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1.
Nat Commun ; 11(1): 5429, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33110084

RESUMO

The practical applications of lithium metal anodes in high-energy-density lithium metal batteries have been hindered by their formation and growth of lithium dendrites. Herein, we discover that certain protein could efficiently prevent and eliminate the growth of wispy lithium dendrites, leading to long cycle life and high Coulombic efficiency of lithium metal anodes. We contend that the protein molecules function as a "self-defense" agent, mitigating the formation of lithium embryos, thus mimicking natural, pathological immunization mechanisms. When added into the electrolyte, protein molecules are automatically adsorbed on the surface of lithium metal anodes, particularly on the tips of lithium buds, through spatial conformation and secondary structure transformation from α-helix to ß-sheets. This effectively changes the electric field distribution around the tips of lithium buds and results in homogeneous plating and stripping of lithium metal anodes. Furthermore, we develop a slow sustained-release strategy to overcome the limited dispersibility of protein in the ether-based electrolyte and achieve a remarkably enhanced cycling performance of more than 2000 cycles for lithium metal batteries.


Assuntos
Dendritos/química , Fontes de Energia Elétrica , Fibroínas/química , Lítio/química , Dendritos/metabolismo , Eletricidade , Eletrodos , Fibroínas/metabolismo , Lítio/metabolismo
2.
Cell Prolif ; 53(11): e12917, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33001510

RESUMO

OBJECTIVES: Articular cartilage plays a vital role in bearing and buffering. Injured cartilage and subchondral bone repair is a crucial challenge in cartilage tissue engineering due to the peculiar structure of osteochondral unit and the requirement of osteogenic/chondrogenic bi-directional differentiation. Based on the bionics principle, a nanotextured silk fibroin (SF)-chondroitin sulphate (CS)/hydroxyapatite (HAp) nanowire tough bilayer structure was prepared for osteochondral repair. METHODS: The SF-CS/HAp membrane was constructed by alcohol-induced ß-sheet formation serving as the physical crosslink. Its osteochondral repairing capacity was evaluated by culturing bone marrow mesenchymal stem cells (BMSCs) in vitro and constructing a rat osteochondral defect model in vivo. RESULTS: The bilayer SF-CS/HAp membrane with satisfactory mechanical properties similar to natural cartilage imitated the natural osteochondral unit structural layers and exerted the function of bearing and buffering timely after in vivo implantation. SF-CS layer upregulated the expression of chondrogenesis-related genes of BMSCs by surface nanotopography and sustained release CS. Meanwhile, nanotextured HAp layer assembled with nanowire endowed the membrane with an osteogenic differentiation tendency for BMSCs. In vivo results proved that the biomimetic bilayer structure dramatically promoted new cartilage formation and subchondral bone remodelling for osteochondral defect model after implantation. CONCLUSIONS: The SF-CS/HAp biomimetic bilayer membrane provides a promising strategy for precise osteochondral repair.


Assuntos
Durapatita/química , Fibroínas/química , Células-Tronco Mesenquimais/citologia , Nanoestruturas/química , Tecidos Suporte/química , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/uso terapêutico , Células Cultivadas , Condrogênese , Durapatita/uso terapêutico , Fibroínas/uso terapêutico , Masculino , Nanoestruturas/uso terapêutico , Nanoestruturas/ultraestrutura , Osteogênese , Ratos Sprague-Dawley
3.
Int J Nanomedicine ; 15: 4991-5004, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764931

