Polymer Vesicles for Antimicrobial Applications

Polymer vesicles, hollow nanostructures with hydrophilic cavity and hydrophobic membrane, have shown significant potentials in biomedical applications including drug delivery, gene therapy, cancer theranostics, and so forth, due to their unique cell membrane-like structure. Incorporation with antibacterial active components like antimicrobial peptides, etc., polymer vesicles exhibited enhanced antimicrobial activity, extended circulation time, and reduced cell toxicity. Furthermore, antibacterial, and anticancer can be achieved simultaneously, opening a new avenue of the antimicrobial applications of polymer vesicles. This review seeks to highlight the state-of-the-art of antimicrobial polymer vesicles, including the design strategies and potential applications in the field of antibacterial. The structural features of polymer vesicles, preparation methods, and the combination principles with antimicrobial active components, as well as the advantages of antimicrobial polymer vesicles, will be discussed. Then, the diverse applications of antimicrobial polymer vesicles such as wide spectrum antibacterial, anti-biofilm, wound healing, and tissue engineering associated with their structure features are presented. Finally, future perspectives of polymer vesicles in the field of antibacterial is also proposed.

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Cellulose–Silver Composites Materials: Preparation and Applications

Biomolecules ◽

10.3390/biom11111684 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1684

Author(s):

Ahmed Salama ◽

Ragab E. Abouzeid ◽

Medhat E. Owda ◽

Iriczalli Cruz-Maya ◽

Vincenzo Guarino

Keyword(s):

High Performance ◽

Chemical Properties ◽

Structural Features ◽

Dip Coating ◽

Thermal Reduction ◽

Preparation Methods ◽

Physico Chemical ◽

Silver Nanocomposites ◽

Potential Applications ◽

Manufacturing Techniques

Cellulose has received great attention owing to its distinctive structural features, exciting physico−chemical properties, and varied applications. The combination of cellulose and silver nanoparticles currently allows to fabricate different promising functional nanocomposites with unique properties. The current work offers a wide and accurate overview of the preparation methods of cellulose–silver nanocomposite materials, also providing a punctual discussion of their potential applications in different fields (i.e., wound dressing, high-performance textiles, electronics, catalysis, sensing, antimicrobial filtering, and packaging). In particular, different preparation methods of cellulose/silver nanocomposites based on in situ thermal reduction, blending and dip-coating, or additive manufacturing techniques were thoroughly described. Hence, the correlations among the structure and physico–chemical properties in cellulose/silver nanocomposites were investigated in order to better control the final properties of the nanocomposites and analyze the key points and limitations of the current manufacturing approaches.

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Diarylethene Dyes

Physical Sciences Reviews ◽

10.1515/psr-2019-0146 ◽

2020 ◽

Vol 5 (7) ◽

Author(s):

Andrew Towns

Keyword(s):

Structural Features ◽

Photochromic Dye ◽

Potential Applications

AbstractThis article introduces the general characteristics of the diarylethene class of photochromic dye and the structural features that make photochromism possible. It touches on the methodologies employed to synthesize these compounds as well as the influences that typical substitution patterns exert on photocoloration. A demonstration is then given of the great diversity pertaining to the potential applications in which researchers are seeking to exploit them as functional colorants.

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Unusual Structural Features in the Adduct of Dirhodium Tetraacetate with Lysozyme

International Journal of Molecular Sciences ◽

10.3390/ijms22031496 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1496

Author(s):

Domenico Loreto ◽

Giarita Ferraro ◽

Antonello Merlino

Keyword(s):

Anticancer Agents ◽

Structural Features ◽

Side Chain ◽

Side Chains ◽

Valuable Insight ◽

Experimental Conditions ◽

Egg White Lysozyme ◽

Potential Applications ◽

Model Protein ◽

Hen Egg White

The structures of the adducts formed upon reaction of the cytotoxic paddlewheel dirhodium complex [Rh2(μ-O2CCH3)4] with the model protein hen egg white lysozyme (HEWL) under different experimental conditions are reported. Results indicate that [Rh2(μ-O2CCH3)4] extensively reacts with HEWL:it in part breaks down, at variance with what happens in reactions with other proteins. A Rh center coordinates the side chains of Arg14 and His15. Dimeric Rh–Rh units with Rh–Rh distances between 2.3 and 2.5 Å are bound to the side chains of Asp18, Asp101, Asn93, and Lys96, while a dirhodium unit with a Rh–Rh distance of 3.2–3.4 Å binds the C-terminal carboxylate and the side chain of Lys13 at the interface between two symmetry-related molecules. An additional monometallic fragment binds the side chain of Lys33. These data, which are supported by replicated structural determinations, shed light on the reactivity of dirhodium tetracarboxylates with proteins, providing useful information for the design of new Rh-containing biomaterials with an array of potential applications in the field of catalysis or of medicinal chemistry and valuable insight into the mechanism of action of these potential anticancer agents.

