Cette recherche a été financée par le Partenariat National Science Foundation pour la recherche et l&#39;éducation dans les Matériaux (PREM) Grant No. DMR-0934218. Il a également été soutenue par le Prix Nombre 2G12RR013646-11 du National Center for Research Resources. Le contenu est exclusivement la responsabilité de leurs auteurs et ne représentent pas nécessairement les vues officielles du Centre National des Ressources de la recherche ou le National Institutes of Health.

1. La préparation des graines d&#39;Argent <ol><li> Préparer une solution stock de nitrate d&#39;argent (AgNO 3) en prenant une masse arbitraire et le mélanger avec 10 ml d&#39;eau désionisée (DI). Calculer la molarité de la solution. Conserver la solution dans un endroit sombre à l&#39;isoler de la lumière. </li><li> Ajouter 14,7 mg de citrate de sodium tribasique (Na 3 C 6 H 5 O 7) à 10 ml d&#39;eau DI pour faire une solution à 5 mM. Agiter le flacon jusqu&#39;à ce que la poudre soit dissoute. </li><li> Ajouter 15,1 mg de borohydrure de sodium (NaBH 4) à un autre flacon de 10 ml d&#39;eau DI pour faire une solution à 40 mM. Fermer le flacon immédiatement. Secouez doucement la solution à la main et le placer dans un bécher avec de la glace. Placer le bécher dans le réfrigérateur et commencer une minuterie (t1 = 0). La solution fraîchement préparée sera utilisé dans 15 minutes, qui est suffisamment de temps pour refroidir. </li><li> De la solution stock de nitrate d&#39;argent, 1,1), préparer 10 mL à 0,25 mM. Placez un aimant d&#39;agitation dans le flacon et stagitant l&#39;art. </li><li> Ajouter 0,25 mL de la solution de citrate de sodium tribasique 1,2) à 1,4). </li><li> A t = 15 min 1 enlever la solution de borohydrure de sodium, 1,3), du réfrigérateur. En utilisant une pipette de prendre 0,4 ml de cette solution et l&#39;ajouter à 1,5). Remarque: Ajouter la solution d&#39;un seul coup rapide. La couleur va tourner au jaune. Agiter la solution pendant 5 min. </li><li> A t 1 = 20 min en remuant arrêter, enlever l&#39;aimant de la fiole et de garder le flacon dans un endroit sombre. Ne pas fermer le flacon. </li><li> Conserver la solution dans l&#39;obscurité à température ambiante pendant au moins 2 heures avant utilisation. Utilisez de préférence les graines dans une semaine de préparation. </li></ol> 2. Préparation de la solution de croissance <ol><li> Préparer 80 mM d&#39;acide ascorbique (C 6 H 8 O 6) par addition de 140 mg à 10 ml d&#39;eau DI. </li><li> Préparer 10 ml d&#39;une solution concentrée de chlorure d&#39;or (HAuCl 4). Calculer la molarité de la solution. Gardez la solution isolée de la lumière. </li><li> Préparer 20 ml de 50 mM de bromure de cétyltriméthylammonium (CTAB - C 19 H 42 BRN) en ajoutant 364 mg dans un flacon avec 20 ml d&#39;eau DI. Immédiatement placer un aimant sous agitation dans le flacon et commencer à remuer sur une plaque chaude à 30 ° C. Après la poudre CTAB est complètement dissous et la solution devient transparente tour hors de la chauffe de la plaque, mais continuez à remuer jusqu&#39;à l&#39;étape 2.7). </li><li> Ajouter la solution 1,1) à la solution 2.3) pour obtenir une molarité finale de 4.9x10 mm -2. Démarrer une minuterie (t 2 = 0). </li><li> A t 2 = 1 min ajouter la solution 2,2) à 2,4) pour obtenir une molarité finale de 0,25 mM. </li><li> A t 2 = 2 min, ajoutez 0,1 ml de 2,1) à 2,5). La solution va