Biomimetics

10 pages, 2632 KiB

Open AccessArticle

New Chitosan/Iron Oxide Composites: Fabrication and Application for Removal of Sr²⁺ Radionuclide from Aqueous Solutions

by Larisa Zemskova, Andrei Egorin, Eduard Tokar, Vladimir Ivanov and Svetlana Bratskaya

Biomimetics 2018, 3(4), 39; https://doi.org/10.3390/biomimetics3040039 - 4 Dec 2018

Cited by 17 | Viewed by 4113

Here, we discuss the fabrication and problems of application of chitosan-based composite materials for the removal of hazardous metal ions from tap water and wastewater. The chitosan-based composites containing iron oxides for the uptake of Sr²⁺ ions were fabricated via a co-precipitation [...] Read more.

Here, we discuss the fabrication and problems of application of chitosan-based composite materials for the removal of hazardous metal ions from tap water and wastewater. The chitosan-based composites containing iron oxides for the uptake of Sr²⁺ ions were fabricated via a co-precipitation method with variation of the iron/chitosan ratio and pH of the medium. The morphology and composition of the fabricated sorbents were characterized using scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDX) and X-ray diffraction (XRD) analysis. We have shown that the suggested fabrication approach allows for a homogeneous distribution of the inorganic phase in the polymer matrix. Investigations of the sorption performance of the composites have shown that they are efficient sorbents for ⁹⁰Sr radionuclides uptake from tap water. The composite sorbent containing amorphous iron oxide in a chitosan matrix and calcined at 105 °C showed the best sorption characteristics. We have also demonstrated that there is an optimal iron oxide content in the composite: with increasing oxide content, the efficiency of the sorbents decreases due to poor stability in solution, especially in alkaline media. The alternative approach yielding magnetic chitosan-based composites with sufficiently good sorption performance and stability in neutral and weakly alkaline media is suggested. Full article

(This article belongs to the Special Issue Chitin- and Chitosan-Based Composite Materials)

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15 pages, 41472 KiB

Open AccessReview

Molecularly Imprinted Polymers for Removal of Metal Ions: An Alternative Treatment Method

by Özgecan Erdem, Yeşeren Saylan, Müge Andaç and Adil Denizli

Biomimetics 2018, 3(4), 38; https://doi.org/10.3390/biomimetics3040038 - 30 Nov 2018

Cited by 44 | Viewed by 5537

Abstract

Aquatic and terrestrial environment and human health have been seriously threatened with the release of metal-containing wastewater by the rapid growth in the industry. There are various methods which have been used for removal of ions from the environment, such as membrane filtration, [...] Read more.

Aquatic and terrestrial environment and human health have been seriously threatened with the release of metal-containing wastewater by the rapid growth in the industry. There are various methods which have been used for removal of ions from the environment, such as membrane filtration, ion exchange, membrane assisted liquid extraction and adsorption. As a sort of special innovation, a polymerization technique, namely molecular imprinting is carried out by specific identification for the target by mixing it with a functional monomer. After the polymerization occurred, the target ion can be removed with suitable methods. At the end of this process, specific cavities, namely binding sites, are able to recognize target ions selectively. However, the selectivity of the molecularly imprinted polymer is variable not only because of the type of ligand but also charge, size coordination number, and geometry of the target ion. In this review, metal ion-imprinted polymeric materials that can be applied for metal ion removal from different sources are discussed and exemplified briefly with different metal ions. Full article

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9 pages, 2968 KiB

Open AccessConference Report

1st Symposium on Polydopamine and NanoTech Poland 2018: Conference Report

by Radosław Mrówczyński, Marco D’Ischia, Haeshin Lee and Stefan Jurga

Biomimetics 2018, 3(4), 37; https://doi.org/10.3390/biomimetics3040037 - 27 Nov 2018

Cited by 1 | Viewed by 4202

Abstract

The NanoTech Poland is an annual international conference with a strong scientific agenda focused on nanotechnology in energy, environment, and biomedicine. The Nanotech Poland 2018 was held at the NanoBioMedical Centre and Department of Physics at Adam Mickiewicz University in Poznań from June [...] Read more.

