Die Autoren bedanken sich einen Zuschuss von der National Health and Medical Research Council of Australia (NHMRC # 1000674) zu LJR Foster.

Ein. Vorbereitung der SurgiLux Lösung <ol><li> Bereiten Sie eine 2% (v / v) Lösung von Essigsäure mit deionisiertem Wasser in einem sauberen Becherglas, verwenden Sie einen Laminarströmungshaube, um eine Kontamination zu vermeiden. </li><li> Wiegen 0,02% (w / v) des Chromophors, Indocyaningrün, IKG, in einer sterilen Eppendorfröhrchen; sicherzustellen das Rohr in Alufolie eingewickelt, um kein Licht eindringen kann. </li><li> Mit einem sauberen, Einwegpipette, übertragen etwa 1 ml der verdünnten Essigsäure-Lösung auf das Rohr, um den Farbstoff zu lösen, leicht schütteln und halten in Folie gewickelt. </li><li> Übertragen des solubilisierten ICG in den Becher und mit 2% (w / v) Chitosan Pulver vor dem Hinzufügen eines sterilen Magnetrührer. </li><li> Das Becherglas mit Parafilm dann in Alufolie zu wickeln, bevor das Mischen der Inhalte bei etwa 125 UpM für 72 h bei Raumtemperatur in einer Sterilbank. </li><li> Transferieren des Inhalts in saubere Röhrchen und Zentrifuge bei 15.000 g für 15 min bei 4 ° C zu entfernen particulate Materie. </li><li> Transferieren es vorsichtig in die grüne SurgiLux Lösung in ein sauberes Becherglas, decken mit Parafilm dann wickeln in Silberfolie, vor dem Speichern in einem Kühlschrank für 12 Stunden, um die Viskosität der Lösung zu erhöhen. </li></ol> 2. Gießen SurgiLux Films <ol><li> Mit einer sterilen Spritze verzichten 8 ml des kalten SurgiLux Lösung in einem sauberen, Petrischale von 95 mm Durchmesser und leicht kippen die Platte um eine vollständige Abdeckung von der Lösung zu gewährleisten. Variation des Verhältnisses von Volumen der Lösung zum Gießen Bereich erlaubt die Kontrolle der Schichtdicke, siehe Abbildung 1. </li><li> Entfernen Sie alle sichtbaren Luftblasen in der Lösung mit der Spitze einer sterilen Nadel. Decken Sie die Schale in Alufolie und in einem Kühlschrank, um alle restlichen Mikrometergröße Luftblasen zu entfernen. </li><li> Nach 20 min vorsichtig die Petrischale aus dem Kühlschrank, in einem Laminarströmungshaube decken mit Silberfolie und lassen Sie die Lösung für 3 Wochen verdampfen. </li><li> Nach Kosolute Verdampfung des Gastes die äußeren Kanten der klaren grünen SurgiLux Film in der Petrischale und sanft &quot;Schale&quot; des Films vom Gericht Oberfläche. </li><li> Die SurgiLux Film sollte flexibel und leicht ohne Reißen oder Brechen manipuliert. </li><li> Bewahren Sie die kreisförmige SurgiLux Filme in der Petrischale in Silberfolie unter trockenen Bedingungen verpackt bis zur Verwendung. </li></ol> 3. Laser Aktivierung SurgiLux Klebefolien <ol><li> Um den Laser Aktivierung zeigen, verwenden wir ein Stück Rindergewebe wie Steak geschnitten zu einer Größe von 15 mm Breite und 20 mm Länge. Präparieren des Gewebes in einer geraden Linie unter Verwendung eines Number 10 chirurgischen Klinge, um zwei Stücke von 15 × 10 mm zu erzeugen. </li><li> Angleichung der zwei Gewebestücke so daß ihre Kanten sich berühren aber nicht überlappen, und mit einem Wattestäbchen oder Gaze, sanft absorbieren überschüssiges Fluid. </li><li> Dann schneiden Sie ein Stück SurgiLux Film 7 x 9 mm und vorsichtig die Folie in Längsrichtung über die halbierten pIECE von Gewebe; drücken Sie dann vorsichtig mit einem trockenen Wattestäbchen. </li><li> SurgiLux Filme werden aktiviert Verwendung eines Infrarot-Diodenlaser bei einer Einstellung von 120 mW. Da es sich um eine Klasse IIIB Laser, sollten geeignete Sicherheitsmaßnahmen zu treffen, einschließlich der Verwendung von geeigneten Schutzbrille für alle Mitarbeiter sein. </li><li> Ab in die Ecke, bestrahlen die SurgiLux mit einem Infrarot-Laser bei 120 mW eingestellt und eine Fleckgröße von 1 mm Durchmesser. Übergeben der Strahlfleck über den grünen Folie bei einer Geschwindigkeit von etwa 1 mm pro Sekunde. Wiederholen Sie die Bestrahlung zwei weitere Male. </li></ol> 4. Stärke der Reparatur <ol><li> Vorsichtig sichern die Enden des Gewebes in den Klemmbacken einer Zugprüfmaschine Instrument. Wir verwenden ein Instron Mini55 System mit einer 50 Newton Kraftmessdose. Die maximale Last, Zugfestigkeit und Bruchdehnung wurden unter Verwendung Bluehill Computersoftware (USA). Mittel aus mindestens 10 Proben wurden bestimmt (n = 10). </li><li> Nehmen Sie die &quot;slack&quot;und dann Trennen der Gewebeteile mit einer Geschwindigkeit von 1 mm pro Sekunde, bis die beiden Teile des Gewebes miteinander durch die SurgiLux Streifens vollständig getrennte gehalten. </li></ol>

