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BACKGROUND Research efforts are been directed in the last few years on tissue- engineering and the possibility of tissue creation by laboratory device. In fact biochemistry, immunology and experimental surgery has been provided new solutions for organs transplant or anatomical structure replacement. Variously method were described to obtain decelullarized matrix from organ or part of them, and how that bioengineered scaffolds can be integrated into recipient organism. The aim of the studies is to provide a source, from animal or cadaver, of engineered organs or tissue flaps available from transplant or reconstructive surgery, free from infective disease, completely functional and without rejection phenomenon. AIM OF THE STUDY The aim of this study is to investigate the bio integration potential of a tissue engineered abdominal wall obtained from a donor, even after a protocol of decellularization than after recellularization with stem cell of recipient, obtained from adipose tissue, in vitro and microsurgical transfer in vivo, in order to create a biocompatible free flap without rejection phenomenon (omo-autologous flap). Similarly a sample of decellularized muscle are transferred to a recipient and histological and sonographic result were evaluated. MATERIAL AND METHODS Samples of the abdominal wall were collected with iliac arterial and vein pedicle as a free flap from rabbits, before sacrifice (donor). At the same time a sample of adipose tissue was collected from a different rabbit (recipient). The abdominal wall samples underwent a 7 days decellularization protocol. Small samples of the tissues were collected before and after that procedure for histological evaluation of the process. The adipose tissue sample of the recipient were treated to obtain a full rich stem cells tissue. Similar sample of muscle without vessel are collected and underwent a decellularization protocol and so on for major vessel sample with a specific one for vascular tissue. A decellularized muscle patch are implanted in vivo and rejection phenomenon, survival of the patch and herniation presence were observed after three weeks even by sonography than by histological evaluation after sacrifice. RESULTS The histological evaluations shown a progressive degeneration and loss of cellular content of the rabbit abdominal wall samples. In parallel, the general ECM structure maintain their staining properties. Particularly relevant is the preservation of vascular channels. Muscle decellularized sample implanted in vivo demonstrated good biointegration at sonography exam and no herniation was observed; histologic evaluation demonstrated presence of limitated granulomatosis reaction , numerously vessels and conservation of original muscle architecture, substituted by fibrosis,without evident rejection. Histological and moreover evaluation of free flap transplant, stem cells seeding and vessel decellularization are in process. CONCLUSION Decellularized muscle patch provide the evidence of a new bioingeneered tissue that could be useful for abdominal wall repair or reconstruction. Biointegration could be improve by use of stem cells and growth factor seeding. Similarly the demonstration of the preservation of the vascular network and extra cellular matrix of abdominal wall sample provide the possibilities of being bio integrated after vascular anastomoses that is the aim of the studies actually on going

Le tecniche ACI cosiddette “di II generazione” sono state sviluppate con l’obiettivo di superare i limiti della tecnica ACI tradizionale grazie all’impiego di tessuti bioingegnerizzati di vario genere sotto forma di scaffold solido (Fig. 1), in grado di fornire un supporto biocompatibile e biodegradabile capace di mantenere il fenotipo differenziato dei condrociti e permetterne una maggior adesione al sito di impianto. Inoltre alcuni di questi supporti permettono la possibilità di utilizzare tecniche artroscopiche, diminuendo tempi e morbidità della procedura chirurgica; rimangono però limitate le conoscenze sulla stabilità a lungo termine di alcuni di questi impianti.

I difetti della cartilagine articolare sono difficilki da trattare a causa delle paculiari caratteristiche strutturali a funzionali della cartilagine ialina e del suo basso potensiale rigenerativo.