfeiting and plastics recycling applications due to their emission in the short-wave infrared (SWIR) region. The unique aspect of this study is the measurement of the absolute photoluminescence quantum yield (QY) of the SWIR (1533 nm) emission for the orthovanadate nano- and microparticles co-doped withF Yb3+ and Er3+ using an integrating sphere. This is the first demonstration that doping with optically neutral Zn2+ ion significantly improves the QY of SWIR emission. A low QY of 0.1% was observed for the GdVO 4 :Yb3+, Er3+, Zn2+ nanoparticles synthesized by the co-precipitation method. However, the QY can be significantly increased (QY of 27.2%) after a 700 °C calcination step. This performance is approximately double that of a reference phosphor – Zn2+-free GdVO 4 :Yb3+,Er3+ synthesized by solid-phase reaction at 1050 °C – which achieved only QY of 13.0%. When micron-sized GdVO 4 :Yb3+, Er3+, Zn2+ particles are dispersed in water, a decrease in QY was observed (2.3%), which is explained by reabsorption of the luminescence by water. However, the water environment strongly quenched the SWIR luminescence (QY < 0.1%) in case of GdVO 4 :Yb3+, Er3+, Zn2+ nanoparticles with size of 125 nm. In summary, GdVO 4 :Yb3+, Er3+, Zn2+ microparticles with a QY of 27.2% can be used as bright luminescent markers in an advanced plastics processing technology - tracer-based sorting. [Display omitted] • Nano- and microparticles of GdVO 4 :Yb3+,Er3+ are sensitized by different methods. • Absolute quantum yield of SWIR luminescence is measured using an integrating sphere. • Quantum yield is 13.0% if high temperature solid state reaction is used. • Zn2+ co-doping and use of co-precipitation method increases quantum yield up 27.2%. [ABSTRACT FROM AUTHOR]

The controlled release of payloads from mesoporous silica nanocapsules (SiNCs) consisting of stimulus-responsive shells is of considerable interest in applications such as self-healing materials and drug delivery. However, the release of payloads from SiNCs before application of external triggers ( i.e. non-selective release) remains a formidable challenge. In fact, the non-selective release of payloads from SiNCs occurs because of the mesoporous nature of the silica shell that cannot trap payloads in the core of SiNCs perfectly. We establish an efficient and straightforward strategy based on the encapsulation of a pro-active payload to hinder the non-selective release of small payloads from mesoporous capsules. A pro-active payload is defined as a compound that is converted to an active functional molecule in the environment where it is needed. In this sense, it is a generalization of a prodrug. Encapsulating a pro-active payload instead of a payload allowed hindering the non-selective release of the payload from SiNCs. A selective release of the payload could be achieved upon reduction of the encapsulated pro-active payload. Furthermore, the total amount of released substance is significantly enhanced by introducing responsive groups in the silica shell. These results show that the pro-active payload strategy combined with the use of stimulus-responsive materials can be successfully exploited to achieve selective release of cargo from mesoporous nanocapsules. [ABSTRACT FROM AUTHOR]

The emergence of nanocarrier systems in drug delivery applications has ushered in rapid development of new classes of therapeutic agents which can provide an essential breakthrough in the fight against refractory diseases. However, successful clinical application of nano-drug delivery devices has been limited mainly due to the lack of control on sustained release of therapeutics from the carriers. A wide range of sophisticated approaches employs the formation of crosslinkable, non-crosslinkable, stimuli-responsive polymer nanocarriers in order to enhance their delivery efficiency. Despite the extensive research conducted on the development of various nanocarriers, the effect of the biological milieu on the drug release profile of these constructs is not yet fully investigated. In particular, the formation of a protein corona on the surface of nanocarriers, when they interact with living organisms in vivo is largely decisive for their biological function. Using a number of synthetized ( i.e. , superparamagnetic iron oxide nanoparticles and polymeric nanocapsules) and commercialized nanocarriers ( i.e. , Abraxane ® , albumin-bound paclitaxel drug), this study demonstrates that the protein corona can shield the nanocarriers and, consequently, alters the release profile of the drugs from the nanocarriers. More specifically, the protein corona could significantly reduce the burst effect of either protein conjugated nanocarriers or carriers with surface loaded drug ( i.e. , SPIONs). However, the corona shell only slightly changed the release profile of polymeric nanocapsules. Therefore, the intermediary, buffer effect of the protein shells on the surface of nanoscale carriers plays a crucial role in their successful high-yield applications in vivo . [ABSTRACT FROM AUTHOR]