The NanoTech Poland is an annual international conference with a strong scientific agenda focused on nanotechnology in energy, environment, and biomedicine. The Nanotech Poland 2018 was held at the NanoBioMedical Centre and Department of Physics at Adam Mickiewicz University in Poznań from June 6th to June 9th. The aim of NanoTech Poland 2018 was to bring together the scientific community’s principal investigators, scientists, researchers, analysts, clinicians, policy makers, industry experts, and well-established and budding entrepreneurs to discuss the present and future perspectives in nanotechnology and nanoscience research and development. This year, the 1st Symposium on Polydopamine was held on June 6th. This forum was dedicated to the application of polydopamine and related catechol materials in a variety of research fields, both at the nano- and macroscale. The symposium gathered leading scientists from this important research field from top universities and institutions that have been involved in the research revolved around polydopamine. With over 200 national and international participants, NanoTech Poland 2018 and the 1st Symposium on Polydopamine provided a forum to present and discuss the latest scientific news from the field of nanotechnology with a strong interdisciplinary aspect and bioinspired materials. Full article

(This article belongs to the Special Issue Selected Papers from NanoTech Poland 2018 and 1st Symposium on Polydopamine)

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13 pages, 4178 KiB

Open AccessArticle

Enzymatically Active Polydopamine @ Alkaline Phosphatase Nanoparticles Produced by NaIO₄ Oxidation of Dopamine

by Salima El Yakhlifi, Dris Ihiawakrim, Ovidiu Ersen and Vincent Ball

Biomimetics 2018, 3(4), 36; https://doi.org/10.3390/biomimetics3040036 - 12 Nov 2018

Cited by 12 | Viewed by 5290

Abstract

Polydopamine (PDA) deposition, obtained from the oxidation of dopamine and other catecholamines, is a universal way to coat all known materials with a conformal coating which can subsequently be functionalized at will. The structural analogies between polydopamine and eumelanin, the black-brown pigment of [...] Read more.

Polydopamine (PDA) deposition, obtained from the oxidation of dopamine and other catecholamines, is a universal way to coat all known materials with a conformal coating which can subsequently be functionalized at will. The structural analogies between polydopamine and eumelanin, the black-brown pigment of the skin, were incited to produce stable polydopamine nanoparticles in solution, instead of amorphous precipitates obtained from the oxidation of dopamine. Herein, we demonstrate that size-controlled and colloidally stable PDA-based nanoparticles can be obtained in acidic conditions, where spontaneous auto-oxidation of dopamine is suppressed, using sodium periodate as the oxidant and a protein, like alkaline phosphatase (ALP), as a templating agent. The size of the PDA@ALP nanoparticles depends on the dopamine/enzyme ratio and the obtained particles display enzymatic activity of alkaline phosphatase, with an activity extending up to two weeks after particle synthesis. The PDA@ALP nanoparticles can be engineered in polyelectrolyte multilayered films to potentially design model biosensors. Full article

(This article belongs to the Special Issue Selected Papers from NanoTech Poland 2018 and 1st Symposium on Polydopamine)

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8 pages, 497 KiB

Open AccessArticle

Effect of Non-Vital Bleaching on the Durability of Resin–Dentin Bond with an Ethanol-Based Etch-And-Rinse Adhesive

by Alireza Boruziniat, Atefeh Atoufi, Zafer Chehreli, Majid Akbari and Mahshid Gifani

Biomimetics 2018, 3(4), 35; https://doi.org/10.3390/biomimetics3040035 - 6 Nov 2018

Cited by 5 | Viewed by 3488

Abstract

To evaluate the bleaching procedure and application of sodium ascorbate on dentin bond durability, the enamel surface of intact human third molars (n = 18) were removed, and the teeth were randomly divided into two groups for immediate and six-month bond strength [...] Read more.