<ol>
	<li>Kjaergard, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suture+support:+is+it+advantageous.">Suture support: is it advantageous.</a> Am. J. Surg. 182, 15S-20S (2001).</li><li>Lauto, A., Mawad, D., Foster, L. J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adhesive+biomaterials+for+tissue+reconstruction.">Adhesive biomaterials for tissue reconstruction.</a> J. Chem. Tech. Biotech. 83, 464-472 (2008).</li><li>Fung, L. C., Mingin, G. C., Massicotte, M., Felsen, D., Poppas, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+temperature+on+tissue+thermal+injury+and+wound+strength+after+photochemical+wound+closure.">Effects of temperature on tissue thermal injury and wound strength after photochemical wound closure.</a> Lasers Surg. Med. 25, 285-290 (1999).</li><li>Piribo, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Glues &amp; Sealants: Industry Background Report. , (2005).</li><li>Lauto, A., Hook, J., Doran, M., Camacho, F., Poole-Warren, L. A., Avolio, A., Foster, L. J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chitosan+adhesive+for+laser+tissue-welding:+in+vitro+characterisation.">Chitosan adhesive for laser tissue-welding: in vitro characterisation.</a> Lasers Surg. Med. 36, 193-201 (2005).</li><li>Lauto, A., Stoodley, M., Marcel, H., Avolio, A., Sarris, M., McKenzie, G., Sampson, D. D., Foster, L. J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+and+in+vivo+tissue+repair+with+laser-activated+chitosan+adhesive.">In vitro and in vivo tissue repair with laser-activated chitosan adhesive.</a> Lasers Surg. Med. 39, 19-27 (2007).</li><li>Lauto, A., Foster, L. J. R., Avolio, A., Sampson, D., Raston, C., Sarris, M., McKenzie, G., Stoodley, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sutureless+Nerve+Repair+with+Laser-Activated+Chitosan+Adhesive:+A+Pilot+in+vivo+Study.">Sutureless Nerve Repair with Laser-Activated Chitosan Adhesive: A Pilot in vivo Study.</a> J. Photomed. Laser. Surg. 26 (3), 227-234 (2008).</li><li>Mar&#231;al, H., Badylak, S. F., Sellaro, T. L., Lauto, A., Foster, L. J. R., Mahler, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+coalescence+of+decellularized+tissue+scaffolds,+laser-activated+chitosan+bioadhesive+and+olfactory+ensheathing+cells+for+tissue+repair+and+regeneration+of+the+spinal+cord.">The coalescence of decellularized tissue scaffolds, laser-activated chitosan bioadhesive and olfactory ensheathing cells for tissue repair and regeneration of the spinal cord.</a> Lasers Med. Sci. 23 (1), 96 (2008).</li><li>Foster, L. J. R., Thomson, K., Marcal, H., Butt, J., Watson, S., Wakefield, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+chitosan-vancomycin+composite+biomaterial+as+a+laser+activated+surgical+adhesive+with+regional+antimicrobial+activity.">A chitosan-vancomycin composite biomaterial as a laser activated surgical adhesive with regional antimicrobial activity.</a> Biomacromolecules. 11 (12), 3563-3570 (2010).</li><li>Shahbazi, J., Marcal, H., Watson, S., Wakefield, D., Sarris, M., Foster, L. J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sutureless+sealing+of+penetrating+corneal+wounds+using+a+laser-activated+thin+film+adhesive.">Sutureless sealing of penetrating corneal wounds using a laser-activated thin film adhesive.</a> Lasers Surg. Med. , .</li><li>Meyers, M. A., Chen, P. -. Y., Lin, A. Y. -. M., Seki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+materials:+Structure+and+mechanical+properties.">Biological materials: Structure and mechanical properties.</a> Prog. Mater. Sci. 53 (1), 1-206 (2008).</li></ol>

