Dynamic Photonic Janus Colloids with Axially Stacked Structural Layers

Diblock copolymer (dBCP) particles capable of dynamic shape and color changes have gained significant attention due to their versatility in programmable shapes and intricate nanostructures. However, their application in photonic systems remains limited due to challenges in achieving a sufficient number of defect-free photonic layers over a tens-of-micrometer scale. In this study, we present a pioneering demonstration of photonic dBCP particles featuring over 300 axially stacked photonic layers with responsive color- and shape-transforming capabilities. Our approach leverages the complex interplay between the macrophase separation of multiple incompatible components and the microphase separation of dBCP from solvent-evaporative microemulsions. Specifically, continuous phase separation of silicone oil from polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP), triggered by solvent evaporation, promotes the anisotropic growth of PS-b-P2VP layers. This results in the formation of Janus colloids, where an oil droplet merges with a nanostructured polymer cone and lamellar structures align along the long axis of the cone. We highlight the capability to precisely adjust the particle morphology and the corresponding orientation, dispersion, and structural color window by modulating both the molecular weight of PS-b-P2VP and the volume ratio between PS-b-P2VP and silicone oil. Furthermore, reversible swelling/deswelling of photonic colloids is visualized and correlated with their structural colors. Finally, we demonstrate the potential of this study by presenting a multicolor-patterned array of photonic colloids, highlighting the possibilities for applications in smart photonic ink and devices.

Enzymatically Activatable Polymers for Disease Diagnosis and Treatment

The irregular expression or activity of enzymes in the human body leads to various pathological disorders and can therefore be used as an intrinsic trigger for more precise identification of disease foci and controlled release of diagnostics and therapeutics, leading to improved diagnostic accuracy, sensitivity, and therapeutic efficacy while reducing systemic toxicity. Advanced synthesis strategies enable the preparation of polymers with enzymatically activatable skeletons or side chains, while understanding enzymatically responsive mechanisms promotes rational incorporation of activatable units and predictions of the release profile of diagnostics and therapeutics, ultimately leading to promising applications in disease diagnosis and treatment with superior biocompatibility and efficiency. By overcoming the challenges, new opportunities will emerge to inspire researchers to develop more efficient, safer, and clinically reliable enzymatically activatable polymeric carriers as well as prodrugs.

The Application of Nanogels as Efficient Drug Delivery Platforms for Dermal/Transdermal Delivery

The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens and other molecules including drugs; in fact, it serves as a primary defense system blocking any particle from entering the body. Therefore, to overcome the skin barriers and poor skin permeability, researchers implement novel carriers which can effectively carry out transdermal delivery of the molecules. Another significant issue which medical society tries to solve is the effective dermal delivery of molecules especially for topical wound delivery. The application of nanogels is only one of the available approaches offering promising results for both dermal and transdermal administration routes. Nanogels are polymer-based networks in nanoscale dimensions which have been explored as potent carriers of poorly soluble drugs, genes and vaccines. The nanogels present unique physicochemical properties, i.e., high surface area, biocompatibility, etc., and, importantly, can improve solubility. In this review, authors aimed to summarize the available applications of nanogels as possible vehicles for dermal and transdermal delivery of active pharmaceutical ingredients and discuss their future in the pharmaceutical manufacturing field.

Non-interference delivery of Ce6 and DOX in NIR light-responsive liposomes for synergetic cervical cancer therapy

Multi-modal combined treatment of malignant tumors can make up for the shortcomings of single treatment through multi-target and multi-path effects to achieve more ideal tumor treatment effect. However, the mutual interference of different drugs in the delivery process in vivo and the difficulty of effective drug accumulation in tumor cells in the first release are the bottlenecks of combined therapy. To this project, light-responsive liposomes (DOX-Ce6-Lip) loading doxorubicin (DOX) and Chlorin e6 (Ce6) without mutual interference were engineered by thin film hydration method. This kind of nano-drug delivery system increased the drugs concentration accumulated in tumors through the EPR effect, and reduce the toxic and side effects of drugs on other tissues in vivo. In addition, after entering the tumor cells, Ce6 produced a large number of reactive oxygen species (ROS) under 660 nm NIR laser irradiation. These ROS further oxidized the unsaturated fatty acid chain in the liposomes and caused the collapse of the liposomes, thus realizing the stimulus-responsive release of Ce6 and DOX. The concentration of DOX and Ce6 in the tumor rapidly reached the peak and achieved a more effective combination of chemotherapy and photodynamic therapy. Consequently, DOX-Ce6-Lip with 660 nm NIR irradiation achieved an efficient tumor growth inhibition of 71.90 ± 3.14%, indicating the versatile potential of chemotherapy and PDT.&#xD.

Photo-Cross-Linked Polymeric Dispersants of Comb-Shaped Benzophenone-Containing Poly(ether amine)

Efficient dispersion of nanoparticles (NPs) is a crucial challenge in the preparation and application of composites that contain NPs, particularly in coatings, inks, and related materials. Physical adsorption and chemical modification are the two common methods used to disperse NPs. However, the former suffers from desorption, and the latter is more specific and has limited versatility. To address these issues, we developed a novel photo-cross-linked polymeric dispersant, comb-shaped benzophenone-containing poly(ether amine) (bPEA), using a one-pot nucleophilic/cyclic-opening addition reaction. The results demonstrated that the bPEA dispersant forms a dense and stable shell on the surface of pigment NPs through physical adsorption and subsequent chemical photo-cross-linking, which effectively overcome the drawbacks of the desorption occurred in physical adsorption and the specificity of the chemical modification. By means of the dispersing effect of bPEA, the obtained pigment dispersions show high solvent, thermal, and pH stability without flocculation during storage. Moreover, the NPs dispersants show good compatibility with screen printing, coating, and 3D printing, endowing the ornamental products with high uniformity, color fastness, and less color shading. These properties make bPEA dispersants ideal candidates in fabrication dispersions of other NPs.

Radio Wave-Activated Chemotherapy-A Novel Nanoparticle Thermoresponsive Copolymer Drug Delivery Platform

Radio waves are highly penetrating, non-ionizing, and cause minimal damage to surrounding tissues. Radio wave control of drug release has been achieved using a novel thermoresponsive copolymer bound to a superparamagnetic iron oxide nanoparticle (SPION) core. A NIPAM-acrylamide-methacrolein copolymer underwent a coil-to-globular structure phase change upon reaching a critical temperature above the human body temperature but below hyperthermic temperatures. The copolymer was covalently bound to SPIONs which increase in temperature upon exposure to radio waves. This effect could be controlled by varying input energies and frequencies. For controlled drug release, proteins were bound via aldehyde groups on the copolymer and amine groups on the protein. The radio wave-induced heating of the complex thereby released the drug-bearing proteins. The fine-tuning of the radio wave exposure allowed multiple cycles of protein-drug release. The fluorescent tagging of the complex by FITC was also achieved in situ, allowing the tagging of the complex. The localization of the complex could also be achieved in vitro under a permanent magnetic field.

