Diseñado vascularizado colgajo de músculo
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
Defectos de la pared abdominal a menudo surgen después de un trauma severo, el tratamiento del cáncer, quemaduras y la eliminación de la malla infectada. Estos defectos implican a menudo la pérdida de tejido significativa, requiriendo procedimientos quirúrgicos complicados y presentar un gran reto para los cirujanos de reconstrucción de plástico 1-4. Investigadores de ingeniería de tejidos que buscan nuevas fuentes de tejidos artificiales han explorado diferentes materiales, fuentes de células y factores de crecimiento. Se informó anteriormente restauraciones exitosas de diversos tejidos, tales como 5,6 tráquea, vejiga 7, 8 córnea, hueso 9 y la piel 10, mediante la implantación de tejidos de ingeniería. Sin embargo, la fabricación de un tejido vascularizado ingeniería de espesor, en particular para la reconstrucción de defectos grandes, sigue siendo un desafío significativo en la ingeniería de tejidos.
Uno de los principales factores que limitan el espesor de una construcción de tejido viable es el control de suministro de oxígeno a sus contrascélulas tituent. Cuando se depende de la difusión, la construcción de espesor se limita a la de una capa muy delgada. La distancia máxima entre oxígeno y nutrientes capilares de suministro in vivo es de aproximadamente 200 micras, que se correlaciona con el límite de difusión de oxígeno 11,12. Vascularización insuficiente puede resultar en isquemia tisular y escalar a la resorción de tejido o necrosis 13.
Además, el material ideal utilizado para la reconstrucción de tejidos debe ser biocompatible y no inmunogénico. También debe ser capaz de promover una mayor integración de las células huésped con el biomaterial, y el mantenimiento de la integridad estructural. Varios biológicos 14-16 y sintéticos 1,17,18 matrices se han explorado previamente para la reconstrucción de tejidos, sin embargo su uso quedará limitado debido a la falta de suministro de sangre eficaz, las infecciones o la fuerza del tejido insuficiente.
En este estudio, un biocompatible, célula-embandamio edded compuesto de Food and Drug Administration (FDA) de ácido L-láctico con aprobación para poli (PLLA) / poli ácido láctico-co-glicólico (PLGA), se implantó alrededor de los vasos de la arteria femoral y la vena (AV) de un ratón desnudo y separado del tejido circundante, lo que garantiza la vascularización de sólo los vasos AV. Una semana después de la implantación, el injerto era viable, grueso y bien vascularizado. Este tejido vascularizado grueso con los vasos de AV, fue trasladado como un colgajo pediculado a un defecto de espesor total abdominal en el mismo ratón. Una semana después de la transferencia, la aleta era viable, vascularizado y bien integrado con el tejido circundante, teniendo resistencia suficiente para soportar las vísceras abdominales. Por lo tanto, el espesor, colgajo de tejido vascularizado ingeniería, teniendo un pedículo autólogo, se presenta un método novedoso para la reparación de defectos de la pared abdominal de espesor completo.
Protocol
Representative Results
Discussion
Los avances en la ingeniería de tejidos se han encontrado con una creciente demanda de tejidos sustitutos para la reconstrucción de los diversos tipos de tejidos. Una variedad de materiales sintéticos y biológicos 1,17,18 14-16, así como métodos de fabricación han sido evaluados por su capacidad para hacer frente a estas demandas. Sin embargo, a pesar de los avances en la atención clínica y en la ingeniería de tejidos, la restauración de defectos de la pared abdominal de espesor completo…
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 |
References
- Engelsman, A. F., van der Mei, H. C., Ploeg, R. J., Busscher, H. J. The phenomenon of infection with abdominal wall reconstruction. Biomaterials. 28 (14), 2314-2327 (2007).
- De Coppi, P., et al. Myoblast-acellular skeletal muscle matrix constructs guarantee a long-term repair of experimental full-thickness abdominal wall defects. Tissue Eng. 12 (7), 1929-1936 (2006).
- Shi, C., et al. Regeneration of full-thickness abdominal wall defects in rats using collagen scaffolds loaded with collagen-binding basic fibroblast growth factor. Biomaterials. 32 (3), 753-759 (2011).
- Yezhelyev, M. V., Deigni, O., Losken, A. Management of full-thickness abdominal wall defects following tumor resection. Ann Plast Surg. 69 (2), 186-191 (2012).
- Macchiarini, P., Walles, T., Biancosino, C., Mertsching, H. First human transplantation of a bioengineered airway tissue. J Thorac Cardiovasc Surg. 128 (4), 638-641 (2004).
- Macchiarini, P., et al. Clinical transplantation of a tissue-engineered airway. Lancet. 372 (9665), 2023-2030 (2008).
- Atala, A., Bauer, S. B., Soker, S., Yoo, J. J., Retik, A. B. Tissue-engineered autologous bladders for patients needing cystoplasty. Lancet. 367 (9518), 1241-1246 (2006).
- Nishida, K., et al. Corneal reconstruction with tissue-engineered cell sheets composed of autologous oral mucosal epithelium. N Engl J Med. 351 (12), 1187-1196 (2004).
- Petite, H., et al. Tissue-engineered bone regeneration. Nat Biotechnol. 18 (9), 959-963 (2000).
- Banta, M. N., Kirsner, R. S. Modulating diseased skin with tissue engineering: actinic purpura treated with Apligraf. Dermatol Surg. 28 (12), 1103-1106 (2002).