Chitosan kann in einer Vielzahl von Molekulargewichten und mit unterschiedlichen Graden an deactylation (DDA) erhalten werden. Variationen in Chitosan Reinheit kann auf das Vorhandensein von Partikeln in der SurgiLux Lösung führen; Zentrifugation wird verwendet, um diese zu beseitigen und sollte in einem transparenten grüne Lösung führen. Allerdings können auch die Filtration als zusätzlichen oder alternativen Herstellungsschritt verwendet werden. Wie bei jedem Materialbearbeitung, Variationen, wie Chitosan DDA u...

<table border="1"><tbody><tr><td> Name des Reagenz / Ausrüstung </td><td> Firma </td><td> Katalog-Nummer </td><td> Kommentare (optional) </td></tr><tr><td> Chitosan </td><td> Sigma-Aldrich </td><td> 448877 </td><td></td></tr><tr><td> Indocyaningrün </td><td> Sigma-Aldrich </td><td> I2633 </td><td> Auch Cardiogreen bekannt </td></tr><tr><td> Essigsäure </td><td> Sigma-Aldrich </td><td> 320099 </td><td></td></tr><tr><td> Infrarot-Diodenlaser mit Faser Lieferung. (808 nm, 120 mW, Breite Kern 200 um) </td><td> CNI Laser </td><td> Fc-808 </td><td> Variables System bis zu 5 W Leistung </td></tr><tr><td> Laserschutzbrillen </td><td> CNI Laser </td><td> LS-G </td><td></td></tr><tr><td> Zugversuch Gerät </td><td> Instron Pty Ltd </td><td> 5542 </td><td> 50 N Wägezelle </td></tr></tbody></table>

a chitosan based, laser activated thin film surgical adhesive, 'surgilux': preparation and demonstration

