Diese Arbeit wurde von der National Science Foundation Partnerships für Forschung und Bildung in der Materialwirtschaft (PREM) Grant No DMR-0934218 gefördert. Es wurde auch von Preis Anzahl 2G12RR013646-11 von National Center for Research Resources unterstützt. Der Inhalt ist ausschließlich in der Verantwortung der Autoren und nicht unbedingt die offizielle Meinung des National Center for Research Resources oder die National Institutes of Health.

1. Silber Saataufbereitungsanlagen <ol><li> Bereiten Sie eine Stammlösung von Silbernitrat (AgNO 3), indem eine beliebige Masse und das Mischen mit 10 ml deionisiertem Wasser (DI). Berechnen Sie Molarität der Lösung. Halten Sie die Lösung in einem dunklen Ort, um sie vor Licht zu isolieren. </li><li> Zusatz von 14,7 mg Natriumcitrat tribasischen (Na 3 C 6 H 5 O 7) zu 10 mL VE-Wasser zu einer 5 mM Lösung zu machen. Schütteln Sie die Durchstechflasche, bis das Pulver aufgelöst ist. </li><li> Add 15,1 mg Natriumborhydrid (NaBH 4) zu einem anderen Fläschchen mit 10 ml VE-Wasser zu einer 40 mM Lösung zu machen. Schließen Sie die Flasche sofort. Schütteln Sie die Lösung per Hand und legen Sie sie in ein Becherglas mit Eis. Das Becherglas in den Kühlschrank und starten Sie eine Zeitschaltuhr (t1 = 0). Die frisch zubereitete Lösung wird in 15 min das ist genug Zeit, um es abzukühlen verwendet werden. </li><li> Aus der Stammlösung von Silbernitrat, 1,1), bereiten 10 mL bei 0,25 mM. Legen Sie eine Rührmagnet in das Fläschchen und stKunst Rühren. </li><li> Add 0,25 ml der Natriumcitrat tribasischen Lösung 1,2) bis 1,4). </li><li> Bei t 1 = 15 min den Natriumborhydridlösung, 1,3), aus dem Kühlschrank. Mit einer Pipette nehmen 0,4 ml dieser Lösung und fügen Sie es 1,5). Hinweis: Fügen Sie die Lösung in einem einzigen schnellen Schlag. Die Farbe wird gelb. Rühren Sie die Lösung für 5 min. </li><li> Bei t 1 = 20 min stoppen Rühren, entfernen Sie den Magneten aus der Flasche und halten Sie die Flasche an einem dunklen Ort. Schließen Sie nicht das Fläschchen. </li><li> Halten Sie die Lösung im Dunkeln bei Raumtemperatur für mindestens 2 Stunden vor der Verwendung. Vorzugsweise sind die Samen innerhalb einer Woche von der Vorbereitung. </li></ol> 2. Growth-Aufbereitung <ol><li> Bereiten 80 mM Ascorbinsäure (C 6 H 8 O 6) durch Zugabe von 140 mg auf 10 mL VE-Wasser. </li><li> Bereiten Sie 10 ml einer konzentrierten Lösung von Goldchlorid (HAuCl 4). Berechnen Sie die Molarität der Lösung. Halten Sie die solution von hell isoliert. </li><li> Es werden 20 ml 50 mM von Cetyltrimethylammoniumbromid (CTAB - C 19 H 42 BRN), indem 364 mg an einem Fläschchen mit 20 ml DI-Wasser. Sofort legen Rührmagnet in die Durchstechflasche und beginnen unter Rühren auf eine warme Platte bei 30 ° C. Nach CTAB Pulver vollständig gelöst und die Lösung wird transparent schalten Sie die Heizung der Platte, aber immer schön rühren bis Schritt 2,7). </li><li> Add-Lösung 1,1) zur Lösung 2,3), um eine endgültige Molarität 4.9x10 -2 mm zu erhalten. Starten einer Zeit (t 2 = 0). </li><li> Bei t 2 = 1 min add-Lösung 2,2) bis 2,4), um eine endgültige Molarität von 0,25 mM zu erhalten. </li><li> Bei t 2 = 2 min 0,1 ml von 2,1) bis 