devenir incolore. </li><li> A t 2 = 2 min 20 sec ajouter 0,05 ml de 1,8) (les graines d&#39;argent) à 2,6). Incorporer la suspension pendant 15 min. La suspension sera d&#39;abord virer au bleu, puis au brun. </li><li> A t 2 = 17 min en remuant arrêter, enlever le mAgNet et maintenir la suspension à température ambiante pendant 24 heures. </li></ol> 3. Séparation nanostars or de CTAB pour l&#39;imagerie, la caractérisation ou l&#39;expérimentation Note: CTAB peut cristalliser à température ambiante. Pour dissoudre la chaleur des cristaux jusqu&#39;à l&#39;or colloïdal à 30 ° C ou immerger le flacon dans l&#39;eau du robinet chaude jusqu&#39;à ce que les cristaux se dissolvent. <ol><li> Soniquer la suspension pendant 2 min. </li><li> Centrifuger la suspension pendant 5 min à 730 fcr. Nanostars s&#39;accumulent sur la paroi du tube. </li><li> Retirez autant de la suspension avec une pipette en prenant soin de ne pas retirer le nanostars. </li><li> Ajouter de l&#39;eau DI pour le tube et soniquer pendant 2 min. </li><li> Centrifuger la suspension pendant 3 min à 460 fcr. La suspension contient moins CTAB, donc inférieure de la force centrifuge est nécessaire de séparer les nanostars. </li><li> Répétez les étapes 3.3) et 3.4). </li><li> Ajouter de l&#39;eau DI à la suspension et centrifuger 3 min à 380 fcr. </li><li> S&#39;acquit<html> t étapes 3.3) et 3.4). Le nanostars sont prêts pour l&#39;imagerie, la spectroscopie, ou d&#39;expérimentation. </li></ol> 4. Les résultats représentatifs: La figure 1 montre la transmission au microscope électronique (TEM) des images de la graine d&#39;argent imagée en utilisant un JEOL 2010-F TEM. Les graines ont une forme sphérique et une taille moyenne de 15 nm. Nanostars or sont imagées par un Hitachi S-5500 au microscope électronique à balayage (MEB) en mode. La figure 2 montre un grossissement croissant de l&#39;nanostars synthétisés avec notre méthode. Particules en forme d&#39;étoile sont environ 70% de toutes les particules dans le colloïde. Non formées étoiles apparaissent comme des grappes amorphes de decahedra et rhomboïdes (non représentée). La figure 3 montre plusieurs nanostars unique de l&#39;or. La taille des gammes nanostars de 200 nm à 300 nm et le nombre de conseils varient de 7 à 10. Si les nanoparticules d&#39;or synthétisée par cette méthode sont laissés dans CTAB qu&#39;ils conservent leur forme pendant au moins un mois après la synthèse. e_content &quot;&gt; Nous avons mesuré les spectres d&#39;absorption de l&#39;argent et des semences nanostars utilisant un Cary-14 Olis spectrophotomètre. Le pic d&#39;absorption des graines était à 400 nm, tandis que le pic d&#39;absorption de l&#39;nanostars était entre 800 nm et 850 nm (figure 4 ). <img src="/files/ftp_upload/3570/3570fig1.jpg" alt="Figure 1" /> Figure 1. Images au microscope électronique à transmission de graines d&#39;argent. <img src="/files/ftp_upload/3570/3570fig2.jpg" alt="Figure 2" /> Figure 2. Numérisation d&#39;images au microscope électronique des nanostars or. <img src="/files/ftp_upload/3570/3570fig3.jpg" alt="Figure 3" /> Figure 3. Numérisation d&#39;images au microscope électronique des nanostars unique de l&#39;or. <img src="/files/ftp_upload/3570/3570fig4.jpg" alt="Figure 6" /> Figure 4. Spectres d&#39;absorption normalisé de graines d&#39;argent (ligne pointillée) et de l&#39;ornanostars (ligne continue).

