Gli autori riconoscono un finanziamento della National Health and Medical Research Council of Australia (NHMRC # 1000674) per LJR Foster.

1. Preparazione della Soluzione SURGILUX <ol><li> Preparare un 2% (v / v) di acido acetico con acqua deionizzata in un bicchiere di vetro pulito, utilizzare una cappa a flusso laminare per evitare la contaminazione. </li><li> Pesare 0,02% (w / v) del cromoforo, verde indocianina, ICG, in una provetta Eppendorf sterile; garantire il tubo viene avvolto in carta stagnola per evitare la penetrazione della luce. </li><li> Utilizzando un pulito, pipetta monouso, trasferire circa 1 ml della soluzione di acido acetico diluito al tubo di sciogliere il colorante, agitare delicatamente e tenere avvolto in carta. </li><li> Trasferire l&#39;ICG solubilizzato nel becher e aggiungere 2% (w / v) di polvere chitosano prima di aggiungere un agitatore magnetico sterile. </li><li> Coprire il becher con Parafilm poi avvolgere in lamina d&#39;argento, prima di mescolare il contenuto a circa 125 giri al minuto per 72 ore a temperatura ambiente in una cappa a flusso laminare. </li><li> Trasferire il contenuto in provette da centrifuga pulite e centrifugare a 15.000 xg per 15 min a 4 ° C per rimuovere qualsiasi particulate la materia. </li><li> Trasferire accuratamente la soluzione verde SURGILUX in un bicchiere di vetro pulito, coprire con Parafilm poi avvolgere in carta stagnola, prima di riporre in frigorifero per 12 ore per aumentare la viscosità della soluzione. </li></ol> 2. Fusione di SURGILUX Films <ol><li> Utilizzando una siringa sterile, dispensare 8 ml della soluzione SURGILUX freddo in un ambiente pulito, piastra di Petri di 95 mm di diametro, e inclinate leggermente la piastra per garantire la copertura completa della soluzione. Variando il rapporto di volume di soluzione di area di colaggio permette di controllare lo spessore del film, vedi Figura 1. </li><li> Rimuovere eventuali bolle visibili nella soluzione con la punta di un ago sterile. Coprire il piatto in foglia argento e posto in frigorifero per rimuovere eventuali residui di micron di dimensioni bolle. </li><li> Dopo 20 min rimuovere attentamente la piastra Petri dal frigorifero, posto in una cappa a flusso laminare, coprire con carta argentata e lasciare evaporare la soluzione per 3 settimane. </li><li> Dopo aver coevaporazione mplete, punteggio i bordi esterni della pellicola trasparente SURGILUX verde nella capsula Petri e delicatamente &#39;buccia&#39; del film dalla superficie della parabola. </li><li> Il film SURGILUX dovrebbe essere flessibile e facilmente manipolata senza strappi o rotture. </li><li> Conservare i film SURGILUX circolari in una capsula di Petri avvolto in lamina d&#39;argento asciutta fino al momento dell&#39;uso. </li></ol> 3. L&#39;attivazione del laser SURGILUX pellicole adesive <ol><li> Per dimostrare il processo di attivazione laser useremo un pezzo di tessuto bovino come bistecca tagliata a una dimensione di 15 mm di larghezza e 20 mm di lunghezza. Sezionare il tessuto in una linea retta con una lama chirurgica Number 10, per produrre due pezzi di 15 per 10 mm. </li><li> Approssimativo i due pezzi di tessuto in modo che i loro bordi si toccano ma non si sovrappongono, e l&#39;utilizzo di un tampone di cotone o garza, delicatamente assorbire il liquido in eccesso. </li><li> Quindi, tagliare un pezzo di pellicola SURGILUX 7 x 9 mm e depositarla lunghezza del cinema in tutto il bisecato pIECE di tessuto, quindi premere delicatamente con un tampone di cotone asciutto. </li><li> Film SURGILUX viene attivato utilizzando raggi infrarossi laser a diodi ad una regolazione di 120 mW. Poiché si tratta di un laser di classe III B, appropriate misure di sicurezza dovrebbero essere prese, compreso l&#39;uso di occhiali di sicurezza adeguate per tutto il personale. </li><li> Avvio in un angolo, irradiare la SURGILUX con un laser infrarosso fissato a 120 mW e una dimensione del punto del fascio di 1 mm di diametro. Passare il punto del fascio sulla pellicola verde ad una velocità di circa 1 mm al secondo. Ripetere il processo di irraggiamento altre due volte. </li></ol> 4. Forza della riparazione <ol><li> Attentamente fissare le estremità del tessuto nei morsetti di un apparecchio di controllo di trazione. Stiamo usando un Instron Mini55 sistema con una cella di carico di 50 Newton. Il carico massimo, resistenza alla trazione e allungamento a rottura sono stati calcolati utilizzando Bluehill software (USA). Mezzi di almeno 10 campioni sono stati determinati (n = 10). </li><li> Prendete il &#39;gioco&#39;e poi separare i pezzi di tessuto ad una velocità di 1 mm al secondo, fino a quando i due pezzi di tessuto tenuti insieme dal nastro SURGILUX separata completamente. </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>

