Dynamic covalent bonds (DCBs) have received significant attention over the past decade. These are covalent bonds that are capable of exchanging or switching between several molecules. Particular ...focus has recently been on utilizing these DCBs in polymeric materials. Introduction of DCBs into a polymer material provides it with powerful properties including self‐healing, shape‐memory properties, increased toughness, and ability to relax stresses as well as to change from one macromolecular architecture to another. This Minireview summarizes commonly used powerful DCBs formed by simple, often “click” reactions, and highlights the powerful materials that can result. Challenges and potential future developments are also discussed.
Polymeric materials containing dynamic covalent bonds, which are capable of exchanging or switching between several molecules, may display properties such as self‐healing and improved malleability, as well as stress‐relaxation and shape‐memory properties. These materials, their intriguing attributes, and potential applications are described in this Minireview.
Intestinal dysfunction is becoming increasingly associated with neurological and endocrine issues, raising concerns about its impact on world health. With the introduction of several breakthrough ...technologies for detecting and treating intestinal illnesses, significant progress has been made in the previous few years. On the other hand, traditional intrusive diagnostic techniques are expensive and time-consuming. Furthermore, the efficacy of conventional drugs (not capsules) is reduced since they are more likely to degrade before reaching their target. In this context, microcapsules based on different types of biological macromolecules have been used to encapsulate active drugs and sensors to track intestinal ailments and address these issues. Several biomacromolecules/biomaterials (natural protein, alginate, chitosan, cellulose and RNA etc.) are widely used for make microcapsules for intestinal diseases, and can significantly improve the therapeutic effect and reduce adverse reactions. This article systematically summarizes microencapsulated based on biomacromolecules material for intestinal health control and efficacy enhancement. It also discusses the application and mechanism research of microencapsulated biomacromolecules drugs in reducing intestinal inflammation, in addition to covering the preparation techniques of microencapsulated drug delivery systems used for intestinal health. Microcapsule delivery systems' limits and potential applications for intestinal disease diagnosis, treatment, and surveillance were highlighted.
•Microcapsules based on biomacromolecules are a promising delivery system.•Microcapsule structure-function ties with material and preparation methods detailed.•Bio-macromolecule-based microcapsules monitor and treat gut diseases.•Bio-macromolecule-based microcapsules: flaws and upgrade paths identified
B21 is a small‐angle X‐ray scattering (SAXS) beamline with a bending magnet source in the 3 GeV storage ring at the Diamond Light Source Ltd synchrotron in the UK. The beamline utilizes a double ...multi‐layer monochromator and a toroidal focusing optic to deliver 2 × 1012 photons per second to a 34 × 40 µm (FWHM) focal spot at the in‐vacuum Eiger 4M (Dectris) detector. A high‐performance liquid chromatography system and a liquid‐handling robot make it possible to load solution samples into a temperature‐controlled in‐vacuum sample cell with a high level of automation. Alternatively, a range of viscous or solid materials may be loaded manually using a range of custom sample cells. A default scattering vector range from 0.0026 to 0.34 Å−1 and low instrument background make B21 convenient for measuring a wide range of biological macromolecules. The beamline has run a full user programme since 2013.
The B21 beamline at Diamond Light Source is optimized for automated measurement of small‐angle X‐ray scattering from solution samples.
The recently developed 3D bioprinting technology has greatly improved the ability to generate biomimetic tissues that are structurally and functionally relevant to their human counterparts. The ...selection of proper biomaterials as the bioinks is a key step toward successful bioprinting. For example, viscosity of a bioink is an important rheological parameter to determine the flexibility in deposition of free‐standing structures and the maintenance of architectural integrity following bioprinting. This requirement, however, has greatly limited the selection of bioinks, especially for those naturally derived due to their commonly low mechanical properties. Here the generalization of a mechanism for extrusion bioprinting of bio‐macromolecular components, mainly focusing on collagen and its derivatives including gelatin and gelatin methacryloyl, is reported. Specifically, a templating strategy is adopted using a composite bioink containing both the desired bio‐macromolecular component and a polysaccharide alginate. The physically crosslinkable alginate component serves as the temporal structural support to stabilize the shape of the construct during bioprinting; upon subsequent chemical or physical crosslinking of the bio‐macromolecular component, alginate can be selectively removed to leave only the desired bio‐macromolecule. It is anticipated that this strategy is general, and can be readily expanded for use of a wide variety of other bio‐macromolecular bioinks.