Nähte sind ein 4.000 Jahre alten Technik, der &quot;goldene Standard&quot; für einen Wundverschluss aufgrund ihrer Reparatur Festigkeit (~ 100 KPa) verbleiben. Allerdings können Nähte als nidus zur Infektion handeln und in vielen Verfahren sind derzeit keine Wundheilung zu bewirken oder zu stören funktionelle Geweberegeneration. 1 Chirurgische Leimen und Klebstoffen, z. B. solche auf Basis von Fibrin und Cyanoacrylaten, sind als Alternativen zu Nähten für entwickelt Die Reparatur dieser Wunden. Jedoch gegenwärtigen kommerziellen Klebstoffen auch erhebliche Nachteile auf, die von viralen und Prion-Transfer und einem Mangel an Reparatur Stärke wie bei den Fibrinkleber, um Gewebe Toxizität und mangelnder Biokompatibilität der Cyanoacrylat basierende Klebstoffe. Weiterhin neigen derzeit verfügbaren chirurgische Klebstoffe sein Gelbasis und kann verlängert Aushärtezeiten, die ihre Anwendung limitieren haben. 2 Ebenso ist die Verwendung von UV-Laser, um eine Vernetzung Mechanismen auf Proteinbasis oder Albumin &#39;Sol erleichternDers &#39;kann zu DNA-Schäden führen, während Laser-Gewebe-Schweißen (LTW) prädisponiert thermische Schäden an Geweben. 3 Trotz ihrer Nachteile, Klebstoffe und LTW eingefangen haben ca. 30% der Wundverschluss Markt berichtet über 5 Mrd. US $ pro Jahr betragen, ein signifikanter Beweis für die Notwendigkeit für nahtlose Technologie. 4 Im Streben nach nahtlosen Technik haben wir Chitosan als Biomaterial verwendet für die Entwicklung eines flexiblen, Dünnschicht, laseraktivierten chirurgischen Klebstoff als &#39;SurgiLux&#39;. Dieser Roman bioadhäsiven nutzt eine einzigartige Kombination von Biomaterialien und Photonik, die FDA zugelassen sind und erfolgreich eingesetzt in einer Vielzahl von biomedizinischen Anwendungen und Produkte. SurgiLux überwindet alle Nachteile, die mit Nahtmaterial und aktuelle chirurgische Klebstoffe (siehe Tabelle 1) zugeordnet ist. In dieser Präsentation berichten wir über die relativ einfaches Protokoll für die Herstellung von SurgiLux und demonstrierenihre Laseraktivierung und Gewebe Nahtfestigkeit. SurgiLux Folien haften Kollagengewebe ohne chemische Modifikation wie Vernetzung und durch Bestrahlung mit einer vergleichsweise leistungsschwachen (120 mW) Infrarotlaser anstelle von UV-Licht. Chitosan Filme haben eine natürliche, aber schwachen Kleber Anziehungskraft auf Kollagen (~ 3 KPa), betont Laseraktivierung der Chitosan basierende SurgiLux Filmen die Stärke dieser Haftung durch Polymerkette Interaktionen als Folge von transienten thermischen Ausdehnung. 5 Ohne diese &quot;Aktivierung&quot;-Prozess werden SurgiLux Folien leicht entfernt. 6-9 SurgiLux sowohl in vitro als auch in vivo wurde auf einer Vielzahl von Geweben, einschließlich Nerven, Darm, Dura mater und Hornhaut getestet. In allen Fällen zeigten gute Biokompatibilität und vernachlässigbare thermische Schädigung als Folge der Bestrahlung. 6-10

Zentrifugation führt zu einem transparenten grüne Lösung, die Viskosität steigt nach Lagerung bei 4-6 ° C. Nach einer Standzeit von 3 Tagen, die grüne Lösung in einen transparenten Film grünen SurgiLux etwa 20 Mikron dick umgewandelt wird und, wie in dem Video gezeigt, ist leicht flexibel. Bei Bestrahlung mit dem Laser, die SurgiLux Film-Bindungen an das Gewebe. Dies kann an den Rändern des Films, wo das Gewebe scheint zusammenziehen wie der Laserstrahl über die Folie (2)</...

Watch this Scientific Journal Video about A Chitosan Based, Laser Activated Thin Film Surgical Adhesive, 'SurgiLux': Preparation and Demonstration at JoVE.com

A Chitosan Based, Laser Activated Thin Film Surgical Adhesive, &#039;SurgiLux&#039;: Preparation and Demonstration

Die Herstellung einer erfindungsgemäßen, flexiblen Dünnfilm chirurgischen Klebstoff aus FDA zugelassenen Inhaltsstoffen, Chitosan und Indocyaningrün beschrieben. Bonden dieser Klebstoff auf Kollagengewebe durch eine einfache Aktivierung mit einer Low-Power-Infrarotlaser nachgewiesen wird.

A Chitosan Based, Laser Activated Thin Film Surgical Adhesive &quot;SurgiLux &#39;: Vorbereitung und Demonstration

Sutures are a 4,000 year old technology that remain the 'gold-standard' for wound closure by virtue of their repair strength (~100 KPa). However, sutures ...

a-chitosan-based-laser-activated-thin-film-surgical-adhesive-surgilux

Research

JoVE Journal

Bioengineering

A Chitosan Based, Laser Activated Thin Film Surgical Adhesive, 'SurgiLux': Preparation and Demonstration

13.1K Aufrufe.  University of New South Wales. Die Herstellung einer erfindungsgemäßen, flexiblen Dünnfilm chirurgischen Klebstoff aus FDA zugelassenen Inhaltsstoffen, Chitosan und Indocyaningrün beschrieben. Bonden dieser Klebstoff auf Kollagengewebe durch eine einfache Aktivierung mit einer Low-Power-Infrarotlaser nachgewiesen wird.