Nessun conflitto di interessi dichiarati.

Chitosano può essere ottenuto in una varietà di pesi molecolari e con diversi gradi di deactylation (DDA). Variazioni purezza chitosano può portare alla presenza di particelle nella soluzione SURGILUX; centrifugazione viene utilizzato per eliminare questi e dovrebbe risultare in una soluzione trasparente verde. Tuttavia, filtrazione può anche essere usato come un passo fabbricazione aggiunta o alternativa. Come per ogni lavorazione dei materiali, le variazioni, come ad esempio chitosano DDA e peso molecolare, hanno ...

<table border="1"><tbody><tr><td> Nome del reagente / attrezzature </td><td> Azienda </td><td> Numero di catalogo </td><td> Commenti (opzionale) </td></tr><tr><td> Chitosano </td><td> Sigma-Aldrich </td><td> 448877 </td><td></td></tr><tr><td> Verde indocianina </td><td> Sigma-Aldrich </td><td> I2633 </td><td> Conosciuto anche come Cardiogreen </td></tr><tr><td> Acido acetico </td><td> Sigma-Aldrich </td><td> 320099 </td><td></td></tr><tr><td> Infrarossi laser a diodi con la consegna in fibra. (808 nm, 120 mW, nucleo Larghezza 200 pm) </td><td> CNI Laser </td><td> Fc-808 </td><td> Sistema variabile fino a 5 W di potenza </td></tr><tr><td> Laser occhiali di sicurezza </td><td> CNI Laser </td><td> LS-G </td><td></td></tr><tr><td> Apparecchi di trazione </td><td> Instron Pty Ltd </td><td> 5542 </td><td> 50 N celle di carico </td></tr></tbody></table>

