Translational Center for Regenerative Medicine Leipzig

Rosenthal, Germany

Translational Center for Regenerative Medicine Leipzig

Rosenthal, Germany
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Lochmann A.,Translational Center for Regenerative Medicine Leipzig | Lochmann A.,Martin Luther University of Halle Wittenberg | Nitzsche H.,Translational Center for Regenerative Medicine Leipzig | von Einem S.,Martin Luther University of Halle Wittenberg | And 3 more authors.
Journal of Controlled Release | Year: 2010

The current clinical success of therapies with recombinant human Bone Morphogenetic Protein 2 (rhBMP-2) is limited due to inefficient delivery. The high doses applied have frequently been related to severe adverse effects such as tissue swelling, seroma, inflammatory effects and heterotopic ossification. The controlled delivery of lower doses is supposed to reduce adverse effect incidence as well as costs. In this study, novel polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) diblock copolymers were used to produce low dose controlled delivery vehicles for rhBMP-2. A method to fabricate a variety of microsphere formulations with a high encapsulation efficiency in high yields was developed. The influence of PEG as an inner phase cosolvent and linked PLGA as copolymer was investigated. Six different microsphere systems with varying PEG amounts in both core and shell were characterised thoroughly with respect to the specific properties of rhBMP-2. The particle size of the microspheres was investigated with both laser diffraction and environmental scanning electron microscopy. Higher PEG/PLGA ratios showed a tendency to increase in size and a wider distribution. Due to the low rhBMP-2 doses, a profound characterisation was very challenging. The growth factor was covalently attached to rhodamine B for the first time. Studies on drug distribution in the microspheres were performed by means of confocal laser scanning microscopy. The addition of PEG to the inner phase was found to impair the formation of spherical microdomains with localized higher growth factor concentrations. Release profiles, determined with ELISA, were linked to the structural changes that were monitored. Distinct, controlled release profiles were achieved in all formulations and showed that PEG is a versatile tool in the effective control of release rates from microspheres. Higher PEG/PLGA ratios in the polymer were shown to increase the release rate from the microspheres. In contrast, PEG administered to the inner phase decreased the release rate. The biological activity of released protein was shown in vitro in an alkaline phosphatase assay. It was demonstrated that PEG-PLGA microspheres are a promising sustained delivery system which allows a reduction of the required rhBMP-2 dose to limit both adverse effects and costs. Furthermore, the data indicated that the use of PEG as an inner phase cosolvent is not suitable for rhBMP-2 in contrast the reported beneficial effects for other growth factors. © 2010 Elsevier B.V.

Loeffler M.,University of Leipzig | Kreuz M.,University of Leipzig | Haake A.,University of Kiel | Hasenclever D.,University of Leipzig | And 14 more authors.
Leukemia | Year: 2015

Follicular lymphoma (FL) with a t(14;18) is a B-cell neoplasm clinically characterized by multiple recurrencies. In order to investigate the clonal evolution of this lymphoma, we studied paired primary and relapse tumor samples from 33 patients with recurrent non-transformed t(14;18)-positive FL. We reconstructed phylogenetic trees of the evolution by taking advantage of the activation-induced cytidine deaminase (AID)-mediated somatic hypermutation (SHM) active in the germinal center reaction using sequences of the clonal V H D H J H rearrangements of the immunoglobulin heavy chain (IGH) locus. Mutational analysis of the IGH locus showed evidence for ongoing somatic mutation and for counter-selection of mutations affecting the BCR conformation during tumor evolution. We further followed evolutionary divergence by targeted sequencing of gene loci affected by aberrant SHM as well as of known driver genes of lymphomagenesis, and by array-based genome-wide chromosomal imbalance and DNA methylation analysis. We observed a wide spectrum of evolutionary patterns ranging from almost no evolution to divergent evolution within recurrent non-transformed t(14;18) FL. Remarkably, we observed a correlation of the magnitude of evolutionary divergence across all genetic and epigenetic levels suggesting co-evolution. The distribution of coding mutations in driver genes and the correlation with SHM suggest CREBBP and AID to be potential modifiers of genetic and epigenetic co-evolution in FL. © 2015 Macmillan Publishers Limited All rights reserved

