TY - JOUR A1 - Hütten, Mareike A1 - Dhanasingh, Anandhan A1 - Hessler, Roland A1 - Stöver, Timo A1 - Esser, Karl-Heinz A1 - Möller, Martin A1 - Lenarz, Thomas A1 - Jolly, Claude A1 - Groll, Jürgen A1 - Scheper, Verena T1 - In Vitro and In Vivo Evaluation of a Hydrogel Reservoir as a Continuous Drug Delivery System for Inner Ear Treatment JF - PLoS ONE N2 - Fibrous tissue growth and loss of residual hearing after cochlear implantation can be reduced by application of the glucocorticoid dexamethasone-21-phosphate-disodium-salt (DEX). To date, sustained delivery of this agent to the cochlea using a number of pharmaceutical technologies has not been entirely successful. In this study we examine a novel way of continuous local drug application into the inner ear using a refillable hydrogel functionalized silicone reservoir. A PEG-based hydrogel made of reactive NCO-sP(EO-stat-PO) prepolymers was evaluated as a drug conveying and delivery system in vitro and in vivo. Encapsulating the free form hydrogel into a silicone tube with a small opening for the drug diffusion resulted in delayed drug release but unaffected diffusion of DEX through the gel compared to the free form hydrogel. Additionally, controlled DEX release over several weeks could be demonstrated using the hydrogel filled reservoir. Using a guinea-pig cochlear trauma model the reservoir delivery of DEX significantly protected residual hearing and reduced fibrosis. As well as being used as a device in its own right or in combination with cochlear implants, the hydrogel-filled reservoir represents a new drug delivery system that feasibly could be replenished with therapeutic agents to provide sustained treatment of the inner ear. KW - gels KW - cochlea KW - silicones KW - deafness KW - inner ear KW - drug delivery KW - inflammation KW - connective tissue Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119375 VL - 9 IS - 8 ER - TY - JOUR A1 - Kasten, Annika A1 - Naser, Tamara A1 - Brüllhoff, Kristina A1 - Fiedler, Jörg A1 - Müller, Petra A1 - Möller, Martin A1 - Rychly, Joachim A1 - Groll, Jürgen A1 - Brenner, Rolf E. T1 - Guidance of Mesenchymal Stem Cells on Fibronectin Structured Hydrogel Films JF - PLOS ONE N2 - Designing of implant surfaces using a suitable ligand for cell adhesion to stimulate specific biological responses of stem cells will boost the application of regenerative implants. For example, materials that facilitate rapid and guided migration of stem cells would promote tissue regeneration. When seeded on fibronectin (FN) that was homogeneously immmobilized to NCO-sP(EO-stat-PO), which otherwise prevents protein binding and cell adhesion, human mesenchymal stem cells (MSC) revealed a faster migration, increased spreading and a more rapid organization of different cellular components for cell adhesion on fibronectin than on a glass surface. To further explore, how a structural organization of FN controls the behavior of MSC, adhesive lines of FN with varying width between 10 mu m and 80 mu m and spacings between 5 mu m and 20 mu m that did not allow cell adhesion were generated. In dependance on both line width and gaps, cells formed adjacent cell contacts, were individually organized in lines, or bridged the lines. With decreasing sizes of FN lines, speed and directionality of cell migration increased, which correlated with organization of the actin cytoskeleton, size and shape of the nuclei as well as of focal adhesions. Together, defined FN lines and gaps enabled a fine tuning of the structural organization of cellular components and migration. Microstructured adhesive substrates can mimic the extracellular matrix in vivo and stimulate cellular mechanisms which play a role in tissue regeneration. KW - adhesion dynamics KW - migration KW - coatings KW - force KW - networks KW - traction KW - stress KW - tension KW - focal adhesions KW - tissue morphogenesis Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114897 VL - 9 IS - 10 ER - TY - JOUR A1 - Projahn, Delia A1 - Simsekyilmaz, Sakine A1 - Singh, Smriti A1 - Kanzler, Isabella A1 - Kramp, Birgit K. A1 - Langer, Marcella A1 - Burlacu, Alexandrina A1 - Bernhagen, Jürgen A1 - Klee, Doris A1 - Zernecke, Alma A1 - Hackeng, Tilman M. A1 - Groll, Jürgen A1 - Weber, Christian A1 - Liehn, Elisa A. A1 - Koenen, Roy R. T1 - Controlled intramyocardial release of engineered chemokines by biodegradable hydrogels as a treatment approach of myocardial infarction JF - Journal of Cellular and Molecular Medicine N2 - Myocardial infarction (MI) induces a complex inflammatory immune response, followed by the remodelling of the heart muscle and scar formation. The rapid regeneration of the blood vessel network system by the attraction of hematopoietic stem cells is beneficial for heart function. Despite the important role of chemokines in these processes, their use in clinical practice has so far been limited by their limited availability over a long time-span in vivo. Here, a method is presented to increase physiological availability of chemokines at the site of injury over a defined time-span and simultaneously control their release using biodegradable hydrogels. Two different biodegradable hydrogels were implemented, a fast degradable hydrogel (FDH) for delivering Met-CCL5 over 24hrs and a slow degradable hydrogel (SDH) for a gradual release of protease-resistant CXCL12 (S4V) over 4weeks. We demonstrate that the time-controlled release using Met-CCL5-FDH and CXCL12 (S4V)-SDH suppressed initial neutrophil infiltration, promoted neovascularization and reduced apoptosis in the infarcted myocardium. Thus, we were able to significantly preserve the cardiac function after MI. This study demonstrates that time-controlled, biopolymer-mediated delivery of chemokines represents a novel and feasible strategy to support the endogenous reparatory mechanisms after MI and may compliment cell-based therapies. KW - chemokines KW - therapy KW - cardiovascular pharmacology KW - remodelling KW - endothelial progenitor cells KW - left-ventricular function KW - heart-failure KW - rat model KW - recruitment KW - factor-I Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116597 SN - 1582-4934 VL - 18 IS - 5 ER -