Journal: Biomaterials

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Elsevier

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1878-5905
0142-9612

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Publications 1 - 10 of 140
  • Hepatocyte performance on different crystallographic faces of rutile
    Item type: Journal Article
    Buchloh, S.; Stieger, B.; Meier, P.J.; et al. (2003)
    Biomaterials
  • An inverted microcontact printing method on topographically structured polystyrene chips for arrayed micro-3-D culturing of single cells
    Item type: Journal Article
    Dusseiller, Marc R.; Schlaepfer, Dominik; Koch, Mirabai; et al. (2005)
    Biomaterials
  • Microengineered biosynthesized cellulose as anti-fibrotic in vivo protection for cardiac implantable electronic devices
    Item type: Journal Article
    Robotti, Francesco; Sterner, Ita; Bottan, Simone; et al. (2020)
    Biomaterials
    Upon cardiac implantable electronic device (CIED) exchange, upgrade, or revision surgery patients are exposed to a considerable risk of adverse events. The presence of firm fibrotic tissue endangers these procedures. Leads can be damaged in the attempt of freeing them from fibrotic tissue. Hematoma can form as result of capsulectomy, pocket debridement and leads dissection. Due to the increasing number of CIED exchange, upgrade and revision surgeries, the incidence of related complications is expected to rise in the near future.The aim of the study was to evaluate the feasibility, safety, and performance of a rationally micro-engineered non-resorbable biosynthesized cellulose (BC) membrane as conformal wrapping protection around CIED implants. Protective membranes were generated by means of a recently established method to transfer on-demand microscale geometries onto the surface of BC. A chronic minipig animal model was selected to investigate the performance of the BC anti-fibrotic protection, directly measured as reduction of fibrotic tissue formation. Sixteen (n = 16) animals received each one BC coated pacemaker (PMC) and one native pacemaker (BI) at equivalent anatomical sites. BC protective layers were juxtaposed around pacemakers through a fast and well-repeatable procedure. Explants were performed at 3 and 12 months after implantation. Endpoint analysis showed that the BC protective layers were 100% integer, with no sign of chemical or mechanical degradation and appeared as a thin layer of white-tan material, adherent to the surrounding thin fibrous capsule, from which it could be peeled off by gently pulling with forceps. The protective effect of micro-engineered BC yielded an average thickness reduction of 66% of the fibrotic tissue thickness generated around PMC, as compared to that measured around the naked counterpart (i.e. the BI). When protected by in BC, both the generator and the proximal parts of the leads were completely free from fibrotic tissue. The insertion of an anti-adhesive, non-resorbable and well-tolerated BC interface between the implant and the surrounding tissue in the surgical pocket significantly reduced the formation of fibrotic tissue, ensuring an easy access to the device pocket, and thus creating the conditions for simplified CIED revision surgeries.
  • A free-form patterning method enabling endothelialization under dynamic flow
    Item type: Journal Article
    Wu, Xi; Moimas, Silvia; Hopf, Raoul; et al. (2021)
    Biomaterials
    Endothelialization strategies aim at protecting the surface of cardiovascular devices upon their interaction with blood by the generation and maintenance of a mature monolayer of endothelial cells. Rational engineering of the surface micro-topography at the luminal interface provides a powerful access point to support the survival of a living endothelium under the challenging hemodynamic conditions created by the implant deployment and function. Surface structuring protocols must however be adapted to the complex, non-planar architecture of the target device precluding the use of standard lithographic approaches. Here, a novel patterning method, harnessing the condensation and evaporation of water droplets on a curing liquid elastomer, is developed to introduce arrays of microscale wells on the surface of a biocompatible silicon layer. The resulting topographies support the in vitro generation of mature human endothelia and their maintenance under dynamic changes of flow direction or magnitude, greatly outperforming identical, but flat substrates. The structuring approach is additionally demonstrated on non-planar interfaces yielding comparable topographies. The intrinsically freeform patterning is therefore compatible with a complete and stable endothelialization of complex luminal interfaces in cardiovascular implants.
  • The fibrotic response of primary liver spheroids recapitulates in vivo hepatic stellate cell activation
    Item type: Journal Article
    Mannaerts, Inge; Eysackers, Nathalie; Van Os, Elise A.; et al. (2020)
    Biomaterials
    A major obstacle in the development of efficient therapies for progressive liver fibrosis is the lack of representative in vitro models of liver fibrosis to aid in understanding the mechanisms of the disease and to promote the development of pharmaceuticals. Our aim was to develop a relevant in vitro mouse liver fibrosis model, based on the central hypothesis that liver fibrosis in vitro cannot be studied using only hepatic stellate cells (HSCs)–the main producer of scar tissue during fibrosis–, but requires cultures in which at least hepatocytes are integrated. We established robust methods to generate co-culture spheroids from freshly isolated mouse hepatocytes and HSCs. Characteristics and functionality of these spheroids were analyzed by qPCR of cell-type specific markers, CYP induction and immunohistochemistry. Compound toxicity was determined by ATP-assays. Hepatocytes and HSCs maintained their cell-type specific marker expression over a 15-day culture period without major hepatocyte dedifferentiation or HSC activation. Exposure of spheroids to TGFβ can directly activate HSCs, while acetaminophen exposure mounts a hepatocyte damage dependent activation of HSCs. Pharmaceuticals with known anti-fibrotic properties, such as Valproic acid and Verteporfin, reduce HSC activation in response to hepatocyte damage in these cultures. A comparison between the fibrotic response of the spheroid co-cultures and in vivo activated HSCs showed that these 3D co-cultures are more representative than the commonly used 2D HSC monocultures. Finally, we showed that the 3D cultures can be integrated in microfluidic chips. We conclude that our hepatocyte-stellate cell-spheroid cultures are a robust in vitro model of liver fibrosis. This model could be used to further unravel the mechanism of HSC activation and facilitate the discovery of, or testing for novel anti-fibrotic compounds, as these spheroids better reproduce HSC in vivo activation compared to the more traditional 2D mono-culture models. © 2020 Elsevier Ltd
  • Endocytosis of PEGylated nanoparticles accompanied by structural and free energy changes of the grafted polyethylene glycol
    Item type: Journal Article
    Li, Ying; Kröger, Martin; Liu, Wing Kam (2014)
    Biomaterials
  • Control of in vitro tissue-engineered bone-like structures using human mesenchymal stem cells and porous silk scaffolds
    Item type: Journal Article
    Hofmann, Sandra; Hagenmüller, Henri; Koch, Annette M.; et al. (2007)
    Biomaterials
  • The inflammatory responses to silk films in vitro and in vivo
    Item type: Journal Article
    Meinel, Lorenz; Hofmann, Sandra; Karageorgiou, Vassilis; et al. (2005)
    Biomaterials
  • Electrospun degradable polyesterurethane membranes
    Item type: Journal Article
    Riboldi, Stefania A.; Sampaolesi, Maurilio; Neuenschwander, Peter; et al. (2005)
    Biomaterials
Publications 1 - 10 of 140