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

Le suture sono una tecnologia vecchia 4000 anni che rimangono il &#39;gold standard&#39; per la chiusura della ferita in virtù della loro forza riparazione (~ 100 kPa). Tuttavia, suture può agire come un nidus di infezione e in molte procedure sono in grado di effettuare la riparazione della ferita o interferire con la rigenerazione del tessuto funzionale. 1 colle chirurgiche e adesivi, come quelli a base di fibrina e cianoacrilati, sono stati sviluppati come alternative per suture la riparazione di tali ferite. Tuttavia, gli attuali adesivi commerciali anche svantaggi significativi, che vanno dal trasferimento virale e prioni e una mancanza di forza riparazione come con le colle di fibrina, a tossicità per i tessuti e la mancanza di biocompatibilità per gli adesivi a base di cianoacrilati. Inoltre, adesivi chirurgiche attualmente disponibili tendono ad essere a base di gel e può essere esteso tempi di polimerizzazione che limitano la loro applicazione. 2 Analogamente, l&#39;uso dei laser UV per facilitare meccanismi di reticolazione a base di proteine ​​o albumina &#39;solDers &#39;può portare a danni al DNA, mentre il tessuto di saldatura laser (LTW) predispone danno termico ai tessuti. 3 Nonostante i loro svantaggi, adesivi e LTW hanno catturato circa il 30% del mercato chiusura della ferita risulta essere superiore a 5 miliardi di dollari all&#39;anno, una testimonianza significativa alla necessità di una tecnologia sutureless. 4 Nella ricerca della tecnologia sutureless abbiamo utilizzato chitosano come biomateriale per lo sviluppo di un flessibile, film sottile, laser adesivo attivato chirurgica denominata &#39;SURGILUX&#39;. Questo bioadesivo romanzo utilizza una combinazione unica di biomateriali e fotonica che sono approvati dalla FDA e utilizzato in una varietà di applicazioni biomediche e prodotti. SURGILUX supera tutti gli svantaggi associati a suture chirurgiche e adesivi attuali (cfr. tabella 1). In questa presentazione riportiamo il protocollo relativamente semplice per la fabbricazione di SURGILUX e dimostraresua attivazione laser e saldatura resistenza del tessuto. Film SURGILUX aderire al tessuto collagenoso senza modificazione chimica come reticolazione per irradiazione e con una relativamente bassa potenza (120 mW) laser infrarosso invece di luce UV. Film chitosano hanno un&#39;attrazione naturale ma debole adesivo collagene (~ 3 KPa), l&#39;attivazione del laser basato chitosano SURGILUX film sottolinea la forza di questa adesione tramite interazioni di catena polimerica come conseguenza della dilatazione termica transitoria. 5 Senza questo processo di &#39;attivazione&#39; , film SURGILUX sono facilmente rimovibili. 6-9 SURGILUX è stata testata sia in vitro che in vivo su una varietà di tessuti compresi nervo, intestino, dura madre e cornea. In tutti i casi è dimostrato buona biocompatibilità e trascurabile danno termico come conseguenza di irradiazione. 6-10

Centrifugazione conduce ad una soluzione trasparente verde, che aumenta la viscosità dopo conservazione a 4-6 ° C. Dopo riposo per 3 settimane, la soluzione verde è convertito in una pellicola trasparente SURGILUX verde di circa 20 micron e, come dimostrato nel video, è facilmente flessibile. Su irraggiamento con il laser, i legami SURGILUX pellicola al tessuto. Ciò può essere osservato i bordi del film in cui il tessuto sembra contrarsi come il fascio laser passa sopra il film <strong...

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, 'SurgiLux': Preparation and Demonstration

La fabbricazione di un romanzo, flessibile adesivo a film sottile chirurgico con ingredienti approvati dalla FDA, chitosano e verde indocianina è descritto. Incollaggio di questo adesivo al tessuto collagene attraverso un processo di attivazione semplice con una bassa potenza laser infrarosso è dimostrata.

Un Based Chitosano, Laser attivato sottile pellicola adesiva chirurgici, &#39;SURGILUX&#39;: Preparazione e dimostrazione

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

13.1K Views.  University of New South Wales. La fabbricazione di un romanzo, flessibile adesivo a film sottile chirurgico con ingredienti approvati dalla FDA, chitosano e verde indocianina è descritto. Incollaggio di questo adesivo al tessuto collagene attraverso un processo di attivazione semplice con una bassa potenza laser infrarosso è dimostrata.

Video: 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.

Costruire un idrogel collagene per la fornitura di Stem Cell-loaded Chitosan Microsfere

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 ...

Ricerca

Bioingegneria

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.