RESUMO

Introduction: Various materials and approaches have been used to reduce the mesh-induced inflammatory response and modify the mesh with tissue-matched mechanical properties, aiming to improve the repair of abdominal wall defects. Materials and Methods: In this study, we fabricated a polycaprolactone (PCL)/silk fibroin (SF) mesh integrated with amoxicillin (AMX)-incorporating multiwalled carbon nanotubes (MWCNTs) via electrospinning, grafting and crosslinking, developing a sustainable antibiotic and flexible mesh. AMX was loaded into the hollow tubular MWCNTs by physical adsorption, and a nanofibrous structure was constructed by electrospinning PCL and SF (40:60 w/w). The AMX@MWCNTs were then chemically grafted onto the surfaces of the PCL/SF nanofibers by treating with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution for simultaneous crosslinking and coating. The incorporation of AMX into the MWCNTs (AMX@MWCNTs) and the integration of the AMX@MWCNTs with the PCL/SF nanofibers were characterized. Then, the functional mesh was fabricated and fully evaluated in terms of antibacterial activity, mechanical properties and host response. Results: Our results demonstrated that the PCL/SF nanofibrous structure was fabricated successfully by electrospinning. After integrating with AMX@MWCNT by grafting and crosslinking, the functional mesh showed undeformed structure, modified surface hydrophilicity and biocompatible interfaces, abdominal wall-matched mechanical properties, and a sustained-release antibiotic profile in E. coli growth inhibition compared to those of PCL/SF mesh in vitro. In a rat model with subcutaneous implantation, the functional mesh incited less mesh-induced inflammatory and foreign body responses than PCL/SF mesh within 14 days. The histological analysis revealed less infiltration of granulocytes and macrophages during this period, resulting in the loosely packed collagen deposition on the functional mesh and prominent collagen incorporation. Discussion: Therefore, this designed PCL/SF-AMX@MWCNT nanofibrous mesh, functionalized with antibacterial and tissue-matched mechanical properties, provides a promising alternative for the repair of abdominal wall defects.


Assuntos
Amoxicilina/química , Antibacterianos/química , Nanofibras/química , Nanotecnologia/métodos , Telas Cirúrgicas , Amoxicilina/farmacocinética , Amoxicilina/farmacologia , Animais , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Colágeno/química , Colágeno/metabolismo , Reagentes para Ligações Cruzadas/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Fibroínas/química , Inflamação/etiologia , Masculino , Teste de Materiais , Camundongos , Nanotubos de Carbono/química , Poliésteres/química , Ratos Sprague-Dawley , Telas Cirúrgicas/efeitos adversos
4.
Proc Natl Acad Sci U S A ; 117(27): 15482-15489, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571918

RESUMO

Bioelectronic scaffolds that support devices while promoting tissue integration could enable tissue hybrids with augmented electronic capabilities. Here, we demonstrate a photo-cross-linkable silk fibroin (PSF) derivative and investigate its structural, electrical, and chemical properties. Lithographically defined PSF films offered tunable thickness and <1-µm spatial resolution and could be released from a relief layer yielding freestanding scaffolds with centimeter-scale uniformity. These constructs were electrically insulating; multielectrode arrays with PSF-passivated interconnects provided stable electrophysiological readouts from HL-1 cardiac model cells, brain slices, and hearts. Compared to SU8, a ubiquitous biomaterial, PSF exhibited superior affinity toward neurons which we attribute to its favorable surface charge and enhanced attachment of poly-d-lysine adhesion factors. This finding is of significant importance in bioelectronics, where tight junctions between devices and cell membranes are necessary for electronic communication. Collectively, our findings are generalizable to a variety of geometries, devices, and tissues, establishing PSF as a promising bioelectronic platform.


Assuntos
Materiais Biocompatíveis/efeitos da radiação , Fontes de Energia Bioelétrica , Fibroínas/efeitos da radiação , Engenharia Tecidual , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/química , Encéfalo , Adesão Celular , Linhagem Celular , Feminino , Fibroínas/química , Coração , Teste de Materiais , Camundongos , Células-Tronco Neurais , Raios Ultravioleta
5.
J Vis Exp ; (159)2020 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-32421007

RESUMO

During the extrusion-based three-dimensional bioprinting process, liquid-like bioinks with low viscosity can protect cells from membrane damage induced by shear stress and improve the survival of the encapsulated cells. However, rapid gravity-driven cell sedimentation in the reservoir could lead to an inhomogeneous cell distribution in bioprinted structures and therefore hinder the application of liquid-like bioinks. Here, we developed a novel multilayered modified strategy for liquid-like bioinks (e.g., gelatin methacryloyl with low viscosity) to prevent the sedimentation of encapsulated cells. Multiple liquid interfaces were manipulated in the multilayered bioink to provide interfacial retention. Consequently, the cell sedimentation action going across adjacent layers in the multilayered system was retarded in the bioink reservoir. It was found that the interfacial retention was much higher than the sedimental pull of cells, demonstrating a critical role of the interfacial retention in preventing cell sedimentation and promoting a more homogeneous dispersion of cells in the multilayered bioink.


