Time filter

Source Type

Markneukirchen, Germany

Hess R.,TU Dresden | Douglas T.,University of Kiel | Myers K.A.,University of Calgary | Rentsch B.,Catgut GmbH | And 5 more authors.
Journal of Biomechanical Engineering | Year: 2010

Human mesenchymal stem cells (hMSCs) from bone marrow are considered a promising cell source for bone tissue engineering applications because of their ability to differentiate into cells of the osteoblastic lineage. Mechanical stimulation is able to promote osteogenic differentiation of hMSC; however, the use of hydrostatic pressure (HP) has not been well studied. Artificial extracellular matrices containing collagen and chondroitin sulfate (CS) have promoted the expression of an osteoblastic phenotype by hMSCs. However, there has been little research into the combined effects of biochemical stimulation by matrices and simultaneous mechanical stimulation. In this study, artificial extracellular matrices generated from collagen and/or CS were coated onto polycaprolactone-co-lactide substrates, seeded with hMSCs and subjected to cyclic HP at various time points during 21 days after cell seeding to investigate the effects of biochemical, mechanical, and combined biochemical and mechanical stimulations. Cell differentiation was assessed by analyzing the expression of alkaline phosphatase (ALP) at the protein- and mRNA levels, as well as for calcium accumulation. The timing of HP stimulation affected hMSC proliferation and expression of ALP activity. HP stimulation after 6 days was most effective at promoting ALP activity. CS-containing matrices promoted the osteogenic differentiation of hMSCs. A combination of both CS-containing matrices and cyclic HP yields optimal effects on osteogenic differentiation of hMSCs on scaffolds compared with individual responses. Copyright © 2010 by ASME. Source

Rentsch C.,TU Dresden | Rentsch B.,Catgut GmbH | Heinemann S.,Leibniz Institute of Polymer Research | Bernhardt R.,Leibniz Institute of Polymer Research | And 5 more authors.
BioMed Research International | Year: 2014

Resorbable polymeric implants and surface coatings are an emerging technology to treat bone defects and increase bone formation. This approach is of special interest in anatomical regions like the calvaria since adults lose the capacity to heal large calvarial defects. The present study assesses the potential of extracellular matrix inspired, embroidered polycaprolactone-co- lactide (PCL) scaffolds for the treatment of 13 mm full thickness calvarial bone defects in rabbits. Moreover the influence of a collagen/chondroitin sulfate (coll I/cs) coating of PCL scaffolds was evaluated. Defect areas filled with autologous bone and empty defects served as reference. The healing process was monitored over 6 months by combining a novel ultrasonographic method, radiographic imaging, biomechanical testing, and histology. The PCL coll I/cs treated group reached 68% new bone volume compared to the autologous group (100%) and the biomechanical stability of the defect area was similar to that of the gold standard. Histological investigations revealed a significantly more homogenous bone distribution over the whole defect area in the PCL coll I/cs group compared to the noncoated group. The bioactive, coll I/cs coated, highly porous, 3-dimensional PCL scaffold acted as a guide rail for new skull bone formation along and into the implant. © 2014 C. Rentsch et al. Source

Rentsch C.,University Hospital Carl Gustav Carus Dresden | Hess R.,Leibniz Institute of Polymer Research | Rentsch B.,Catgut GmbH | Hofmann A.,Leibniz Institute of Polymer Research | And 4 more authors.
In Vitro Cellular and Developmental Biology - Animal | Year: 2010

The current study was undertaken with the goal being isolation, cultivation, and characterization of ovine mesenchymal stem cells (oMSC). Furthermore, the objective was to determine whether biological active polycaprolactone-co-lactide (trade name PCL) scaffolds support the growth and differentiation of oMSC in vitro. The oMSC were isolated from the iliac crest of six merino sheep. Three factors were used to demonstrate the MSC properties of the isolated cells in detail. (1) Their ability to proliferate in culture with a spindle-shaped morphology, (2) presence of specific surface marker proteins, and (3) their capacity to differentiate into the three classical mesenchymal pathways, osteoblastic, adipogenic, and chondrogenic lineages. Furthermore, embroidered PCL scaffolds were coated with collagen I (coll I) and chondroitin sulfate (CS). The porous structure of the scaffolds and the coating with coll I/CS allowed the oMSC to adhere, proliferate, and to migrate into the scaffolds. The coll I/CS coating on the PCL scaffolds induced osteogenic differentiation of hMSC, without differentiation supplements, indicating that the scaffold also has an osteoinductive character. In conclusion, the isolated cells from the ovine bone marrow have similar morphologic, immunophenotypic, and functional characteristics as their human counterparts. These cells were also found to differentiate into multiple mesenchymal cell types. This study demonstrates that embroidered PCL scaffolds can act as a temporary matrix for cell migration, proliferation, and differentiation of oMSC. The data presented will provide a reliable model system to assess the translation of MSC-based therapy into a variety of valuable ovine experimental models under autologous settings. © 2010 The Society for In Vitro Biology. Source

Rentsch C.,Universitatsklinikum Carl Gustav Carus Dresden | Rentsch B.,Catgut GmbH | Scharnweber D.,Max Bergmann Zentrum fur Biomaterialien | Zwipp H.,Universitatsklinikum Carl Gustav Carus Dresden | Rammelt S.,Universitatsklinikum Carl Gustav Carus Dresden
Unfallchirurg | Year: 2012

Due to the special characteristics, autologous bone for bone grafting remains the gold standard for defect filling. Besides allogenic bone transplants, as an alternative a set of bone substitutes has been established. An overview of the bone substitutes presently on the market is almost lost due to the abundance of products. The present paper gives a review of the materials available on the market. Different classification systems regarding origin, vitality, biological priority and chemical composition are described as well as the individual materials including the advantages and disadvantages. Finally, a description of tissue engineering and gene therapy gives a view of future prospective. © 2012 Springer-Verlag. Source

Rentsch C.,University Hospital Carl Gustav Carus Dresden | Rentsch B.,Catgut GmbH | Breier A.,Leibniz Institute of Polymer Research | Hofmann A.,Leibniz Institute of Polymer Research | And 4 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2010

The aim of this study was to evaluate the osteogenic potential and the vascularization of embroidered, tissue engineered, and cell-seeded 3D poly(3)hydroxybutyrate (PHB) scaffolds in nude rats. Collagen I (coll I)- and collagen I/chondroitin sulfate (coll I/CS)-coated PHB scaffolds were seeded with human mesenchymal stem cells (hMSCs). Proliferation and differentiation were characterized by different biochemical assays in vitro. For animal experiments, the cells were cultivated on coll I- or coll I/ CS-coated scaffolds and either expanded or osteogenically differentiated. Scaffolds were piled up to create a 3D scaffold pad and implanted subcutaneously into nude rats. In vitro hMSC showed proliferation and differentiation on PHB scaffolds. Alkaline phosphatase (ALP) and calcium increased in the differentiation medium and in the presence of coll I/CS. In vivo blood vessels were found in the scaffold-stack. Histological/immunohistological analyses of explanted scaffolds showed osteogenic markers such as osteopontin, osteonectin, and coll I around the PHB fibers. Coll I/CS-coated scaffolds with expanded hMSC showed higher values of ALP and calcium than the other combinations. Embroidered PHB scaffolds, coated with extracellular matrix components, provided an adequate environment and, therefore, a template for hMSC which could be differentiated in osteogenic direction. © 2009 Wiley Periodicals, Inc. Source

Discover hidden collaborations