Fabbricazione e applicazione di Rosa Bengala-chitosano Films in riparazione dei tessuti Laser

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

Bridging the Bio-Electronic Interface with Biofabrication

Advancements in lab-on-a-chip technology promise to revolutionize both research and medicine through lower costs, better sensitivity, portability, and higher throughput. The incorporation of biological components onto biological microelectromechanical systems (bioMEMS) has shown great potential for achieving these goals. Microfabricated electronic chips allow for micrometer-scale features as well as an electrical connection for sensing and actuation. Functional biological components give the system the capacity for specific detection of analytes, enzymatic functions, and whole-cell capabilities. Standard microfabrication processes and bio-analytical techniques have been successfully utilized for decades in the computer and biological industries, respectively. Their combination and interfacing in a lab-on-a-chip environment, however, brings forth new challenges. There is a call for techniques that can build an interface between the electrode and biological component that is mild and is easy to fabricate and pattern.
Biofabrication, described here, is one such approach that has shown great promise for its easy-to-assemble incorporation of biological components with versatility in the on-chip functions that are enabled. Biofabrication uses biological materials and biological mechanisms (self-assembly, enzymatic assembly) for bottom-up hierarchical assembly. While our labs have demonstrated these concepts in many formats 1,2,3, here we demonstrate the assembly process based on electrodeposition followed by multiple applications of signal-based interactions. The assembly process consists of the electrodeposition of biocompatible stimuli-responsive polymer films on electrodes and their subsequent functionalization with biological components such as DNA, enzymes, or live cells 4,5. Electrodeposition takes advantage of the pH gradient created at the surface of a biased electrode from the electrolysis of water 6,7,. Chitosan and alginate are stimuli-responsive biological polymers that can be triggered to self-assemble into hydrogel films in response to imposed electrical signals 8. The thickness of these hydrogels is determined by the extent to which the pH gradient extends from the electrode. This can be modified using varying current densities and deposition times 6,7. This protocol will describe how chitosan films are deposited and functionalized by covalently attaching biological components to the abundant primary amine groups present on the film through either enzymatic or electrochemical methods 9,10. Alginate films and their entrapment of live cells will also be addressed 11. Finally, the utility of biofabrication is demonstrated through examples of signal-based interaction, including chemical-to-electrical, cell-to-cell, and also enzyme-to-cell signal transmission. 
Both the electrodeposition and functionalization can be performed under near-physiological conditions without the need for reagents and thus spare labile biological components from harsh conditions. Additionally, both chitosan and alginate have long been used for biologically-relevant purposes 12,13. Overall, biofabrication, a rapid technique that can be simply performed on a benchtop, can be used for creating micron scale patterns of functional biological components on electrodes and can be used for a variety of lab-on-a-chip applications.

This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.

Colmare il Bio-Electronic Interface con Biofabrication

Advancements in lab-on-a-chip technology promise to revolutionize both research and medicine through lower costs, better sensitivity, portability, and ...

Thin Film Composite Silicon Elastomers for Cell Culture and Skin Applications: Manufacturing and Characterization

In this protocol, we present methods to fabricate thin elastomer composite films for advanced cell culture applications and for the development of skin adhesives. Two different poly-(dimethyl siloxanes) (PDMS and soft skin adhesive (SSA)), have been used for in depth investigation of biological effects and adhesive characteristics. The composite films consist of a flexible backing layer and an adhesive top coating. Both layers have been manufactured by doctor blade application technique. In the present investigation, the adhesive behavior of the composite films has been investigated as a function of the layer thickness or a variation of the Young&#39;s modulus of the top layer. The Young&#39;s modulus of PDMS has been changed by varying the base to crosslinker mixing ratio. In addition, the thickness of SSA films has been varied from approx. 16 &#181;m to approx. 320 &#181;m. Scanning electron microscopy (SEM) and optical microscopy have been used for thickness measurements. The adhesive properties of elastomer films depend strongly on the film thickness, the Young&#39;s modulus of the polymers and surface characteristics. Therefore, normal adhesion of these films on glass substrates exhibiting smooth and rough surfaces has been investigated. Pull-off stress and work of separation are dependent on the mixing ratio of silicone elastomers.
Additionally, the thickness of the soft skin adhesive placed on top of a supportive backing layer has been varied in order to produce patches for skin applications. Cytotoxicity, proliferation and cellular adhesion of L929 murine fibroblasts on PDMS films (mixing ratio 10:1) and SSA films (mixing ratio 50:50) have been conducted. We have shown here, for the first time, the side by side comparison of thin composite films manufactured of both polymers and present the investigation of their biological- and adhesive properties.