To evaluate the bleaching procedure and application of sodium ascorbate on dentin bond durability, the enamel surface of intact human third molars (n = 18) were removed, and the teeth were randomly divided into two groups for immediate and six-month bond strength evaluation. The specimens were further assigned into three subgroups according to treatment procedure, as follows: subgroup A, no bleaching (positive control) was performed prior to the etch-and-rinse bonding with single bond and subsequent build-up with Z250 composite; subgroup B, the samples were bleached with 20% carbamide peroxide 6 h/day for five consecutive days prior to bonding; and subgroup C, bleaching was performed as in subgroup B, after which 10% sodium ascorbate was applied on dentin surface for 10 min before the bonding procedures. A microtensile bond strength test was performed and the failure modes were evaluated under a stereomicroscope. The data were analyzed using two-way analysis of variance (ANOVA) and Tukey’s post-hoc tests with a level of significance of 0.05. Bleaching significantly decreased the immediate and six-month bond strength. The application of sodium ascorbate had no significant effect on the immediate and six-month bond strength of bleached specimens. We conclude that the bleaching procedure may decrease the durability of the resin–dentin bond of the tested etch-and-rinse adhesive. Full article

(This article belongs to the Special Issue Biomimetic Restorative Dentistry)

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17 pages, 7474 KiB

Open AccessArticle

Bioinspired Optical Sensor for Remote Measurement of Small Displacements at a Distance

by Susan A. Frost, Leslie A. Yates and Hiroyuki S. Kumagai

Biomimetics 2018, 3(4), 34; https://doi.org/10.3390/biomimetics3040034 - 30 Oct 2018

Cited by 3 | Viewed by 4051

Abstract

Identifying appropriate sites for landing a spacecraft or building permanent structures is critical for extraterrestrial exploration. By tracking the movement of land masses and structures on a planetary surface, scientists can better predict issues that could affect the integrity of the site or [...] Read more.

Identifying appropriate sites for landing a spacecraft or building permanent structures is critical for extraterrestrial exploration. By tracking the movement of land masses and structures on a planetary surface, scientists can better predict issues that could affect the integrity of the site or structures. A lightweight, low-cost, low-power bioinspired optical sensor is being developed at the National Aeronautics and Space Administration (NASA) Ames Research Center to remotely measure small displacements of land masses on either side of a fault. This paper describes the sensor, which is inspired by the compound eye vision system found in many insects, and the algorithms developed to estimate displacement. The results are presented for indoor and outdoor tests using the sensor to measure the displacement of a specially designed target that is located 0.35, 6, and 30 m from the sensor and is moved 10 mm to the left and right of a centered position, simulating the displacement of land masses on either side of a fault. Measurement uncertainties estimates were a few tenths of a millimeter when the target was located 0.35 and 6 m from the sensor. At the 30 m distance, corrections were required to obtain accuracies in the order of 1 mm. Full article

(This article belongs to the Special Issue Biomimetic Design and Techniques for Space Applications)

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2 pages, 153 KiB

Open AccessAddendum

Addendum: Oil-In-Water Microemulsions as Hosts for Benzothiophene-Based Cytotoxic Compounds: An Effective Combination. Biomimetics 2018, 3, 13

by Ioanna Theochari, Vassiliki Papadimitriou, Demetris Papahatjis, Nikos Assimomytis, Efthimia Pappou, Harris Pratsinis, Aristotelis Xenakis and Vasiliki Pletsa

Biomimetics 2018, 3(4), 33; https://doi.org/10.3390/biomimetics3040033 - 25 Oct 2018

Cited by 2 | Viewed by 2464

Abstract

It was brought to our attention that due to recent changes in the regulation that governs the Ph. [...] Full article

29 pages, 12302 KiB

Open AccessReview

Biomechanics in Soft Mechanical Sensing: From Natural Case Studies to the Artificial World

by Afroditi Astreinidi Blandin, Irene Bernardeschi and Lucia Beccai

Biomimetics 2018, 3(4), 32; https://doi.org/10.3390/biomimetics3040032 - 24 Oct 2018

Cited by 18 | Viewed by 8258

Abstract

Living beings use mechanical interaction with the environment to gather essential cues for implementing necessary movements and actions. This process is mediated by biomechanics, primarily of the sensory structures, meaning that, at first, mechanical stimuli are morphologically computed. In the present paper, we [...] Read more.