Serie: A Chitosan Based, Laser Activated Thin Film Surgical Adhesive, 'SurgiLux': Preparation and Demonstration

Constructing a Collagen Hydrogel for the Delivery of Stem Cell-loaded Chitosan Microspheres

Multipotent stem cells have been shown to be extremely useful in the field of regenerative medicine1-3. However, in order to use these cells effectively for tissue regeneration, a number of variables must be taken into account. These variables include: the total volume and surface area of the implantation site, the mechanical properties of the tissue and the tissue microenvironment, which includes the amount of vascularization and the components of the extracellular matrix. Therefore, the materials being used to deliver these cells must be biocompatible with a defined chemical composition while maintaining a mechanical strength that mimics the host tissue. These materials must also be permeable to oxygen and nutrients to provide a favorable microenvironment for cells to attach and proliferate. Chitosan, a cationic polysaccharide with excellent biocompatibility, can be easily chemically modified and has a high affinity to bind with in vivo macromolecules4-5. Chitosan mimics the glycosaminoglycan portion of the extracellular matrix, enabling it to function as a substrate for cell adhesion, migration and proliferation. In this study we utilize chitosan in the form of microspheres to deliver adipose-derived stem cells (ASC) into a collagen based three-dimensional scaffold6. An ideal cell-to-microsphere ratio was determined with respect to incubation time and cell density to achieve maximum number of cells that could be loaded. Once ASC are seeded onto the chitosan microspheres (CSM), they are embedded in a collagen scaffold and can be maintained in culture for extended periods. In summary, this study provides a method to precisely deliver stem cells within a three dimensional biomaterial scaffold.

A major hurdle in current stem cell therapies is determining the most effective method to deliver these cells to host tissues. Here, we describe a chitosan-based delivery method that is efficient and simple in approach, while allowing adipose-derived stem cells to maintain their multipotency.

Der Bau einer Kollagen-Hydrogel für die Lieferung von Stem Cell-beladenen Chitosan-Mikrokügelchen

Multipotent stem cells have been shown to be extremely useful in the field of regenerative medicine1-3. However, in order to use these cells effectively ...

Forschung

Biotechnik

Fabrication and Application of Rose Bengal-chitosan Films in Laser Tissue Repair

Photochemical tissue bonding (PTB) is a sutureless technique for tissue repair, which is achieved by applying a solution of rose bengal (RB) between two tissue edges1,2. These are then irradiated by a laser that is selectively absorbed by the RB. The resulting photochemical reactions supposedly crosslink the collagen fibers in the tissue with minimal heat production3. In this report, RB has been incorporated in thin chitosan films to fabricate a novel tissue adhesive that is laser-activated. Adhesive films, based on chitosan and containing ~0.1 wt% RB, are fabricated and bonded to calf intestine and rat tibial nerves by a solid state laser (&lambda;=532 nm, Fluence~110 J/cm2, spot size~0.5 cm). A single-column tensiometer, interfaced with a personal computer, is used to test the bonding strength. The RB-chitosan adhesive bonds firmly to the intestine with a strength of 15 &plusmn; 6 kPa, (n=30). The adhesion strength drops to 2 &plusmn; 2 kPa (n=30) when the laser is not applied to the adhesive. The anastomosis of tibial nerves can be also completed without the use of sutures. A novel chitosan adhesive has been fabricated that bonds photochemically to tissue and does not require sutures.

Sutures are usually needed to repair tissue during surgical procedures. However, their application can be problematic as they are invasive and may damage tissue. The fabrication and application methods of a novel tissue adhesive are here reported. This adhesive film is laser-activated and does not require the use of sutures.

Herstellung und Anwendung von Rose Bengal-Chitosan-Films in Laser Tissue Repair

Photochemical tissue bonding (PTB) is a sutureless technique for tissue repair, which is achieved by applying a solution of rose bengal (RB) between two ...

Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as growth factors. Here, we outline a method to create opposing gradients of adhesive and soluble cues in a microfluidic chamber, which is compatible with live cell imaging. A copolymer of poly-L-lysine and polyethylene glycol (PLL-PEG) is employed to passivate glass coverslips and prevent non-specific adsorption of biomolecules and cells. Next, microcontact printing or dip pen lithography are used to create tracks of streptavidin on the passivated surfaces to serve as anchoring points for the biotinylated peptide arginine-glycine-aspartic acid (RGD) as the adhesive cue. A microfluidic device is placed onto the modified surface and used to create the gradient of adhesive cues (100% RGD to 0% RGD) on the streptavidin tracks. Finally, the same microfluidic device is used to create a gradient of a chemoattractant such as fetal bovine serum (FBS), as the soluble cue in the opposite direction of the gradient of adhesive cues.

A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.

Erstellen Adhesive und löslichen Farbverläufe for Imaging Cell Migration mit Fluoreszenz-Mikroskopie

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as ...

Insertion of Flexible Neural Probes Using Rigid Stiffeners Attached with Biodissolvable Adhesive

Microelectrode arrays for neural interface devices that are made of biocompatible thin-film polymer are expected to have extended functional lifetime because the flexible material may minimize adverse tissue response caused by micromotion. However, their flexibility prevents them from being accurately inserted into neural tissue. This article demonstrates a method to temporarily attach a flexible microelectrode probe to a rigid stiffener using biodissolvable polyethylene glycol (PEG) to facilitate precise, surgical insertion of the probe. A unique stiffener design allows for uniform distribution of the PEG adhesive along the length of the probe. Flip-chip bonding, a common tool used in microelectronics packaging, enables accurate and repeatable alignment and attachment of the probe to the stiffener. The probe and stiffener are surgically implanted together, then the PEG is allowed to dissolve so that the stiffener can be extracted leaving the probe in place. Finally, an in vitro test method is used to evaluate stiffener extraction in an agarose gel model of brain tissue. This approach to implantation has proven particularly advantageous for longer flexible probes (&gt;3 mm). It also provides a feasible method to implant dual-sided flexible probes. To date, the technique has been used to obtain various in vivo recording data from the rat cortex.

Insertion of flexible neural microelectrode probes is enabled by attaching probes to rigid stiffeners with polyethylene glycol (PEG). A unique assembly process ensures uniform and repeatable attachment. After insertion into tissue, the PEG dissolves and the stiffener is extracted. An in vitro test method evaluates the technique in agarose gel.

Einfügen von Flexible Neural Sonden mit starren Versteifungen Biodissolvable mit Klebstoff befestigt

Microelectrode  arrays for neural interface devices that are made of biocompatible thin-film  polymer are expected to have extended functional lifetime ...

Development of Amelogenin-chitosan Hydrogel for In Vitro Enamel Regrowth with a Dense Interface

Biomimetic enamel reconstruction is a significant topic in material science and dentistry as a novel approach for the treatment of dental caries or erosion. Amelogenin has been proven to be a critical protein for controlling the organized growth of apatite crystals. In this paper, we present a detailed protocol for superficial enamel reconstruction by using a novel amelogenin-chitosan hydrogel. Compared to other conventional treatments, such as topical fluoride and mouthwash, this method not only has the potential to prevent the development of dental caries but also promotes significant and durable enamel restoration. The organized enamel-like microstructure regulated by amelogenin assemblies can significantly improve the mechanical properties of etched enamel, while the dense enamel-restoration interface formed by an in situ regrowth of apatite crystals can improve the effectiveness and durability of restorations. Furthermore, chitosan hydrogel is easy to use and can suppress bacterial infection, which is the major risk factor for the occurrence of dental caries. Therefore, this biocompatible and biodegradable amelogenin-chitosan hydrogel shows promise as a biomaterial for the prevention, restoration, and treatment of defective enamel.

Development of Amelogenin-chitosan Hydrogel for In Vitro Enamel Regrowth with a Dense Interface

In this article, we describe a protocol for fabricating an amelogenin-chitosan hydrogel for superficial enamel reconstruction. Organized in situ growth of apatite crystals in the hydrogel formed a dense enamel-restoration interface, which will improve the effectiveness and durability of restorations.