A protocol for the manufacturing process of polymeric thin film composite structures possessing either different Young&#39;s moduli or thicknesses is presented. Films are produced for advanced cell culture studies or as skin adhesives.

Thin Film composito silicone elastomeri per colture cellulari e applicazioni della pelle: produzione e caratterizzazione

In this protocol, we present methods to fabricate thin elastomer composite films for advanced cell culture applications and for the development of skin ...

Biologia dello sviluppo

Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer the clinical advantages of being implanted minimally invasively and easily forming space-filling solids in irregularly shaped defects. Injectable biomaterials have been widely investigated as scaffolds for tissue engineering. However, for the repair of certain load-bearing areas in the body, such as the intervertebral disc, scaffolds should possess adhesive properties. This will minimize the risk of dislocation during motion and ensure intimate contact with the surrounding tissue, providing adequate transmission of forces. Here, we describe the preparation and characterization of a scaffold composed of thermally sensitive poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAM-g-CS) and alginate microparticles. The PNIPAAm-g-CS copolymer forms a viscous solution in water at RT, into which alginate particles are suspended to enhance adhesion. Above the lower critical solution temperature (LCST), around 30 &#176;C, the copolymer forms a solid gel around the microparticles. We have adapted standard biomaterials characterization procedures to take into account the reversible phase transition of PNIPAAm-g-CS. Results indicate that the incorporation of 50 or 75 mg/ml&#160;alginate particles into 5% (w/v) PNIPAAm-g-CS solutions quadruple the adhesive tensile strength of PNIPAAm-gCS alone (p&#60;0.05). The incorporation of alginate microparticles also significantly increases swelling capacity of PNIPAAm-g-CS (p&#60;0.05), helping to maintain a space-filling gel within tissue defects. Finally, results of the in vitro toxicology assay kit, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) and Live/Dead viability assay indicate that the adhesive is capable of supporting the survival and proliferation of encapsulated Human Embryonic Kidney (HEK) 293 cells over 5 days.

Synthesis of Thermogelling PolyN-isopropylacrylamide-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

An injectable tissue engineering scaffold composed of poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAm-g-CS)-containing alginate microparticles was prepared. The adhesive strength, swelling properties and in vitro biocompatibility are analyzed in this study. The characterization techniques developed here may be applicable to other thermogelling systems.

Sintesi di Thermogelling poli (N-isopropilacrilammide) -graft-condroitin solfato compositi con alginato microparticelle per ingegneria dei tessuti

Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer ...

TAPE: A Biodegradable Hemostatic Glue Inspired by a Ubiquitous Compound in Plants for Surgical Application

This video describes the simplest protocol for preparing biodegradable surgical glue that has an effective hemostatic ability and greater water-resistant adhesion strength than commercial tissue adhesives. Medical adhesives have attracted great attention as potential alternative tools to sutures and staples due to their convenience in usage with minimal invasiveness. Although there are several protocols for developing tissue adhesives including those commercially available such as fibrin glues and cyanoacrylate-based materials, mostly they require a series of chemical syntheses of organic molecules, or complicated protein-purification methods, in the case of bio-driven materials (i.e., fibrin glue). Also, the development of surgical glues exhibiting high adhesive properties while maintaining biodegradability is still a challenge due to difficulties in achieving good performance in the wet environment of the body. We illustrate a new method to prepare a medical glue, known as TAPE, by the weight-based separation of a water-immiscible supramolecular aggregate formed after a physical mixing of a plant-derived, wet-resistant adhesive molecule,&#160;Tannic Acid (TA), and a well-known biopolymer, Poly(Ethylene) glycol (PEG). With our approach, TAPE shows high adhesion strength, which is 2.5-fold more than commercial fibrin glue in the presence of water. Furthermore, TAPE is biodegradable in physiological conditions and can be used as a potent hemostatic glue against tissue bleeding. We expect the widespread use of TAPE in a variety of medical settings and drug delivery applications, such as polymers for muco-adhesion, drug depots, and others.