Living beings use mechanical interaction with the environment to gather essential cues for implementing necessary movements and actions. This process is mediated by biomechanics, primarily of the sensory structures, meaning that, at first, mechanical stimuli are morphologically computed. In the present paper, we select and review cases of specialized sensory organs for mechanical sensing—from both the animal and plant kingdoms—that distribute their intelligence in both structure and materials. A focus is set on biomechanical aspects, such as morphology and material characteristics of the selected sensory organs, and on how their sensing function is affected by them in natural environments. In this route, examples of artificial sensors that implement these principles are provided, and/or ways in which they can be translated artificially are suggested. Following a biomimetic approach, our aim is to make a step towards creating a toolbox with general tailoring principles, based on mechanical aspects tuned repeatedly in nature, such as orientation, shape, distribution, materials, and micromechanics. These should be used for a future methodical design of novel soft sensing systems for soft robotics. Full article

(This article belongs to the Special Issue Soft Robotics)

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13 pages, 17436 KiB

Open AccessCommunication

AMROBS: All-Metal Replicas of Biological Surfaces—A Novel Approach Combining Established Techniques

by Florian Hischen, Mirjana Keser and Werner Baumgartner

Biomimetics 2018, 3(4), 31; https://doi.org/10.3390/biomimetics3040031 - 19 Oct 2018

Viewed by 3616

Abstract

Biomimetic work often concerns to biological surfaces and their interaction with the environment. Liquid handling, barrier function and protection against heat, pathogens and predators, to name just a few, require biological surfaces to exhibit specific material properties—properties that often are not suited for [...] Read more.

Biomimetic work often concerns to biological surfaces and their interaction with the environment. Liquid handling, barrier function and protection against heat, pathogens and predators, to name just a few, require biological surfaces to exhibit specific material properties—properties that often are not suited for specific measurements under lab conditions. In particular, the lack of the necessary sample toughness or conductivity can prove difficult to perform certain experiments. Hence, we present a novel approach to achieve all-metal replicas from biological surfaces (AMROBS). Resulting replicas exhibit microscale accurate replication of morphological topography while providing tough, conductive subjects for investigation and easy chemical surface modification. Combining established techniques like polymer casting (e.g., silicone), chemical silver precipitation and electroplating, all-metal replicas of several technical and biological surfaces (e.g., diffraction foils, lizard skin, flat bug surface) were produced and compared to their original counterparts with regard to morphology and functionality. By using scanning electron microscopy and video analysis, we show that a high degree of replication accuracy is achievable, and conclude the future possibilities of AMROBS in a comprehensive discussion, including the general “do’s” and “do nots” of metal replication following this approach. Full article

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20 pages, 7525 KiB

Open AccessArticle

Photonic Crystal Characterization of the Cuticles of Chrysina chrysargyrea and Chrysina optima Jewel Scarab Beetles

by William E. Vargas, Esteban Avendano, Marcela Hernández-Jiménez, Daniel E. Azofeifa, Eduardo Libby, Ángel Solís and Cynthia Barboza-Aguilar

Biomimetics 2018, 3(4), 30; https://doi.org/10.3390/biomimetics3040030 - 11 Oct 2018

Cited by 16 | Viewed by 5869

Abstract

A unified description involving structural morphology and composition, dispersion of optical constants, modeled and measured reflection spectra and photonic crystal characterization is devised. Light reflection spectra by the cuticles of scarab beetles (Chrysina chrysargyrea and Chrysina optima), measured in the wavelength [...] Read more.

