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A Arkudas

Publications and source records attributed to A Arkudas.

3 recordsLinked to original sources
PubMed2006

[Prevascularisation strategies in tissue engineering].

INTRODUCTION: Experiments on animals have underlined the importance of vascularisation for biointegration and functionality of any given tissue engineering device. The aim of this investigation was to dissect the angiogenetic process in the frame of axial neovascularisation of a xenogenic solid matrix. The ultimate goal of this series of studies is the application of cells onto a prevascularised matrix, with the ambition to enhance cell survival after transplantation in vivo. MATERIALS AND METHODS: We performed a study in the rat with different vascular configurations in an isolation chamber. A disc-formed biogenic hard matrix (9 x 5 mm) was encased into an isolation chamber made of Teflon. In group 1, an arteriovenous fistula (AV loop) between the femoral vessels was microsurgically constructed and was placed around the matrix (n = 15). In group 2, the vascular carrier had the form of an arteriovenous ligated pedicle (n = 15). Evaluation intervals were two, four and eight weeks after implantation. The modes of evaluation included histology, scanning electron microscopy of corrosion casts as well as intravital micro-magnetic resonance imaging (MRI). RESULTS: The arteriovenous loop as vascular carrier revealed a higher capacity for angiogenesis over the bundle configuration. The neo-fibrovascular tissue displayed minimal inflammatory elements but dense vascularisation. Scanning electron microscopy demonstrated a vivid angiogenesis with rapid evolution of the vascular bead into mature, hierarchically organised network. Micro-MRI could be used for serial investigation in terms of flow measurements and detection of thrombosis. DISCUSSION: The presence of a vascular bed prior to cell transplantation might protect against hypoxia-induced cellular death, especially at central portions of the matrix, and therefore ensure physiological function of the device. The generation of vascularised bioartificial tissue substitutes might offer new modalities of surgical reconstruction for use in reparative medicine.

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PubMedDate not supplied

A new approach to tissue engineering of vascularized skeletal muscle.

Tissue Engineering of skeletal muscle tissue still remains a major challenge. Every neo-tissue construct of clinically relevant dimensions is highly dependent on an intrinsic vascularisation overcoming the limitations of diffusion conditioned survival. Approaches incorporating the arteriovenous-loop model might bring further advances to the generation of vascularised skeletal muscle tissue. In this study 12 syngeneic rats received transplantaion of carboxy-fluorescine diacetate-succinimidyl ester (CFDA)-labelled, expanded primary myoblasts into a previously vascularised fibrin matrix, containing a microsurgically created AV loop. As control cells were injected into fibrin-matrices without AV-loops. Intra-arterial ink injection followed by explantation was performed 2, 4 and 8 weeks after cell implantation. Specimens were evaluated for CFDA, MyoD and DAPI staining, as well as for mRNA expression of muscle specific genes. Results showed enhanced fibrin resorption in dependence of AV loop presence. Transplanted myoblasts could be detected in the AV loop group even after 8 weeks by CFDA-fluorescence, still showing positive MyoD staining. RT-PCR revealed gene expression of MEF-2 and desmin after 4 weeks on the AVloop side, whereas expression analysis of myogenin and MHC(embryo) was negative. So far myoblast injection in the microsurgical rat AV loop model enhances survival of the cells, keeping their myogenic phenotype, within pre-vascularised fibrin matrices. Probably due to the lack of potent myogenic stimuli and additionally the rapid resorption of the fibrin matrix, no formation of skeletal muscle-like tissue could be observed. Thus further studies focussing on long term stability of the matrix and the incorporation of neural stimuli will be necessary for generation of vascularised skeletal muscle tissue.

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