• Shellac-based nanoparticles are prepared by nanoprecipitation and miniemulsion-solvent evaporation techniques. • Release of payloads from nanoparticles are controlled by blending shellac with other biopolymers. • PEGylation of shellac improves significantly colloidal stability. Shellac is a biomaterial obtained from secretion of lac insects. Nanoparticles based on shellac are prepared by nanoprecipitation and miniemulsion techniques. The corrosion inhibitor 2-mercaptobenzothiazole can be efficiently encapsulated in nanoparticles. Release kinetics of the inhibitor from the nanocarriers is controlled by pH of the surrounding environment as well as the introduction of other biopolymers such as lignin and zein. To overcome the low colloidal stability of shellac nanoparticles in saline conditions, shellac is conjugated with poly(ethylene glycol) moieties. After PEGylation, nanoparticles with higher critical aggregation concentration are obtained and provide release kinetics of 2-mercaptobenzothiazole similar to shellac nanoparticles. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) inevitably interact with proteins upon exposure to biological fluids, leading to the formation of an adsorption layer known as the "protein corona". This corona imparts NPs with a new biological identity, directly influencing their interactions with living systems and dictating their fates in vivo . Thus, gaining a comprehensive understanding of the dynamic interplay between NPs and proteins in biological fluids is crucial for predicting therapeutic effects and advancing the clinical translation of nanomedicines. Numerous methods have been established to decode the protein corona fingerprints. However, these methods primarily rely on prior isolation of NP-protein complex from the surrounding medium by centrifugation, resulting in the loss of outer-layer proteins that directly interact with the biological system and determine the in vivo fate of NPs. We discuss here separation techniques as well as in situ characterization methods tailored for comprehensively unraveling the inherent complexities of NP-protein interactions, highlighting the challenges of in situ protein corona characterization and its significance for nanomedicine development and clinical translation.

The preparation of coordination polymer (CP) alloys is demonstrated by the use of two meltable, one-dimensional crystal structures via melt-kneading. The polymer structures of the alloys are studied by synchrotron X-ray absorption and scattering, solid-state NMR spectroscopy, DSC, and viscoelastic measurements. Crystalline and amorphous domains and thermal properties (melting and glass transition) in the alloys depend on the ratio of the two constituent CPs. The glassy alloy composed of an equivalent amount of two CPs shows high plastic deformation properties, and the fracture point reaches 128% without a filler or compatibilizing agent, hence behaving as ductile materials.

