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Lou L, Dolmetsch T, Aguiar BA, Mohammed SMAK, Agarwal A. Quantum Dots on a String: In Situ Observation of Branching and Reinforcement Mechanism of Electrospun Fibers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2311073. [PMID: 38566548 DOI: 10.1002/smll.202311073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Immobilization of quantum dots (QDs) on fiber surfaces has emerged as a robust approach for preserving their functional characteristics while mitigating aggregation and instability issues. Despite the advancement, understanding the impacts of QDs on jet-fiber evolution during electrospinning, QDs-fiber interface, and composites functional behavior remains a knowledge gap. The study adopts a high-speed imaging methodology to capture the immobilization effects on the QDs-fiber matrix. In situ observations reveal irregular triangular branches within the QDs-fiber matrix, exhibiting distinctive rotations within a rapid timeframe of 0.00667 ms. The influence of FeQDs on Taylor cone dynamics and subsequent fiber branching velocities is elucidated. Synthesis phenomena are correlated with QD-fiber's morphology, crystallinity, and functional properties. PAN-FeQDs composite fibers substantially reduced (50-70%) nano-fibrillar length and width while their diameter expanded by 17%. A 30% enhancement in elastic modulus and reduction in adhesion force for PAN-FeQDs fibers is observed. These changes are attributed to chemical and physical intertwining between the FeQDs and the polymer matrix, bolstered by the shifts in the position of C≡N and C═C bonds. This study provides valuable insights into the quantum dot-fiber composites by comprehensively integrating and bridging jet-fiber transformation, fiber structure, nanomechanics, and surface chemistry.
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Affiliation(s)
- Lihua Lou
- Plasma Forming Laboratory, Mechanical and Materials Engineering, School of Biomedical, Materials and Mechanical Engineering, College of Engineering and Computing, Florida International University, Miami, FL, 33174, USA
| | - Tyler Dolmetsch
- Plasma Forming Laboratory, Mechanical and Materials Engineering, School of Biomedical, Materials and Mechanical Engineering, College of Engineering and Computing, Florida International University, Miami, FL, 33174, USA
| | - Brandon A Aguiar
- Plasma Forming Laboratory, Mechanical and Materials Engineering, School of Biomedical, Materials and Mechanical Engineering, College of Engineering and Computing, Florida International University, Miami, FL, 33174, USA
| | - Sohail Mazher Ali Khan Mohammed
- Plasma Forming Laboratory, Mechanical and Materials Engineering, School of Biomedical, Materials and Mechanical Engineering, College of Engineering and Computing, Florida International University, Miami, FL, 33174, USA
| | - Arvind Agarwal
- Plasma Forming Laboratory, Mechanical and Materials Engineering, School of Biomedical, Materials and Mechanical Engineering, College of Engineering and Computing, Florida International University, Miami, FL, 33174, USA
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2
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Langwald SV, Ehrmann A, Sabantina L. Measuring Physical Properties of Electrospun Nanofiber Mats for Different Biomedical Applications. MEMBRANES 2023; 13:488. [PMID: 37233549 PMCID: PMC10220787 DOI: 10.3390/membranes13050488] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
Electrospun nanofiber mats are nowadays often used for biotechnological and biomedical applications, such as wound healing or tissue engineering. While most studies concentrate on their chemical and biochemical properties, the physical properties are often measured without long explanations regarding the chosen methods. Here, we give an overview of typical measurements of topological features such as porosity, pore size, fiber diameter and orientation, hydrophobic/hydrophilic properties and water uptake, mechanical and electrical properties as well as water vapor and air permeability. Besides describing typically used methods with potential modifications, we suggest some low-cost methods as alternatives in cases where special equipment is not available.