Assuntos
Materiais Biocompatíveis/química , Bioimpressão , Células/metabolismo , Hidrogéis/química , Tinta , Impressão Tridimensional , Animais , Sobrevivência Celular , Fibroínas/química , Gelatina/química , Metacrilatos/química , Camundongos , Células NIH 3T3 , Viscosidade
6.
Sci Rep ; 10(1): 4198, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144298

RESUMO

Herein, the preparation of gold nanoparticles-silk fibroin (SF-AuNPs) dispersion and its label-free colorimetric detection of the organophosphate pesticide, namely chlorpyrifos, at ppb level are reported. The silk fibroin solution was extracted from B. mori silk after performing degumming, dissolving and dialysis steps. This fibroin solution was used for synthesis of gold nanoparticles in-situ without using any external reducing and capping agent. X-ray Diffractometry (XRD), Field Emission Transmission Electron Microscopy (FETEM) along with Surface Plasmon Resonance based optical evaluation confirmed generation of gold nanoparticles within SF matrix. The resultant SF-AuNPs dispersion exhibited rapid and excellent colorimetric pesticide sensing response even at 10 ppb concentration. Effect of additional parameters viz. pH, ionic concentration and interference from other pesticide samples was also studied. Notably, SF-AuNPs dispersion exhibited selective colorimetric pesticide sensing response which can be calibrated. Furthermore, this method was extended to various simulated real life samples such as tap water, soil and agricultural products including plant residues to successfully detect the presence of chlorpyrifos pesticide. The proposed colorimetric sensor system is facile yet effective and can be employed by novice rural population and expert researchers alike. It can be exploited as preliminary tool for label-free colorimetric chlorpyrifos pesticide sensing in water and agricultural products.


Assuntos
Clorpirifos/química , Colorimetria/métodos , Fibroínas/química , Ouro/química , Nanopartículas Metálicas/química , Nanocompostos/química , Praguicidas/química , Fibroínas/ultraestrutura , Hidrodinâmica , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Difração de Raios X
7.
Opt Express ; 28(4): 5179-5188, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32121743

RESUMO

In this paper, pure silk protein was extracted from Bombyx mori silks and fabricated into a new kind of disordered bio-microfiber structure using electrospinning technology. Coherent random lasing emission with low threshold was achieved in the silk fibroin fibers. The random lasing emission wavelength can be tuned in the range of 33 nm by controlling the pump location with different scattering strengths. Therefore, the bio-microfiber random lasers can be a wide spectral light source when the system is doped with a gain or energy transfer medium with a large fluorescence emission band. Application of the random lasers of the bio-microfibers as a low-coherence light source in speckle-free imaging had also been studied.


Assuntos
Fibroínas/química , Lasers , Luz , Animais , Bombyx , Fibroínas/ultraestrutura , Processamento de Imagem Assistida por Computador , Dispositivos Ópticos
8.
Proc Natl Acad Sci U S A ; 117(11): 5655-5663, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123100

RESUMO

Epithelial tissues mechanically deform the surrounding extracellular matrix during embryonic development, wound repair, and tumor invasion. Ex vivo measurements of such multicellular tractions within three-dimensional (3D) biomaterials could elucidate collective dissemination during disease progression and enable preclinical testing of targeted antimigration therapies. However, past 3D traction measurements have been low throughput due to the challenges of imaging and analyzing information-rich 3D material deformations. Here, we demonstrate a method to profile multicellular clusters in a 96-well-plate format based on spatially heterogeneous contractile, protrusive, and circumferential tractions. As a case study, we profile multicellular clusters across varying states of the epithelial-mesenchymal transition, revealing a successive loss of protrusive and circumferential tractions, as well as the formation of localized contractile tractions with elongated cluster morphologies. These cluster phenotypes were biochemically perturbed by using drugs, biasing toward traction signatures of different epithelial or mesenchymal states. This higher-throughput analysis is promising to systematically interrogate and perturb aberrant mechanobiology, which could be utilized with human-patient samples to guide personalized therapies.