A unified description involving structural morphology and composition, dispersion of optical constants, modeled and measured reflection spectra and photonic crystal characterization is devised. Light reflection spectra by the cuticles of scarab beetles (Chrysina chrysargyrea and Chrysina optima), measured in the wavelength range 300–1000 nm, show spectrally structured broad bands. Scanning electron microscopy analysis shows that the pitches of the twisted structures responsible for the left-handed circularly polarized reflected light change monotonically with depth through the cuticles, making it possible to obtain the explicit depth-dependence for each cuticle arrangement considered. This variation is a key aspect, and it will be introduced in the context of Berreman’s formalism, which allows us to evaluate reflection spectra whose main features coincide in those displayed in measurements. Through the dispersion relation obtained from the Helmholtz’s equation satisfied by the circular components of the propagating fields, the presence of a photonic band gap is established for each case considered. These band gaps depend on depth through the cuticle, and their spectral positions change with depth. This explains the presence of broad bands in the reflection spectra, and their spectral features correlate with details in the variation of the pitch with depth. The twisted structures consist of chitin nanofibrils whose optical anisotropy is not large enough so as to be approached from modeling the measured reflection spectra. The presence of a high birefringence substance embedded in the chitin matrix is required. In this sense, the presence of uric acid crystallites through the cuticle is strongly suggested by frustrated attenuated total reflection and Raman spectroscopy analysis. The complete optical modeling is performed incorporating the wavelength-dependent optical constants of chitin and uric acid. Full article

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16 pages, 2850 KiB

Open AccessReview

Straining Flow Spinning of Artificial Silk Fibers: A Review

by José Pérez-Rigueiro, Rodrigo Madurga, Alfonso M. Gañán-Calvo, Gustavo R. Plaza, Manuel Elices, Patricia A. López, Rafael Daza, Daniel González-Nieto and Gustavo V. Guinea

Biomimetics 2018, 3(4), 29; https://doi.org/10.3390/biomimetics3040029 - 5 Oct 2018

Cited by 15 | Viewed by 5094

Abstract

This work summarizes the main principles and some of the most significant results of straining flow spinning (SFS), a technology developed originally by the authors of this work. The principles on which the technology is based, inspired by the natural spinning system of [...] Read more.

This work summarizes the main principles and some of the most significant results of straining flow spinning (SFS), a technology developed originally by the authors of this work. The principles on which the technology is based, inspired by the natural spinning system of silkworms and spiders, are presented, as well as some of the main achievements of the technique. Among these achievements, spinning under environmentally friendly conditions, obtaining high-performance fibers, and imparting the fibers with emerging properties such as supercontraction are discussed. Consequently, SFS appears as an efficient process that may represent one of the first realizations of a biomimetic technology with a significant impact at the production level. Full article

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18 pages, 3234 KiB

Open AccessArticle

Reprogramming Cells for Synergistic Combination Therapy with Nanotherapeutics against Uveal Melanoma

by Paula Milán Rois, Alfonso Latorre, Ciro Rodriguez Diaz, Álvaro Del Moral and Álvaro Somoza

Biomimetics 2018, 3(4), 28; https://doi.org/10.3390/biomimetics3040028 - 25 Sep 2018

Cited by 16 | Viewed by 5922

Abstract

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and around half of the patients develop metastasis and die shortly after because of the lack of effective therapies for metastatic UM. Consequently, new therapeutic approaches to this disease are [...] Read more.

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and around half of the patients develop metastasis and die shortly after because of the lack of effective therapies for metastatic UM. Consequently, new therapeutic approaches to this disease are welcome. In this regard, microRNAs have been shown to have a key role in neoplasia progression and have the potential to be used as therapeutic tools. In addition, in different cancers including UM, a particular microRNA signature appears that is different from healthy cells. Thus, restoring the regular levels of microRNAs could restore the normal behavior of cells. In this study, four microRNAs downregulated in UM have been chosen to reprogram cancer cells, to promote cell death or increase their sensitivity to the chemotherapeutic SN38. Furthermore, to improve the internalization, stability and/or solubility of the therapeutic molecules employed in this approach, gold nanoparticles (AuNPs) were used as carriers. Remarkably, this study found a synergistic effect when the four oligonucleotides were employed and when the chemotherapeutic drug was added. Full article

(This article belongs to the Special Issue Selected Papers from NanoBio&Med 2017)

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Biomimetics, Volume 3, Issue 4 (December 2018) – 12 articles

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