Embracing complexity in biomaterials design

Animate materials, man-made materials behaving like living systems, are attracting enormous interest across a range of sectors, from construction and transport industry to medicine. In this leading opinion article, we propose that embracing complexity in biomaterials design offers untapped opportunities to create biomaterials with innovative life-like properties that extend their capabilities and unleash new paradigms in medical treatmen

Spontaneous reorganization of DNA-based polymers in higher ordered structures fueled by RNA

We demonstrate a strategy that allows for the spontaneous reconfiguration of self-assembled DNA polymers exploiting RNA as chemical fuel. To do this, we have rationally designed orthogonally addressable DNA building blocks that can be transiently deactivated by RNA fuels and subtracted temporarily from participation in the self-assembly process. Through a fine modulation of the rate at which the building blocks are reactivated we can carefully control the final composition of the polymer and convert a disordered polymer in a higher order polymer, which is disfavored from a thermodynamic point of view. We measure the dynamic reconfiguration via fluorescent signals and confocal microscopy, and we derive a kinetic model that captures the experimental results. Our approach suggests a novel route toward the development of biomolecular materials in which engineered chemical reactions support the autonomous spatial reorganization of multiple components

Application of Robot Programming to the Teaching of Object-Oriented Computer Languages

Object-oriented programming (OOP) abstract concepts are often difficult to understand for students, since it is not easy to find the equivalence of such concepts in daily life. In this paper we will study if an interdisciplinary approach based on an introduction to robotics and robot programming helps the student in acquiring theOOPconcepts. For our experiments, we selected a sample of thirty individuals among students with an adequate knowledge of procedural programming. This sample was divided into two groups of fifteen students each: for the first one we used a standard introductory approach to C#, whereas for the second one we developed an experimental course that included a demonstration program that illustrated OOP basic concepts using the features of a specific type of commercial ball-shaped robot with sensing, wireless communication and output capabilities. After the courses, both groups were evaluated by completing a multiple-choice exam and aC#programming exercise. Our results show that the student group that attended the course including the robot demo showed a higher interest level (i.e. they felt more motivated) than those students that attended the standard introductory C# course. Furthermore, the students from the experimental group also achieved an overall better mark

Simple, Direct Routes to Polymer Brush Traps and Nanostructures for Studies of Diffusional Transport in Supported Lipid Bilayers

Patterned poly(oligo ethylene glycol) methyl ether methacrylate (POEGMEMA) brush structures may be formed by using a combination of atom-transfer radical polymerization (ATRP) and UV photopatterning. UV photolysis is used to selectively dechlorinate films of 4-(chloromethyl)phenyltrichlorosilane (CMPTS) adsorbed on silica surfaces, by exposure either through a mask or using a two-beam interferometer. Exposure through a mask yields patterns of carboxylic acid-terminated adsorbates. POEGMEMA may be grown from intact Cl initiators that were masked during exposure. Corrals, traps, and other structures formed in this way enable the patterning of proteins, vesicles, and, following vesicle rupture, supported lipid bilayers (SLBs). Bilayers adsorbed on the carboxylic acid-terminated surfaces formed by C–Cl bond photolysis in CMPTS exhibit high mobility. SLBs do not form on POEGMEMA. Using traps consisting of carboxylic acid-functionalized regions enclosed by POEGMEMA structures, electrophoresis may be observed in lipid bilayers containing a small amount of a fluorescent dye. Segregation of dye at one end of the traps was measured by fluorescence microscopy. The increase in the fluorescence intensity was found to be proportional to the trap length, while the time taken to reach the maximum value was inversely proportional to the trap length, indicating uniform, rapid diffusion in all of the traps. Nanostructured materials were formed using interferometric lithography. Channels were defined by exposure of CMPTS films to maxima in the interferogram, and POEGMEMA walls were formed by ATRP. As for the micrometer-scale patterns, bilayers did not form on the POEGMEMA structures, and high lipid mobilities were measured in the polymer-free regions of the channels

Conceptual Modeling Enables Systems Thinking in Sustainable Chemistry and Chemical Engineering

This study aims to equip students with conceptual modeling skills to address compelling 21st-century challenges in chemistry and chemical engineering education. System-based concept mapping is a critical competence for analyzing global, often complex, problems. We examined how conceptual modeling could scaffold practical experimental design, transitioning from problem identification to testable hypotheses. We set up a project in which first-year undergraduates in chemical engineering work in groups of 5–6 students. Their task was to develop concrete hypotheses for assignments that center on finding sustainable solutions for polluted environments. A set of educational roles (i.e., lecturers, tutors, learning assistants, educational specialist, and project coordinator) were implemented to ensure that students could accomplish their main learning outcome; that is, to become familiar with the academic way of thinking and apply critical thinking skills as a team. Interviews were conducted after the project was finished and revealed that, while conceptual modeling helped students to structure their ideas (i.e., to learn how to design research questions, incorporate interventions, and test models), developing hypotheses remains a challenging task. Our findings brought us to the recommendations for teaching conceptual modeling in the curriculum rather than at the project level, allowing students to progressively transition from understanding and applying concept mapping in their first year into creating solutions within the context of solving complex real-world problems in the final year of their bachelor’s degree. The collaborative learning environment and project format employed in this work could spark new ways to teach science that facilitates systems thinking in chemistr

ASAM : Automatic Architecture Synthesis and Application Mapping; dl. 3.2: Instruction set synthesis

No abstract

Phase Separation in Supramolecular Hydrogels Based on Peptide Self-Assembly from Enzyme-Coated Nanoparticles

International audienceSpatial localization of biocatalysts, such as enzymes, has recently proven to be an effective process to direct supramolecular self-assemblies in a spatiotemporal way. In this work, silica nanoparticles (NPs) functionalized covalently by alkaline phosphatase (NPs@AP) induce the localized growth of self-assembled peptide nanofibers from NPs by dephosphorylation of Fmoc-FFpY peptides (Fmoc: fluorenylmethyloxycarbonyl; F: phenylalanine; Y: tyrosine; p: phosphate group). The fibrillary nanoarchitecture around NPs@AP underpins a homogeneous hydrogel, which unexpectedly undergoes a macroscopic shape change over time. This macroscopic change is due to a phase separation leading to a dense phase (in NPs and nanofibers) in the center of the vial and surrounded by a dilute one, which still contains NPs and peptide self-assemblies. We thus hypothesize that the phase separation is not a syneresis process. Such a change is only observed when the enzymes are localized on the NPs. The dense phase contracts with time until reaching a constant volume after several days. For a given phosphorylated peptide concentration, the dense phase contracts faster when the NPs@AP concentration is increased. For a given NPs@AP concentration, it condenses faster when the peptide concentration increases. We hypothesize that the appearance of a dense phase is not only due to attractive interactions between NPs@AP but also to the strong interactions of self-assembled peptide nanofibers with the enzymes, covalently fixed on the NPs