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Affiliation(s)
- Sarah Vanessa Langwald
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences and Arts, 33619 Bielefeld, Germany;
| | - Andrea Ehrmann
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences and Arts, 33619 Bielefeld, Germany;
| | - Lilia Sabantina
- Faculty of Clothing Technology and Garment Engineering, School of Culture + Design, HTW Berlin—University of Applied Sciences, 12459 Berlin, Germany
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3
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Production of nanoparticles from resistant starch via a simple three-step physical treatment. Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2022.108412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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4
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Abdolmaleki H, Haugen AB, Buhl KB, Daasbjerg K, Agarwala S. Interfacial Engineering of PVDF-TrFE toward Higher Piezoelectric, Ferroelectric, and Dielectric Performance for Sensing and Energy Harvesting Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205942. [PMID: 36594621 PMCID: PMC9951327 DOI: 10.1002/advs.202205942] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The electrical properties of pristine fluoropolymers are inferior due to their low polar crystalline phase content and rigid dipoles that tend to retain their fixed moment and orientation. Several strategies, such as electrospinning, electrohydrodynamic pulling, and template-assisted growing, have been proven to enhance the electrical properties of fluoropolymers; however, these techniques are mostly very hard to scale-up and expensive. Here, a facile interfacial engineering approach based on amine-functionalized graphene oxide (AGO) is proposed to manipulate the intermolecular interactions in poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE) to induce β-phase formation, enlarge the lamellae dimensions, and align the micro-dipoles. The coexistence of primary amine and hydroxyl groups on AGO nanosheets offers strong hydrogen bonding with fluorine atoms, which facilitates domain alignment, resulting in an exceptional remnant polarization of 11.3 µC cm-2 . PVDF-TrFE films with 0.1 wt.% AGO demonstrate voltage coefficient, energy density, and energy-harvesting figure of merit values of 0.30 Vm N-1 , 4.75 J cm-3 , and 14 pm3 J-1 , respectively, making it outstanding compared with state-of-the-art ceramic-free ferroelectric films. It is believed that this work can open-up new insights toward structural and morphological tailoring of fluoropolymers to enhance their electrical and electromechanical performance and pave the way for their industrial deployment in next-generation wearables and human-machine interfaces.
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Affiliation(s)
- Hamed Abdolmaleki
- Department of Electrical and Computer EngineeringAarhus UniversityAarhusDenmark
| | - Astri Bjørnetun Haugen
- Department of Energy Conversion and StorageTechnical University of Denmark (DTU)LyngbyDenmark
| | | | - Kim Daasbjerg
- Novo Nordisk Foundation (NNF) Research CenterDepartment of Chemistry and Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
| | - Shweta Agarwala
- Department of Electrical and Computer EngineeringAarhus UniversityAarhusDenmark
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5
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Maurya AK, Mias E, Schoeller J, Collings IE, Rossi RM, Dommann A, Neels A. Understanding multiscale structure-property correlations in PVDF-HFP electrospun fiber membranes by SAXS and WAXS. NANOSCALE ADVANCES 2022; 4:491-501. [PMID: 35178501 PMCID: PMC8765355 DOI: 10.1039/d1na00503k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/14/2021] [Indexed: 06/14/2023]
Abstract
Electrospinning is a versatile technique to produce nanofibrous membranes with applications in filtration, biosensing, biomedical and tissue engineering. The structural and therefore physical properties of electrospun fibers can be finely tuned by changing the electrospinning parameters. The large parameter window makes it challenging to optimize the properties of fibers for a specific application. Therefore, a fundamental understanding of the multiscale structure of fibers and its correlation with their macroscopic behaviors is required for the design and production of systems with dedicated applications. In this study, we demonstrate that the properties of poly(vinylidene fluoride-co-hexafluoro propylene) (PVDF-HFP) electrospun fibers can be tuned by changing the rotating drum speed used as a collector during electrospinning. Indeed, with the help of multiscale characterization techniques such as scanning electron microscopy (SEM), small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering (WAXS), we observe that increasing the rotating drum speed not only aligns the fibers but also induces polymeric chain rearrangements at the molecular scale. Such changes result in enhanced mechanical properties and an increase of the piezoelectric β-phase of the PVDF-HFP fiber membranes. We detect nanostructural deformation behaviors when the aligned fibrous membrane is uniaxially stretched along the fiber alignment direction, while an increase in the alignment of the fibers is observed for randomly aligned samples. This was analyzed by performing in situ SAXS measurements coupled with uniaxial tensile loading of the fibrous membranes along the fiber alignment direction. The present study shows that fibrous membranes can be produced with varying degrees of fiber orientation, piezoelectric β-phase content, and mechanical properties by controlling the speed of the rotating drum collector during the fiber production. Such aligned fiber membranes have potential applications for neural or musculoskeletal tissue engineering.