Assuntos
Movimento Celular , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Células Epiteliais/fisiologia , Transição Epitelial-Mesenquimal , Tecidos Suporte/química , Fenômenos Biomecânicos , Linhagem Celular , Colágeno/química , Fibroínas/química , Humanos , Hidrogéis/química , Fenótipo , Medicina de Precisão/métodos , Cultura Primária de Células/métodos , Esferoides Celulares/fisiologia
9.
Food Chem ; 319: 126432, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32172045

RESUMO

The main aim of the present study was the measurement of nickel metal ion in the real samples of crab, oyster and rice by the designed magnetic nano adsorbent silk fibroin-EDTA ligand (SF-Fe3O4-EDTA). Due to the structure of silk fibroin (possessing lots of functional groups which are suitable for attachment of ligands and high surface area), it was used in the structure of fabricated nano-adsorbent. To follow the fabrication processes of the magnetic nano-adsorbent, different techniques of fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Visible), vibrating sample magnetometer (VSM), and field emission scanning electron microscopy (FE-SEM) were used. The optimization processes were performed with the chemometric method of response surface modeling with sufficient accuracy and precision. Using this chemometric method, the optimum values of pH, absorption time, the concentration of nano-adsorbent and temperature were calculated to be 6, 21 min, 4 mg L-1 and 28 °C, respectively. Due to the magnetic nature of the constructed nano-adsorbent, a magnet bar was used to separate the nano-adsorbent from the solution and then inject to the furnace atomic absorption device. Using the magnetic nano-adsorbent of silk fibroin-EDTA ligand and furnace atomic absorption a detection limit of 0.0017 µg L-1 and a linear range of 0.0030-5.0 µg L-1 for determination of nickel metal ion were obtained. The determination of nickel metal ion in the crab tissue, oyster tissue and rice samples were performed and the obtained results revealed the successful applicability of the designed method for determination of nickel metal ion in the real samples.


Assuntos
Braquiúros/química , Fibroínas/química , Níquel/análise , Oryza/química , Frutos do Mar , Animais , Ácido Edético/química , Ligantes , Limite de Detecção , Magnetismo , Imãs , Espectrofotometria Atômica
10.
ACS Appl Mater Interfaces ; 12(8): 10039-10049, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32017854

RESUMO

Superwetting surfaces that repel various liquids have been exciting for biomimetic research and have displayed versatile potential applications. Generally, superhydrophobic coatings can allow for droplet rolling off and antifouling, whereas it is a challenge to achieve superomniphobic surfaces with transparency, flexibility, and conductivity. Here, we adopt an effective and simple method to fabricate a superomniphobic, transparent, and flexible smart silk fibroin (SF) membrane by spray-coating long AgNWs dispersed in polydimethylsiloxane (PDMS), followed by treatment with vacuum drying. The resulting SF/AgNWs membranes are super-repellent to different liquids with low surface tension and water, and demonstrate high contact angles (CAs) more than 150° and low rolling-off angles (RAs) even less than 10°. Moreover, the obtained membranes display superior sensitivity under stretching and bending, as well as intact stability of high transparency, which can be considered as promising flexible sensing electronics to detect human motions under wet conditions.


Assuntos
Eletrônica , Fibroínas/química , Nanofios/química , Prata/química , Dimetilpolisiloxanos/química , Humanos
11.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-32098911

RESUMO

Silkwormsilk protein fibroin is widely exploited to develop novel silk-based biomaterials due to its stable ß-sheet structure, providing high crystallinity and tensile strength. The polymorphic behaviour of silk fibroin provides a window to modulate its structural transitions during self-assembly for different functional outcomes. Most studies are therefore mainly focused on formation of well-developed ß-sheet structure and self-assembly of silk fibroin which are regulated by many parameters. Glyoxal, a highly reactive α-oxoaldehyde, reacts with different proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. Considering the significance of protein modification by glyoxal-derived AGEs, in the present study the effect of glyoxal (250, 500 and 1000 µM) on the structure of silk fibroin has been investigated. CD and fluorescence studies reveal that higher concentrations of the α-oxoaldehyde induce considerable alterations of secondary and tertiary structure of the protein leading to aggregation following incubation with for 3 weeks. The aggregates exhibit fibrillar morphology with amyloidal nature as evident from SEM, FTIR and XRD experiments. The findings highlight that glycationinduced modification can be a possible approach for modulating the conformation of the silk protein which may be relevant in connection to clinical, biomedical or synthetic biology based applications.