Entwicklung von Amelogenin-Chitosan-Hydrogel für<em&gt; In-vitro-</em&gt; Emaille Nachwachsen mit einem dichten Schnittstelle

Biomimetic enamel reconstruction is a significant topic in material science and dentistry as a novel approach for the treatment of dental caries or ...

Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e.,&#160;gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.

AN MRI-compatible&#160;custom-designed laser-based heating apparatus has been developed to provide local heating of subcutaneous tumors in order to activate release of agents from thermosensitive liposomes specifically at the tumor region.

Kundenspezifische Laser-basierte Heizvorrichtung zum ausgelöste Freisetzung von Cisplatin von wärmeempfindlichen Liposomen mit Magnet-Resonanz-Bild Anleitung

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect ...

Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film

An artificial lipid bilayer, or black lipid membrane (BLM), is a powerful tool for studying ion channels and protein interactions, as well as for biosensor applications. However, conventional BLM formation techniques have several drawbacks and they often require specific expertise and laborious processes. In particular, conventional BLMs suffer from low formation success rates and inconsistent membrane formation time. Here, we demonstrate a storable and transportable BLM formation system with controlled thinning-out time and enhanced BLM formation rate by replacing conventionally used films (polytetrafluoroethylene, polyoxymethylene, polystyrene) to polydimethylsiloxane (PDMS). In this experiment, a porous-structured polymer such as PDMS thin film is used. In addition, as opposed to conventionally used solvents with low viscosity, the use of squalene permitted a controlled thinning-out time via slow solvent absorption by PDMS, prolonging membrane lifetime. In addition, by using a mixture of squalene and hexadecane, the freezing point of the lipid solution was increased (~16 &#176;C), in addition, membrane precursors were produced that can be indefinitely stored and readily transported. These membrane precursors have reduced BLM formation time of &#60; 1 hr and achieved a BLM formation rate of ~80%. Moreover, ion channel experiments with gramicidin A demonstrated the feasibility of the membrane system.

We demonstrate a storable, transportable lipid bilayer formation system. A lipid bilayer membrane can be formed within 1 hr with over 80% success rate when a frozen membrane precursor is brought to ambient temperature. This system will reduce laborious processes and expertise associated with ion channels.

Automatisierte Lipid Bilayer Membrane Formation eines Polydimethylsiloxans Dünnschicht unter Verwendung

An artificial lipid bilayer, or black lipid membrane (BLM), is a powerful tool for studying ion channels and protein interactions, as well as for ...

Image-guided, Laser-based Fabrication of Vascular-derived Microfluidic Networks

This detailed protocol outlines the implementation of image-guided, laser-based hydrogel degradation for the fabrication of vascular-derived microfluidic networks embedded in PEGDA hydrogels. Here, we describe the creation of virtual masks that allow for image-guided laser control; the photopolymerization of a micromolded PEGDA hydrogel, suitable for microfluidic network fabrication and pressure head-driven flow; the setup and use of a commercially available laser scanning confocal microscope paired with a femtosecond pulsed Ti:S laser to induce hydrogel degradation; and the imaging of fabricated microfluidic networks using fluorescent species and confocal microscopy. Much of the protocol is focused on the proper setup and implementation of the microscope software and microscope macro, as these are crucial steps in using a commercial microscope for microfluidic fabrication purposes that contain a number of intricacies. The image-guided component of this technique allows for the implementation of 3D image stacks or user-generated 3D models, thereby allowing for creative microfluidic design and for the fabrication of complex microfluidic systems of virtually any configuration. With an expected impact in tissue engineering, the methods outlined in this protocol could aid in the fabrication of advanced biomimetic microtissue constructs for organ- and human-on-a-chip devices. By mimicking the complex architecture, tortuosity, size, and density of in vivo vasculature, essential biological transport processes can be replicated in these constructs, leading to more accurate in vitro modeling of drug pharmacokinetics and disease.

This protocol outlines the implementation of image-guided, laser-based hydrogel degradation to fabricate vascular-derived, biomimetic microfluidic networks embedded in poly(ethylene glycol) diacrylate (PEGDA) hydrogels. These biomimetic microfluidic systems may be useful for tissue engineering applications, generation of in vitro disease models, and fabrication of advanced "on-a-chip" devices.