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Affiliation(s)
- Anjani K Maurya
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- ARTORG Center for Biomedical Engineering Research, University of Bern Murtenstrasse 50 3008 Bern Switzerland
| | - Eloïse Mias
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
| | - Jean Schoeller
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- ETH Zürich, Department of Health Science and Technology 8092 Zürich Switzerland
| | - Ines E Collings
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
| | - René M Rossi
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- ETH Zürich, Department of Health Science and Technology 8092 Zürich Switzerland
| | - Alex Dommann
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- ARTORG Center for Biomedical Engineering Research, University of Bern Murtenstrasse 50 3008 Bern Switzerland
| | - Antonia Neels
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Center for X-Ray Analytics Lerchenfeldstrasse 5 9014 St. Gallen Switzerland
- Department of Chemistry, University of Fribourg Avenue de l'Europe 20 1700 Fribourg Switzerland
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6
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Guo Y, Chen Z, Yang W, Li K, Yang D, Zhang Q, Wang H. Multifunctional Mechanical Sensing Electronic Device Based on Triboelectric Anisotropic Crumpled Nanofibrous Mats. ACS APPLIED MATERIALS & INTERFACES 2021; 13:55481-55488. [PMID: 34767341 DOI: 10.1021/acsami.1c18449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Integrating multiple mechanical sensing capabilities in one device is highly desired to mimic the amazing functions of human skin, and it demonstrates promising applications in the human-machine interface and wearable robotic exoskeletons. Yet, challenges remain in how to couple the multisensations using as few modules as possible to increase the compactness and conformality of the electronics. Herein, we report a self-powered multiple mechanical sensing electronic device capable of sensing multiple motion modes of strain ratios, strain direction, and pressure. The self-powered property derives from the triboelectric working mechanism of the sensor. The multiple mechanical sensing is realized by utilizing an anisotropic crumpled nanofibrous membrane as the triboelectric layer and ionic conductor as the electrode layer. For strain ratios and pressure sensing, the output voltages of the sensor changed with the changes of these external stimulus with a comparable sensitivity. More importantly, contributed by the anisotropic structure of the designed crumples, the directional strain sensing is realized by the anisotropic sensitivity in three stretched directions.
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Affiliation(s)
- Yinben Guo
- School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, P.R. China
| | - Zixi Chen
- School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, P.R. China
| | - Weifeng Yang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Kerui Li
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Dongye Yang
- School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, P.R. China
| | - Qinghong Zhang
- Engineering Research Center of Advanced Glasses Manufacturing Technology, Ministry of Education, Donghua University, Shanghai 201620, P.R. China
| | - Hongzhi Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
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7
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Tian B, Heringa JR, Bouwman WG. Scattering from oriented objects analysed by the anisotropic Guinier–Porod model. FOOD STRUCTURE 2021. [DOI: 10.1016/j.foostr.2021.100221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Maurya AK, Parrilli A, Kochetkova T, Schwiedrzik J, Dommann A, Neels A. Multiscale and multimodal X-ray analysis: Quantifying phase orientation and morphology of mineralized turkey leg tendons. Acta Biomater 2021; 129:169-177. [PMID: 34052502 DOI: 10.1016/j.actbio.2021.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/16/2021] [Accepted: 05/19/2021] [Indexed: 12/11/2022]
Abstract