Assuntos
Proteínas Amiloidogênicas/química , Fibroínas/química , Glioxal/metabolismo , Animais , Bombyx , Conformação Proteica , Análise Espectral/métodos
12.
Int J Nanomedicine ; 15: 735-747, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099362

RESUMO

Introduction: Gambogic acid (GA) is proved to have anti-tumor effects on gastric cancer. Due to poor solubility, non-specific biological distribution, toxicity to normal tissues and short half-life, it is hard to be applied into the clinic. To overcome these issues, we developed a thermosensitive and injectable hydrogel composed of hydroxypropyl cellulose, silk fibroin and glycerol, with short gelling time, good compatibility and sustained release, and demonstrated that the hydrogel packaged with gambogic acid nanoparticles (GA-NPs) and tumor-penetrating peptide iRGD could improve the anti-tumor activity. Methods: The Gelling time and micropore size of the hydrogels were regulated through different concentrations of glycerol. Controlled release characteristics of the hydrogels were evaluated with a real-time near-infrared fluorescence imaging system. Location of nanoparticles from different carriers was traced by confocal laser scanning microscopy. The in vivo antitumor activity of the hydrogels packaging GA-NPs and iRGD was evaluated by investigating tumor volume and tumor size. Results: The thermo-sensitive properties of hydrogels were characterized by 3-4 min, 37°C, when glycerol concentration was 20%. The hydrogels physically packaged with GA-NPs and iRGD showed higher fluorescence intensity than other groups. The in vivo study indicated that the co-administration of GA-NPs and iRGD by hydrogels had higher antitumor activity than the GA-loaded hydrogels and free GA combining with iRGD. Free GA group showed few antitumor effects. Compared with the control group, the body weight in other groups had no obvious change, and the count of leukocytes and hemoglobin was slightly decreased. Discussion: The hydrogel constructed iRGD and GA-NPs exerted an effective anti-tumor effect possibly due to retention effect, local administration and continuous sustained release of iRGD promoting the penetration of nanoparticles into a deep part of tumors. The delivery system showed little systemic toxicity and would provide a promising strategy to improve anti-gastric cancer efficacy.


Assuntos
Antineoplásicos/uso terapêutico , Hidrogéis/química , Nanopartículas/química , Oligopeptídeos/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Temperatura , Xantonas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Bombyx , Linhagem Celular Tumoral , Fibroínas/química , Glicerol/química , Humanos , Derivados da Hipromelose/química , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/ultraestrutura , Porosidade , Neoplasias Gástricas/patologia , Distribuição Tecidual , Xantonas/farmacologia
13.
Macromol Rapid Commun ; 41(6): e1900583, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32009279

RESUMO

A unique cuboid spider silk from the outer egg sac of Nephila pilipes, with an unusual square cross-section, is disclosed. The structure-function relationships within this silk are first studied through structural characterization, mechanical measurement, protein conformation, and polypeptide signature of silk proteins. This silk maintains the higher stiffness property of egg sac silks, and also shows a species difference. Environmental response of the mechanical properties within this silk are observed. Synchrotron FTIR microspectroscopy is used to monitor the silk protein conformation in a single natural silk. The ß-sheet structure aligns parallel to the fiber axis with a content of 22% ± 2.6%. The de novo resulting polypeptide from the solid silk fibers are novel, and an abundant polar amino acid insertion is observed. Short polyalanine (An , n ≤ 3), alternating serine and alanine (S/A)X, and alternating glycine and alanine (G/A)X, GGX, and SSX dominates in the resulting de novo polypeptide. This accords with the composition pattern of other egg sac silk proteins, besides the rarely observed GGX. This study broadens the library of egg sac spider silks and provides a new perspective to uncover structure-function relationships in spider silk.


Assuntos
Aminoácidos/química , Fibroínas/química , Peptídeos/química , Seda/química , Alanina/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Fibroínas/ultraestrutura , Glicina/química , Teste de Materiais , Conformação Proteica em Folha beta , Serina/química , Seda/ultraestrutura , Aranhas/química , Relação Estrutura-Atividade
14.
Carbohydr Polym ; 234: 115861, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070500

RESUMO

Short staple microfibers (SSM) based on chitosan (CS) or silk fibroin (SF) were fabricated via the wet-rotate-spinning technique and employed to adsorb hexavalent chromium from aqueous solution. Adsorption efficiencies, physicochemical and morphological properties of CS and SF-SSM were systematically investigated and evaluated before and after adsorption of Cr(VI) using different techniques like ATR-FTIR, TGA, XRD, XPS, and SEM. CS and SF-SSM showed removal efficiency (>90 %) toward Cr(VI) ions. Pseudo-second order kinetic and Langmuir isotherm models could describe the Cr(VI) ions uptake process. Considering the inexpensive, sustainability and higher adsorption capacity of CS and SF-SSM hold great promising applications as natural adsorbent materials for removing different hazardous metals from aqueous medium.


