@article{LauGossenLendleinetal.2022,
  author    = {Lau, Skadi and Gossen, Manfred and Lendlein, Andreas and Jung, Friedrich},
  title     = {Differential sensitivity of assays for determining vein endothelial cell senescence},
  series = {Clinical hemorheology and microcirculation : blood flow and vessels},
  volume    = {81},
  journal   = {Clinical hemorheology and microcirculation : blood flow and vessels},
  number    = {3},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1386-0291},
  doi       = {10.3233/CH-211294},
  pages     = {191 -- 203},
  year      = {2022},
  abstract  = {In vivo endothelialization of polymer-based cardiovascular implant materials is a promising strategy to reduce the risk of platelet adherence and the subsequent thrombus formation and implant failure. However, endothelial cells from elderly patients are likely to exhibit a senescent phenotype that may counteract endothelialization. The senescence status of cells should therefore be investigated prior to implantation of devices designed to be integrated in the blood vessel wall. Here, human umbilical vein endothelial cells (HUVEC) were cultivated up to passage (P) 4, 10 and 26/27 to determine the population doubling time and the senescence status by four different methods. Determination of the senescence-associated beta-galactosidase activity (SA-beta-Gal) was carried out by colorimetric staining and microscopy (i), as well as by photometric quantification (ii), and the expression of senescence-associated nuclear proteins p16 and p21 as well as the proliferation marker Ki67 was assessed by immunostaining (iii), and by flow cytometry (iv). The population doubling time of P27-cells was remarkably greater (103 +/- 65 h) compared to P4-cells (24 +/- 3 h) and P10-cell (37 +/- 15 h). Among the four different methods tested, the photometric SA-beta-Gal activity assay and the flow cytometric determination of p16 and Ki67 were most effective in discriminating P27-cells from P4- and P10-cells. These methods combined with functional endothelial cell analyses might aid predictions on the performance of implant endothelialization in vivo.},
  language  = {en}
}
@article{TartivelBlockiBrauneetal.2022,
  author    = {Tartivel, Lucile and Blocki, Anna M. and Braune, Steffen and Jung, Friedrich and Behl, Marc and Lendlein, Andreas},
  title     = {An Inverse shape-memory hydrogel scaffold switching upon cooling in a tissue-tolerated temperature range},
  series = {Advanced materials interfaces},
  volume    = {9},
  journal   = {Advanced materials interfaces},
  number    = {6},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2196-7350},
  doi       = {10.1002/admi.202101588},
  pages     = {9},
  year      = {2022},
  abstract  = {Tissue reconstruction has an unmet need for soft active scaffolds that enable gentle loading with regeneration-directing bioactive components by soaking up but also provide macroscopic dimensional stability. Here microporous hydrogels capable of an inverse shape-memory effect (iSME) are described, which in contrast to classical shape-memory polymers (SMPs) recover their permanent shape upon cooling. These hydrogels are designed as covalently photo cross-linked polymer networks with oligo(ethylene glycol)-oligo(propylene glycol)-oligo(ethylene glycol) (OEG-OPG-OEG) segments. When heated after deformation, the OEG-OPG-OEG segments form micelles fixing the temporary shape. Upon cooling, the micelles dissociate again, the deformation is reversed and the permanent shape is obtained. Applicability of this iSME is demonstrated by the gentle loading of platelet-rich plasma (PRP) without causing any platelet activation during this process. PRP is highly bioactive and is widely acknowledged for its regenerative effects. Hence, the microporous inverse shape-memory hydrogel (iSMH) with a cooling induced pore-size effect represents a promising candidate scaffold for tissue regeneration for potential usage in minimally invasive surgery applications.},
  language  = {en}
}