Systemic inflammation as a biomarker of seizure propensity and a target for treatment to reduce seizure propensity

People with diabetes can wear a device that measures blood glucose and delivers just the amount of insulin needed to return the glucose level to within bounds. Currently, people with epilepsy do not have access to an equivalent wearable device that measures a systemic indicator of an impending seizure and delivers a rapidly acting medication or other intervention (e.g., an electrical stimulus) to terminate or prevent a seizure. Given that seizure susceptibility is reliably increased in systemic inflammatory states, we propose a novel closed-loop device where release of a fast-acting therapy is governed by sensors that quantify the magnitude of systemic inflammation. Here, we review the evidence that patients with epilepsy have raised levels of systemic indicators of inflammation than controls, and that some anti-inflammatory drugs have reduced seizure occurrence in animals and humans. We then consider the options of what might be incorporated into a responsive anti-seizure system.

Electrostatic Fields Stimulate Absorption of Small Neutral Molecules in Gradient Polyelectrolyte Brushes

Molecules can partition from a solution into a polymer coating, leading to a local enrichment. If one can control this enrichment via external stimuli, one can implement such coatings in novel separation technologies. Unfortunately, these coatings are often resource intensive as they require stimuli in the form changes of bulk solvent conditions such as acidity, temperature, or ionic strength. Electrically driven separation technology may provide an appealing alternative, as this will allow local, surface-bound stimuli instead of system-wide bulk stimuli to induce responsiveness. Therefore, we investigate via coarse grained molecular dynamics simulations the possibility of using coatings with charged moieties, specifically gradient polyelectrolyte brushes, to control the enrichment of the neutral target molecules near the surface with applied electric fields. We find that targets which interact more strongly with the brush show both more absorption and a larger modulation by electric fields. For the strongest interactions evaluated in this work, we obtained absorption changes of over 300 % between the collapsed and extended state of the coating.

Digital Phenotyping Data to Predict Symptom Improvement and Mental Health App Personalization in College Students: Prospective Validation of a Predictive Model

BACKGROUND

Mental health apps offer a transformative means to increase access to scalable evidence-based care for college students. Yet low rates of engagement currently preclude the effectiveness of these apps. One promising solution is to make these apps more responsive and personalized through digital phenotyping methods able to predict symptoms and offer tailored interventions.

OBJECTIVE

Following our protocol and using the exact model shared in that paper, our primary aim in this study is to assess the prospective validity of mental health symptom prediction using the mindLAMP app through a replication study. We also explored secondary aims around app intervention personalization and correlations of engagement with the Technology Acceptance Model (TAM) and Digital Working Alliance Inventory scale in the context of automating the study.

METHODS

The study was 28 days in duration and followed the published protocol, with participants collecting digital phenotyping data and being offered optional scheduled and algorithm-recommended app interventions. Study compensation was tied to the completion of weekly surveys and was not otherwise tied to engagement or use of the app.

RESULTS

The data from 67 participants were used in this analysis. The area under the curve values for the symptom prediction model ranged from 0.58 for the UCLA Loneliness Scale to 0.71 for the Patient Health Questionnaire-9. Engagement with the scheduled app interventions was high, with a study mean of 73%, but few participants engaged with the optional recommended interventions. The perceived utility of the app in the TAM was higher (P=.01) among those completing at least one recommended intervention.

CONCLUSIONS

Our results suggest how digital phenotyping methods can be used to create generalizable models that may help create more personalized and engaging mental health apps. Automating studies is feasible, and our results suggest targets to increase engagement in future studies.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/37954.

Soft Poly(N-vinylcaprolactam) Based Aqueous Particles

Soft nanoparticles are an important class of material with potential to be used as carriers of active compounds. Swollen, penetrable particles can act as a host for the active ingredients and provide stability, stimuli-responsiveness and recyclability for the guest. Thermoresponsive colloidal gel particles are especially attractive for such applications due to the extremely soft structure, size and responsiveness. Poly(N-vinylcaprolactam) (PNVCL) is a much studied, popular thermoresponsive polymer. The polymer has low toxicity and the phase transition temperature is close to body temperature. During the phase transition, the polymer becomes less soluble, the particle expels a large part of water and the particle collapses to a more compact form. The diffusion of material in and from the particles is largely affected by this transition.  As the solubility of the polymer changes, so do the interactions with the loaded compound.  This feature article focuses on the synthetic methods, properties and applications of soft PNVCL particles.

Maternal Responsive Parenting Trajectories From Birth to Age 3 and Children's Self-Esteem at First Grade

This paper examines the quality and stability of the responsive parenting practices of mothers with infants and the longitudinal links between these practices and children’s self-esteem. Using data presented by the Panel Study on Korean Children, this study identified Korean mothers’ responsive parenting trajectories from birth to age three and examined their associations with children’s self-esteem at first grade. Korean mothers developed one of three responsive parenting patterns from birth to age three: low (19.0%), moderate (66.0%), or high (15.0%). Children’s self-esteem differed according to their mother’s responsive parenting trajectory. First-graders with mothers displaying the low responsive parenting trajectory were more likely to have lower self-esteem than children of mothers with the moderate responsive parenting trajectory and children of mothers with the high responsive parenting trajectory. The longitudinal link between mother-reported responsive parenting patterns during infancy and child-reported self-esteem at first grade was verified. This finding highlights the significance of early responsive parenting from mothers as a predictor of the self-esteem of children in later developmental stages.

Self-Bonded Hydrogel Inverse Opal Particles as Sprayed Flexible Patch for Wound Healing

Wound healing is an important issue for regenerative medicine. Attempts in this area tend to develop functional wound patches to promote the healing. Here, we present self-bonded hydrogel inverse opal particles as sprayed flexible patch for wound healing. Such particles were fabricated by infusing drugs-loaded gelatin (GT) and carrageenan (CG) pregel into inverse opal scaffolds, which were composed of biocompatible hyaluronic acid methacryloyl (HAMA) and gelatin methacryloyl (GelMA) with graphene oxide quantum dots (GO QDs) doping. Due to the photothermal conversion capability of GO QDs and temperature reversible phase-changing performance of GT/CG, the hybrid particles could undergo GT/CG liquid transformation under the near-infrared (NIR) irradiation, which made them adhere to each other and finally form a flexible patch. Following by the phase-change of GT/CG hydrogel, the encapsulated drugs were also controllably released from the inverse opal scaffold. As the inverse opal scaffolds of the hybrid particles were maintained, their drug release induced refractive index changes could be detected as visual structural color shifting, which could be utilized to monitor their delivery processes. Based on these features, we have demonstrated that the self-bonded particles, administered in the form of spray, could be applied for wound tissue healing and drug delivery monitoring. These results indicate that the self-bonded hydrogel particles have potential value as a multifunctional patch for clinical applications.