Assuntos
Quitosana/química , Cromo/isolamento & purificação , Fibroínas/química , Termodinâmica , Configuração de Carboidratos , Cromo/química , Cinética , Tamanho da Partícula , Propriedades de Superfície
15.
ACS Appl Mater Interfaces ; 12(5): 6442-6450, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31935061

RESUMO

Nowadays, great effort has been devoted to establishing wearable electronics with excellent stretchability, high sensitivity, good mechanical strength, and multifunctional characteristics. Herein, a soft conductive hydrogel is rationally designed by proportionally mixing silk fibroin, polyacrylamide, graphene oxide, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The resultant hydrogel has considerable stretchability and compressibility, which enables it to be assembled into a strain/pressure sensor with a wide sensing range (strain, 2%-600%; pressure, 0.5-119.4 kPa) and reliable stability. Then, the corresponding sensor is capable of monitoring a series of physical signals of the human body (e.g., joint movement, facial gesture, pulse, breathing, etc.). In particular, the hydrogel-based sensor is biocompatible, with no anaphylactic reaction on human skin. More interestingly, this conductive hydrogel exhibits a positive response when it works in a triboelectric nanogenerator; consequently, it lights up 20 commericial green light-emitting diodes. Thus, this silk fibroin-based hydrogel is a kind of multifunctional material toward wearable electronics with versatile applications in health and exercise monitors, soft robots, and power sources.


Assuntos
Materiais Biocompatíveis/química , Fibroínas/química , Hidrogéis/química , Dispositivos Eletrônicos Vestíveis , Resinas Acrílicas/química , Eletrônica , Grafite/química , Humanos , Nanotecnologia , Poliestirenos/química , Pressão
16.
Sci Rep ; 10(1): 235, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937841

RESUMO

During storage in the silk gland, the N-terminal domain (NT) of spider silk proteins (spidroins) keeps the aggregation-prone repetitive region in solution at extreme concentrations. We observe that NTs from different spidroins have co-evolved with their respective repeat region, and now use an NT that is distantly related to previously used NTs, for efficient recombinant production of the amyloid-ß peptide (Aß) implicated in Alzheimer's disease. A designed variant of NT from Nephila clavipes flagelliform spidroin, which in nature allows production and storage of ß-hairpin repeat segments, gives exceptionally high yields of different human Aß variants as a solubility tag. This tool enables efficient production of target peptides also in minimal medium and gives up to 10 times more isotope-labeled monomeric Aß peptides per liter bacterial culture than previously reported.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Fibroínas/química , Fibroínas/metabolismo , Sequência de Aminoácidos , Animais , Modelos Moleculares , Domínios Proteicos
17.
ACS Appl Mater Interfaces ; 12(5): 5601-5609, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31927972

RESUMO

Wearable epidermal sensors are of great importance to the next generation of personalized healthcare. The adhesion between the flexible sensor and skin surface is critical for obtaining accurate, reliable, and stable signals. Herein we present a facile approach to fabricate a microstructured, natural silk fibroin protein-based adhesive for achieving highly conformal, comfortable, adjustable, and biocompatible adhesion on the skin surface. The microstructured fibroin adhesive (MSFA) exhibits reliable and stable bonding force on skin surfaces, even under humid or wet conditions, and can be easily peeled off from the skin without causing significant pain. Such an MSFA can greatly improve the sensitivity and reusability of epidermal strain sensors because of its conformal and tunable adhesion on skin surfaces. The MFSA has a great potential to be applied as a functional adhesive for various epidermal electronic sensors in the era of personalized healthcare.


