Austrian Cluster for Tissue Regeneration

Vienna, Austria

Austrian Cluster for Tissue Regeneration

Vienna, Austria
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Teuschl A.H.,University of Applied Sciences Technikum Wien | Van Griensven M.,Austrian Cluster for Tissue Regeneration | Van Griensven M.,Ludwig Boltzmann Research Institute | Redl H.,Austrian Cluster for Tissue Regeneration | Redl H.,Ludwig Boltzmann Research Institute
Tissue Engineering - Part C: Methods | Year: 2014

Silk fibroin has previously been described as a promising candidate for ligament tissue engineering (TE) approaches. For biocompatibility reasons, silkworm silk requires removal of sericin, which can elicit adverse immune responses in the human body. One disadvantage of the required degumming process is the alteration of the silk fiber structural properties, which can hinder textile engineering of high order hierarchical structures. Therefore, the aim of this study was to find a way to remove sericin from a compact and highly ordered raw silk fiber matrix. The wire rope design of the test model scaffold comprises several levels of geometric hierarchy. Commonly used degumming solutions fail in removing sericin in this wire rope design. Weight loss measurements, picric acid and carmine staining as well as scanning electron microscopy demonstrated that the removal of sericin from the model scaffold of a wire rope design can be achieved through a borate buffer-based system. Furthermore, the borate buffer degummed silks were shown to be nontoxic and did not alter cell proliferation behavior. The possibility to remove sericin after the textile engineering process has taken place eases the production of highly ordered scaffold structures and may expand the use of silk as scaffold material in further TE and regenerative medicine applications. © 2014 Mary Ann Liebert, Inc.

Gruber R.,Medical University of Vienna | Gruber R.,University of Bern | Leimer M.,Medical University of Vienna | Fischer M.B.,Medical University of Vienna | And 2 more authors.
Archives of Oral Biology | Year: 2013

Objective Catecholamines released from β-adrenergic neurons upon stress can interfere with periodontal regeneration. The cellular mechanisms, however, are unclear. Here, we assessed the effect of catecholamines on proliferation of periodontal fibroblasts. Methods Fibroblasts from the gingiva and the periodontal ligament were exposed to agonists of the β-adrenergic receptors; isoproterenol (ISO, non-selective β-adrenergic agonist), salbutamol (SAL, selective β2-adrenergic receptor agonist) and BRL 37344 (BRL selective β3-receptor agonist). Proliferation was stimulated with platelet-derived growth factor-BB (PDGF-BB). Pharmacological inhibitors and gene expression analysis further revealed β-adrenergic signalling. Results Gingiva and periodontal ligament fibroblast express the β2-adrenergic receptor. ISO and SAL but not BRL decreased proliferation of fibroblasts in the presence of PDGF-BB. The inhibitory effect of β-adrenergic signalling on proliferation but not protein synthesis in response to PDGF-BB was reduced by propranolol, a non-selective β-adrenergic antagonist. Conclusions These results suggest that β2-receptor agonists can reduce the mitogenic response of periodontal fibroblasts. These data add to the compelling concept that blocking of β2-receptor signalling can support tissue maintenance and regeneration. © 2013 Elsevier Ltd.

Teuschl A.H.,University of Applied Sciences Technikum Wien | Neutsch L.,University of Vienna | Monforte X.,University of Applied Sciences Technikum Wien | Runzler D.,University of Applied Sciences Technikum Wien | And 5 more authors.
Acta Biomaterialia | Year: 2014

Various tissue engineering (TE) approaches are based on silk fibroin (SF) as scaffold material because of its superior mechanical and biological properties compared to other materials. The translation of one-step TE approaches to clinical application has generally failed so far due to the requirement of a prolonged cell seeding step before implantation. Here, we propose that the plant lectin WGA (wheat germ agglutinin), covalently bound to SF, will mediate cell adhesion in a time frame acceptable to be part of a one-step surgical intervention. After the establishment of a modification protocol utilizing carbodiimide chemistry, we examined the attachment of cells, with a special focus on adipose-derived stromal cells (ASC), on WGA-SF compared to pure native SF. After a limited time frame of 20 min the attachment of ASCs to WGA-SF showed an increase of about 17-fold, as compared to pure native SF. The lectin-mediated cell adhesion further showed an enhanced resistance to trypsin (as a protease model) and to applied fluid shear stress (mechanical stability). Moreover, we could demonstrate that the adhesion of ASCs on the WGA-SF does not negatively influence proliferation or differentiation potential into the osteogenic lineage. To test for in vitro immune response, the proliferation of peripheral blood mononuclear cells in contact with the WGA-SF was determined, showing no alterations compared to plain SF. All these findings suggest that the WGA modification of SF offers important benefits for translation of SF scaffolds into clinical applications. © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Rohringer S.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | Hofbauer P.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | Schneider K.H.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | Husa A.-M.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | And 6 more authors.
Angiogenesis | Year: 2014