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Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties

International Journal of Molecular Sciences ◽

10.3390/ijms22115781 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5781

Author(s):

Janarthanan Supramaniam ◽

Darren Yi Sern Low ◽

See Kiat Wong ◽

Loh Teng Hern Tan ◽

Bey Fen Leo ◽

...

Keyword(s):

Plant Biomass ◽

Cellulose Nanofibers ◽

High Strength ◽

Salmonella Typhi ◽

Particle Sizes ◽

Mechanical Reinforcement ◽

Uniform Size ◽

Preparation Methods ◽

Potential Applications

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.

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Prokaryotic Diversity from Extreme Environments of Pakistan and its Potential Applications at Regional Levels

10.1101/342949 ◽

2018 ◽

Author(s):

Raees Khan ◽

Muhammad Israr Khan ◽

Amir Zeb ◽

Nazish Roy ◽

Muhammad Yasir ◽

...

Keyword(s):

Bacterial Diversity ◽

Functional Diversity ◽

Wide Spectrum ◽

Extreme Environments ◽

Regional Level ◽

Bioenergy Production ◽

Prokaryotic Diversity ◽

Potential Applications ◽

Biotechnological Processes

AbstractExtremophiles, the microorganisms thriving in extreme environments, provide valuable resources for practicing novel biotechnological processes. Pakistan homes a wide spectrum of extreme environments which harbor various biotechnologically significant microorganisms. This review gauges the structural and functional bacterial diversity of several extreme environments, emphasizing their potentials as a source of extremozymes, and in bioleaching, bioremediation, and bioenergy production at regional level. Further, this review highlights a panoramic account of the local natural conservatories of extremophiles. The inadequacies of current fragmental research are discussed with suggestions to quantitatively define the structural and functional diversity of unexplored extreme localities.

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Advances in preparation, modification, and application of polypropylene membrane

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0112 ◽

2016 ◽

Vol 36 (4) ◽

pp. 329-362 ◽

Cited By ~ 65

Author(s):

Nurul F. Himma ◽

Sofiatun Anisah ◽

Nicholaus Prasetya ◽

I Gede Wenten

Keyword(s):

Thermal Stability ◽

High Performance ◽

Chemical Resistance ◽

Low Cost ◽

Comprehensive Overview ◽

Preparation Methods ◽

Good Thermal Stability ◽

Polypropylene Membrane ◽

Membrane Fabrication ◽

Potential Applications

Abstract Polypropylene (PP) is one of the most used polymers for microporous membrane fabrication due to its good thermal stability, chemical resistance, mechanical strength, and low cost. There have been numerous studies reporting the developments and applications of PP membranes. However, PP membrane with high performance is still a challenge. Thus, this article presents a comprehensive overview of the advances in the preparation, modification and application of PP membrane. The preparation methods of PP membrane are firstly reviewed, followed by the modification approaches of PP membrane. The modifications includes hydrophilic and superhydrophobic modification so that the PP membranes become more suitable to be applied either in aqueous applications or in non-aqueous ones. The fouling resistant of hydrophilized PP membrane and the wetting resistant of superhydrophobized PP membrane are then reviewed. Finally, special attention is given to the various potential applications and industrial outlook of the PP membranes.

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A critical review on the development and performance of polymer/graphene nanocomposites

Science and Engineering of Composite Materials ◽

10.1515/secm-2017-0199 ◽

2018 ◽

Vol 25 (6) ◽

pp. 1059-1073 ◽

Cited By ~ 7

Author(s):

Weifeng Chen ◽

Hu Weimin ◽

Dejiang Li ◽

Shaona Chen ◽

Zhongxu Dai

Keyword(s):

Polymer Nanocomposites ◽

Electronic Conductivity ◽

Future Research ◽

Preparation Methods ◽

Graphene Nanocomposites ◽

Advantages And Disadvantages ◽

Solution Blending ◽

Potential Applications ◽

New Type ◽

And Performance

AbstractGraphene (graphene) is a new type of two-dimensional inorganic nanomaterial developed in recent years. It can be used as an ideal inorganic nanofiller for the preparation of polymer nanocomposites because of its high mechanical strength, excellent electrical conductivity and plentiful availability (from graphite). In this review, the preparation methods of graphene/polymer nanocomposites, including solution blending, melt blending and in situ polymerization, are introduced in order to study the relationship between these methods and the final characteristics and properties. Each method has an influence on the final characteristics and properties of the nanocomposites. The advantages and disadvantages of these methods are discussed. In addition, a variety of nanocomposites with different properties, such as mechanical properties, electronic conductivity, thermal conductivity and thermal properties, are summarized comprehensively. The potential applications of these nanocomposites in conductive materials, electromagnetic shielding materials, photocatalytic materials and so on, are briefly presented. This review demonstrates that polymer/graphene nanocomposites exhibit superior comprehensive performance and will be applied in the fields of new materials and novel devices. Future research directions of the nanocomposites are also presented.