2,5). Die Lösung wird wiederum farblos. </li><li> Bei t 2 = 2 min 20 sec add 0,05 ml 1,8) (silber Samen) bis 2,6). Rühren Sie die Suspension für 15 min. Die Suspension wird zunächst blau und dann braun. </li><li> Bei t 2 = 17 min stoppen Rühren, entfernen Sie die mAgnet und halten Sie die Suspension bei Raumtemperatur für 24 Stunden. </li></ol> 3. Trennung des Goldes nanostars von CTAB für die Bildgebung, Charakterisierung oder Experimente Hinweis: CTAB kann bei Raumtemperatur kristallisieren. Um die Kristalle aufheizen Goldkolloid auflösen zu 30 ° C oder tauchen Sie das Fläschchen in heißes Leitungswasser, bis die Kristalle auflösen. <ol><li> Mit Ultraschall die Suspension 2 min. </li><li> Die Suspension für 5 min bei 730 rcf. Nanostars wird an der Wand des Rohres ansammeln. </li><li> Entfernen Sie so viel von der Suspension mit einer Pipette dabei nicht um die nanostars entfernen. </li><li> Add DI Wasser in die Röhre und beschallen für 2 min. </li><li> Die Suspension für 3 min bei 460 rcf. Die Suspension enthält weniger CTAB, ist daher geringer Zentrifugalkraft benötigt, um die nanostars trennen. </li><li> Wiederholen Sie die Schritte 3,3) und 3,4). </li><li> Add DI-Wasser, die Aussetzung und Zentrifuge für 3 min bei 380 rcf. </li><li> WIEDERHOLT<html> t Schritte 3,3) und 3,4). Die nanostars sind bereit für die Bildgebung, der Spektroskopie oder Experimentieren. </li></ol> 4. Repräsentative Ergebnisse: Abbildung 1 zeigt Transmissionselektronenmikroskop (TEM)-Bilder der silbernen Samen aufgenommen mit einem JEOL 2010-F TEM. Die Samen haben eine kugelförmige Gestalt und einer durchschnittlichen Größe von 15 nm auf. Gold nanostars abgebildet mit einem Hitachi S-5500 in einem Rasterelektronenmikroskop (SEM)-Modus. Abbildung 2 zeigt zunehmende Vergrößerung des nanostars mit unserer Methode synthetisiert. Stern geformten Teilchen sind etwa 70% aller Partikel in dem Kolloid. Non-gebildete Sterne erscheinen wie amorphen Clustern Dekaedern und Rauten (nicht dargestellt). Abbildung 3 zeigt einige Einzel Gold nanostars. Die Größe der nanostars reicht von 200 nm bis 300 nm und die Anzahl der Spitzen variieren von 7 bis 10. Wenn der Gold-Nanopartikel synthetisiert durch dieses Verfahren in CTAB verließen sie behalten ihre Form für mindestens 1 Monat nach der Synthese. e_content &quot;&gt; Wir maßen die Absorptionsspektren der Silber Samen und nanostars mit einem Olis Cary-14-Spektralphotometer. Das Absorptionsmaximum der Samen wurde bei 400 nm, während die Spitze Absorption der nanostars wurde zwischen 800 nm und 850 nm (Abbildung 4 ). <img src="/files/ftp_upload/3570/3570fig1.jpg" alt="Abbildung 1" /> Abbildung 1. Transmissionselektronenmikroskop Bilder von Silber Samen. <img src="/files/ftp_upload/3570/3570fig2.jpg" alt="Abbildung 2" /> Abbildung 2. Rasterelektronenmikroskop-Aufnahmen von Gold nanostars. <img src="/files/ftp_upload/3570/3570fig3.jpg" alt="Abbildung 3" /> Abbildung 3. Rasterelektronenmikroskop-Aufnahmen von einzelnen Gold nanostars. <img src="/files/ftp_upload/3570/3570fig4.jpg" alt="Abbildung 6" /> Abbildung 4. Normierte Absorptionsspektren von Silber Samen (gestrichelte Linie) und Goldnanostars (durchgezogene Linie).