Described is chitinase immobilization on magnetic nanoparticles (MNPs) as biocompatible support for enzymatic production of di-N-acetyl chitobiose from chitin waste. Chitinase immobilization was feasible with an immobilization yield of 88.9 ± 1.6 % with 97.8 ± 1.0 % retention of activity and compared to free enzyme work, immobilization conferred better thermal and storage stability. As practical benefit the attachment to magnetic nanocarriers enabled easy enzyme recovery after repeated application runs and thus sustainable reuse. In fixed state chitinase retained a remarkable 39.7 ± 2.6 % of the starting activity after 16 reaction cycles. Furthermore, immobilized chitinase showed higher catalytic activity than free chitinase in converting shrimp shells and squid-pens chitins into di-N-acetyl chitobiose in a single-step reaction. The final yield of purified compound was 37.0 ± 1.2 % from shrimp shells and 61.1 ± 0.5 % from squid-pens chitin. In conclusion, an efficient MNP-based chitinase immobilization system with the potential for large-scale production was developed., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Wipa Suginta reports financial support was provided by Vidyasirimedhi Institute of Science and Technology. Ailada Charoen reports financial support was provided by Vidyasirimedhi Institute of Science and Technology. Daniel Crespy reports financial support was provided by Vidyasirimedhi Institute of Science and Technology. Albert Schulte reports financial support was provided by Vidyasirimedhi Institute of Science and Technology. Wipa Suginta reports financial support was provided by National Research Council of Thailand. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The formation of a protein corona gives nanomedicines a distinct biological identity, profoundly influencing their fate in the body. Nonspecific nanoparticle-protein interactions are typically highly heterogeneous, which can lead to unique biological behaviors and in vivo fates for individual nanoparticles that remain underexplored. To address this, we have established an in situ approach that allows quantitative examination of nanoparticle-protein adsorption at the individual nanoparticle level. This method integrates dual fluorescence quantification techniques, wherein the nanoparticles are first individually analyzed via nanoflow cytometry to detect fluorescent signals from adsorbed proteins. The obtained fluorescence intensity is then translated into protein quantities through calibration with microplate reader quantification. Consequently, this approach enables analysis of interparticle heterogeneity of nano-protein interactions, as well as in situ monitoring of protein adsorption kinetics and nanoparticle aggregation status in blood serum, preconditioning for a comprehensive understanding of nano-bio interactions, and predicting in vivo fate of nanomedicines.

Coating metal structures with a protective material is a popular strategy to prevent their deterioration due to corrosion. However, maintaining the barrier properties of coatings after their mechanical damage is challenging. Herein, we prepared multifunctional coatings with self-healing ability to conserve their anticorrosion performance after damage. The coating was formed by blending synthesized redox-responsive copolymers with the ability to release a corrosion inhibitor upon the onset of corrosion with synthesized self-healing polyurethanes containing disulfide bonds. The corrosion rate of steel substrates coated with a blend is approximately 24 times lower than that of steel coated with only self-healing polyurethane. An exceptional healing efficiency, as high as 95%, is obtained after mechanical damage. The antibiofouling property against bacterial and microalgal attachments on coatings is facilitated by the repellent characteristic of fluorinated segments and the biocidal activity of the inhibitor moieties in the copolymer.

Understanding the transport of nanoparticles from and within hydrogels is a key issue for the design of nanocomposite hydrogels for drug delivery systems and tissue engineering. To investigate the translocation of nanocarriers from and within hydrogel networks triggered by changes of temperature, ultrasmall (8 nm) and small (80 nm) silica nanocapsules are embedded in temperature-responsive hydrogels and non-responsive hydrogels. The ultrasmall silica nanocapsules are released from temperature-responsive hydrogels to water or transported to other hydrogels upon direct activation by heating or indirect activation by Joule heating; while, they are not released from non-responsive hydrogel. Programmable transport of nanocarriers from and in hydrogels provides insights for the development of complex biomedical devices and soft robotics., (© 2024 Wiley‐VCH GmbH.)

Organic coatings are one of the most popular and powerful strategies for protecting metals against corrosion. They can be applied in different ways, such as by dipping, spraying, electrophoresis, casting, painting, or flow coating. They offer great flexibility of material designs and cost effectiveness. Moreover, self-healing has evolved as a new research topic for protective organic coatings in the last two decades. Responsive materials play a crucial role in this new research field. However, for targeting the development of high-performance self-healing coatings for corrosion protection, it is not sufficient just to focus on smart responsive materials and suitable active agents for self-healing. A better understanding of how coatings can react on different stimuli induced by corrosion, how these stimuli can spread in the coating, and how the released agents can reach the corroding defect is also of high importance. Such knowledge would allow the design of coatings that are optimized for specific applications. Herein, the requirements and possibilities from the corrosion and synthesis perspectives for designing materials for preparing self-healing coatings for corrosion protection are discussed., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