A general templating strategy for extrusion bioprinting of bio‐macromolecules is reported by using a composite bioink containing both the desired bio‐macromolecular component and a polysaccharide alginate. The physically crosslinkable alginate component serves as the temporal structural support to stabilize the shape of the construct during bioprinting, followed by its removal after subsequent crosslinking of the bio‐macromolecular component, leaving only the latter.
This review describes different synthetic strategies towards sequence‐defined, monodisperse macromolecules, which are built up by iterative approaches and lead to linear non‐natural polymer ...structures. The review is divided in three parts: solution phase‐, solid phase‐, and fluorous‐ and polymer‐tethered approaches. Moreover, synthesis procedures leading to conjugated and non‐conjugated macromolecules are considered and discussed in the respective sections. A major focus in the evaluation is the applicability of the different approaches in polymer chemistry. In this context, simple procedures for monomer and oligomer synthesis, overall yields, scalability, purity of the oligomers, and the achievable level of control (side‐chains, backbone, stereochemistry) are important benchmarks.
A review of synthesis procedures leading to monodisperse and sequence‐defined linear macromolecules, including conjugated and non‐conjugated oligomers, is presented. The approaches are summarized and analyzed in terms of applicability in polymer science. Simple synthesis procedures, scales, overall yields, achievable level of control, and the purity of the obtained macromolecules are important benchmarks.
Hyperbranched polymers (HPs) are highly branched three-dimensional (3D) macromolecules. Their globular and dendritic architectures endow them with unique structures and properties such as abundant ...functional groups, intramolecular cavities, low viscosity, and high solubility. HPs can be facilely synthesized
via
a one-pot polymerization of traditional small molecular monomers or emerging macromonomers. The great development in synthetic strategies, from click polymerization (
i.e.
, copper-catalyzed azide-alkyne cycloaddition, metal-free azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, thiol-ene/yne addition, Diels-Alder cycloaddition, Menschutkin reaction, and aza-Michael addition) to recently reported multicomponent reactions, gives rise to diverse HPs with desirable functional/hetero-functional groups and topologies such as segmented or sequential ones. Benefiting from tailorable structures and correspondingly special properties, the achieved HPs have been widely applied in various fields such as light-emitting materials, nanoscience and technology, supramolecular chemistry, biomaterials, hybrid materials and composites, coatings, adhesives, and modifiers. In this review, we mainly focus on the progress in the structural control, synthesis, functionalization, and potential applications of both conventional and segmented HPs reported over the last decade.
This review summarizes the advances in hyperbranched polymers from the viewpoint of structure, click synthesis and functionalization towards their applications in the last decade.
Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and ...detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.