Assuntos
Fibroínas/química , Fenômenos Fisiológicos da Pele , Adesivos/química , Análise de Elementos Finitos , Humanos , Pele/metabolismo , Dispositivos Eletrônicos Vestíveis
18.
Int J Biol Macromol ; 146: 588-595, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31923493

RESUMO

The dissolution of silk fibroin in highly concentrated neutral salt solution and the subsequent long time-costing desalination have long inhibited silk regeneration. Here, a 4-fold volume of acetone was first added into a silk fibroin of 9.3 M LiBr solution (SF-LBS) to extract the dissolved silk protein. In fact, acetone extracted the salt and water from SF-LBS rather than silk protein. The extracted protein has less than half of the original amount of LiBr and could be redissolved easily in water. The dialysis time of the extracted protein could reduce the original dialysis time by approximately half. SDS-PAGE revealed that acetone extraction didn't induce any breakage to the peptide chains of the extracted silk fibroin. FTIR indicated that the structure of the extracted fibroin was very similar to that of the unextracted fibroin, and displayed predominantly a mixture of random coil and α-helices. X-ray diffraction also showed that acetone extraction had no effect on the crystal structure of the fibroin. In addition, both acetone and LiBr from the processing waste could easily be recycled for silk regeneration. This novel method can significantly enhance the desalination efficiency of highly concentrated LiBr solution containing silk protein without affecting its structure.


Assuntos
Acetona/química , Fibroínas/química , Sais/química , Animais , Bombyx , Brometos/química , Condutividade Elétrica , Compostos de Lítio/química , Peptídeos/química , Solubilidade , Soluções , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Difração de Raios X
19.
Nat Commun ; 11(1): 351, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953407

RESUMO

Despite advances in directing the assembly of biomacromolecules into well-defined nanostructures, leveraging pathway complexity of molecular disorder to order transition while bridging materials fabrication from nano- to macroscale remains a challenge. Here, we present templated crystallization of structural proteins to nanofabricate hierarchically structured materials up to centimeter scale, using silk fibroin as an example. The process involves the use of ordered peptide supramolecular assemblies as templates to direct the folding and assembly of silk fibroin into nanofibrillar structures. Silk polymorphs can be engineered by varying the peptide seeds used. Modulation of the relative concentration between silk fibroin and peptide seeds, silk fibroin molecular weight and pH allows control over nanofibrils morphologies and mechanical properties. Finally, facile integration of the bottom-up templated crystallization with emerging top-down techniques enables the generation of macroscopic nanostructured materials with potential applications in information storage/encryption, surface functionalization, and printable three-dimensional constructs of customized architecture and controlled anisotropy.


Assuntos
Fibroínas/química , Nanofibras/química , Nanoestruturas/química , Peptídeos/química , Materiais Biocompatíveis/química , Cristalização/métodos , Cinética , Micelas , Impressão Tridimensional , Dobramento de Proteína , Seda/química , Engenharia Tecidual/métodos
20.
Artif Cells Nanomed Biotechnol ; 48(1): 425-434, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31916462

RESUMO

Abdominal wall defects are associated with abdominal wall surgery, infection and tumour resection. Polypropylene (PP) mesh, which has excellent mechanical strength, is currently the primary clinical repair material. In repairing the abdominal wall, the mesh can erode the bowel and cause other problems. Constructing a barrier that induces a weak inflammatory response and promotes rapid recovery of the peritoneum is important. We used electrospinning technology to construct a silk fibroin coating on the abdominal surface of a PP patch. A rat model was used to compare the inflammatory responses, regeneration of peritoneal tissue, and antiadhesion effects of electrospun regenerated silk fibroin (RSF) coatings, polycaprolactone (PCL) coatings, and noncoated PP meshes. The inflammatory responses, antiadhesion fractions, and areas of RSF and PCL were better than those of PP at 6 weeks. RSF was associated with complete peritoneal regeneration, in contrast to PCL. At 12 weeks, the structure of the PCL peritoneum was unstable, and the adhesion fraction and area were significantly higher than those of RSF. The intact peritoneum could not be effectively regenerated. The RSF group exhibited lower IL-6 levels than the PCL and PP groups but higher VEGF, IL-10 and TGF-ß levels, making RSF more conducive to the regeneration of peritoneal and abdominal wall tissues.


Assuntos
Parede Abdominal/cirurgia , Materiais Biocompatíveis/química , Fibroínas/química , Polipropilenos/química , Telas Cirúrgicas , Aderências Teciduais/prevenção & controle , Parede Abdominal/patologia , Animais , Linhagem Celular , Ratos , Ratos Sprague-Dawley , Aderências Teciduais/metabolismo , Aderências Teciduais/patologia
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