Fibrous biocomposites like bone and tendons exhibit a hierarchical arrangement of their components ranging from the macroscale down to the molecular level. The multiscale complex morphology, together with the correlated orientation of their constituents, contributes significantly to the outstanding mechanical properties of these biomaterials. In this study, a systematic road map is provided to quantify the hierarchical structure of a mineralized turkey leg tendon (MTLT) in a holistic multiscale evaluation by combining micro-Computed Tomography (micro-CT), small-angle X-ray scattering (SAXS), and wide-angle X-ray diffraction (WAXD). We quantify the interplay of the main MTLT components with respect to highly ordered organic parts such as fibrous collagen integrating inorganic components like hydroxyapatite (HA). The microscale fibrous morphology revealing different types of porous features and their orientation was quantified based on micro-CT investigations. The quantitative analysis of the alignment of collagen fibrils and HA crystallites was established from the streak-like signal in SAXS using the Ruland approach and the broadening of azimuthal profiles of the small and wide-angle diffraction peaks. It has been in general agreement that HA crystallites are co-aligned with the nanostructure of mineralized tissue. However, we observe relatively lower degree of orientation of HA crystallites compared to the collagen fibrils, which supports the recent findings of the structural interrelations within mineralized tissues. The generic multiscale characterization approach of this study is relevant to any hierarchically structured biomaterials or bioinspired materials from the μm-nm-Å scale. Hence, it gives the basis for future structure-property relationship investigations and simulations for a wide range of hierarchically structured materials. STATEMENT OF SIGNIFICANCE: Many fibrous biocomposites such as tendon, bone, and wood possess multiscale hierarchical structures, responsible for their exceptional mechanical properties. In this study, the 3-dimensional hierarchical structure, the degree of orientation and composition of mineralized tendon extracted from a turkey leg were quantified using a multimodal X-ray based approach combining small-angle X-ray scattering and wide-angle X-ray diffraction with micro-Computed Tomography. We demonstrate that hydroxyapatite (HA) domains are co-aligned with the nanostructure of mineralized tissue. However, the lower degree of orientation of HA crystallites was observed when compared to the collagen fibrils. The generic multiscale characterization approach of this study is relevant to any hierarchically structured biomaterials or bioinspired materials from the micrometer over the nanometer to the Angström scale level.
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9
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Nguyen NQ, Chen TF, Lo CT. Confined crystallization and chain conformational change in electrospun poly(ethylene oxide) nanofibers. Polym J 2021. [DOI: 10.1038/s41428-021-00492-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Maurya AK, Mandal S, Wheeldon DE, Schoeller J, Schmid M, Annaheim S, Camenzind M, Fortunato G, Dommann A, Neels A, Sadeghpour A, Rossi RM. Effect of radiant heat exposure on structure and mechanical properties of thermal protective fabrics. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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11
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Kochetkova T, Peruzzi C, Braun O, Overbeck J, Maurya AK, Neels A, Calame M, Michler J, Zysset P, Schwiedrzik J. Combining polarized Raman spectroscopy and micropillar compression to study microscale structure-property relationships in mineralized tissues. Acta Biomater 2021; 119:390-404. [PMID: 33122147 DOI: 10.1016/j.actbio.2020.10.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/07/2020] [Accepted: 10/22/2020] [Indexed: 02/07/2023]
Abstract
Bone is a natural composite possessing outstanding mechanical properties combined with a lightweight design. The key feature contributing to this unusual combination of properties is the bone hierarchical organization ranging from the nano- to the macro-scale. Bone anisotropic mechanical properties from two orthogonal planes (along and perpendicular to the main bone axis) have already been widely studied. In this work, we demonstrate the dependence of the microscale compressive mechanical properties on the angle between loading direction and the mineralized collagen fibril orientation in the range between 0° and 82°. For this, we calibrated polarized Raman spectroscopy for quantitative collagen fibril orientation determination and validated the method using widely used techniques (small angle X-ray scattering, micro-computed tomography). We then performed compression tests on bovine cortical bone micropillars with known mineralized collagen fibril angles. A strong dependence of the compressive micromechanical properties of bone on the fibril orientation was found with a high degree of anisotropy for both the elastic modulus (Ea/Et=3.80) and the yield stress (σay/σty=2.54). Moreover, the post-yield behavior was found to depend on the MCF orientation with a transition between softening to hardening behavior at approximately 50°. The combination of methods described in this work allows to reliably determine structure-property relationships of bone at the microscale, which may be used as a measure of bone quality.