Grafting six fluorene units to a benzene ring generates a new highly twisted core of hexakis(fluoren‐2‐yl)benzene. Based on the new core, six‐arm star‐shaped oligofluorenes from the first generation ...T1 to third generation T3 are constructed. Their thermal, photophysical, and electrochemical properties are studied, and the relationship between the structures and properties is discussed. Simple double‐layer electroluminescence (EL) devices using T1–T3 as non‐doped solution‐processed emitters display deep‐blue emissions with Commission Internationale de l'Eclairage (CIE) coordinates of (0.17, 0.08) for T1, (0.16, 0.08) for T2, and (0.16, 0.07) for T3. These devices exhibit excellent performance, with maximum current efficiency of up to 5.4 cd A−1, and maximum external quantum efficiency of up to 6.8%, which is the highest efficiency for non‐doped solution‐processed deep‐blue organic light‐emitting diodes (OLEDs) based on starburst oligofluorenes, and is even comparable with other solution‐processed deep‐blue fluorescent OLEDs. Furthermore, T2‐ and T3‐based devices show striking blue EL color stability independent of driving voltage. In addition, using T0–T3 as hole‐transporting materials, the devices of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS)/T0–T3/tris(8‐hydroxyquinolinato)aluminium (Alq3)/LiF/Al achieve maximum current efficiencies of 5.51–6.62 cd A−1, which are among the highest for hole‐transporting materials in identical device structure.
Grafting six fluorene units to a benzene ring generates a novel highly twisted core of hexakis(fluoren‐2‐yl)benzene. The new star‐shaped macromolecules T1–T3, based on the propeller‐like core, show high efficiency deep‐blue emission. T2‐ and T3‐based organic light‐emitting diodes (OLEDs) exhibit the highest efficiency for non‐doped solution‐processed deep‐blue OLEDs based on starburst oligofluorenes. These star‐shaped oligofluorenes are also demonstrated to be good hole‐transporting materials.
A fundamental endeavour in macromolecular science is the control of molecular-level complexity, including molecular weight distribution, end groups and architecture. Since the discovery that native ...biomacromolecules can have a specific sequence translating in a specific biological function, controlling individual monomer sequence has become the ultimate expression of molecular-level complexity. Replicating this remarkable structural precision in abiological macromolecules has emerged as a defining goal and challenge within polymer science. In this Review, we survey developments in synthetic methods, characterisation techniques, simulation workflows and applications relevant to this goal. We also address the broader question of to what extent is such control of molecular-level complexity significant in macromolecules. Specifically, we will focus on characterisation in this Review because of its importance in connecting synthesis with applications.
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This work aims at the production and characterization of promissory food packaging films based on chitosan (CS), zein (ZN), and poly (vinyl alcohol) (PVA). CS and ZN are biodegradable, biocompatible, ...and extracting from natural-sources and renewable. Although PVA is a synthetic polymer, it is also considered biocompatible and present water-solubility. From binary and ternary macromolecule mixtures based on CS/ZN/PVA, were obtained films solvent-free. In this facet, extrusion of the macromolecule mixture following by a hot compression to acquire the films' solvent-free. The films were characterized by several techniques such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), prioritization query based on critical packaging requirements which underwent visual and sensorial (smell), mechanical properties, scanning electron microscopy (SEM), and barrier property analysis. Our findings showed that a higher proportion of ZN led to yellowish films with lower transparency and/or higher opacity. Therefore, PVA high content is interesting for our proposal since it allows films with translucency, handling, absence of rupture, and odor. The mechanical tests showed that the ZN effect is associated with reduced tensile strength, increasing elongation, and Young's modulus. Thus, ZN's presence, even if in a smaller proportion to PVA, allows the formation of more rigid films. The morphological analysis indicates the formation of compact films and homogeneous surfaces. However, films with higher amounts of CS and ZN presented greater roughness, globular clusters' presence, and heterogeneity (films' cross-section) that may have influenced water vapor permeability values and better barrier property due to tortuosity that decreases as the PVA content is increased. This finding can be associated with the higher crystallinity of the film when the film's formulation presents significant CS and ZN concentrations. Finally, we demonstrate the feasibility of using films based on the mixture of CS, ZN, and PVA as proposals for a food pack.
•Combination of biodegradable macromolecules (chitosan, zein and PVA) to obtain films for food packaging.•Films for food packaging were obtained solvent-free through extrusion and hot compression.•The as-obtained films showed a good barrier property.•From design of experiments the effects of each component on properties were evaluated.•The laboratory-scale showed promissory and can be scaled up.
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