Vascularization of tissue-engineered constructs is essential to provide sufficient nutrient supply and hemostasis after implantation into target sites. Co-cultures of adipose-derived stem cells (ASC) with outgrowth endothelial cells (OEC) in fibrin gels were shown to provide an effective possibility to induce vasculogenesis in vitro. However, the mechanisms of the interaction between these two cell types remain unclear so far. The aim of this study was to evaluate differences of direct and indirect stimulation of ASC-induced vasculogenesis, the influence of ASC on network stabilization and molecular mechanisms involved in vascular structure formation. Endothelial cells (EC) were embedded in fibrin gels either containing non-coated or ASC-coated microcarrier beads as well as ASC alone. Moreover, EC-seeded constructs incubated with ASC-conditioned medium were used in addition to constructs with ASC seeded on top. Vascular network formation was visualized by green fluorescent protein expressing cells or immunostaining for CD31 and quantified. RT-qPCR of cells derived from co-cultures in fibrin was performed to evaluate changes in the expression of EC marker genes during the first week of culture. Moreover, angiogenesis-related protein levels were measured by performing angiogenesis proteome profiler arrays. The results demonstrate that proximity of endothelial cells and ASC is required for network formation and ASC stabilize EC networks by developing pericyte characteristics. We further showed that ASC induce controlled vessel growth by secreting pro-angiogenic and regulatory proteins. This study reveals angiogenic protein profiles involved in EC/ASC interactions in fibrin matrices and confirms the usability of OEC/ASC co-cultures for autologous vascular tissue engineering. © 2014 Springer Science+Business Media Dordrecht.

Witzeneder K.,Red Cross | Lindenmair A.,Austrian Cluster for Tissue Regeneration | Lindenmair A.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | Gabriel C.,Red Cross | And 5 more authors.
Transfusion Medicine and Hemotherapy | Year: 2013

Objective: The need for an alternative to fetal bovine serum (FBS) is known to scientists and users involved in cell therapy or advanced therapy medicinal products. Human serum (huS) and platelet lysate (hPL) can be used as alternatives resulting in similar or even superior results concerning cell expansion. Methods: We developed protocols for the production of huS and two types of hPL and tested them in the expansion of human fibroblasts and adipose tissue-derived stem cells (ASC). Quality control included cell counts (platelets, red and white blood cells), sterility testing, pH levels, total protein concentrations and growth factor levels. ASC and fibroblasts were expanded for three passages in media supplemented with FBS, huS or hPL and evaluated microscopically. Proliferation in terms of population doubling times (PDT) was determined. In case of ASC, differentiation was performed as well. Results: All three alternatives demonstrated shorter PDT for fibroblasts and ASC compared to FBS. Furthermore, ASC maintained their differentiation potential. Conclusion: We conclude that hPL and huS can be used as alternatives to FBS for the cultivation and expansion of cells intended for human use. © 2014 S. Karger GmbH, Freiburg.

PubMed | Ludwig Boltzmann Institute for Experimental and Clinical Traumatology and Austrian Cluster for Tissue Regeneration
Type: Journal Article | Journal: Advanced healthcare materials | Year: 2015

Abdominal wall hernia is a recurrent issue world-wide and requires the implantation of over 1 million meshes per year. Because permanent meshes such as polypropylene and polyester are not free of complications after implantation, many mesh modifications and new functionalities have been investigated over the last decade. Indeed, mesh optimization is the focus of intense development and the biomaterials utilized are now envisioned as being bioactive substrates that trigger various physiological processes in order to prevent complications and to promote tissue integration. In this context, it is of paramount interest to review the most relevant bio-functionalities being brought to new meshes and to open new avenues for the innovative development of the next generation of meshes with enhanced properties for functional abdominal wall hernia repair.

PubMed | University of Applied Sciences Technikum Wien, Austrian Cluster for Tissue Regeneration and Tufts University
Type: Journal Article | Journal: Journal of biomedical materials research. Part A | Year: 2016

The control of bleeding is one of the most important interventions after a traumatic injury. Hemostatic devices delivering blood clotting accelerating agents such as fibrinogen are increasingly used due to their efficacy and their ease of application. In the present study, we describe a method to incorporate the coagulant supplements fibrinogen and thrombin in silk protein sponges by mixing the coagulants with an aqueous silk solution, followed by molding, freeze-drying, and water annealing. In this combination system, we demonstrate the delivery of fibrinogen while maintaining its hemostatic potential. Concentration ratios of silk to fibrinogen of 1.0%/2.8%, 2.3%/1.5%, and 3.0%/0.8% were used. The thrombin-induced fibrin polymeric network filled the space in and next to the silk spongy structure but also remained interconnected to the silk, providing an intact network. The mechanical characterization of the fibrinogen-releasing silk sponges before and after the induction of the fibrinogen polymerization demonstrated that the fibrin network resulted in reduced permanent deformation from 21.1% to 6.5%, 19.6% to 5.7%, and 12.7% to 9.4% for the 2.8%, 1.5%, and 0.8% fibrinogen-containing silk sponges, respectively. Moreover, the fibrin formation lead to a more linear elastic behavior over longer strain ranges. In combination, the Calcein-AM/PI staining and MTT assay results indicate uniform cell adhesion on the surface and cytocompatibility of the silk/fibrin sponges, respectively. Moreover, the co-delivery of thrombin with fibrinogen via silk as carrier material is described, offering a more mechanically robust and durable system while preserving hemostatic features of the coagulant substances for the generation of hemostatic devices. 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 687-696, 2017.