Solvent and pH Stability of Poly(styrene-alt-maleic acid) (PSaMA) Membranes Prepared by Aqueous Phase Separation (APS)

In the single-polyelectrolyte aqueous phase separation (APS) approach, membranes are prepared by precipitating a weak polyelectrolyte from a concentrated aqueous solution using a pH switch. This has proven to be a versatile and more sustainable method compared to conventional approaches as it significantly reduces the use of organic solvents. Poly(styrene-alt-maleic acid) (PSaMA) is a polymer that has been extensively investigated for APS and has been the basis for both open and dense membranes with good performances. These membranes are chemically crosslinked and, in this work, we further investigated ultrafiltration (UF) and nanofiltration (NF) membranes prepared with PSaMA for their stability in various organic solvents and under different pH conditions. It was shown that these membranes had stable performances in both isopropanol (IPA) and toluene, and a slightly reduced performance in N-methyl-2-pyrollidone (NMP). However, PSaMA did not perform well as a selective layer in these solvents, indicating that the real opportunity would be to use the UF-type PSaMA membranes as solvent-stable support membranes. Additionally, the membranes proved to be stable in an acidic-to-neutral pH regime (pH 2–7); and, due to the pH-responsive nature of PSaMA, for the NF membranes, a pH-dependent retention of Mg²⁺ and SO₄²⁻ ions was observed and, for the UF membranes, a strong responsive behavior was observed, where the pH can be used to control the membrane permeability. However, long-term exposure to elevated pH conditions (pH 8–10) resulted in severe swelling of the NF membranes, resulting in defect formation, and compaction of the UF membranes. For the UF membranes, this compaction did prove to be reversible for some but not all of the membrane samples measured. These results showed that in aqueous systems, membranes prepared with PSaMA had interesting responsive behaviors but performed best at neutral and acidic pH values. Moreover, the membranes exhibited excellent stability in the organic solvents IPA and toluene

Smart magnetic resonance imaging-based theranostics for cancer

Smart theranostics are dynamic platforms that integrate multiple functions, including at least imaging, therapy, and responsiveness, in a single agent. This review showcases a variety of responsive theranostic agents developed specifically for magnetic resonance imaging (MRI), due to the privileged position this non-invasive, non-ionising imaging modality continues to hold within the clinical imaging field. Different MRI smart theranostic designs have been devised in the search for more efficient cancer therapy, and improved diagnostic efficiency, through the increase of the local concentration of therapeutic effectors and MRI signal intensity in pathological tissues. This review explores novel small-molecule and nanosized MRI theranostic agents for cancer that exhibit responsiveness to endogenous (change in pH, redox environment, or enzymes) or exogenous (temperature, ultrasound, or light) stimuli. The challenges and obstacles in the design and in vivo application of responsive theranostics are also discussed to guide future research in this interdisciplinary field towards more controllable, efficient, and diagnostically relevant smart theranostics agents.

Utilizing Stimuli Responsive Linkages to Engineer and Enhance Polymer Nanoparticle-Based Drug Delivery Platforms

The devastating nature of cancer continues to be one of the leading causes of death in the world. Chemotherapy is among the most common forms of cancer treatment but comes with a host of adverse effects caused by the therapeutic agents damaging healthy tissue and organs. To limit these side effects, scientists have been designing stimuli responsive drug delivery vessels for targeted release. This Review focuses on the incorporation of stimuli responsive linkages in targeted drug delivery systems to enhance therapeutic efficiency. These platforms are primarily employed to control the distribution of anticancer agents in the body to reduce the adverse side effects caused by their toxicities. We will outline how drug delivery vessels are constructed so that exposure to select environmental and external stimuli releases the enclosed drug only at the target site. Stimuli responsive components are integrated within drug delivery vessels in the form of cross-linkers, polymers, and surface modifications. The changes, these moieties undergo upon stimuli exposure, cascade into larger scale alterations to the platforms, resulting in complete disassembly, reversible morphological variations, and enhanced cellular uptake. The ability for these modes of delivery to be initiated exclusively under stimuli exposure allows for release of toxic therapeutic agents to be confined only to the affected area.

Construction of a pH/TGase "Dual Key"-Responsive Gold Nano-radiosensitizer with Liver Tumor-Targeting Ability

The method of tumor microenvironment (TME)-responsive aggregation has become a promising approach to enhance treatment effect by improving the accumulation of nanoparticles in tumors. The enzymatic cross-linking strategy has widely attracted attention owing to its good aggregation stability and biocompatibility. However, the enzymes in nontumor tissue can also catalyze the cross-linking reaction and reduce accumulation of nanoparticles in tumor. In this work, a "dual key"-responsive strategy is utilized to construct a transglutaminase (TGase)/pH-responsive radiosensitizer (Au@TAcoGal) with specific aggregation behavior in hepatic tumor cells. Au@TAcoGal can retain its stability in blood circulation (pH 7.4) even in the presence of TGase in plasma. On reaching tumor sites, it can be endocytosed by hepatoma cells by the active targeting of phenylboronic acid (PBA) and aggregated under acidity and overexpression of TGase in cells. Due to its specific accumulation in hepatoma cells, radiotherapy can be operated under a lower dose of X-ray. The results show that the cellular accumulation of Au@TAcoGal increases by 30-70%, and the cell survival rate is less than 25% under X-ray irradiation. The antineoplastic results show that Au@TAcoGal exhibits a higher therapeutic effect, and the tumor inhibition rate can reach 84.21%.

Discordant Supramolecular Fibres Reversibly Depolymerised by Temperature and Light

Synthetic stimuli responsive supramolecular polymers attract increasing interest for their ability to mimic the unique properties of natural assemblies. Here we focus on the well-studied benzene-1,3,5-tricarboxamide (BTA) motif, and substitute it with two (S)-3,7-dimethyloctyl groups and an azobenzene photoswitch. We demonstrate the UV (λ=365 nm) induced depolymerisation of the helical hydrogen-bonded polymers in methylcyclohexane (MCH) through circular dichroism and UV-vis spectroscopy in dilute solution (15 μm), and NMR and iPAINT super-resolution microscopy in concentrated solution (300 μm). The superstructure can be regenerated after thermal depolymerization, whilst repeated depolymerisation can be reversed without degradation by irradiating at λ=455 nm. Molecular dynamics simulations show that the most energetically favourable configuration for these polymers in MCH is a left-handed helical network of hydrogen-bonds between the BTA cores surrounded by two right-handed helices of azobenzenes. The responsiveness to two orthogonal triggers across a broad concentration range holds promise for use in, for example, photo-responsive gelation.

Activatable Nanoparticles: Recent Advances in Redox-Sensitive Magnetic Resonance Contrast Agent Candidates Capable of Detecting Inflammation

The emergence of activatable magnetic resonance (MR) contrast agents has prompted significant interest in the detection of functional markers of diseases, resulting in the creation of a plethora of nanoprobes capable of detecting these biomarkers. These markers are commonly dysregulated in several chronic diseases, specifically select cancers and inflammatory diseases. Recently, the development of redox-sensitive nanoparticle-based contrast agents has gained momentum given advances in medicine linking several inflammatory diseases to redox imbalance. Researchers have pinpointed redox dysregulation as an opportunity to use activatable MR contrast agents to detect and stage several diseases as well as monitor the treatment of inflammatory diseases or conditions. These new classes of agents represent an advancement in the field of MR imaging as they elicit a response to stimuli, creating contrast while providing evidence of biomarker changes and commensurate disease state. Most redox-sensitive nanoparticle-based contrast agents are sensitive to reductive glutathione or oxidative reactive oxygen species. In this review, we will explore recent investigations into redox-activatable, nanoparticle-based MR contrast agent candidates.

