Ricostruzione della parete addominale con scaffold decellularizzati studio sperimentale

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 goin

Prognostic value of CXCL12 expression in 40 low-grade oligodendrogliomas and oligoastrocytomas.

Both clinical and biological features have been reported as prognostic factors in low-grade gliomas. Among these, histotype, tumor size, enhancement, age and genetic pattern. Microvessel density (MVD) has been correlated to clinical outcome in astrocytomas, but its impact in oligodendrogliomas and mixed tumors is not sure. The pro-angiogenic chemokine stromal cell-derived factor (SDF-1/CXCL12) and its receptor CXC chemokine receptor 4 (CXCR4) have been described in low-grade gliomas, with a correlation between CXCL12 expression and shorter time to progression (TTP). The intermediate filament Nestin is expressed in proliferating vessels. Platelet-derived growth factor B (PDGF-B) and its receptor PDGFR-beta are also involved in angiogenesis and malignant progression in gliomas

Arterially Perfused Neurosphere-Derived Cells Distribute Outside the Ischemic Core in a Model of Transient Focal Ischemia and Reperfusion In Vitro

BACKGROUND: Treatment with neural stem cells represents a potential strategy to improve functional recovery of post-ischemic cerebral injury. The potential benefit of such treatment in acute phases of human ischemic stroke depends on the therapeutic viability of a systemic vascular delivery route. In spite of the large number of reports on the beneficial effects of intracerebral stem cells injection in experimental stroke, very few studies demonstrated the effectiveness of the systemic intravenous delivery approach. METODOLOGY/PRINCIPAL FINDINGS: We utilized a novel in vitro model of transient focal ischemia to analyze the brain distribution of neurosphere-derived cells (NCs) in the early 3 hours that follow transient occlusion of the medial cerebral artery (MCA). NCs obtained from newborn C57/BL6 mice are immature cells with self-renewal properties that could differentiate into neurons, astrocytes and oligodendrocytes. MCA occlusion for 30 minutes in the in vitro isolated guinea pig brain preparation was followed by arterial perfusion with 1x10(6) NCs charged with a green fluorescent dye, either immediately or 60 minutes after reperfusion onset. Changes in extracellular pH and K(+) concentration during and after MCAO were measured through ion-sensitive electrodes. CONCLUSION/SIGNIFICANCE: It is demonstrated that NCs injected through the vascular system do not accumulate in the ischemic core and preferentially distribute in non-ischemic areas, identified by combined electrophysiological and morphological techniques. Direct measurements of extracellular brain ions during and after MCA occlusion suggest that anoxia-induced tissue changes, such as extracellular acidosis, may prevent NCs from entering the ischemic area in our in vitro model of transitory focal ischemia and reperfusion suggesting a role played by the surrounding microenviroment in driving NCs outside the ischemic core. These findings strongly suggest that the potential beneficial effect of NCs in experimental focal brain ischemia is not strictly dependent on their homing into the ischemic region, but rather through a bystander mechanism possibly mediated by the release of neuroprotective factors in the peri-infarct region

SARS-CoV-2 vaccination modelling for safe surgery to save lives : data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population.Peer reviewe

Extracellular vesicles are independent metabolic units with asparaginase activity.