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12
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Tien ND, Maurya AK, Fortunato G, Rottmar M, Zboray R, Erni R, Dommann A, Rossi RM, Neels A, Sadeghpour A. Responsive Nanofibers with Embedded Hierarchical Lipid Self-Assemblies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11787-11797. [PMID: 32936649 DOI: 10.1021/acs.langmuir.0c01487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We introduce the design and study of a hybrid electrospun membrane with a dedicated nanoscale structural hierarchy for controlled functions in the biomedical domain. The hybrid system comprises submicrometer-sized internally self-assembled lipid nanoparticles (ISAsomes or mesosomes) embedded into the electrospun membrane with a nanofibrous polymer network. The internal structure of ISAsomes, studied by small-angle X-ray scattering (SAXS) and electron microscopy, demonstrated a spontaneous response to variations in the environmental conditions as they undergo a bicontinuous inverse cubic phase (cubosomes) in solution to a crystalline lamellar phase in the polymer membrane; nevertheless, this phase reorganization is reversible. As revealed by in situ SAXS measurements, if the membrane was put in contact with aqueous media, the cubic phase reappeared and submicrometer-sized cubosomes were released upon dissolution of the nanofibers. Furthermore, the hybrid membranes exhibited a specific anisotropic feature and morphological response under an external strain. While nanofibers were aligned under external strain in the microscale, the semicrystalline domains from the polymer phase were positioned perpendicular to the lamellae of the lipid phase in the nanoscale. The fabricated membranes and their spontaneous responses offer new strategies for the development of structure-controlled functions in electrospun nanofibers for biomedical applications, such as drug delivery or controlled interactions with biointerfaces.
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Affiliation(s)
- Nguyen D Tien
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Anjani K Maurya
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Cellular and Biomedical Sciences, Faculty of Medicine, University of Bern, Bern CH-3012, Switzerland
| | - Giuseppino Fortunato
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Markus Rottmar
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Robert Zboray
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Rolf Erni
- Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf CH-8600, Switzerland
| | - Alex Dommann
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Cellular and Biomedical Sciences, Faculty of Medicine, University of Bern, Bern CH-3012, Switzerland
| | - René M Rossi
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
| | - Antonia Neels
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Department of Chemistry, University of Fribourg, Fribourg 79085, Switzerland
| | - Amin Sadeghpour
- Center for X-Ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen CH-9014, Switzerland
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13
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Jain A, Maurya AK, Ulrich L, Jaeger M, Rossi RM, Neels A, Schucht P, Dommann A, Frenz M, Akarçay HG. Polarimetric imaging in backscattering for the structural characterization of strongly scattering birefringent fibrous media. OPTICS EXPRESS 2020; 28:16673-16695. [PMID: 32549485 DOI: 10.1364/oe.390303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Interpreting the polarimetric data from fiber-like macromolecules constitutive of tissue can be difficult due to strong scattering. In this study, we probed the superficial layers of fibrous tissue models (membranes consisting of nanofibers) displaying varying degrees of alignment. To better understand the manifestation of membranes' degree of alignment in polarimetry, we analyzed the spatial variations of the backscattered light's Stokes vectors as a function of the orientation of the probing beam's linear polarization. The degree of linear polarization reflects the uniaxially birefringent behavior of the membranes. The rotational (a-)symmetry of the backscattered light's degree of linear polarization provides a measure of the membranes' degree of alignment.