Configurational and Constitutional Dynamics of Enamine Molecular Switches

Dual configurational and constitutional dynamics in systems based on enamine molecular switches has been systematically studied. pH-responsive moieties, such as 2-pyridyl and 2-quinolinyl units, were required on the "stator" part, also providing enamine stability through intramolecular hydrogen-bonding (IMHB) effects. Upon protonation or deprotonation, forward and backward switching could be rapidly achieved. Extension of the stator π-system in the 2-quinolinyl derivative provided a higher E-isomeric equilibrium ratio under neutral conditions, pointing to a means to achieve quantitative forward/backward isomerization processes. The "rotor" part of the enamine switches exhibited constitutional exchange ability with primary amines. Interestingly, considerably higher exchange rates were observed with amines containing ester groups, indicating potential stabilization of the transition state through IMHB. Acids, particularly BiIII , were found to efficiently catalyze the constitutional dynamic processes. In contrast, the enamine and the formed dynamic enamine system showed excellent stability under basic conditions. This coupled configurational and constitutional dynamics expands the scope of dynamic C-C and C-N bonds and potentiates further studies and applications in the fields of molecular machinery and systems chemistry.

Applications of Cellulose Nanomaterials in Stimuli-Responsive Optics

As one of the most abundant biopolymers, cellulose has been a basic but essential building block of human society, with its use dating back thousands of years. With recent developments in nanotechnology and increasing environmental concerns, cellulose-based nanomaterials are now gaining attention as promising green material candidates for many high-value applications as a result of their biocompatibility and advantageous physical and chemical properties. In particular, cellulose nanocrystals are notable for their optical properties that can respond to various environmental stimuli as a result of the unique chiral nematic structure of the material. Compositing cellulosic materials with functional polymers, small molecules, and other nanomaterials can further stabilize and amplify these responsive optical signals and introduce multiple new functionalities. On the basis of these capabilities, many advanced applications of cellulose nanomaterials have been proposed, including chemical sensors, photonic papers, decorative coatings, data security, and smart textiles. In this review, we discuss and summarize recent advances in this emerging field of stimuli-responsive optics based on cellulose nanomaterials.

Enzyme-instructed morphological transition of the supramolecular assemblies of branched peptides

Here, we report the use of an enzymatic reaction to cleave the branch off branched peptides for inducing the morphological transition of the assemblies of the peptides. The attachment of DEDDDLLI sequences to the ε-amine of the lysine residue of a tetrapeptide produces branched peptides that form micelles. Upon the proteolytic cleavage of the branch, catalyzed by proteinase K, the micelles turn into nanofibers. We also found that the acetylation of the N-terminal of the branch increased the stability of the branched peptides. Moreover, these branched peptides facilitate the delivery of the proteins into cells. This work contributes insights for the development of peptide supramolecular assemblies via enzymatic noncovalent synthesis in cellular environment.

HealthLit4Kids: Supporting schools to be health literacy responsive organisations

ISSUE ADDRESSED

To reduce inequity, services and community organisations must respond to the health literacy needs and strengths of each individual accessing their services. As a social determinant, health literacy is compounded by interactions between the service provider, the individual, and their wider community. Schools provide a critical nexus between the teacher (as service provider), the student (as learner) and their family (carers and wider community) to support the development of children's health literacy.

METHODS

Five Tasmanian primary schools (84 teachers) completed an assessment of their school in relation to the domains of a health literate organisation using the HeLLOTas! (HEalth Literacy Learning Organisations Tasmania) Self-Assessment Checklist, before and after taking part in the HealthLit4Kids program.

RESULTS

While the differences between pre- and post-intervention ratings were not large, they moved in a positive direction for all six domains. There was a significant main effect of time, F (1, 4) = 83.9, P < .001, ƞ²  = 0.99, showing that overall ratings increased from before to after the intervention. Teacher-recommended actions across all schools were grouped for insight into their interpretation and application of the tool in the school context.

CONCLUSION

Using the HeLLOTas! Self-Assessment Checklist served a dual purpose. Teachers developed a shared understanding of the characteristics of a health-literate organisation to produce a schoolwide action plan. Simultaneously, we gained valuable insights into the processes required to support the development of organisational health literacy in schools, and we share ten propositions applicable to other schools locally, nationally and internationally. SO WHAT?: To the best of our knowledge, this is the first time that a school's health literacy responsiveness has been measured. Our key propositions will support future efforts by policy makers, researchers and school principals.

Determining Perceptions to Electronically-Delivered, Personally-Adaptive, Multimedia Exercise Prompts for Middle-Age Adults

Due to high interaction rates, smart devices are being utilized for mobile health (mHealth) interventions. Multimedia capabilities may be leveraged to improve mHealth exercise interventions. Our purpose was to explore individuals' perceptions of multimedia exercise prompts tailored to their immediate mental/physical states. Using electronic surveys, respondents provided in-the-moment ratings of emotional state, energy, fatigue, physical discomfort, and thirst, with higher scores reflecting a higher "readiness to exercise" (i.e., if a person is currently in a pleasant mood with high energy and low discomfort, he/she is likely to have a greater capacity for a larger dose of exercise). They were then provided with an exercise prompt designed to match their readiness to exercise, demonstrated via text and graphic interchange format (GIF) showing a research member completing the recommended activity. Survey data regarding GIF quality, self-efficacy, and methodological feedback were then collected and analyzed using a combination of parametric statistics and thematic analysis of open-ended feedback. Respondents (N=204; 47±10 years; BMI 29±6 kg/m2) indicated GIFs loaded quickly (5.29±1.2, scale 0-6), were clear (5.36±1.1), and easily understandable (5.43±1.1). High task self-efficacy scores (9.34±1.62, scale 0-10) and statistically significant differences in coping self-efficacy (i.e., how well a person would be able to complete the recommended activity when feeling mentally/physically worse or better; F=3.229, p<.01) were found. Five themes relating to the exercise prompt were noted: improve attractiveness, limiting factors, exercise clarification, liked/understandable/doable, and disliked/unwilling to complete. Further refinement of these methods is warranted prior to using multimedia prompts to elicit actual exercise performance.

Mixed Polymer Brushes for "Smart" Surfaces

Mixed polymer brushes (MPBs) are composed of two or more disparate polymers covalently tethered to a substrate. The resulting phase segregated morphologies have been extensively studied as responsive "smart" materials, as they can be reversible tuned and switched by external stimuli. Both computational and experimental work has attempted to establish an understanding of the resulting nanostructures that vary as a function of many factors. This contribution highlights state-of-the-art MPBs studies, covering synthetic approaches, phase behavior, responsiveness to external stimuli as well as novel applications of MPBs. Current limitations are recognized and possible directions for future studies are identified.

Light-Mediated Shape Transformation of a Self-Rolling Nanocomposite Hydrogel Tube

Self-rolling of a planar hydrogel sheet represents an advanced approach for fabricating a tubular construct, which is of significant interest in biomedicine. However, the self-rolling tube is usually lacking in remote controllability and requires a relatively tedious fabrication procedure. Herein, we present an easy and controllable approach for fabricating self-rolling tubes that can respond to both magnetic field and light. With the introduction of magnetic nanorods in a hydrogel precursor, a strain gradient is created across the thickness of the formed hydrogel sheet during the photopolymerization process. After the removal of the strain constraint, the nanocomposite sheet rolls up spontaneously. The self-rolling scenario of the sheet can be tuned by varying the sheet geometry and the magnetic nanorod concentration in the hydrogel precursor. The nanocomposite hydrogel tube translates in the presence of a magnetic field and produces heat upon a near-infrared (NIR) light illumination by virtue of the magnetic and photo-thermal properties of the magnetic nanorods. The self-rolling tube either opens up or expands its diameter under NIR light irradiation depending on the number of rolls in the tube. With the use of a thermo-responsive hydrogel material, we demonstrate the magnetically guided motion of the chemical-bearing nanocomposite hydrogel tube and its controlled chemical release through its light-mediated deformation. The approach reported herein is expected to be applicable to other self-rolling polymer-based dry materials, and the nanocomposite hydrogel tube presented in this work may find potential applications in soft robot and controlled release of drug.