Flemmig J.,Translational Center for Regenerative Medicine Leipzig | Flemmig J.,University of Leipzig | Rusch D.,University of Leipzig | Czerwinska M.E.,Medical University of Warsaw | And 2 more authors.
Archives of Biochemistry and Biophysics | Year: 2014

We investigated in vitro the ability of a standardised olive leaf dry extract (Ph. Eur.) (OLE) as well as of its single components to circumvent the hydrogen peroxide-induced inhibition of the hypothiocyanite-producing activity of lactoperoxidase (LPO). The rate of hypothiocyanite (-OSCN) formation by LPO was quantified by spectrophotometric detection of the oxidation of 5-thio-2-nitrobenzoic acid (TNB). By using excess hydrogen peroxide, we forced the accumulation of inactive enzymatic intermediates which are unable to promote the two-electronic oxidation of thiocyanate. Both OLE and certain extract components showed a strong LPO-reactivating effect. Thereby an o-hydroxyphenolic moiety emerged to be essential for a good reactivity with the inactive LPO redox states. This basic moiety is found in the main OLE components oleuropein, oleacein, hydroxytyrosol, caffeic acid as well as in different other constituents including the OLE flavone luteolin. As LPO is a key player in the humoral immune response, these results propose a new mode of action regarding the well-known bacteriostatic and anti-inflammatory properties of the leaf extract of Olea europaea L. © 2014 Elsevier Inc. All rights reserved.

Wilde F.,University of Ulm | Heufelder M.,University of Ulm | Winter K.,Translational Center for Regenerative Medicine Leipzig | Hendricks J.,University of Leipzig | And 3 more authors.
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology | Year: 2011

Objectives: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) seems resistant to conventional treatment approaches. We report a study with a surgical concept characterized by resection of the necrotic bone followed by sufficient wound closure. Study design: In a clinical study of 24 patients with 33 sites of BRONJ, the surgical basis of the treatment was as follows: (1) conservative treatment with antimicrobiological rinsing, (2) resection of the entire necrotic bone and smoothening of any sharp bone edges, and (3) coverage of the remaining bone by use of a bilayered wound closure. Results: In 88% of cases, BRONJ could be treated with success by use of this surgical therapy. Median follow-up was 60 weeks. There was no statistically significant difference between treatment results irrespective of whether or not bisphosphonate treatment was continued. Conclusion: Because of the high success rate of this surgical technique it seems that patients with BRONJ may benefit from this approach. © 2011 Mosby, Inc. All rights reserved.

Frerich B.,University of Rostock | Winter K.,University of Rostock | Winter K.,Translational Center for Regenerative Medicine Leipzig | Scheller K.,Martin Luther University of Halle Wittenberg | Braumann U.-D.,The Interdisciplinary Center
Artificial Organs | Year: 2012

Adipose tissue engineering has been advocated for soft-tissue augmentation and for the treatment of soft tissue defects. The efficacy in terms of persistence of the engineered fat is, however, not yet understood and could depend on the nature of fabrication and application. The high metabolic demand of adipose tissue also points to the problem of vascularization. Endothelial cell (EC) cotransplantation could be a solution. Human adipose tissue-derived stromal cells were seeded on collagen microcarriers and submitted to adipogenic differentiation ("microparticles"). In a first run of experiments, these microparticles were implanted under the skin of severe combined immunodeficient (SCID) mice (n=45) with and without the addition of human umbilical vein ECs (HUVECs). A group of carriers without any cells served as control. In a second run, adipose tissue constructs were fabricated by embedding microparticles in fibrin matrix with and without the addition of HUVEC, and were also implanted in SCID mice (n=30). The mice were sacrificed after 12 days, 4 weeks, and 4 months. Mature adipose tissue, fibrous tissue, and acellular regions were quantified on whole-specimen histological sections. The implantation of microparticles showed a better sustainment of tissue volume and a higher degree of mature adipose tissue compared with adipose tissue constructs. Immunohistology proved obviously perfused human tissue-engineered vessels. There was a limited but not significant advantage in EC cotransplantation after 4 weeks in terms of tissue volume. In groups with EC cotransplantation, there were significantly fewer acellular/necrotic areas after 4 weeks and 4 months. In conclusion, the size of the implanted tissue equivalents is a crucial parameter, affecting volume maintenance and the gain of mature adipose tissue. EC cotransplantation leads to functional stable vascular networks connecting in part to the host vasculature and contributing to tissue perfusion; however, the long-term benefit depends on additional basic conditions that need further research. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Lempe-Troillet A.,University of Leipzig | Ludewig E.,University of Leipzig | Brehm W.,University of Leipzig | Budras K.-D.,Free University of Berlin | And 2 more authors.
Veterinary and Comparative Orthopaedics and Traumatology | Year: 2013