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Keine Interessenskonflikte erklärt.

In dieser Arbeit haben wir eine Methode, um Gold nanostars mit Silber Samen synthetisieren vorgestellt. Wir fanden, dass Silber Samen in einer Ausbeute von 70% der Produktion von nanostars geführt. Die nanostars eine Nah-Infrarot-Absorptions-Peak, entsprechend ihrer Oberflächen-Plasmon-Resonanz-Modus, zwischen 800 nm und 850 nm 7, 23 zentriert. Diese Eigenschaften Eigenschaften ermöglichen es unseren Gold nanostars von Nutzen für biomedizinische Anwendungen 24-26, wie Foto-Thermoablation werden...

<table border="1"><tbody><tr><td> Name des Reagenzes </td><td> Firma </td><td> Katalog-Nummer </td><td> Reinheit </td></tr><tr><td> Natriumcitrat tribasischen dehydrieren </td><td> Sigma </td><td> S4641 </td><td> 99,0% </td></tr><tr><td> Silbernitrat </td><td> Aldrich </td><td> 204390 </td><td> 99,9999% </td></tr><tr><td> Natriumborhydrid </td><td> Aldrich </td><td> 213462 </td><td> 99% </td></tr><tr><td> L-Ascorbinsäure </td><td> Sigma-Aldrich </td><td> 255564 </td><td> 99 +% </td></tr><tr><td> Gold-chlorid-Trihydrat </td><td> Aldrich </td><td> 520918 </td><td> 99,9 +% </td></tr><tr><td> Hexadecyltrimethylammoniumbromid (CTAB) </td><td> Sigma </td><td> H6269 </td><td></td></tr></tbody></table><table border="1"><tbody><tr><td> Name der Ausrüstung </td><td> Firma </strong&gt; </td><td> Kommentare </td></tr><tr><td> JEOL 2010-F </td><td> JEOL </td><td> Transmissions-Elektronenmikroskop </td></tr><tr><td> Hitachi S-5500 </td><td> Hitachi </td><td> Gebrauchte in Rasterelektronenmikroskop-Modus </td></tr><tr><td> Olis Cary-14 Spektrophotometer </td><td> Olis </td><td> Spektrophotometer </td></tr></tbody></table>

gold nanostar synthesis with a silver seed mediated growth method

Die physikalischen, chemischen und optischen Eigenschaften von Nano-Kolloide sind abhängig von ihrer stofflichen Zusammensetzung, Größe und Form 1-5. Es gibt ein großes Interesse im Umgang mit Nano-Kolloide für photo-thermische Ablation, Drug Delivery und viele andere biomedizinische Anwendungen 6. Gold ist vor allem wegen ihrer geringen Toxizität 7-9 verwendet. Eine Eigenschaft der Metall-Nano-Kolloide ist, dass sie eine starke Oberflächen-Plasmon-Resonanz-10 haben. Der Höhepunkt der Oberflächen-Plasmon-Resonanz-Modus hängt von der Struktur und Zusammensetzung des Metalls Nano-Kolloide. Da die Oberflächen-Plasmon-Resonanz-Modus mit Licht angeregt wird, gibt es einen Bedarf an der Spitze Absorption im nahen Infrarotbereich, wo biologisches Gewebe Transmissivität ist maximal 11, 12 haben. Wir präsentieren eine Methode zur sternförmigen kolloidalem Gold, auch als sternförmige Nanopartikel 13-15 oder nanostars 16 bekannt zu synthetisieren. Diese Methode beruht auf als Basislösung mit Silber Samen, die als Nukleierungsmittel für anisotropes Wachstum von Gold-Kolloide 17-22 verwendet werden. Rasterelektronenmikroskopie (SEM)-Analyse der resultierenden Goldkolloid zeigte, dass 70% der Nanostrukturen nanostars wurden. Die anderen 30% der Partikel wurden amorphe Cluster Dekaedern und Rauten. Die Absorption Höhepunkt der nanostars erkannt wurde, um im nahen Infrarot (840 nm) werden. So produziert unser Verfahren gold nanostars für biomedizinische Anwendungen geeignet, besonders für Foto-thermischen Ablation.

