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, &#039;SurgiLux&#039;: 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 ...

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Research

JoVE Journal

Bioengineering

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

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 ...

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.

Creazione di sfumature adesivi e solubile per la migrazione di imaging cellulare con microscopia a fluorescenza

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.

Inserimento di Flexible Neural Sonde Uso Rinforzi rigida collegata con Biodissolvable adesivo

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.

Sviluppo di amelogenina-chitosano Hydrogel per<em&gt; In Vitro</em&gt; Smalto ricrescita con una interfaccia Dense

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.

Appositamente studiata apparecchi di riscaldamento a base laser per la Release Innescata di Cisplatino da termosensibile liposomi con Risonanza Magnetica Guidance Immagine

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.

Formazione automatizzato doppio strato lipidico della membrana Utilizzando un Polidimetilsilossano 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 ...

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.

Immagine-guidate, Fabrication laser a base di reti microfluidici vascolare-derivati

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.

Film secco basati su Photoresist biosensore elettrochimico Microfluidic Platform: Fabbricazione di dispositivi, saggio su chip preparazione e funzionamento del sistema

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.