Objectives: The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. Methods: Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologically. For statistical analysis, horses were divided into two groups (≤3 years and >3 years) for evaluating signal intensity and homogeneity of the plantar tendons and ligaments. Results: Focal increase of the signal intensity within the deep digital flexor tendon was significantly more present in horses older than three years. Signal alterations of the long plantar ligament were seen without a significant dependency to age. The accessory ligament of the deep digital flexor tendon could not be visualized on all images within the region of interest. The morphology of the proximal suspensory ligament was not affected by age-related changes. Clinical relevance: Spin and gradient echoes in MRI were suitable to identify and assess soft tissue structures at the plantar aspect of the equine tarsus and proximal metatarsus. Age-related appearance must be considered when interpreting magnetic resonance images. © Schattauer 2013.

Wilde F.,University of Ulm | Winter K.,Translational Center for Regenerative Medicine Leipzig | Kletsch K.,University of Ulm | Lorenz K.,University of Ulm | Schramm A.,University of Ulm
International Journal of Computer Assisted Radiology and Surgery | Year: 2014

Purpose:  Mandible reconstruction with reconstruction plates requires bending the plates during the operation and fixation using the “standard method” (ST-method). The ST-method is limited when a pathological process has perforated the mandibular outer cortex. A transfer key method (TK-method) was developed where plates are pre-bent using a patient-specific mandible model and positioned on the mandible with the help of transfer keys. The ST-method and TK-method were compared in a clinical trial.Methods:  Mandibular reconstruction was performed on 42 patients in this study: 22 were performed using the TK-method and 20 using the ST-method. Pre- and postoperative CT scans were evaluated by measuring the distances between six corresponding landmarks on the mandibular condyles and rami. The difference between pre- and postoperative distances was used to evaluate reconstruction accuracy.Results:  The median deviation of the unsigned/ absolute values of all six distances was 1.07 mm for the TK-method and 1.67 mm for the ST-method. The TK-method showed significantly better results. For the signed values, the median deviation of the six distances was -0.6 mm for the TK-method and -1.47 mm for the ST-method, indicating that the mandibles became narrower with both methods. This width difference was not statistically significant.Conclusion:  The TK-method was more accurate than the ST-method in a clinical trial. The TK-method was effective and accurate for mandible reconstruction using pre-bent fixation plates. © 2014, CARS.

Melzer S.,University of Leipzig | Zachariae S.,University of Leipzig | Bocsi J.,University of Leipzig | Engel C.,University of Leipzig | And 3 more authors.
Cytometry Part B - Clinical Cytometry | Year: 2015

Background Reference intervals for leukocyte subsets from peripheral blood are helpful for the understanding of disease states and therapy effects. Methods We performed in-depth immunophenotyping for 608 healthy German adults from the Leipzig region from 40 to 79 years by 10-color flow cytometry (FCM) to gain reference information for various leukocyte subsets including subsets of granulocytes, monocytes and lymphocytes. Results First, we derived gender- and age-specific reference intervals for males and females from 40 to 59 and from 60 to 79 years, respectively. Second, we further investigated the influence of gender and age on leukocyte counts. We found significantly higher cell counts for monocytes (P-<-0.001) and NK cells (P-<-0.001) in men, whereas women had higher counts for B cells (P-<-0.001), Th cells (P-<-0.001) and regulatory T cells (P-=-0.008). Furthermore, with increasing age, a decrease in Tc cells (about 8% within 5 years) and an increase in NK cells (<4% within 5 years) were observed. Conclusion In future research, it should be investigated whether these are real ageing effects that can be confirmed in longitudinal studies. Furthermore, it is important to understand if the Tc cell count drop is functionally compensated by the increase of NK cells. © 2015 International Clinical Cytometry Society.