Deterministic Self-Morphing of Soft-Stiff Hybridized Polymeric Films for Acoustic Metamaterials

We reported a soft-stiff hybridized polymeric film that can self-morph to dedicated three-dimensional (3D) structures for application in acoustic metamaterials. The hybridized film was fabricated by laterally adhering a soft and responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel to stiff and passive SU-8 patterns. Upon thermal stimulation, deformation of the tough PNIPAM hydrogel was locally constrained by the stiff SU-8 patterns, thereby causing laterally nonuniform strain to their interfaces for mechanically buckling the hybridized films to 3D structures. Combined with finite element analysis, we demonstrated that the stiff SU-8 patterns effectively alleviated the uncontrollability and uncertainty during the self-morphing process, which was caused by unexpected mutual deformation between the active and passive domains in the self-morphing materials. Therefore, deterministic self-buckling to dedicated 3D structures was physically realized such as a wave-shaped peak-valley structure, 3D checkerboard patterns, and Gaussian curved surfaces from the hybridized polymeric films. Finally, we demonstrated that the self-morphed 3D structures with predesigned patterns can be used as acoustic materials for subwavelength noise control. This transformative way of constructing 3D structures by self-morphing of the hybridized polymeric films will be a substantial progress in fabricating smart and multifunctional materials for widespread applications in metamaterials, soft robotics, and 3D electronics.

Toward Impedimetric Measurement of Acidosis with a pH-Responsive Hydrogel Sensor

A pH-responsive, poly(2-hydroxyethyl methacrylate) [poly(HEMA)]-based hydrogel has been fashioned into an impedimetric pH sensor for the continual measurement and monitoring of tissue acidosis that can arise due to hemorrhaging trauma. Four hydrogel systems molecularly engineered to influence water distribution and ionic abundance were studied: a cationogenic primary amine, N-(2-aminoethyl) methacrylate (AEMA), a tertiary amine moiety, N,N-(2-dimethylamino)ethyl methacrylate (DMAEMA), and a combined AEMA-DMAEMA formulation. Electrochemical impedance spectroscopy (EIS) of hydrogel discs held between platinized Type 304 stainless steel mesh electrodes in pH-adjusted 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid sodium salt (HEPES) buffer and equivalent circuit modeling indicated that the AEMA hydrogel had the highest sensitivity containing the relevant pathophysiological range (pH 7.0-8.0). Thus, the AEMA formulation was studied at 0, 1, 3, 4.4, and 30 mol % AEMA. The 1 mol % AEMA was found to significantly (p < 0.05) discern nominal pH (7.35, 7.40, 7.45). The Taguchi Design of Experiments approach was employed and confirmed composition as a factor and 1 mol % AEMA to be the most robust. DMAEMA (0, 4.4, 14, 30 mol %) and AEMA-DMAEMA (0, 4.4, 14, 30 mol %) allowed the use of the one-factor Response Surface Methodology optimizer to confirm the AEMA 1 mol % system to be most robust, sensitive, and possessing optimal sensitivity in the pathophysiological pH sensing range (7.35-7.45) for hemorrhagic trauma. This composition was fashioned as a responsive membrane on a microlithographically fabricated interdigitated microsensor electrode and the sensitivity was determined using R(QR)(QR) analysis. Water distribution within the AEMA (0, 1, 4.4, 30 mol %), determined by gravimetric analysis and differential scanning calorimetry, revealed a strong anticorrelation between nonfreezable bound water and pH sensitivity (-0.82) and was in good agreement with the total hydration (-0.70). Nonfreezable bound water was found to be the most strongly correlated factor that governs the pH response of hydrogels.

Grab and Heat: Highly Responsive and Shape Adaptive Soft Robotic Heaters for Effective Heating of Objects of Three-Dimensional Curvilinear Surfaces

Soft actuators have received great research attention because of the recent rise of soft robotics. However, these actuators could perform only relatively simple deformations (such as bending, twisting, etc.) for manipulation, limiting their functionality. Here, we develop highly responsive and shape adaptive soft robotic heaters which not only can achieve large degree of deformation but also can grab and heat objects of three-dimensional (3D) curvilinear surfaces. With intentionally synthesized and selected materials for device fabrication, a U-shaped soft robotic heater exhibits a deformation angle of more than 860° and a curvature of 4.0 cm^-1 at a very low voltage of 2 V, and its curvature can quickly reach 1.31 cm^-1 within 6 s. Moreover, the device can also function as a stable heat source with temperature of 203 °C upon actuation, demonstrating a maximum energy efficiency of 7.44% as a heater. Importantly, the soft robotic heaters can deform to enclose 3D curvilinear surfaces with pressure to enable intimate contact for more effective heat transfer. The unique utility of the soft robotic heaters is illustrated through the heating of objects of various 3D shapes, showcasing their potential applications in soft robotics, advanced thermal therapy, food handling and processing, etc.

Stimulus Responsive 3D Assembly for Spatially Resolved Bifunctional Sensors

3D electronic/optoelectronic devices have shown great potentials for various applications due to their unique properties inherited not only from functional materials, but also from 3D architectures. Although a variety of fabrication methods including mechanically guided assembly have been reported, the resulting 3D devices show no stimuli-responsive functions or are not free standing, thereby limiting their applications. Herein, the stimulus responsive assembly of complex 3D structures driven by temperature-responsive hydrogels is demonstrated for applications in 3D multifunctional sensors. The assembly driving force, compressive buckling, arises from the volume shrinkage of the responsive hydrogel substrates when they are heated above the lower critical solution temperature. Driven by the compressive buckling force, the 2D-formed membrane materials, which are pre-defined and selectively bonded to the substrates, are then assembled to 3D structures. They include "tent," "tower," "two-floor pavilion," "dome," "basket," and "nested-cages" with delicate geometries. Moreover, the demonstrated 3D bifunctional sensors based on laser induced graphene show capability of spatially resolved tactile sensing and temperature sensing. These multifunctional 3D sensors would open new applications in soft robotics, bioelectronics, micro-electromechanical systems, and others.

Tunable Upconverted Circularly Polarized Luminescence in Cellulose Nanocrystal Based Chiral Photonic Films

Integrating chromophores into chiral photonic crystals to fabricate materials that exhibit circularly polarized luminescence (CPL) is promising as this method allows efficient manipulation of the spontaneous emission within photonic bandgaps (PBGs). However, tuning the wavelength of CPL and the dissymmetry factor ( g_lum) in a convenient and accurate manner remains a significant challenge. Here, right-handed, tunable upconverted CPL (UC-CPL) emission was achieved by integrating multiple emissive, upconverting nanoparticles into cellulose nanocrystal based chiral photonic films that had tunable PBGs. Glycerol was used to tune the PBGs of the chiral photonic films, which yielded tunable UC-CPL emission at 450 and 620 nm with a tailored g_lum. Moreover, humidity responsive UC-CPL at blue wavelength was obtained from glycerol-composite photonic film, with a g_lum that ranged from -0.156 to -0.033. It was possible because the PBG and chirality of photonic composite was responded to the relative humidity. This work gives valuable insight into tunable and stimuli-responsive CPL photonic systems.