Reusable face masks are an important alternative for minimizing costs of disposable and surgical face masks during pandemics. Often complementary to washing, a prolonged lifetime of face masks relies on the incorporation of self-cleaning materials. The development of self-cleaning face mask materials requires the presence of a durable catalyst to deactivate contaminants and microbes after long-term use without reducing filtration efficiency. Herein, we generate self-cleaning fibers by functionalizing silicone-based (polydimethylsiloxane, PDMS) fibrous membranes with a photocatalyst. Coaxial electrospinning is performed to fabricate fibers with a non-crosslinked silicone core within a supporting shell scaffold, followed by thermal crosslinking and removal of the water-soluble shell. Photocatalytic zinc oxide nanoparticles (ZnO NPs) are immobilized on the PDMS fibers by colloid-electrospinning or post-functionalization procedures. The fibers functionalized with ZnO NPs can degrade a photo-sensitive dye and display antibacterial properties against Gram-positive and Gram-negative bacteria ( Escherichia coli and Staphylococcus aureus ) due to the generation of reactive oxygen species upon irradiation with UV light. Furthermore, a single layer of functionalized fibrous membrane shows an air permeability in the range of 80-180 L/m 2 s and 65% filtration efficiency against fine particulate matter with a diameter less than 1.0 µm (PM 1.0 )., Supplementary Information: The online version contains supplementary material available at 10.1007/s42765-023-00291-7., Competing Interests: Conflict of interestThe authors declare no competing interests., (© The Author(s) 2023.)

The catalytic cycloaddition of CO 2 to epoxides to afford cyclic carbonates as useful monomers, intermediates, solvents, and additives is a continuously growing field of investigation as a way to carry out the atom-economic conversion of CO 2 to value-added products. Metal-free organocatalytic compounds are attractive systems among various catalysts for such transformations because they are inexpensive, nontoxic, and readily available. Herein, we highlight and discuss key advances in the development of polymer-based organocatalytic materials that match these requirements of affordability and availability by considering their synthetic routes, the monomers, and the supports employed. The discussion is organized according to the number (monofunctional versus bifunctional materials) and type of catalytically active moieties, including both halide-based and halide-free systems. Two general synthetic approaches are identified based on the postsynthetic functionalization of polymeric supports or the copolymerization of monomers bearing catalytically active moieties. After a review of the material syntheses and catalytic activities, the chemical and structural features affecting catalytic performance are discussed. Based on such analysis, some strategies for the future design of affordable and readily available polymer-based organocatalysts with enhanced catalytic activity under mild conditions are considered.

Complex coacervates are liquid-like droplets that can be used to create adaptive cell-like compartments. These compartments offer a versatile platform for the construction of bioreactors inspired by living cells. However, the lack of a membrane significantly reduces the colloidal stability of coacervates in terms of fusion and surface wetting, which limits their suitability as compartments. Here, we describe the formation of caged-coacervates surrounded by a semipermeable shell of silica nanocapsules. We demonstrate that the silica nanocapsules create a protective shell that also regulates the molecular transport of water-soluble compounds as a function of nanocapasule size. The adjustable semipermeability and intrinsic affinity of enzymes for the interior of the caged-coacervates allowed us to assemble biomimetic microreactors with enhanced colloidal stability.

Investigations of the densities of chemicals and materials bring valuable insights into the fundamental understanding of matter and processes. Recently, advanced density-based methods have been developed with wide measurement ranges ( i.e. 0-23 g cm -3 ), high resolutions ( i.e. 10 -6 g cm -3 ), compatibility with different types of samples and the requirement of extremely low volumes of sample (as low as a single cell). Certain methods, such as magnetic levitation, are inexpensive, portable and user-friendly. Advanced density-based methods are, therefore, beneficially used to obtain absolute density values, composition of mixtures, characteristics of binding events, and kinetics of chemical and biological processes. Herein, the principles and applications of magnetic levitation, acoustic levitation, electrodynamic balance, aqueous multiphase systems, and suspended microchannel resonators for materials science are discussed.