Extracellular vesicles (EVs) are membrane particles involved in the exchange of a broad range of bioactive molecules between cells and the microenvironment. Although it has been shown that cells can traffic metabolic enzymes via EVs, much remains to be elucidated with regard to their intrinsic metabolic activity. Accordingly, herein we assessed the ability of neural stem/progenitor cell (NSC)-derived EVs to consume and produce metabolites. Our metabolomics and functional analyses both revealed that EVs harbor L-asparaginase activity, catalyzed by the enzyme asparaginase-like protein 1 (Asrgl1). Critically, we show that Asrgl1 activity is selective for asparagine and is devoid of glutaminase activity. We found that mouse and human NSC EVs traffic Asrgl1. Our results demonstrate, for the first time, that NSC EVs function as independent metabolic units that are able to modify the concentrations of critical nutrients, with the potential to affect the physiology of their microenvironment.This work has received support from the Italian Multiple Sclerosis Association (AISM, grant 2010/R/31 and grant 2014/PMS/4 to SP), the Italian Ministry of Health (GR08-7 to SP), the European Research Council (ERC) under the ERC-2010-StG Grant agreement n° 260511-SEM_SEM, the Medical Research Council, the Engineering and Physical Sciences Research Council, and the Biotechnology and Biological Sciences Research Council UK Regenerative Medicine Platform Hub “Acellular Approaches for Therapeutic Delivery” (MR/K026682/1 to SP), The Evelyn Trust (RG 69865 to SP), The Bascule Charitable Trust (RG 75149 to SP) and core support grant from the Wellcome Trust and Medical Research Council to the Wellcome Trust – MRC Cambridge Stem Cell Institute. N.I. was supported by a FEBS long-term fellowship. C.F., A.S.H., and E.G. were funded by the Medical Research Council, Core Fund SKAG006

Ricostruzione della parete addominale con scaffold decellularizzati studio sperimentale

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 goingPRESUPPOSTI DELLO STUDIO La ricerca per ottenere un tessuto o un intero organo bioingegnerizzato è attualmente la più intensa e foriera di speranze nel campo della trapiantologia e della traumatologia, che devono fronteggiare la scarsa disponibilità di organi e tessuti omologhi, le problematiche legate al rigetto e l’inevitabile comorbidità qualora si ricorra al prelievo di tessuti autologhi. La bioingegneria dei tessuti è quella branca nata dalla fusione di diverse esperienze in campo biomolecolare, immunologico, anatomico e di chirurgia sperimentale volto ad ottenere la possibilità di utilizzare nell’uomo organi e tessuti ottenuti in laboratorio a partenza da materiale biologico. Ad oggi una delle maggiori limitazioni al raggiungimento di tale scopo è rappresentata dalla difficoltà di ottenere un costrutto con un’adeguata architettura vascolare al suo interno, tale da permetterne la sopravvivenza una volta impiantato in vivo. Per superare tale limitazione si è cercato di ottenere in laboratorio delle strutture che fungessero da impalcature, i cosiddetti “ scaffold”, in grado di favorire la crescita cellulare ordinata , ottenendo un tessuto bioingegnerizzato. Le prime osservazioni vennero fatte mediante l’impiego di costrutti costituiti da materiali di sintesi ma successivamente i risultati più incoraggianti si sono verificati grazie all’impiego di scaffold biologici ottenuti attraverso il procedimento noto come “decelullarizzazione” . Tale procedura, con aspetti tecnici diversificati per tipologia di tessuto, permette di eliminare le cellule, fonte di incompatibilità nei trapianti, mantenendo la citoarchiettura nativa ove è possibile promuovere e guidare un processo di neoangiogenesi e susseguente rivascolarizzazione una volta impiantati in vivo. Alternativamente si è studiata la possibilità di sviluppare scaffold con una rete vascolare preformata al loro interno, ma nessun tentativo è stato fatto di provvedere una rivascolarizzazione diretta nell’impianto in vivo. SCOPO DELLO STUDIO Questo studio pone le sue basi nella ricostruzione della parete addominale ottenuta mediante trapianto da cadavere nei casi di trapianto multiviscerale. Si è cercato di valutare la realizzabilità nel modello animale di ottenere un similare lembo microchirurgico miofasciale che potesse essere decellularizzato e trasferito su di un ricevente sia in questa forma che dopo averlo colonizzato con cellule staminali derivate dal tessuto adiposo del ricevente medesimo per aumentare l’immunocompatibilità ( lembo omo-autologo). Inoltre è stata studiata la ricostruzione della parete addominale mediante impianto di un patch muscolare decellularizzato. MATERIALI E METODI Sono stati prelevati mediante ingradimento al microscopio operatorio lembi del muscolo retto dell’addome dalla parete addominale di coniglio assieme al loro asse vascolare artero-venoso sino alle iliache e ,dopo il sacrificio dell’animale, sono stati sottoposti ad un protocollo di decellularizzazione della durata di 7 giorni, sviluppato adattandone uno per il tessuto muscolare pubblicato in letteratura. Identici campioni privi di asse vascolare sono stati prelevati e sottoposti alla medesima procedura mentre campioni di assi vascolari sono stati separatamente sottoposti a trattamento mediante protocollo per decelullarizzazione dei vasi. Sia prima che durante le fasi del processo sono stati eseguiti prelievi dei campioni tissutali ed eseguite multiple colorazioni istologiche al fine di verificare l’efficacia del procedimento. Sono stati altresì eseguiti prelievo di tessuto adiposo ed omento al fine di verificarne la cellularità e la possibilità di estrazione di cellule staminali derivate dal tessuto adiposo (ADSC). Un patch di tessuto muscolare decellularizzato è stato impiantato a riparo di una perdita di sostanza muscolare addominale a tutto spessore in un animale ricevente che, a distanza di 3 settiman,e è stato sottoposto a controllo ecografico e a prelievo dell’impianto , che veniva sottoposto ad analisi istologica a tre colorazioni. RISULTATI Il tessuto muscolare dopo decellularizzazione dimostra una mancanza di nuclei e di fibre muscolari mantenendo integra la matrice extracellulare e la struttura dei canali vascolari, di cui rimangono apprezzabili i diversi strati delle pareti, compresi gli strati di fibre elastiche. L’analisi della decellularizzazione dei vasi maggiori è tuttora in corso. L’impianto muscolare eseguito ha dimostrato all’ecografia stabilità, assenza di fenomeni di rigetto e ricostituzione della contenzione dei visceri addominali con assenza di erniazione. L’esame istologico presenta un ricco pattern vascolare con presenza non diffusa da parte di cellule infiammatorie ( reazione granulomatosa) mantenendo l’architettura originale delle fibre muscolari occupate per la maggior parte da processo fibrotico. CONCLUSIONI La decellularizzazione del tessuto muscolare ed il suo impianto in vivo hanno permesso di identificare una struttura biologica in grado di offrire una valida alternativa ai materiali attualmente impiegati per la riparazione delle erniazioni addominali. Ulteriori valutazioni andranno fatte sulla possibilità di aumentarne le chance di biointegrazione mediante inserimento di cellule staminali del ricevente e fattori di crescita . Parimenti i processi di decellularizzazione del lembo e del suo asse vascolare, con e senza impianto staminale, sono tutt’ora in corso per poterne verificare la fattibilità ed i risultati di un trasferimento microchirurgic