A multifunctional supramolecular vesicle based on complex of cystamine dihydrochloride capped pillar[5]arene and galactose derivative for targeted drug delivery

Background: Supramolecular vesicles are a novel class of nanocarriers that have great potential in biomedicine.Methods: A multifunctional supramolecular vesicle (CAAP5G) based on the complex of CAAP5 and galactose derivative (G) assembled via host-guest interaction was constructed. Results: Using Human embryonic kidney T (293T) cells as experimental models, the cytotoxic effects of CAAP5G was investigated to 0-50 µmol/L for 24 h. Notably, the CAAP5G vesicles revealed low-toxicity to 293T cells, it was critical to designing drug nano-carriers. Simultaneously, we have evaluated doxorubicin hydrochloride (DOX)-loaded CAAP5G vesicles anticancer efficiency, where DOX-loaded CAAP5G vesicles and free DOX incubated with Human hepatocellular carcinoma cancer cell (HpeG2 cells) and 293T cells for 24 h, 48 h, 72 h. It turned out that CAAP5G vesicles encapsulated anticancer drug (DOX) could decrease DOX side-effect on 293T cells and increase DOX anticancer efficiency. More importantly, the cysteamine as an adjuvant chemotherapy drug was released from CAAP5G vesicles in HepG2 cells where a higher GSH concentration exists. The adjuvant chemotherapy efficiency was evaluated, where free DOX and DOX-loaded CAAP5G vesicles incubated with DOX-resistance HepG2 cells (HepG2-ADR cells) for 24, 48, 72 h, respectively. Conclusion: The results revealed that the DOX encapsulated by CAAP5G vesicles could enhance the cytotoxicity of DOX and provide insights for designing advanced nano-carriers toward adjuvant chemotherapies.

GSH-Activated Light-Up Near-Infrared Fluorescent Probe with High Affinity to αvβ3 Integrin for Precise Early Tumor Identification

The development of tumor-associated, stimuli-driven, turn-on near-infrared (NIR) fluorophores requires urgent attention because of their potential in selective and precise tumor diagnosis. Herein, we describe a NIR fluorescent probe (CyA-cRGD) comprised of a fluorescence reporting unit (a cyanine dye) linked with a GSH-responsive unit (nitroazo aryl ether group) and a tumor-targeting unit (cRGD). The NIR fluorescence of CyA-cRGD with sensitive and selective response to GSH can act as a direct off-on signal reporter for GSH monitoring. Notably, CyA-cRGD possesses improved biocompatibility compared with CyA, which is highly desirable for in vivo fluorescence tracking of cancer. Confocal fluorescence imaging confirmed the tumor-targeting capability and GSH detection ability of CyA-cRGD in tumor cells, normal cells, and coincubated tumor /normal cells and in the three-dimensional multicellular tumor spheroid. Furthermore, it was validated that CyA-cRGD could detect tumor precisely in GSH and integrin α_vβ ₃ high-expressed tumor-bearing mouse models. Importantly, it was confirmed that CyA-cRGD possessed high efficiency for early-stage tumor imaging in mouse models with tumor cells implanted within 72 h. This method provided significant advances toward more in-depth understanding and exploration of tumor imaging, which may potentially be applied for clinical early tumor diagnosis.

H2O2-Responsive Nanoparticle Based on the Supramolecular Self-Assemble of Cyclodextrin

Designing stimuli responsive, controllable and biocompatible multifunctional nanoparticles is an important progress in the current quest for drug delivery systems. Herein, we devoted to developing a β-cyclodextrin (β-CD) based drug delivery nanoparticles (NPs) that release Bovine serum albumin (BSA) via glucose-responsive gate. The design involves synthesis of sodium alginate with β-CD modified (Alg-β-CD) and methoxypolyethylene glycol (mPEG-Fc) containing ferrocene (Fc) uncharged end-capping. When α-cyclodextrin (α-CD) was added with these two segments, the stable non-covalent supramolecular structure of Alg-β-CD/mPEG-Fc/α-CD can be self-assembled into NPs in aqueous solution. BSA loaded Alg-β-CD/mPEG-Fc/α-CD also has been prepared. Interestingly, these supramolecular Alg-β-CD/mPEG-Fc/α-CD/BSA NPs showed uniform sphere structure and constant BSA loading content. Also, this new kind of NPs can disassemble in the present of hydrogen peroxide (H2O2). Since glucose oxidase (GOD) can oxidize glucose and produce H2O2, so this kind of polymeric NPs can also have glucose responsive behavior in the GOD containing environment. Developed functional Alg-β-CD/mPEG-Fc/α-CD might be a promising drug delivery strategy for diabetes or immunotherapy with more efficiency.

Full Color Camouflage in a Printable Photonic Blue-Colored Polymer

A blue reflective photonic polymer coating which can be patterned in full color, from blue to red, by printing with an aqueous calcium nitrate solution has been fabricated. Color change in the cholesteric liquid-crystalline polymer network over the entire visible spectrum is obtained by the use of nonreactive mesogen. The pattern in the coating is hidden in the blue color dry state and appears upon exposure to water or by exhaling breath onto it due to different degrees of swelling of the polymer network. The degree of swelling depends on the printed amount of calcium which acts as a cross-linker. The printed full color pattern can also be hidden simply by using a circular polarizer. The responsive full color camouflage polymers are interesting for various applications ranging from responsive house and automobile decors to anticounterfeit labels and data encryption.

How will the sustainable development goals deliver changes in well-being? A systematic review and meta-analysis to investigate whether WHOQOL-BREF scores respond to change

Introduction

The Sustainable Development Goals (SDGs) 2015 aim to ‘…promote well-being for all’, but this has raised questions about how its targets will be evaluated. A cross-cultural measure of subjective perspectives is needed to complement objective indicators in showing whether SDGs improve well-being. The WHOQOL-BREF offers a short, generic, subjective quality of life (QoL) measure, developed with lay people in 15 cultures worldwide; 25 important dimensions are scored in environmental, social, physical and psychological domains. Although validity and reliability are demonstrated, clarity is needed on whether scores respond sensitively to changes induced by treatments, interventions and major life events. We address this aim.

Methods

The WHOQOL-BREF responsiveness literature was systematically searched (Web of Science, PubMed, EMBASE and Medline). From 117 papers, 15 (24 studies) (n=2084) were included in a meta-analysis. Effect sizes (Cohen’s d) assessed whether domain scores changed significantly during interventions/events, and whether such changes are relevant and meaningful to managing clinical and social change.