Bildgestützte, laserbasierte Herstellung von Mikrofluidik-Networks-Vascular abgeleitet

This detailed protocol outlines the implementation of image-guided, laser-based hydrogel degradation for the fabrication of vascular-derived microfluidic ...

Dry Film Photoresist-based Electrochemical Microfluidic Biosensor Platform: Device Fabrication, On-chip Assay Preparation, and System Operation

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An easy-to-use and low-cost sensor platform is highly desired to measure various types of analytes (e.g., biomarkers, hormones, and drugs) quantitatively and specifically. For this reason, dry film photoresist technology - enabling cheap, facile, and high-throughput fabrication - was used to manufacture the microfluidic biosensor presented here. Depending on the bioassay used afterwards, the versatile platform is capable of detecting various types of biomolecules. For the fabrication of the device, platinum electrodes are structured on a flexible polyimide (PI) foil in the only clean-room process step. The PI foil serves as a substrate for the electrodes, which are insulated with an epoxy-based photoresist. The microfluidic channel is subsequently generated by the development and lamination of dry film photoresist (DFR) foils onto the PI wafer. By using a hydrophobic stopping barrier in the channel, the channel is separated into two specific areas: an immobilization section for the enzyme-linked assay and an electrochemical measurement cell for the amperometric signal readout.
The on-chip bioassay immobilization is performed by the adsorption of the biomolecules to the channel surface. The glucose oxidase enzyme is used as a transducer for electrochemical signal generation. In the presence of the substrate, glucose, hydrogen peroxide is produced, which is detected at the platinum working electrode. The stop-flow technique is applied to obtain signal amplification along with rapid detection. Different biomolecules can quantitatively be measured by means of the introduced microfluidic system, giving an indication of different types of diseases, or, in regard to therapeutic drug monitoring, facilitating a personalized therapy.

A microfluidic biosensor platform was designed and fabricated using low-cost dry film photoresist technology for the rapid and sensitive quantification of various analytes. This single-use system allows for the electrochemical readout of on-chip-immobilized enzyme-linked assays by means of the stop-flow technique.

Trockenen Film Photoresist-basierte elektrochemische mikrofluidischen Biosensor Plattform: Gerät Fertigung, On-Chip-Test Vorbereitung und Systembetrieb

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An ...

Rat Model of Adhesive Capsulitis of the Shoulder

This proposal aims to create an in vivo rat model of adhesive capsulitis for researching potential treatment options for this condition and other etiologies of comparable arthrofibrosis. The model includes extra-articular fixation of the shoulder in rats via scapular to humeral suturing, resulting in a secondary contracture without invading the intra-articular space and resulting in decreased rotational ROM and increased joint stiffness.
We used 10 Sprague-Dawley rats for the purpose of this study. Baseline ROM measurements were taken before glenohumeral immobilization. The rats were subjected to 8 weeks of immobilization before the fixation sutures were removed and changes in ROM and joint stiffness were evaluated. To evaluate whether immobilization resulted in a significant reduction in ROM, changes in kinematics were calculated. ROM was measured at each time point in the follow-up period and was compared to the baseline internal and external ROM measurements. In order to evaluate the stiffness, joint kinetics were calculated by determining the differences in torque (text and tint ) needed to reach the initial external rotation of 60&#176; and initial internal rotation of 80&#176;.
After the removal of the extra-articular suture fixation on follow-up day 0, we found a 63% decrease in total ROM compared to baseline. We observed continuous improvement until week 5 of follow-up, with the progress slowing down around a 19% restriction. On week 8 of follow-up, there was still an 18% restriction of ROM. Additionally, on follow-up day 0, we found the torque increased by 13.3 Nmm when compared to baseline. On week 8, the total torque was measured to be 1.4 &#177; 0.2 Nmm higher than initial measurements. This work introduces a rat model of shoulder adhesive capsulitis with lasting reduced ROM and increased stiffness.

This protocol presents an in vivo rat model of adhesive capsulitis. The model includes an internal fixation of the glenohumeral joint with extra-articular suture fixation for an extended time, resulting in a decreased rotational range of motion (ROM) and increased joint stiffness.