Long-chain cyclic carbonates (LC-CC) are attractive building blocks and non-ionic surfactants. We demonstrate a convenient methodology to prepare LC-CC in miniemulsions of epoxide droplets in water. The pre-organization and confinement of the reagents from H-bond and hydrophobic interactions allow the target process to proceed at mild temperatures under atmospheric CO 2 .

Apolipoproteins are an important class of proteins because they provide a so-called stealth effect to nanoparticles. The stealth effect on nanocarriers leads to a reduced unspecific uptake into immune cells and thereby to a prolonged blood circulation time. Herein, a novel strategy to bind apolipoproteins specifically on nanoparticles by adjusting the temperature during their incubation in human plasma is presented. This specific binding, in turn, allows a control of the stealth behavior of the nanoparticles. Nanoparticles with a well-defined poly(N-isopropylacrylamide) shell are prepared, displaying a reversible change of hydrophobicity at a temperature around 32 °C. It is shown by label-free quantitative liquid chromatography-mass spectrometry that the nanoparticles are largely enriched with apolipoprotein J (clusterin) at 25 °C while they are enriched with apolipoprotein A1 and apolipoprotein E at 37 °C. The temperature-dependent protein binding is found to significantly influence the uptake of the nanoparticles by RAW264.7 and HeLa cells. The findings imply that the functionalization of nanoparticles with temperature-responsive materials is a suitable method for imparting stealth properties to nanocarriers for drug-delivery., (© 2021 The Authors. Small published by Wiley-VCH GmbH.)

Water-soluble low molecular weight drugs, such as the synthetic glucocorticoid dexamethasone (DXM), can easily leak out of nanocarriers after encapsulation due to their hydrophilic nature and small size. This can lead to a reduced therapeutic efficacy and therefore to unwanted adverse effects on healthy tissue. Targeting DXM to inflammatory cells of the liver like Kupffer cells or macrophages is a promising approach to minimize typical side effects. Therefore, a controlled transport to the cells of interest and selective on-site release is crucial. Aim of this study was the development of a DXM-phosphate-based polyprodrug and the encapsulation in silica nanocontainers (SiO 2 NCs) for the reduction of inflammatory responses in liver cells. DXM was copolymerized with a linker molecule introducing pH-cleavable hydrazone bonds in the backbone and obtaining polyprodrugs (PDXM). Encapsulation of PDXMs into SiO 2 NCs provided a stable confinement avoiding uncontrolled leakage. PDXMs were degraded under acidic conditions and subsequently released out of SiO 2 NCs. Biological studies showed significantly enhanced anti-inflammatory capacity of the polyprodrug nanoformulations over non-encapsulated DXM or soluble polyprodrugs. These results demonstrate the advantage of combining the polyprodrug strategy with nanocarrier-mediated delivery for enhanced control of the delivery of water-soluble low molecular weight drugs.

Silica nanocapsules (SiO 2 NCs) are usually prepared with cationic surfactants that are not cytocompatible. Dialysis can be used to remove surfactants but leads to instability of the SiO 2 NCs when they are in the presence of proteins or biological media. Herein, SiO 2 NCs stabilized with a reactive surfactant are synthesized to prevent leaching upon dialysis. The SiO 2 NCs show superior stability and biocompatibility compared with SiO 2 NCs prepared with conventional surfactants. The SiO 2 NCs can be used in self-healing materials, smart agriculture and biomedical applications.

