Progettato Vascolarizzato muscolare Flap
Summary
To date, thick tissue defects are typically reconstructed by applying autologous tissue flaps or engineered tissues. In this protocol, we present a new method for engineering vascularized tissue flap bearing an autologous pedicle, to serve as a substitute to autologous flaps.
Abstract
One of the main factors limiting the thickness of a tissue construct and its consequential viability and applicability in vivo, is the control of oxygen supply to the cell microenvironment, as passive diffusion is limited to a very thin layer. Although various materials have been described to restore the integrity of full-thickness defects of the abdominal wall, no material has yet proved to be optimal, due to low graft vascularization, tissue rejection, infection, or inadequate mechanical properties. This protocol describes a means of engineering a fully vascularized flap, with a thickness relevant for muscle tissue reconstruction. Cell-embedded poly L-lactic acid/poly lactic-co-glycolic acid constructs are implanted around the mouse femoral artery and vein and maintained in vivo for a period of one or two weeks. The vascularized graft is then transferred as a flap towards a full thickness defect made in the abdomen. This technique replaces the need for autologous tissue sacrifications and may enable the use of in vitro engineered vascularized flaps in many surgical applications.
Introduction
Difetti della parete addominale spesso sorgono a seguito di traumi gravi, il trattamento del cancro, le ustioni e la rimozione della rete infetti. Questi difetti spesso comportano una significativa perdita di tessuto, che richiedono procedure chirurgiche complesse e la presentazione di una grande sfida per i chirurghi plastici di ricostruzione 1-4. Ricercatori di ingegneria dei tessuti alla ricerca di nuove fonti per i tessuti artificiali hanno esplorato diversi materiali, fonti di cellule e fattori di crescita. Restauri positivo di vari tessuti, come trachea 5,6, vescica 7, cornea 8, 9 e osso pelle 10, per impiantazione di tessuti ingegnerizzati sono stati segnalati in precedenza. Tuttavia, la fabbricazione di uno spesso ingegneria tessutale vascolarizzato, in particolare per la ricostruzione di grandi difetti, rimane una sfida significativa in ingegneria dei tessuti.
Uno dei principali fattori limitanti lo spessore di un costrutto tessuto vitale è il controllo dell'alimentazione di ossigeno ad suoi svantaggicellule tituent. Quando basandosi sulla diffusione, costruire spessore è limitato a quello di uno strato molto sottile. La distanza massima tra ossigeno e nutrienti capillari fornitura in vivo è di circa 200 micron, che è correlato con il limite diffusione dell'ossigeno 11,12. Vascolarizzazione insufficiente può provocare ischemia tissutale e aumentare al riassorbimento del tessuto o necrosi 13.
Inoltre, il materiale ideale utilizzato per la ricostruzione del tessuto deve essere biocompatibile e non immunogenica. Deve anche essere in grado di promuovere una maggiore integrazione di cellule ospiti con il biomateriale, e mantenendo l'integrità strutturale. Vari biologici 14-16 e sintetiche 1,17,18 matrici sono stati precedentemente esplorati per la ricostruzione dei tessuti, ma il loro uso rimane limitato a causa della mancanza di afflusso di sangue efficace, infezioni o la forza del tessuto insufficiente.
In questo studio, un biocompatibile, cell-embimpalcatura edded composto da Food and Drug Administration (FDA) l'acido L-lattico poli -approvato (PLLA) / poli acido lattico-co-glicolico (PLGA), è stato impiantato intorno all'arteria femorale e vena (AV) le navi di un topo nudo e separato dal tessuto circostante, assicurando vascolarizzazione solo dai vasi AV. Una settimana dopo l'impianto, l'innesto è stato vitale, denso e ben vascolarizzato. Questo tessuto vascolarizzato spessore con vasi AV, è stato poi trasferito come lembo peduncolato un difetto a tutto spessore addominale nel mouse stesso. Una settimana dopo il trasferimento, il lembo era praticabile, vascolarizzato e ben integrato con il tessuto circostante, tenendo forza sufficiente a sostenere visceri addominali. Così, la spessa, lembo di tessuto vascolarizzato ingegneria, recanti un peduncolo autologo, presenta un nuovo metodo per la riparazione di difetti della parete addominale a tutto spessore.
Protocol
Representative Results
Discussion
I progressi in ingegneria dei tessuti sono stati raggiunti con una crescente domanda per i tessuti sostitutivi per la ricostruzione dei vari tipi di tessuto. Una varietà di sintesi 1,17,18 e biologici 14-16 materiali, nonché i metodi di fabbricazione sono stati valutati per la loro capacità di far fronte a queste esigenze. Tuttavia, nonostante i progressi nella cura clinica e in ingegneria dei tessuti, il restauro di difetti della parete addominale a tutto spessore rimane una sfida. Un tessuto a…
Divulgations
The authors have nothing to disclose.
Acknowledgements
This research was supported by the FP7 European Research Council Grant 281501, ENGVASC.
Materials
| small fine straight scissors | Fine Science Tools (FST) | 14090-09 | |
| spring scissors | Fine Science Tools (FST) | 15003-08 | |
| straight forceps with fine tip | Fine Science Tools (FST) | 11251-20 | |
| serrated forceps | Fine Science Tools (FST) | 11050-10 | |
| needle holder | Fine Science Tools (FST) | 12500-12 | |
| Small vessel cauterizer | Fine Science Tools (FST) | 18000-00 | |
| Duratears | Alcon | 5686 | |
| Sedaxylan | Euravet | DJ03 | |
| Clorketam 1000 | Vetoquinol | 4A0726B | |
| Buprenorphine | vetmarket | B15100 | |
| 4-0 silk sutures | Assut sutures | 647 | |
| 6-0 polypropylene sutures | Assut sutures | 9351F | |
| 8-0 silk sutures | Assut sutures | 684568 | |
| Insulin syringe (6mm needle) | BD | 324911 | |
| Vevo 2100 high-resolution ultrasound system | VisualSonics inc. | ||
| MS250 non-linear transducer | VisualSonics inc. | ||
| Micromarker non-targeted contrast agent | VisualSonics inc. | VS-11694 | |
| tail vein catheter | VisualSonics inc. | VS-11912 | |
| Vevo 2100 software | VisualSonics inc. | ||
| fluorescein isothiocyanate-conjugated dextran | Sigma | FD500S | |
| Matlab | Mathworks, MA, USA | ||
| Kimwipes | Kimtech | 34120 | |
| antigen unmasking solution | Vector laboratories | H-3300 | |
| anti-CD31 antibody | Abcam | ab28364 | |
| biotinylated goat anti-rabbit (secondary) antibody | Vector laboratories | BA-1000 | |
| streptavidin-peroxidase | Jackson | 016-030-084 | |
| Mayer's hamatoxylin solution | Sigma-Aldrich | MHS-16 | |
| aminoethylcarbazole (AEC) substrate kit | Life technologies, Invitrogen | 00-2007 | |
| Vectamount | Vector laboratories | H-5501 |
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