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Coiled-Coils: The Molecular Zippers that Self-Assemble Protein Nanostructures

International Journal of Molecular Sciences ◽

10.3390/ijms21103584 ◽

2020 ◽

Vol 21 (10) ◽

pp. 3584 ◽

Cited By ~ 1

Author(s):

Won Min Park

Keyword(s):

Modular Design ◽

Coiled Coil ◽

Molecular Complexes ◽

Building Blocks ◽

Structural Features ◽

Coiled Coils ◽

Design Strategies ◽

Protein Motifs ◽

Self Assembling ◽

Current Design

Coiled-coils, the bundles of intertwined helical protein motifs, have drawn much attention as versatile molecular toolkits. Because of programmable interaction specificity and affinity as well as well-established sequence-to-structure relationships, coiled-coils have been used as subunits that self-assemble various molecular complexes in a range of fields. In this review, I describe recent advances in the field of protein nanotechnology, with a focus on programming assembly of protein nanostructures using coiled-coil modules. Modular design approaches to converting the helical motifs into self-assembling building blocks are described, followed by a discussion on the molecular basis and principles underlying the modular designs. This review also provides a summary of recently developed nanostructures with a variety of structural features, which are in categories of unbounded nanostructures, discrete nanoparticles, and well-defined origami nanostructures. Challenges existing in current design strategies, as well as desired improvements for controls over material properties and functionalities for applications, are also provided.

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A structural and kinetic survey of GH5_4 endoglucanases reveals determinants of broad substrate specificity and opportunities for biomass hydrolysis

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.015328 ◽

2020 ◽

Vol 295 (51) ◽

pp. 17752-17769

Author(s):

Evan M. Glasgow ◽

Elias I. Kemna ◽

Craig A. Bingman ◽

Nicole Ing ◽

Kai Deng ◽

...

Keyword(s):

Substrate Specificity ◽

Protein Design ◽

Plant Biomass ◽

Catalytic Efficiency ◽

Structural Features ◽

Glycoside Hydrolases ◽

Design Strategies ◽

Biomass Hydrolysis ◽

Diverse Range ◽

Broad Specificity

Broad-specificity glycoside hydrolases (GHs) contribute to plant biomass hydrolysis by degrading a diverse range of polysaccharides, making them useful catalysts for renewable energy and biocommodity production. Discovery of new GHs with improved kinetic parameters or more tolerant substrate-binding sites could increase the efficiency of renewable bioenergy production even further. GH5 has over 50 subfamilies exhibiting selectivities for reaction with β-(1,4)–linked oligo- and polysaccharides. Among these, subfamily 4 (GH5_4) contains numerous broad-selectivity endoglucanases that hydrolyze cellulose, xyloglucan, and mixed-linkage glucans. We previously surveyed the whole subfamily and found over 100 new broad-specificity endoglucanases, although the structural origins of broad specificity remained unclear. A mechanistic understanding of GH5_4 substrate specificity would help inform the best protein design strategies and the most appropriate industrial application of broad-specificity endoglucanases. Here we report structures of 10 new GH5_4 enzymes from cellulolytic microbes and characterize their substrate selectivity using normalized reducing sugar assays and MS. We found that GH5_4 enzymes have the highest catalytic efficiency for hydrolysis of xyloglucan, glucomannan, and soluble β-glucans, with opportunistic secondary reactions on cellulose, mannan, and xylan. The positions of key aromatic residues determine the overall reaction rate and breadth of substrate tolerance, and they contribute to differences in oligosaccharide cleavage patterns. Our new composite model identifies several critical structural features that confer broad specificity and may be readily engineered into existing industrial enzymes. We demonstrate that GH5_4 endoglucanases can have broad specificity without sacrificing high activity, making them a valuable addition to the biomass deconstruction toolset.

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Lanthanide Doped Complexes and Organometallic Clusters: Design Strategies and their Applications in Biology and Photonics

Current Physical Chemistry ◽

10.2174/1877946809666190919100324 ◽

2019 ◽

Vol 9 (3) ◽

pp. 166-217 ◽

Cited By ~ 1

Author(s):

Gangadharan A. Kumar

Keyword(s):

Nanostructured Materials ◽

Rational Design ◽

Near Infrared ◽

Organic Ligand ◽

Central Core ◽

Design Strategies ◽

Ceramic Core ◽

Light Emitting ◽

Potential Applications ◽

Lanthanide Atoms

In this review, we discuss the rational design of a new class of lanthanide-doped organometallic nanostructured materials called `molecular minerals`. Molecular minerals are nanostructured materials with a ceramic core made from chalcogenide groups and other heavy metals. Part of the central core atoms is replaced by suitable lanthanide atoms to impart fluorescent spectral properties. The ceramic core is surrounded by various types of organic networks thus making the structure partly ceramic and organic. The central core has superior optical properties and the surrounding organic ligand makes it easy to dissolve several kinds of organic solvents and fluoropolymers to make several kinds of active and passive photonic devices. This chapter starts with elaborate design strategies of lanthanidebased near-infrared emitting materials followed by the experimental results of selected near-infrared emitting lanthanide clusters. Finally, their potential applications in telecommunication, light-emitting diodes and medical imaging are discussed.

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