- Vunjak-Novakovic, G., et al. Challenges in cardiac tissue engineering. Tissue engineering. Part B, Reviews. 16 (2), 169-187 (2010).
- Novosel, E. C., Kleinhans, C., Kluger, P. J. Vascularization is the key challenge in tissue engineering. Advanced Drug Delivery Reviews. 63 (4-5), 300-311 (2011).
- Lesman, A., Gepstein, L., Levenberg, S. Vascularization shaping the heart. Ann N Y Acad Sci. 1188, 46-51 (2010).
- Patton Jr, H., Berry, S., Kralovich, K. A. Use of human acellular dermal matrix in complex and contaminated abdominal wall reconstructions. The Am J of Surg. 193 (3), 360-363 (2007).
- Menon, N. G., et al. Revascularization of human acellular dermis in full-thickness abdominal wall reconstruction in the rabbit model. Ann Plast Surg. 50 (5), 523-527 (2003).
- Buinewicz, B., Rosen, B. Acellular cadaveric dermis (AlloDerm): a new alternative for abdominal hernia repair. Ann Plast Surg. 52 (2), 188-194 (2004).
- Bringman, S., et al. Hernia repair: the search for ideal meshes. Hernia. 14 (1), 81-87 (2010).
- Meintjes, J., Yan, S., Zhou, L., Zheng, S., Zheng, M. Synthetic biological and composite scaffolds for abdominal wall reconstruction. Exp rev of med dev. 8 (2), 275-288 (2011).
- Cheng, G., et al. Engineered blood vessel networks connect to host vasculature via wrapping-and-tapping anastomosis. Blood. 118 (17), 4740-4749 (2011).
- Shandalov, Y., et al. An engineered muscle flap for reconstruction of large soft tissue defects. PNAS of the USA. 111 (16), 6010-6015 (2014).
- Zhang, T. Y., Suen, C. Y. A fast parallel algorithm for thinning digital patterns. Commun. ACM. 27 (3), 236-239 (1984).
- Luna, L. G., Luna, L. G. . Manual of Histo Stain Meth ; of the Arm Forcs Inst of Path. , (1968).
- Choi, J. H., et al. Adipose tissue engineering for soft tissue regeneration. Tissue engineering. Part B, Reviews. 16 (4), 413-426 (2010).
- Bellows, C. F., Alder, A., Helton, W. S. Abdominal wall reconstruction using biological tissue grafts: present status and future opportunities. Exp rev of med dev. 3 (5), 657-675 (2006).
- Caspi, O., et al. Tissue engineering of vascularized cardiac muscle from human embryonic stem cells. Circ Res. 100 (2), 263-272 (2007).
- Kaufman-Francis, K., Koffler, J., Weinberg, N., Dor, Y., Levenberg, S. Engineered vascular beds provide key signals to pancreatic hormone-producing cells. PloS one. 7 (7), e40741 (2012).
- Kaully, T., Kaufman-Francis, K., Lesman, A., Levenberg, S. Vascularization–the conduit to viable engineered tissues. Tiss eng. Part B, Reviews. 15 (2), 159-169 (2009).
- Koffler, J., et al. Improved vascular organization enhances functional integration of engineered skeletal muscle grafts. PNAS of the USA. 108 (36), 14789-14794 (2011).
- Lesman, A., et al. Transplantation of a tissue-engineered human vascularized cardiac muscle. Tisseng. Part A. 16 (1), 115-125 (2010).
- Levenberg, S., et al. Engineering vascularized skeletal muscle tissue. Nat Biotechnol. 23 (7), 879-884 (2005).
- Bearzi, C., et al. PlGF-MMP9-engineered iPS cells supported on a PEG-fibrinogen hydrogel scaffold possess an enhanced capacity to repair damaged myocardium. Cell death & disease. 5, e1053 (2014).
- Zhang, M., et al. SDF-1 expression by mesenchymal stem cells results in trophic support of cardiac myocytes after myocardial infarction. FASEB J : official publication of the .Fed Am Soc Exp Biol. 21 (12), 3197-3207 (2007).
- Dvir, T., et al. Prevascularization of cardiac patch on the omentum improves its therapeutic outcome. PNAS. 106 (35), 14990-14995 (2009).
- Marsano, A., et al. The effect of controlled expression of VEGF by transduced myoblasts in a cardiac patch on vascularization in a mouse model of myocardial infarction. Biomaterials. 34 (2), 393-401 (2013).
- Rufaihah, A. J., et al. Enhanced infarct stabilization and neovascularization mediated by VEGF-loaded PEGylated fibrinogen hydrogel in a rodent myocardial infarction model. Biomaterials. 34 (33), 8195-8202 (2013).
- Nillesen, S. T. M., et al. Increased angiogenesis in acellular scaffolds by combined release of FGF2 and VEGF. J of Contr Release. 116 (2), e88-e90 (2006).
- Sekine, H., et al. In vitro fabrication of functional three-dimensional tissues with perfusable blood vessels. Nat Commun. 4, 1399 (2013).
- Tee, R., et al. Transplantation of engineered cardiac muscle flaps in syngeneic rats. Tiss eng. Part A. (19-20), 1992-1999 (2012).
- Morritt, A. N., et al. Cardiac tissue engineering in an in vivo vascularized chamber. Circulation. 115 (3), 353-360 (2007).