Results

Scores changed significantly over time on all domains: small to moderate for physical (d=0.37; CI 0.25 to 0.49) and psychological QoL (d=0.22; CI 0.14 to 0.30), and small for social (d=0.10; CI 0.05 to 0.15) and environmental QoL (d=0.12; CI 0.06 to 0.18). More importantly, effect size was significant for every domain (p<0.001), indicating clinically relevant change, even when differences are small. Domains remained equally responsive regardless of sample age, gender and evaluation interval.

Conclusion

International evidence from 11 cultures shows that all WHOQOL-BREF domains detect relevant, meaningful change, indicating its suitability to assess SDG well-being targets.

Bioinspired Heterogeneous Structural Color Stripes from Capillaries

As an important characteristic of many creatures, structural colors play a crucial role in the survival of organisms. Inspired by these features, an intelligent structural color material with a heterogeneous striped pattern and stimuli-responsivity by fast self-assembly of colloidal nanoparticles in capillaries with a certain diameter range are presented here. The width, spacing, color, and even combination of the structural color stripe patterns can be precisely tailored by adjusting the self-assembly parameters. Attractively, with the integration of a near-infrared (NIR) light responsive graphene hydrogel into the structural color stripe pattern, the materials are endowed with light-controlled reversible bending behavior with self-reporting color indication. It is demonstrated that the striped structural color materials can be used as NIR-light-triggered dynamic barcode labels for the anti-counterfeiting of different products. These features of the bioinspired structural color stripe pattern materials indicate their potential values for mimicking structural color organisms, which will find important applications in constructing intelligent sensors, anti-counterfeiting devices, and so on.

Bioinspired Programmable Polymer Gel Controlled by Swellable Guest Medium

Responsive materials with functions of forming three-dimensional (3D) origami and/or kirigami structures have a broad range of applications in bioelectronics, metamaterials, microrobotics, and microelectromechanical (MEMS) systems. To realize such functions, building blocks of actuating components usually possess localized inhomogeneity so that they respond differently to external stimuli. Previous fabrication strategies lie in localizing nonswellable or less-swellable guest components in their swellable host polymers to reduce swelling ability. Herein, inspired by ice plant seed capsules, we report an opposite strategy of implanting swellable guest medium inside nonswellable host polymers to locally enhance the swelling inhomogeneity. Specifically, we adopted a skinning effect induced surface polymerization combined with direct laser writing to control gradient of swellable cyclopentanone (CP) in both vertical and lateral directions of the nonswellable SU-8. For the first time, the laser direct writing was used as a novel strategy for patterning programmable polymer gel films. Upon stimulation of organic solvents, the dual-gradient gel films designed by origami or kirigami principles exhibit reversible 3D shape transformation. Molecular dynamics (MD) simulation illustrates that CP greatly enhances diffusion rates of stimulus solvent molecules in the SU-8 matrix, which offers the driving force for the programmable response. Furthermore, this bioinspired strategy offers unique capabilities in fabricating responsive devices such as a soft gripper and a locomotive robot, paving new routes to many other responsive polymers.

Stimuli-Responsive Self-Assembled DNA Nanomaterials for Biomedical Applications

Stimuli-responsive DNA-based materials represent a major class of remarkable functional nanomaterials for nano-biotechnological applications. In this review, recent progress in the development of stimuli-responsive systems based on self-assembled DNA nanostructures is introduced and classified. Representative examples are presented in terms of their design, working principles and mechanisms to trigger the response of the stimuli-responsive DNA system upon expose to a large variety of stimuli including pH, metal ions, oligonucleotides, small molecules, enzymes, heat, and light. Substantial in vitro studies have clearly revealed the advantages of the use of stimuli-responsive DNA nanomaterials in different biomedical applications, particularly for biosensing, drug delivery, therapy and diagnostic purposes in addition to bio-computing. Some of the challenges faced and suggestions for further development are also highlighted.

Coral-like Janus Porous Spheres

A Janus porous sphere with a coral-like microstructure is prepared by stepwise dealloying a metallic alloy sphere and sequential modification (for example, using silanes and polymers). Nanoscale coral-like microstructure of the internal skeleton gives remarkable capillary force, thus accelerating the mass transportation. Starting from the outer layer of the sphere, stepwise dealloying can achieve different layers inwardly, thus introducing different composition and performance. As an example, poly(ethylene glycol)-poly(N-isopropylacrylamide) (PEG-PNIPAM)- and poly(ethylene glycol)-poly(N,N-diethylamino-2-ethylmethacrylate) (PEG-PDEAEMA)-responsive Janus porous spheres can quickly capture oil by simply changing temperature or pH. Similarly, release is also triggered.

Intracellular redox-responsive nanocarrier for plasmid delivery: in vitro characterization and in vivo studies in mice

Although some modifications of polyethyleneimine (PEI) properties have been explored to balance the transfection efficiency and cytotoxicity, its successful plasmid delivery in vitro and in vivo to realize its true therapeutic potentials remains a major challenge, mainly due to intracellular trafficking barriers. Herein, we present a delivery nanocarrier Pluronic-PEI-SS by conjugating reducible disulfide-linked PEI (PEI-SS) to biocompatible Pluronic for enhanced DNA delivery and transfection efficiency in vitro and in vivo. Pluronic-PEI-SS strongly condensed plasmid DNA to low positively charged nanocomplexes, exhibited good stability against deoxyribonuclease I digestion, and tended to be easily degraded in the presence of reducing agent 1,4-dithiothreitol. The in vitro transfection of the complex Pluronic-PEI-SS/DNA into HeLa and 293T cells resulted in lower cytotoxicity as well as significantly higher cellular uptake, nucleus transfection, and gene expression than Pluronic-PEI (25 kDa), PEI-SS, and PEI 25 kDa given alone. Furthermore, the in vivo transfection study demonstrated that Pluronic-PEI-SS/DNA complexes induced a higher enrichment than the commercial PEI/DNA complex in the tumor, indicating their potential application as biocompatible vector in gene delivery.

Tailoring Patterns of Surface-Attached Multiresponsive Polymer Networks

A new strategy for the fabrication of micropatterns of surface-attached hydrogels with well-controlled chemistry is reported. The "grafting onto" approach is preferred to the "grafting from" approach. It consists of cross-linking and grafting preformed and functionalized polymer chains through thiol-ene click chemistry. The advantage is a very good control without adding initiators. A powerful consequence of thiol-ene click reaction by UV irradiation is the facile fabrication of micropatterned hydrogel thin films by photolithography. It is achieved either with photomasks using common UV lamp or without photomasks by direct drawing due to laser technology. Our versatile approach allows the fabrication of various chemical polymer networks on various solid substrates. It is demonstrated here with silicon wafers, glass and gold surfaces as substrates, and two responsive hydrogels, poly(N-isopropylacrylamide) for its responsiveness to temperature and poly(acrylic acid) for its pH-sensitivity. We also demonstrate the fabrication of stable hydrogel multilayers (or stacked layers) in which each elementary layer height can widely range from a few nanometers to several micrometers, providing an additional degree of freedom to the internal architecture of hydrogel patterns. This facile route for the synthesis of micrometer-resolute hydrogel patterns with tailored architecture and multiresponsive properties should have a strong impact.