Watch this Scientific Journal Video about Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method at JoVE.com

Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

Wir synthetisierten sternförmigen Gold nanostars mit einem silbernen Saat vermitteltes Wachstum Methode. Der Durchmesser der nanostars reicht von 200 bis 300 nm und die Anzahl der Spitzen variieren von 7 bis 10. Die Nanopartikel haben eine große Oberflächen-Plasmon-Resonanz-Modus im nahen Infrarot zentriert.

Gold Nanostar Synthesis mit einem Silver Seed vermitteltes Wachstum Methode

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest ...

gold-nanostar-synthesis-with-a-silver-seed-mediated-growth-method

Research

JoVE Journal

Bioengineering

24.9K Aufrufe.  The University of Texas at San Antonio. Wir synthetisierten sternförmigen Gold nanostars mit einem silbernen Saat vermitteltes Wachstum Methode. Der Durchmesser der nanostars reicht von 200 bis 300 nm und die Anzahl der Spitzen variieren von 7 bis 10. Die Nanopartikel haben eine große Oberflächen-Plasmon-Resonanz-Modus im nahen Infrarot zentriert.

Serie: Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

Axon Stretch Growth: The Mechanotransduction of Neuronal Growth

During pre-synaptic embryonic development, neuronal processes traverse short distances to reach their targets via growth cone. Over time, neuronal somata are separated from their axon terminals due to skeletal growth of the enlarging organism (Weiss 1941; Gray, Hukkanen et al. 1992). This mechanotransduction induces a secondary mode of neuronal growth capable of accommodating continual elongation of the axon (Bray 1984; Heidemann and Buxbaum 1994; Heidemann, Lamoureux et al. 1995; Pfister, Iwata et al. 2004).
Axon Stretch Growth (ASG) is conceivably a central factor in the maturation of short embryonic processes into the long nerves and white matter tracts characteristic of the adult nervous system. To study ASG in vitro, we engineered bioreactors to apply tension to the short axonal processes of neuronal cultures (Loverde, Ozoka et al. 2011). Here, we detail the methods we use to prepare bioreactors and conduct ASG. First, within each stretching lane of the bioreactor, neurons are plated upon a micro-manipulated towing substrate. Next, neurons regenerate their axonal processes, via growth cone extension, onto a stationary substrate. Finally, stretch growth is performed by towing the plated cell bodies away from the axon terminals adhered to the stationary substrate; recapitulating skeletal growth after growth cone extension.
Previous work has shown that ASG of embryonic rat dorsal root ganglia neurons are capable of unprecedented growth rates up to 10mm/day, reaching lengths of up to 10cm; while concurrently resulting in increased axonal diameters (Smith, Wolf et al. 2001; Pfister, Iwata et al. 2004; Pfister, Bonislawski et al. 2006; Pfister, Iwata et al. 2006; Smith 2009). This is in dramatic contrast to regenerative growth cone extension (in absence of mechanical stimuli) where growth rates average 1mm/day with successful regeneration limited to lengths of less than 3cm (Fu and Gordon 1997; Pfister, Gordon et al. 2011). Accordingly, further study of ASG may help to reveal dysregulated growth mechanisms that limit regeneration in the absence of mechanical stimuli.

A unique tissue engineering method was developed to elongate numerous nerve fibers in culture by recapitulating axon stretch growth; a form of nervous system growth whereby nerves elongate in conjunction with growth of the enlarging body.

Axon Stretch Growth: The Mechanotransduktion des neuronalen Wachstums

During pre-synaptic embryonic development, neuronal processes traverse short distances to reach their targets via growth cone. Over time, neuronal somata ...

Forschung

Biotechnik

Synthesis, Assembly, and Characterization of Monolayer Protected Gold Nanoparticle Films for Protein Monolayer Electrochemistry

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM).1-3 In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction4 and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton (1H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials.5-8

Alkanethiolate stabilized gold colloids known as monolayer protected clusters (MPCs) are synthesized, characterized, and assembled into thin films as an adsorption interface for protein monolayer electrochemistry of simple redox protein like Pseudomonas aeruginosa azurin (AZ) and cytochrome c (cyt c).