Optical imaging probes have played a major role in detecting and monitoring a variety of diseases. In particular, nonlinear optical imaging probes, such as second harmonic generating (SHG) nanoprobes, hold great promise as clinical contrast agents, as they can be imaged with little background signal and unmatched long-term photostability. As their chemical composition often includes transition metals, the use of inorganic SHG nanoprobes can raise long-term health concerns. Ideally, contrast agents for biomedical applications should be degraded in vivo without any long-term toxicological consequences to the organism. Here, we developed biodegradable harmonophores (bioharmonophores) that consist of polymer-encapsulated, self-assembling peptides that generate a strong SHG signal. When functionalized with tumor cell surface markers, these reporters can target single cancer cells with high detection sensitivity in zebrafish embryos in vivo . Thus, bioharmonophores will enable an innovative approach to cancer treatment using targeted high-resolution optical imaging for diagnostics and therapy.

Antibacterial materials containing biocides suffer from the fact that biocides are usually quickly released and hence display a limited antibacterial ability over a long period of time. To overcome this problem, the antibacterial agent 6-chloropurine is conjugated to a monomer via a hemiaminal ether linkage. The functional monomer is then reacted with a urethane acrylate by photopolymerization to yield thin polymer coatings. The release of the antibacterial agent from the coatings is sustained due to the slow kinetics of the hydrolysis of the hemiaminal ether linkage. Antibacterial performance is achieved against S. aureus and E. coli bacteria. This simple strategy can be applied for the rapid preparation of antibacterial coatings on various substrates and other applications such as antifouling or anticorrosion coatings.

For nanocarriers with low protein affinity, we show that the interaction of nanocarriers with cells is mainly affected by the density, the molecular weight, and the conformation of polyethylene glycol (PEG) chains bound to the nanocarrier surface. We achieve a reduction of nonspecific uptake of ovalbumin nanocarriers by dendritic cells using densely packed PEG chains with a "brush" conformation instead of the collapsed "mushroom" conformation. We also control to a minor extent the dysopsonin adsorption by tailoring the conformation of attached PEG on the nanocarriers. The brush conformation of PEG leads to a stealth behavior of the nanocarriers with inhibited uptake by phagocytic cells, which is a prerequisite for successful in vivo translation of nanomedicine to achieve long blood circulation and targeted delivery. We can clearly correlate the brush conformation of PEG with inhibited phagocytic uptake of the nanocarriers. This study shows that, in addition to the surface's chemistry, the conformation of polymers controls cellular interactions of the nanocarriers.

Corrosion is a financial and enviromental plague which leads to the deterioration of our infrastructures. Using corrosion inhibitors at low concentrations in coatings is one effective method for preventing corrosion. Inspired by the development of polymer-drug conjugates, corrosion inhibitors are incorporated in various polymer structures to create novel materials for hindering corrosion. We discuss the strategies to covalently integrate corrosion inhibitors in polymer structures to form polymer-inhibitor conjugates. Inhibitors are conjugated to polymers via non-labile or stimuli-labile linkages to allow the release of the inhibitors upon onset of corrosion. The application and anticorrosion performance of representative polymers are also discussed.

Strategies for corrosion protection are required to prolong the life span of metallic structures used by the construction, aerospace, and transport industries. Currently, there are no coatings that can provide at the same time information about the corrosion status of the coated metal and protect the metal against corrosive species and mechanical damage. Herein, triple-functional microcarriers with functions of corrosion sensing, self-healing, and corrosion inhibition are produced and embedded in coatings to prolong the lifetime of metals and enhance the anticorrosion performance of coatings. The microcarriers are prepared by creating Pickering droplets loaded with a corrosion inhibitor and a healing agent and stabilized by silica nanocapsules containing thymol blue as corrosion sensor. The microcarriers are then embedded in a water-based polymer matrix coated on metal substrates. When the coating or metal is mechanically damaged, the healing agent is released from the droplets to hinder further corrosion of the metal. When the local pH value near the metal surface is changing by the generation of hydroxide ion due to the corrosion process, a change of color is detected as well as a release of corrosion inhibitor, leading to a significant decrease of corrosion rate of the coated metal.