Multiscale Surface-Attached Hydrogel Thin Films with Tailored Architecture

A facile route for the fabrication of surface-attached hydrogel thin films with well-controlled chemistry and tailored architecture on wide range of thickness from nanometers to micrometers is reported. The synthesis, which consists in cross-linking and grafting the preformed and ene-reactive polymer chains through thiol-ene click chemistry, has the main advantage of being well-controlled without the addition of initiators. As thiol-ene click reaction can be selectively activated by UV-irradiation (in addition to thermal heating), micropatterned hydrogel films are easily synthesized. The versatility of our approach is illustrated by the possibility to fabricate various chemical polymer networks, like stimuli-responsive hydrogels, on various solid substrates, such as silicon wafers, glass, and gold surfaces. Another attractive feature is the development of new complex hydrogel films with targeted architecture. The fabrication of various architectures for polymer films is demonstrated: multilayer hydrogel films in which single-networks are stacked one onto the other, interpenetrating networks films with mixture of two networks in the same layer, and nanocomposite hydrogel films where nanoparticles are stably trapped inside the mesh of the network. Thanks to its simplicity and its versatility this novel approach to surface-attached hydrogel films should have a strong impact in the area of polymer coatings.

Responsive neurostimulation in epilepsy

Various neurostimulation modalities have emerged in the field of epilepsy. Despite the fact that delivery of an electrical current to the hyperexcitable epileptic brain might, at first, seem contradictory, neurostimulation has become an established therapeutic option with a promising efficacy and adverse effects profile. In "responsive" neurostimulation the strategy is to interfere as early as possible with the accumulation of seizure activity to prematurely abort or even prevent an upcoming seizure. The design of technology required for responsive stimulation is more challenging compared with devices for open-loop neurostimulation. The achievement of therapeutic success is dependent on adequate sensing and stimulation algorithms and a fast coupling between both. The benefits of delivering current only at the time of an approaching seizure merit further investigation. Current experience with responsive neurostimulation in epilepsy is still limited, but seems promising.

Smart Polymeric Nanoparticles as Emerging Tools for Imaging--The Parallel Evolution of Materials

The field of imaging has developed considerably over the past decade and recent advances in the area of nanotechnology, in particular nanomaterials, have opened new opportunities. Polymeric nanoparticles are particularly interesting and a number of novel materials, characterized by stimuli-responsive characteristics and fluorescent tagging, have allowed visualization, intracellular labeling and real-time tracking. In some of the latest applications the nanoparticles have been used for imagining of tumor cells, both in vivo and ex vivo.

Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives

Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase increases the expression of interferon-responsive genes

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) pathway is an important metabolic route that is present in almost every organism. However, whether HMGCR affects the expression of interferon (IFN)-responsive genes is unclear. In the present study, expression levels of IFN-responsive genes were monitored by real time polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that expression levels of IFN-responsive genes were significantly increased in HMGCR-downregulated cells and HMGCR inhibitor-treated cells, indicating that inhibition of HMGCR activates the expression of IFN-responsive genes. The result in this study will provide new insight into the role of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in antiviral research.

Programmed DNAzyme-Triggered Dissolution of DNA-Based Hydrogels: Means for Controlled Release of Biocatalysts and for the Activation of Enzyme Cascades

Acrylamide/acrylamide-modified nucleic acid copolymer chains provide building units for the construction of acrylamide-DNA hydrogels. Three different hydrogels are prepared by the cross-linking of the acrylamide-DNA chains with metal ion-dependent DNAzyme sequences and their substrates. The metal ion-dependent DNAzyme sequences used in the study include the Cu(2+)-, Mg(2+)-, and Zn(2+)-dependent DNAzymes. In the presence of the respective metal ions, the substrates of the respective DNAzymes are cleaved, leading to the separation of the cross-linking units and to the dissolution of the hydrogel. The different hydrogels were loaded with a fluorophore-modified dextran or with a fluorophore-functionalized glucose oxidase. Treatment of the different hydrogels with the respective ions led to the release of the loaded dextran or the enzyme, and the rates of releasing of the loaded macromolecules followed the order of Cu(2+) > Mg(2+) > Zn(2+). Also, the different hydrogels were loaded with the enzymes β-galactosidase (β-Gal), glucose oxidase (GOx), or horseradish peroxidase (HRP). In the presence of the appropriate metal ions, the respective hydrogels were dissolved, resulting in the activation of the β-Gal/GOx or GOx/HRP bienzyme cascades and of the β-Gal/GOx/HRP trienzyme cascade.

A Novel Bioinspired Switchable Adhesive with Three Distinct Adhesive States

A novel switchable adhesive, inspired by the gecko's fibrillar dry attachment system, is introduced. It consists of a patterned surface with an array of mushroom-shaped pillars having two distinct heights. The different pillar heights allow control of the pull-off force in two steps by application of a low and a high preload. For low preload, only the long pillars form contact, resulting in a low pull-off force. At higher preload, all pillars form contact, resulting in high pull-off force. Even further loading leads to buckling induced detachment of the pillars which corresponds to extremely low pull-off force. To achieve the respective samples a new fabrication method called double inking is developed, to achieve multiple-height pillar structures. The adhesion performance of the two-step switchable adhesive is analysed at varying preload and for different pillar aspect ratios and height relations. Finally, the deformation behavior of the samples is investigated by in situ monitoring.

Closed-loop neurostimulation: the clinical experience

Neurostimulation is now an established therapy for the treatment of movement disorders, pain, and epilepsy. While most neurostimulation systems available today provide stimulation in an open-loop manner (i.e., therapy is delivered according to preprogrammed settings and is unaffected by changes in the patient's clinical symptoms or in the underlying disease), closed-loop neurostimulation systems, which modulate or adapt therapy in response to physiological changes, may provide more effective and efficient therapy. At present, few such systems exist owing to the complexities of designing and implementing implantable closed-loop systems. This review focuses on the clinical experience of four implantable closed-loop neurostimulation systems: positional-adaptive spinal cord stimulation for treatment of pain, responsive cortical stimulation for treatment of epilepsy, closed-loop vagus nerve stimulation for treatment of epilepsy, and concurrent sensing and stimulation for treatment of Parkinson disease. The history that led to the development of the closed-loop systems, the sensing, detection, and stimulation technology that closes the loop, and the clinical experiences are presented.

Poly(N-isopropylacrylamide) surfactant-functionalized responsive silver nanoparticles and superlattices

Metal nanoparticles exhibit unique optical characteristics in visible spectra produced by local surface plasmon resonance (SPR) for a wide range of optical and electronic applications. We report the synthesis of poly(N-isopropylacrylamide) surfactant (PNIPAM-C18)-functionalized metal nanoparticles and ordered superlattice arrays through an interfacial self-assembly process. The method is simple and reliable without using complex chemistry. The PNIPAM-C18-functionalized metal nanoparticles and ordered superlattices exhibit responsive behavior modulated by external temperature and relative humidity (RH). In situ grazing-incidence small-angle X-ray scattering studies confirmed that the superlattice structure of PNIPAM-C18 surfactant-functionalized nanoparticle arrays shrink and spring back reversibly based on external thermal and RH conditions, which allow flexible manipulation of interparticle spacing for tunable SPR. PNIPAM-C18 surfactants play a key role in accomplishing this responsive property. The ease of fabrication of the responsive nanostructure facilitates investigation of nanoparticle coupling that depends on interparticle separation for potential applications in chemical and biological sensors as well as energy storage devices.