Synthesis, Assembly und Charakterisierung von Monolayer Protected Gold-Nanopartikeln Films für die Protein-Monoschicht Elektrochemie

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently ...

Observing and Quantifying Fibroblast-mediated Fibrin Gel Compaction

Cells embedded in collagen and fibrin gels attach and exert traction forces on the fibers of the gel. These forces can lead to local and global reorganization and realignment of the gel microstructure. This process proceeds in a complex manner that is dependent in part on the interplay between the location of the cells, the geometry of the gel, and the mechanical constraints on the gel. To better understand how these variables produce global fiber alignment patterns, we use time-lapse differential interference contrast (DIC) microscopy coupled with an environmentally controlled bioreactor to observe the compaction process between geometrically spaced explants (clusters of fibroblasts). The images are then analyzed with a custom image processing algorithm to obtain maps of the strain. The information obtained from this technique can be used to probe the mechanobiology of various cell-matrix interactions, which has important implications for understanding processes in wound healing, disease development, and tissue engineering applications.

Time-lapse microscopy and image processing techniques were used to observe and analyze fibroblast-mediated gel compaction and fibrin fiber realignment in an environmentally controlled bioreactor over a 48 hr&#160;period.

Beobachtung und Quantifizierung von Fibroblasten-vermittelter Fibrin-Gelverdichtung

Cells embedded in collagen and fibrin gels attach and exert traction forces on the fibers of the gel. These forces can lead to local and global ...

Synthesis of an Intein-mediated Artificial Protein Hydrogel

We present the synthesis of a highly stable protein hydrogel mediated by a split-intein-catalyzed protein trans-splicing reaction. The building blocks of this hydrogel are two protein block-copolymers each containing a subunit of a trimeric protein that serves as a crosslinker and one half of a split intein. A highly hydrophilic random coil is inserted into one of the block-copolymers for water retention. Mixing of the two protein block copolymers triggers an intein trans-splicing reaction, yielding a polypeptide unit with crosslinkers at either end that rapidly self-assembles into a hydrogel. This hydrogel is very stable under both acidic and basic conditions, at temperatures up to 50 &#176;C, and in organic solvents. The hydrogel rapidly reforms after shear-induced rupture. Incorporation of a &#34;docking station peptide&#34; into the hydrogel building block enables convenient incorporation of &#34;docking protein&#34;-tagged target proteins. The hydrogel is compatible with tissue culture growth media, supports the diffusion of 20 kDa molecules, and enables the immobilization of bioactive globular proteins. The application of the intein-mediated protein hydrogel as an organic-solvent-compatible biocatalyst was demonstrated by encapsulating the horseradish peroxidase enzyme and corroborating its activity.

We present the synthesis of a split-intein-mediated protein hydrogel. The building blocks of this hydrogel are two protein copolymers each containing a subunit of a trimeric protein that serves as a crosslinker and one half of a split intein. Mixing of the two protein copolymers triggers an intein trans-splicing reaction, yielding a polypeptide unit that self-assembles into a hydrogel. This hydrogel is highly pH- and temperature-stable, compatible with organic solvents, and easily incorporates functional globular proteins.

Synthese einer Intein-vermittelten Protein-Hydrogel Künstliche

We present the synthesis of a highly stable protein hydrogel mediated by a split-intein-catalyzed protein trans-splicing reaction. The building blocks of ...