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Pas de conflits d&#39;intérêt déclarés.

Dans ce travail nous avons présenté une méthode pour synthétiser nanostars or en utilisant des semences d&#39;argent. Nous avons constaté que les graines d&#39;argent conduit à un rendement de production de 70% des nanostars. Le nanostars avoir un pic d&#39;absorption dans le proche infrarouge, ce qui correspond à leur mode de résonance plasmonique de surface, centrée entre 800 nm et 850 nm 7, 23. Ces propriétés permettent à nos propriétés nanostars d&#39;or pour être d&#39;utilisation pour des...

<table border="1"><tbody><tr><td> Nom du réactif </td><td> Société </td><td> Numéro de catalogue </td><td> Pureté </td></tr><tr><td> Le citrate de sodium tribasique déshydratent </td><td> Sigma </td><td> S4641 </td><td> 99,0% </td></tr><tr><td> Le nitrate d&#39;argent </td><td> Aldrich </td><td> 204390 </td><td> 99,9999% </td></tr><tr><td> Le borohydrure de sodium </td><td> Aldrich </td><td> 213462 </td><td> 99% </td></tr><tr><td> Acide L-ascorbique </td><td> Sigma-Aldrich </td><td> 255564 </td><td> 99% + </td></tr><tr><td> Trihydrate de chlorure d&#39;or </td><td> Aldrich </td><td> 520918 </td><td> + 99,9% </td></tr><tr><td> Bromure de Hexadecyltrimethylammonium (CTAB) </td><td> Sigma </td><td> H6269 </td><td></td></tr></tbody></table><table border="1"><tbody><tr><td> Nom de l&#39;équipement </td><td> Société </strong&gt; </td><td> Commentaires </td></tr><tr><td> JEOL 2010-F </td><td> JEOL </td><td> Microscope électronique à transmission </td></tr><tr><td> Hitachi S-5500 </td><td> Hitachi </td><td> Utilisé en mode balayage au microscope électronique </td></tr><tr><td> Olis Cary-14 spectrophotomètre </td><td> Olis </td><td> Spectrophotomètre </td></tr></tbody></table>

gold nanostar synthesis with a silver seed mediated growth method

Les propriétés physiques, chimiques et optiques des nano-échelle colloïdes dépendent de leur composition, la taille et la forme 1-5. Il ya un grand intérêt dans l&#39;utilisation de nano-colloïdes pour la photo-thermique d&#39;ablation, la livraison de médicaments et de nombreuses autres applications biomédicales 6. L&#39;or est particulièrement utilisé en raison de sa faible toxicité 7-9. Une propriété de métal nano-colloïdes est qu&#39;ils peuvent avoir une surface solide résonance plasmonique 10. Le pic du mode de résonance plasmonique de surface dépend de la structure et la composition du métal de nano-colloïdes. Depuis le mode de résonance plasmonique de surface est stimulé avec la lumière il ya un besoin d&#39;avoir l&#39;absorbance de pointe dans le proche infrarouge, où transmissivité tissu biologique est maximale 11, 12. Nous présentons une méthode pour synthétiser étoile d&#39;or en forme colloïdale, aussi connu comme les nanoparticules en forme d&#39;étoile ou de 13 à 15 nanostars 16. Cette méthode est basée sur leolution contenant des graines d&#39;argent qui sont utilisés comme agent de nucléation pour la croissance anisotrope des colloïdes d&#39;or 17-22. Microscopie électronique à balayage (MEB) de l&#39;or colloïdal résultant a montré que 70% des nanostructures ont été nanostars. L&#39;autre 30% des particules ont été amas amorphe de decahedra et rhomboïdes. Le pic d&#39;absorbance de l&#39;nanostars a été détectée pour être dans le proche infrarouge (840 nm). Ainsi, notre méthode produit nanostars d&#39;or conviennent pour des applications biomédicales, en particulier pour la photo-thermique d&#39;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

Nous avons synthétisé nanostars étoile d&#39;or en forme en utilisant une méthode de graines d&#39;argent médiation croissance. Le diamètre de la nanostars varie de 200 à 300 nm et le nombre de conseils varient de 7 à 10. Les nanoparticules ont une surface large résonance plasmonique de mode centré dans le proche infrarouge.

Or Nanostar synthèse avec une méthode de graines Silver croissance Mediated

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 vues.  The University of Texas at San Antonio. Nous avons synthétisé nanostars étoile d'or en forme en utilisant une méthode de graines d'argent médiation croissance. Le diamètre de la nanostars varie de 200 à 300 nm et le nombre de conseils varient de 7 à 10. Les nanoparticules ont une surface large résonance plasmonique de mode centré dans le proche infrarouge.

Vidéo: 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.

Croissance stretch Axon: La mécanotransduction de croissance neuronale

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

Recherche

Bio-ingénierie

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).

Synthèse, l&#39;Assemblée, et caractérisation des nanoparticules Monocouche protégées Films d&#39;or pour Electrochimie monocouche de protéines

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.

Observation et quantification du compactage du gel de fibrine médié par les fibroblastes

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.

Synthèse d&#39;une protéine artificielle induite par une intéine 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 ...

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.

Formation de biomembrane puces à ADN avec une méthode Assemblée basée à raclette

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.

Synthèse de nanofibres à base de kératine de génie biomédical

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.

Synthèse de l&#39;or nanoparticules liposomes intégré photosensible et mesurer leur microbulles cavitation sur Pulse Laser excitation

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.

Synthèse des hydrogels avec des propriétés antisalissure Membranes pour la purification de l&#39;eau

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.

Synthèse des fonctionnalisées 10 nm revêtement polymère des particules d’or pour le ciblage de l’endothélium et MEDICAMENTS

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.

Synthèse des Nanotubes de carbone Multi modifiés avec des nanoparticules d’argent et de l’évaluation de leurs activités antibactériennes et propriétés cytotoxiques

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