Wilde F.,University of Ulm | Plail M.,University of Ulm | Riese C.,University of Ulm | Schramm A.,University of Ulm | Winter K.,Translational Center for Regenerative Medicine Leipzig
International Journal of Computer Assisted Radiology and Surgery | Year: 2012

Purpose Patient-specific mandible reconstruction plates maybe pre-bent to facilitate the surgical procedure.Amethod using transfer keys (TK) for repositioning pre-bent plateswas compared with the standard method on mandibular models to evaluate its feasibility. Method Ten mandible models were used to pre-bend reconstruction plates. After plate fixing on the models, TK were fabricated. Plates and TK were removed and segmental resections were performed. The plates were replaced on the models by the standardmethod of determining the plate position using previous screw holes. Plates were removed and then relocated by use of the TK. To compare the accuracy of both methods, the distances between four corresponding points of the condyles and the mandibular rami were measured. Results The mean deviation of the absolute values from the initial values for the models between the condyles and the rami was 0.964 mm for the standard method and 0.821 mm for the TK method. To determine whether there was enlargement or shrinkage between the rami or the condyles, we analysed the relative values of the data. For the standardmethod, the mean deviation from the initial values was +0.178 mm; for the TK method, it was +0.080 mm. In both cases, the differences were not significant. Conclusion Pre-bent reconstruction plates using patient-specific 3D models can be useful in mandible reconstruction. The TK method was tested in vitro and shown to be as accurate as the standard method. The TK method may shorten the procedure and may be useful for secondary cases and cases where the pathology involves the outer corte of the mandible. © CARS 2011.

Giri S.,University of Leipzig | Acikgoz A.,University of Leipzig | Pathak P.,The Interdisciplinary Center | Pathak P.,Translational Center for Regenerative Medicine Leipzig | And 4 more authors.
Journal of Cellular Physiology | Year: 2012

Till date, no bioartificial liver (BAL) procedure has obtained FDA approval or widespread clinical acceptance, mainly because of multifactorial limitations such as the use of microscale or undefined biomaterials, indirect and lower oxygenation levels in liver cells, short-term undesirable functions, and a lack of 3D interaction of growth factor/cytokine signaling in liver cells. To overcome preclinical limitations, primary rat liver cells were cultured on a naturally self-assembling peptide nanoscaffold (SAPN) in a clinically relevant bioreactor for up to 35 days, under 3D interaction with suitable growth factors and cytokine signaling agents, alone or combination (e.g., Group I: EPO, Group II: Activin A, Group III: IL-6, Group IV: BMP-4, Group V: BMP4+EPO, Group VI: EPO+IL-6, Group VII: BMP4+IL-6, Group VIII: Activin A+EPO, Group IX: IL-6+Activin A, Group X: Activin A+BMP4, Group XI: EPO+Activin A+BMP-4+IL-6+HGF, and Group XII: Control). Major liver specific functions such as albumin secretion, urea metabolism, ammonia detoxification, phase contrast microscopy, immunofluorescence of liver specific markers (Albumin and CYP3A1), mitochondrial status, glutamic oxaloacetic transaminase (GOT) activity, glutamic pyruvic transaminase (GPT) activity, and cell membrane stability by the lactate dehydrogenase (LDH) test were also examined and compared with the control over time. In addition, we examined the drug biotransformation potential of a diazepam drug in a two-compartment model (cell matrix phase and supernatant), which is clinically important. This present study demonstrates an optimized 3D signaling/scaffolding in a preclinical BAL model, as well as preclinical drug screening for better drug development. © 2011 Wiley Periodicals, Inc.

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