Formation of Biomembrane Microarrays with a Squeegee-based Assembly Method

Lipid bilayer membranes form the plasma membranes of cells and define the boundaries of subcellular organelles. In nature, these membranes are heterogeneous mixtures of many types of lipids, contain membrane-bound proteins and are decorated with carbohydrates. In some experiments, it is desirable to decouple the biophysical or biochemical properties of the lipid bilayer from those of the natural membrane. Such cases call for the use of model systems such as giant vesicles, liposomes or supported lipid bilayers (SLBs). Arrays of SLBs are particularly attractive for sensing applications and mimicking cell-cell interactions. Here we describe a new method for forming SLB arrays. Submicron-diameter SiO2 beads are first coated with lipid bilayers to form spherical SLBs (SSLBs). The beads are then deposited into an array of micro-fabricated submicron-diameter microwells. The preparation technique uses a "squeegee" to clean the substrate surface, while leaving behind SSLBs that have settled into microwells. This method requires no chemical modification of the microwell substrate, nor any particular targeting ligands on the SSLB. Microwells are occupied by single beads because the well diameter is tuned to be just larger than the bead diameter. Typically, more 75% of the wells are occupied, while the rest remain empty. In buffer SSLB arrays display long-term stability of greater than one week. Multiple types of SSLBs can be placed in a single array by serial deposition, and the arrays can be used for sensing, which we demonstrate by characterizing the interaction of cholera toxin with ganglioside GM1. We also show that phospholipid vesicles without the bead supports and biomembranes from cellular sources can be arrayed with the same method and cell-specific membrane lipids can be identified.

Supported lipid bilayers and natural membrane particles are convenient systems that can approximate the properties of cell membranes and be incorporated in a variety of analytical strategies. Here we demonstrate a method for preparing microarrays composed of supported lipid bilayer-coated SiO2 beads, phospholipid vesicles or natural membrane particles.

Bildung Biomembrane Microarrays mit einem Rakel-basierten Montageverfahren

Lipid bilayer membranes form the plasma membranes of cells and define the boundaries of subcellular organelles. In nature, these membranes are ...

Synthesis of Keratin-based Nanofiber for Biomedical Engineering

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of these porous nanofibers is of great interest due to their unique physiochemical properties. Here we elaborate on the fabrication of keratin containing poly (&#949;-caprolactone) (PCL) nanofibers (i.e., PCL/keratin composite fiber). Water soluble keratin was first extracted from human hair and mixed with PCL in different ratios. The blended solution of PCL/keratin was transformed into nanofibrous membranes using a laboratory designed electrospinning set up. Fiber morphology and mechanical properties of the obtained nanofiber were observed and measured using scanning electron microscopy and tensile tester. Furthermore, degradability and chemical properties of the nanofiber were studied by FTIR. SEM images showed uniform surface morphology for PCL/keratin fibers of different compositions. These PCL/keratin fibers also showed excellent mechanical properties such as Young&#39;s modulus and failure point. Fibroblast cells were able to attach and proliferate thus proving good cell viability. Based on the characteristics discussed above, we can strongly argue that the blended nanofibers of natural and synthetic polymers can represent an excellent development of composite materials that can be used for different biomedical applications.

Electrospun nanofibers have a high surface area to weight ratio, excellent mechanical integrity, and support cell growth and proliferation. These nanofibers have a wide range of biomedical applications. Here we fabricate keratin/ PCL nanofibers, using the electrospinning technique, and characterize the fibers for possible applications in tissue engineering.

Synthese von Keratin-basierten Nanofaser für Biomedizinische Technik

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of ...

Synthesis of Gold Nanoparticle Integrated Photo-responsive Liposomes and Measurement of Their Microbubble Cavitation upon Pulse Laser Excitation

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the development process and are unprocurable by clinics. Here, we describe a facile fabrication of these photo-responsive NPs with commercially available gold NPs and thermo-responsive liposomes. Calcein is used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Finally, we show that this photo-triggered release is due to the membrane disruption caused by microbubble cavitation, which can be measured with hydrophone.

This protocol describes a simple preparation method for gold nanoparticle integrated photo-responsive liposomes with the commercially available materials. It also shows how to measure the microbubble cavitation process of the synthesized liposomes upon the treatment of pulsed laser.

Synthese von Gold-Nanopartikeln Integrated Photo-responsive Liposomen und Messung ihrer Mikroblasen Kavitation auf Pulse Laseranregung

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control ...