We describe the simplest protocol to prepare biodegradable medical glue that has an effective hemostatic ability. TAPE is a water-immiscible supramolecular aggregate prepared by mixing of tannic acid, a ubiquitous compound found in plants, and poly(ethylene) glycol, yielding a 2.5 times greater water-resistant adhesion compared with commercial fibrin glue.

TAPE: Biodegradabile Una Hemostatic Glue Ispirato da un composto Ubiquitous nelle piante per applicazioni chirurgiche

This video describes the simplest protocol for preparing biodegradable surgical glue that has an effective hemostatic ability and greater water-resistant ...

Simple Lithography-Free Single Cell Micropatterning using Laser-Cut Stencils

Micropatterning techniques have been widely used in cell biology to study effects of controlling cell shape and size on cell fate determination at single cell resolution. Current state-of-the-art single cell micropatterning techniques involve soft lithography and micro-contact printing, which is a powerful technology, but requires trained engineering skills and certain facility support in microfabrication. These limitations require a more accessible technique. Here, we describe a simple alternative lithography-free method: stencil-based single cell patterning. We provide step-by-step procedures including stencil design, polyacrylamide hydrogel fabrication, stencil-based protein incorporation, and cell plating and culture. This simple method can be used to pattern an array of as many as 2,000 cells. We demonstrate the patterning of cardiomyocytes derived from single human induced pluripotent stem cells (hiPSC) with distinct cell shapes, from a 1:1 square to a 7:1 adult cardiomyocyte-like rectangle. This stencil-based single cell patterning is lithography-free, technically robust, convenient, inexpensive, and most importantly accessible to those with a limited bioengineering background.

This protocol introduces a lithography-free micropatterning method that is simple and accessible to those with a limited bioengineering background. This method utilizes customized laser-cut stencils to micropattern extracellular matrix proteins in a shape of interest for modulating cell morphologies. The procedure for micropatterning is demonstrated using induced pluripotent stem cell derived cardiomyocytes.

Micropatterning a cella singola semplice senza litografia con stencil laser-cut

Micropatterning techniques have been widely used in cell biology to study effects of controlling cell shape and size on cell fate determination at single ...

3D Microtissues for Injectable Regenerative Therapy and High-throughput Drug Screening

To upgrade traditional 2D cell culture to 3D cell culture, we have integrated microfabrication with cryogelation technology to produce macroporous microscale cryogels (microcryogels), which can be loaded with a variety of cell types to form 3D microtissues. Herein, we present the protocol to fabricate versatile 3D microtissues and their applications in regenerative therapy and drug screening. Size and shape-controllable microcryogels can be fabricated on an array chip, which can be harvested off-chip as individual cell-loaded carriers for injectable regenerative therapy or be further assembled on-chip into 3D microtissue arrays for high-throughput drug screening. Due to the high elastic nature of these microscale cryogels, the 3D microtissues exhibit great injectability for minimally invasive cell therapy by protecting cells from mechanical shear force during injection. This ensures enhanced cell survival and therapeutic effect in the mouse limb ischemia model. Meanwhile, assembly of 3D microtissue arrays in a standard 384-multi-well format facilitates the use of common laboratory facilities and equipment, enabling high-throughput drug screening on this versatile 3D cell culture platform.