Photocatalytic degradation of organic pollutants is a promising way to clean wastewater. Herein, we develop and compare two processes for fabricating nanofibrous membranes with photocatalytic properties. Hybrid nanofibers are produced by colloid-electrospinning and composed of metal oxide nanoparticles on sintered SiO 2 nanoparticles. The latter serves as support for the photocatalyst and preserves the structural integrity of nanofibers. Adsorption of metal salts on crosslinked polymer/SiO 2 fibers followed by calcination allows for the obtention of fibers with large amounts of metal oxide. Nanofibrous membranes with supported ZnO, In 2 O 3 , or mixture of both, display photocatalytic activity upon UV irradiation. The membranes can degrade a dye and an organophosphate pesticide more effectively than membranes directly fabricated from the calcination of metal oxides.

Nanoparticles have been widely used for many applications such as catalysis, biomedicine, or self-healing. Core-shell nanoparticles are very promising for biomedical applications due to several features such as possibility of sequence-controlled release of drugs and protection of sensitive payloads from surrounding environment. Core-shell structures incorporating payloads such as drugs, peptides, or hormones have been investigated in pre-clinical studies. The present review describes state of the art techniques for designing core-shell particles for biomedical applications. We also present recent advances in the field of drug, protein/peptide, and gene delivery using different types of core-shell nanoparticles. The function of core-shell particles as contrast agents and labels for bioimaging in magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography imaging (CT), ultrasound, and optical imaging is highlighted as well as their applications as biosensors.

Smart nanocarriers for the transport of drugs to tumor cells are nowadays of great interest for treating cancer. The use of enzymatic stimuli to cleave peptide-based drug nanocapsules for the selective release of nanocapsule cargo in close proximity to tumor cells opens new possibilities in cancer research. In the present work, we demonstrate a methodology for finding and optimizing cleavable substrate sequences by the type II transmembrane serine protease hepsin, which is highly overexpressed in prostate cancer. The design and screening of combinatorial libraries in silico against the binding cavity of hepsin allow the identification of a panel of promising substrates with high-calculated docking scores. In vitro screening verifies the predictions and showed that all substrates are cleaved by hepsin with higher efficiency than the literature known hepsin substrate RQLR↓VVGG. The introduction of d-amino acids on a selected peptide with the highest catalytic efficiency ( k cat / K m ) renders it resistant to cleavage by plasma or serum while maintaining their susceptibility to hepsin.

In the past decade, we witnessed limited success in the clinical translation of therapeutic nanoparticles (NPs). One of the main reasons for this limited success is our poor understanding of the biological identity of NPs. Herein, we report magnetic levitation (MagLev) as a complementary analytical tool to investigate the homogeneity of the created protein corona (PC) coated NPs through an ex vivo model. Our results demonstrate that the MagLev system not only has the capacity to separate corona coated NPs, but also enables us to study the homogeneity/heterogeneity of the PC. Our findings suggest that current ex vivo isolation methods cause a heterogeneous coverage of PC profiles at the surface of NPs. The MagLev technique, therefore, would be instrumental in identifying and separating fully PC coated NPs which, in turn, enables us to achieve more accurate information on protein corona composition. Ultimately, we believe that the MagLev technique can be used for the fast screening of the homogeneity of corona coated NPs before quantitative analysis of the corona profile/composition, hence definitely improving our fundamental understanding of nano-bio interfaces.