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and thus achieving stable water permeability through membranes over time. Here, we report a facile method to prepare hydrogels based on zwitterions for membrane applications. Freestanding films can be prepared from sulfobetaine methacrylate (SBMA) with a crosslinker of poly(ethylene glycol) diacrylate (PEGDA) via photopolymerization. The hydrogels can also be prepared by impregnation into hydrophobic porous supports to enhance the mechanical strength. These films can be characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the degree of conversion of the (meth)acrylate groups, using goniometers for hydrophilicity and differential scanning calorimetry (DSC) for polymer chain dynamics. We also report protocols to determine the water permeability in dead-end filtration systems and the effect of foulants (bovine serum albumin, BSA) on membrane performance.

This paper reports practical methods to prepare hydrogels in freestanding films and impregnated membranes and to characterize their physical properties, including water transport properties.

Synthese von Hydrogelen mit Antifouling-Eigenschaften als Membranen für die Wasserreinigung

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...

Synthesis of Functionalized 10-nm Polymer-coated Gold Particles for Endothelium Targeting and Drug Delivery

Gold nanoparticles (AuNPs) have been used extensively in medical research due to their size, biocompatibility, and modifiable surface. Specific targeting and drug delivery are some of the applications of these AuNPs, but endothelial extracellular matrices&#39; defensive properties hamper particle uptake. To address this issue, we describe a synthesis method for ultrasmall gold nanoparticles to improve vascular delivery, with customizable functional groups and polymer lengths for further adjustments. The protocol yields 2.5 nm AuNPs that are capped with tetrakis(hydroxymethyl)phosphonium chloride (THPC). The replacement of THPC with hetero-functional polyethylene glycol (PEG) on the surface of the AuNP increases the hydrodynamic radius to 10.5 nm while providing various functional groups on the surface. The last part of the protocol includes an optional addition of a fluorophore to allow the AuNPs to be visualized under fluorescence to track nanoparticle uptake. Dialysis and lyophilization were used to purify and isolate the AuNPs. These fluorescent nanoparticles can be visualized in both in vitro and in vivo experiments due to the biocompatible PEG coating and fluorescent probes. Additionally, the size range of these nanoparticles render them an ideal candidate for probing the glycocalyx without disrupting normal vasculature function, which may lead to improved delivery and therapeutics.

We describe a method of synthesizing biocompatible 10-nm gold nanoparticles, functionalized by coating poly-ethylene glycol onto the surface. These particles can be used in vitro and in vivo for delivering therapeutics to nanoscale cellular and extracellular spaces that are difficult to access with conventional nanoparticle sizes.

Synthese von funktionalisierten 10 nm Polymer beschichteten Goldpartikeln für Targeting Endothel und Drug-Delivery

Gold nanoparticles (AuNPs) have been used extensively in medical research due to their size, biocompatibility, and modifiable surface. Specific targeting ...

Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

In this study, multi-walled carbon nanotubes (MWCNTs) were treated with an aqueous sulfuric acid solution to form an oxygen-based functional group. Silver MWCNTs were prepared by the reductive deposition of silver from an aqueous solution of AgNO3 on the oxidized MWCNTs. Given the unique color of the CNTs, it was not possible to apply them to the minimum inhibitory concentration or mitochondrial toxicity assays to evaluate the toxicity and antibacterial properties, since they would interfere with the assays. The inhibition zone and minimum bactericidal concentration for the Ag-MWCNTs were measured and Live/Dead and Trypan Blue assays were used to measure the toxicity and antibacterial properties without interfering with the color of the CNTs.

In this study, antimicrobial nanomaterials were synthesized by acidic oxidation of multiwalled carbon nanotubes and subsequent reductive deposition of silver nanoparticles. Antimicrobial activity and cytotoxicity tests were performed with the as-prepared nanomaterials.

Synthese von Multi-walled Carbonnanotubes mit Silber-Nanopartikeln und Bewertung ihrer antibakteriellen Aktivitäten und zytotoxische Eigenschaften modifiziert

In this study, multi-walled carbon nanotubes (MWCNTs) were treated with an aqueous sulfuric acid solution to form an oxygen-based functional group. Silver ...