This protocol describes the fabrication of elastic 3D macroporous microcryogels by integrating microfabrication with cryogelation technology. Upon loading with cells, 3D microtissues are generated, which can be readily injected in vivo to facilitate regenerative therapy or assembled into arrays for in vitro high-throughput drug screening.

Microtissues 3D per la terapia rigenerativa iniettabile e droga di High-throughput Screening

To upgrade traditional 2D cell culture to 3D cell culture, we have integrated microfabrication with cryogelation technology to produce macroporous ...

An &#8220;All-laser&#8221; Endothelial Transplant

The &#8220;all laser&#8221; assisted endothelial keratoplasty is a procedure that is performed with a femtosecond laser used to cut the donor tissue at an intended depth, and a near infrared diode laser to weld the corneal tissue. The proposed technique enables to reach the three main goals in endothelial keratoplasty: a precise control in the thickness of the donor tissue; its easy insertion in the recipient bed and a reduced risk of donor lenticule dislocation. The donor cornea thickness is measured in the surgery room with optical coherence tomography (OCT), in order to correctly design the donor tissue dimensions. A femtosecond laser is used to cut the donor cornea. The recipient eye is prepared by manual stripping of the descemetic membrane. The donor endothelium is inserted into a Busin-injector, the peripheral inner side is stained with a proper chromophore (a water solution of Indocyanine Green) and then it is pulled in the anterior chamber. The transplanted tissue is placed in the final and correct location and then diode laser welding is induced from outside the eyeball. The procedure has been performed on more than 15 patients evidencing an improvement in surgery performances, with a good recovery of visual acuity and a reduced donor lenticule dislocation event.

An all laser procedure is proposed in the endothelial transplant. The surgical technique is based on the use of a femtosecond laser to prepare the donor tissue. Laser welding technique is then used to secure the donor endothelium in the correct position.

Un &quot;All-laser&quot; Endothelial Transplant

The &#8220;all laser&#8221; assisted endothelial keratoplasty is a procedure that is performed with a femtosecond laser used to cut the donor tissue at an ...

Medicina

Fabrication of Size-Controlled and Emulsion-Free Chitosan-Genipin Microgels for Tissue Engineering Applications

Chitosan microgels are of significant interest in tissue engineering due to their wide range of applications, low cost, and immunogenicity. However, chitosan microgels are commonly fabricated using emulsion methods that require organic solvent rinses, which are toxic and harmful to the environment. The present protocol presents a rapid, non-cytotoxic, non-emulsion-based method for fabricating chitosan-genipin microgels without the need for organic solvent rinses. The microgels described herein can be fabricated with precise size control. They exhibit sustained release of biomolecules, making them highly relevant for tissue engineering, biomaterials, and regenerative medicine. Chitosan is crosslinked with genipin to form a hydrogel network, then passed through a syringe filter to produce the microgels. The microgels can be filtered to create a range of sizes, and they show pH-dependent swelling and degrade over time enzymatically. These microgels have been employed in a rat growth plate injury model and were demonstrated to promote increased cartilage tissue repair and to show complete degradation at 28 days in vivo. Due to their low cost, high convenience, and ease of fabrication with cytocompatible materials, these chitosan microgels present an exciting and unique technology in tissue engineering.

The present protocol describes a non-emulsion-based method for the fabrication of chitosan-genipin microgels. The size of these microgels can be precisely controlled, and they can display pH-dependent swelling, degrade in vivo,&#160;and be loaded with therapeutic molecules that release over time in a sustained manner, making them highly relevant for tissue engineering applications.

Fabbricazione di microgel di chitosano-genipina a grandezza controllata e priva di emulsioni per applicazioni di ingegneria tissutale

Chitosan microgels are of significant interest in tissue engineering due to their wide range of applications, low cost, and immunogenicity. However, ...

Un Based Chitosano, Laser attivato sottile pellicola adesiva chirurgici, 'SURGILUX': Preparazione e dimostrazione

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