Hand reconstruction using the thin anterolateral thigh flap

Perforator flaps have been introduced for various kinds of reconstruction and resurfacing; in particular, the free thin anterolateral thigh flap is becoming one of the most preferred options for reconstruction of soft-tissue defects

Abdominal Wall Transplantation and Technique

Many patients undergoing intestinal or multivisceral transplantation have a past history of complete midgut removal with the loss of the domain of the abdominal compartment or have severely damaged abdominal walls from repeated laparotomies or enterocutaneous fistulae. These patients may encounter severe abdominal wall closure problems at the end of transplantation, resulting in increased morbidity and mortality. It is, therefore, of paramount importance to properly cover transplanted organs in order to reduce postoperative complications. Abdominal wall transplantation was proposed for closure of patients undergoing both small bowel and multivisceral transplantation. We present our experience in abdominal wall transplantation in which, by taking advantage of microsurgical experience, we were able to re-vascularize the composite tissue allograft anastomosing the deep inferior epigastric vessels of the graft to those of the recipient. This technique allows to preserve donor\u2019s vascular pedicle that can be used as grafts for vascular procedures

Reverse Pedicled and Disepithelized Forearm Flap for Hand Reconstruction

none8DOI volume: 10.1159/000224773. Abstract n° 170noneC. Gelati; R. Sgarzani; E. Fabbri; F. Contedini; V. Pinto; P. Nejad; L. Negosanti; R. CiprianiC. Gelati; R. Sgarzani; E. Fabbri; F. Contedini; V. Pinto; P. Nejad; L. Negosanti; R. Ciprian