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14
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Nazir R, Parida D, Guex AG, Rentsch D, Zarei A, Gooneie A, Salmeia KA, Yar KM, Alihosseini F, Sadeghpour A, Gaan S. Structurally Tunable pH-responsive Phosphine Oxide Based Gels by Facile Synthesis Strategy. ACS APPLIED MATERIALS & INTERFACES 2020; 12:7639-7649. [PMID: 31972075 DOI: 10.1021/acsami.9b22808] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Design and synthesis of nanostructured responsive gels have attracted increasing attention, particularly in the biomedical domain. Polymer chain configurations and nanodomain sizes within the network can be used to steer their functions as drug carriers. Here, a catalyst-free facile one-step synthesis strategy is reported for the design of pH-responsive gels and controlled structures in nanoscale. Transparent and impurity free gels were directly synthesized from trivinylphosphine oxide (TVPO) and cyclic secondary diamine monomers via Michael addition polymerization under mild conditions. NMR analysis confirmed the consumption of all TVPO and the absence of side products, thereby eliminating post purification steps. The small-angle X-ray scattering (SAXS) elucidates the nanoscale structural features in gels, that is, it demonstrates the presence of collapsed nanodomains within gel networks and it was possible to tune the size of these domains by varying the amine monomers and the nature of the solvent. The fabricated gels demonstrate structure tunability via solvent-polymer interactions and pH specific drug release behavior. Three different anionic dyes (acid blue 80, acid blue 90, and fluorescein) of varying size and chemistry were incorporated into the hydrogel as model drugs and their release behavior was studied. Compared to acidic pH, a higher and faster release of acid blue 80 and fluorescein was observed at pH 10, possibly because of their increased solubility in alkaline pH. In addition, their release in phosphate buffered saline (PBS) and simulated body fluid (SBF) matrix was positively influenced by the ionic interaction with positively charged metal ions. In the case of hydrogel containing acid blue 90 a very low drug release (<1%) was observed, which is due to the reaction of its accessible free amino group with the vinyl groups of the TVPO. In vitro evaluation of the prepared hydrogel using human dermal fibroblasts indicates no cytotoxic effects, warranting further research for biomedical applications. Our strategy of such gel synthesis lays the basis for the design of other gel-based functional materials.
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Affiliation(s)
- Rashid Nazir
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Dambarudhar Parida
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Anne Géraldine Guex
- Laboratory for Biointerfaces and Laboratory for Biomimetic Membranes and Textiles , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Daniel Rentsch
- Laboratory for Functional Polymers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129 , 8600 Dübendorf , Switzerland
| | - Afsaneh Zarei
- Department of Textile Engineering , Isfahan University of Technology , Isfahan , 84156-83111 , Iran
| | - Ali Gooneie
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Khalifah A Salmeia
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Kevin M Yar
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Farzaneh Alihosseini
- Department of Textile Engineering , Isfahan University of Technology , Isfahan , 84156-83111 , Iran
| | - Amin Sadeghpour
- Center for X-Ray Analytics , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
| | - Sabyasachi Gaan
- Laboratory of Advanced Fibers , Empa, Swiss Federal Laboratories for Materials Science and Technology , Lerchenfeldstrasse 5 , CH-9014 St. Gallen , Switzerland
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15
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Morel A, Oberle SC, Ulrich S, Yazgan G, Spano F, Ferguson SJ, Fortunato G, Rossi RM. Revealing non-crystalline polymer superstructures within electrospun fibers through solvent-induced phase rearrangements. NANOSCALE 2019; 11:16788-16800. [PMID: 31465059 DOI: 10.1039/c9nr04432a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The design of nanofibers for biomedical applications requires a deep understanding of the fiber formation process and the resulting internal structure. In this regard, non-crystalline, mesomorphic structures play a central role in the processing of many polymers as precursors in the formation of crystalline superstructures (e.g. shish-kebab) and influence strongly the physical properties of polymers with a low degree of crystallinity. Yet, our ability to probe these relevant features is often greatly limited by their low contrast differences with the amorphous phase. We present an approach to reveal the organization of the mesomorphic superstructures within such polymeric materials, on the example of electrospun poly(l-lactide) nanofibers. Based on solvent-induced crystallization, this method employs fine-tuned solvent/non-solvent systems to enhance the contrast of these structural features by selectively triggering and controlling reorganization of the phases. Hereby, the mesomorphic regions are transformed into an α-crystalline phase, while the nanoscale spatial arrangement of the underlying superstructures is preserved. Combined with X-ray analytical techniques and electron microscopy, our approach provides detailed insights into the nanofiber's inner architecture, allowing for its direct visualization. Thereby, the influence of electrospinning parameters on the fiber formation process is explained as well as the impact of the resulting non-crystalline superstructures on single fiber mechanical properties. The method can be applied to comparable polymers for the development of materials with controlled, tailored properties.
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Affiliation(s)
- Alexandre Morel
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, 9014 St Gallen, Switzerland.
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