Immunosuppression with glucocorticoids is a common treatment for autoimmune liver diseases and after liver transplant, which is however associated with severe side-effects. Targeted delivery of glucocorticoids to inflammatory cells, e.g. liver macrophages and Kupffer cells, is a promising approach for minimizing side effects. Herein, we prepare core-shell silica nanocapsules (SiO 2 NCs) via a sol-gel process confined in nanodroplets for targeted delivery of dexamethasone (DXM) for liver immunosuppressive therapy. DXM with concentrations up to 100 mg mL -1 in olive oil are encapsulated while encapsulation efficiency remains over 95% after 15 days. Internalization of NCs by non-parenchymal murine liver cells significantly reduces the release of inflammatory cytokines, indicating an effective suppression of inflammatory response of liver macrophages. Fluorescent and magnetic labeling of the NCs allows for monitoring their intracellular trafficking and biodegradation. Controlled interaction with blood proteins and good colloidal stability in blood plasma are achieved via PEGylation of the NCs. Specific proteins responsible for stealth effect, such as apolipoprotein A-I, apolipoprotein A-IV, and clusterin, are present in large amounts on the PEGylated NCs. In vivo biodistribution investigations prove an efficient accumulation of NCs in the liver, underlining the suitability of the SiO 2 NCs as a dexamethasone carrier for treating inflammatory liver diseases.

Given the large amount of anthropogenic CO 2 emissions, it is advantageous to use CO 2 as feedstock for the fabrication of everyday products, such as fuels and materials. An attractive way to use CO 2 in the synthesis of polymers is by the formation of five-membered cyclic organic carbonate monomers (5CCs). The sustainability of this synthetic approach is increased by using scaffolds prepared from renewable resources. Indeed, recent years have seen the rise of various types of carbonate syntheses and applications. 5CC monomers are often polymerized with diamines to yield polyhydroxyurethanes (PHU). Foams are developed from this type of polymers; moreover, the additional hydroxyl groups in PHU, absent in classical polyurethanes, lead to coatings with excellent adhesive properties. Furthermore, carbonate groups in polymers offer the possibility of post-functionalization, such as curing reactions under mild conditions. Finally, the polarity of carbonate groups is remarkably high, so polymers with carbonates side-chains can be used as polymer electrolytes in batteries or as conductive membranes. The target of this Review is to highlight the multiple opportunities offered by polymers prepared from and/or containing 5CCs. Firstly, the preparation of several classes of 5CCs is discussed with special focus on the sustainability of the synthetic routes. Thereafter, specific classes of polymers are discussed for which the use and/or presence of carbonate moieties is crucial to impart the targeted properties (foams, adhesives, polymers for energy applications, and other functional materials)., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

To promote drug delivery to exact sites and cell types, the surface of nanocarriers is functionalized with targeting antibodies or ligands, typically coupled by covalent chemistry. Once the nanocarrier is exposed to biological fluid such as plasma, however, its surface is inevitably covered with various biomolecules forming the protein corona, which masks the targeting ability of the nanoparticle. Here, we show that we can use a pre-adsorption process to attach targeting antibodies to the surface of the nanocarrier. Pre-adsorbed antibodies remain functional and are not completely exchanged or covered by the biomolecular corona, whereas coupled antibodies are more affected by this shielding. We conclude that pre-adsorption is potentially a versatile, efficient and rapid method of attaching targeting moieties to the surface of nanocarriers.

The enhanced relaxation of hydrogen atoms of surrounding water from suitable contrast agent promotes magnetic resonance imaging as one of the most important medical diagnosis technique. The key challenge for the preparation of performant contrast agents for magnetic resonance imaging with high relaxivity is to ensure a high local concentration of contrast agent while allowing a contact between water and the contrast agent. Both requirements are answered by tailoring a semipermeable confinement for a gadolinium complex used as contrast agent. A locally high concentration is achieved by successfully encapsulating the complex in polymer nanocontainers that serves to protect and retain the complex inside a limited space. The access of water to the complex is achieved by carefully controlling the chemistry of the shell and the core of the nanocontainers. The confinement of the nanocontainers enables an increased relaxivity compared to an aqueous solution of the contrast agent. The nanocontainers are successfully applied in vivo to yield enhanced contrast in magnetic resonance imaging., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

From particles to fibers: Nanofibers with different morphologies and periodicities can be fabricated by supraparticular assembly of magnetic spherical nanoparticles. A linear sintering process is used to merge the assembled colloids together. The structure of the obtained fibers is controlled by the process parameters and the morphology of the spherical colloidal building blocks., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)