PubMed | Ludwig Boltzmann Research Institute and Austrian Cluster for Tissue Regeneration
Type: Journal Article | Journal: Journal of materials science. Materials in medicine | Year: 2016

Schwann cells play a key role in peripheral nerve regeneration. Failure in sufficient formation of Bngner bands due to impaired Schwann cell proliferation has significant effects on the functional outcome after regeneration. Therefore, the growth substrate for Schwann cells should be considered with highest priority in any peripheral nerve tissue engineering approach. Due to its excellent biocompatibility silk fibroin has most recently attracted considerable interest as a biomaterial for use as conduit material in peripheral nerve regeneration. In this study we established a protocol to covalently bind collagen and laminin, which have been isolated from human placenta, to silk fibroin utilizing carbodiimide chemistry. Altered adhesion, viability and proliferation of Schwann cells were evaluated. A cell adhesion assay revealed that the functionalization with both, laminin or collagen, significantly improved Schwann cell adhesion to silk fibroin. Moreover laminin drastically accelerated adhesion. Schwann cell proliferation and viability assessed with BrdU and MTT assay, respectively, were significantly increased in the laminin-functionalized groups. The results suggest beneficial effects of laminin on both, cell adhesion as well as proliferative behaviour of Schwann cells. To conclude, the covalent tailoring of silk fibroin drastically enhances its properties as a cell substratum for Schwann cells, which might help to overcome current hurdles bridging long distance gaps in peripheral nerve injuries with the use of silk-based nerve guidance conduits.

PubMed | Austrian Cluster for Tissue Regeneration and Medical University of Vienna
Type: Journal Article | Journal: Clinical oral implants research | Year: 2016

Sinus augmentation is a standard procedure to increase vertical bone supply for dental implants in the atrophic posterior maxilla. Despite the longstanding application of this method, information about some basic factors that could potentially influence bone regeneration after sinus augmentation is rare. The objective of this study was therefore to quantify the impact of the maxillary region (premolar/molar) and patients age and sex on bone regeneration after sinus grafting.Sinus augmentation procedures were performed in 107 patients (66 female: 52.8 11.0 years, 41 male: 50.6 11.3 years). After 6 1 months, 201 sinus biopsies were harvested and histomorphometrically analysed. Height (oldHt) and bone volume fraction of pristine bone (oldBV/TV), as well as the amount of new bone (newBV/TV) and bone-to-bone substitute contact (BBSC) in the augmentation area, were assessed.In women, newBV/TV in the augmented sinus decreased significantly by 0.22 0.08% per year. In men, no similar trend was observed. There were strong influences of the maxillary region and the dimensions of the host bone. In the premolar region, newBV/TV was 23.1 7.9% and 25.1 10.1%; in the molar region, newBV/TV averaged 20.4 9.4% and 17.8 8.8% for women and men, respectively. The greater the thickness of the wall of the sinus floor (mainly in the former premolar region), the greater was the amount of new bone tissue formed in the spaces in-between bone substitute particles.These empirical results derived from a large human sample, link factors that influence the quality of biomaterial integration to the known clinical risks for the success of dental implants.

PubMed | Austrian Cluster for Tissue Regeneration and Medical University of Vienna
Type: Journal Article | Journal: Journal of biomedical materials research. Part B, Applied biomaterials | Year: 2015

Inhibition of prolyl hydroxylases stimulates bone regeneration. Consequently, bone substitute materials were developed that release prolyl hydroxylase inhibitors. However, the impact of prolyl hydroxylase inhibitors released from these carriers on osteoclastogenesis is not clear. We therefore assessed the effect of bone substitute materials that release prolyl hydroxylase inhibitors on osteoclastogenesis.Dimethyloxalylglycine, desferrioxamine, and l-mimosine were lyophilized onto bovine bone mineral and hydroxyapatite, and supernatants were generated. Osteoclastogenesis was induced in murine bone marrow cultures in the presence of the supernatants from bone substitute materials. The formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and TRAP activity were determined. To test for possible effects on osteoclast progenitor cells, we measured the effect of the supernatants on proliferation and viability. In addition, experiments were performed where prolyl hydroxylase inhibitors were directly added to the bone marrow cultures.We found that prolyl hydroxylase inhibitors released within the first hours from bone substitute materials reduce the number and activity of TRAP-positive multinucleated cells. In line with this, addition of prolyl hydroxylase inhibitors directly to the bone marrow cultures dose-dependently reduced the number of TRAP-positive multinucleated cells and the overall resorption activity. Moreover, the released prolyl hydroxylase inhibitors decreased proliferation but not viability of osteoclast progenitor cells.Our results show that prolyl hydroxylase inhibitors released from bone substitute materials decrease osteoclastogenesis in murine bone marrow cultures.

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