@article{DengWangXuetal.2020,
  author    = {Deng, Zijun and Wang, Weiwei and Xu, Xun and Ma, Nan and Lendlein, Andreas},
  title     = {Modulation of mesenchymal stem cell migration using programmable polymer sheet actuators},
  series = {MRS advances},
  volume    = {5},
  journal   = {MRS advances},
  number    = {46-47},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {2059-8521},
  doi       = {10.1557/adv.2020.235},
  pages     = {2381 -- 2390},
  year      = {2020},
  abstract  = {Recruitment of mesenchymal stem cells (MSCs) to damaged tissue is a crucial step to modulate tissue regeneration. Here, the migration of human adipose-derived stem cells (hADSCs) responding to thermal and mechanical stimuli was investigated using programmable shape-memory polymer actuator (SMPA) sheets. Changing the temperature repetitively between 10 and 37 degrees C, the SMPA sheets are capable of reversibly changing between two different pre-defined shapes like an artificial muscle. Compared to non-actuating sheets, the cells cultured on the programmed actuating sheets presented a higher migration velocity (0.32 +/- 0.1 vs. 0.57 +/- 0.2 mu m/min). These results could motivate the next scientific steps, for example, to investigate the MSCs pre-loaded in organoids towards their migration potential.},
  language  = {en}
}
@article{DengWangXuetal.2021,
  author    = {Deng, Zijun and Wang, Weiwei and Xu, Xun and Ma, Nan and Lendlein, Andreas},
  title     = {Polydopamine-based biofunctional substrate coating promotes mesenchymal stem cell migration},
  series = {MRS advances : a journal of the Materials Research Society (MRS)},
  volume    = {6},
  journal   = {MRS advances : a journal of the Materials Research Society (MRS)},
  number    = {31},
  publisher = {Springer Nature Switzerland AG},
  address   = {Cham},
  issn      = {2059-8521},
  doi       = {10.1557/s43580-021-00091-4},
  pages     = {739 -- 744},
  year      = {2021},
  abstract  = {Rapid migration of mesenchymal stem cells (MSCs) on device surfaces could support in vivo tissue integration and might facilitate in vitro organoid formation. Here, polydopamine (PDA) is explored as a biofunctional coating to effectively promote MSC motility. It is hypothesized that PDA stimulates fibronectin deposition and in this way enhances integrin-mediated migration capability. The random and directional cell migration was investigated by time-lapse microscopy and gap closure assay respectively, and analysed with softwares as computational tools. A higher amount of deposited fibronectin was observed on PDA substrate, compared to the non-coated substrate. The integrin beta 1 activation and focal adhesion kinase (FAK) phosphorylation at Y397 were enhanced on PDA substrate, but the F-actin cytoskeleton was not altered, suggesting MSC migration on PDA was regulated by integrin initiated FAK signalling. This study strengthens the biofunctionality of PDA coating for regulating stem cells and offering a way of facilitating tissue integration of devices.},
  language  = {en}
}
@article{DengWangXuaetal.2020,
  author    = {Deng, Zijun and Wang, Weiwei and Xua, Xun and Gould, Oliver E. C. and Kratz, Karl and Ma, Nan and Lendlein, Andreas},
  title     = {Polymeric sheet actuators with programmable bioinstructivity},
  series = {PNAS},
  volume    = {117},
  journal   = {PNAS},
  number    = {4},
  publisher = {National Academy of Sciences},
  address   = {Washington, DC},
  issn      = {1091-6490},
  doi       = {10.1073/pnas.1910668117},
  pages     = {1895 -- 1901},
  year      = {2020},
  abstract  = {Stem cells are capable of sensing and processing environmental inputs, converting this information to output a specific cell lineage through signaling cascades. Despite the combinatorial nature of mechanical, thermal, and biochemical signals, these stimuli have typically been decoupled and applied independently, requiring continuous regulation by controlling units. We employ a programmable polymer actuator sheet to autonomously synchronize thermal and mechanical signals applied to mesenchymal stem cells (MSC5). Using a grid on its underside, the shape change of polymer sheet, as well as cell morphology, calcium (Ca2+) influx, and focal adhesion assembly, could be visualized and quantified. This paper gives compelling evidence that the temperature sensing and mechanosensing of MSC5 are interconnected via intracellular Ca2+. Up-regulated Ca2+ levels lead to a remarkable alteration of histone H3K9 acetylation and activation of osteogenic related genes. The interplay of physical, thermal, and biochemical signaling was utilized to accelerate the cell differentiation toward osteogenic lineage. The approach of programmable bioinstructivity provides a fundamental principle for functional biomaterials exhibiting multifaceted stimuli on differentiation programs. Technological impact is expected in the tissue engineering of periosteum for treating bone defects.},
  language  = {en}
}
@misc{DengWangXuaetal.2020,
  author    = {Deng, Zijun and Wang, Weiwei and Xua, Xun and Gould, Oliver E. C. and Kratz, Karl and Ma, Nan and Lendlein, Andreas},
  title     = {Polymeric sheet actuators with programmable bioinstructivity},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {4},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51549},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515490},
  pages     = {9},
  year      = {2020},
  abstract  = {Stem cells are capable of sensing and processing environmental inputs, converting this information to output a specific cell lineage through signaling cascades. Despite the combinatorial nature of mechanical, thermal, and biochemical signals, these stimuli have typically been decoupled and applied independently, requiring continuous regulation by controlling units. We employ a programmable polymer actuator sheet to autonomously synchronize thermal and mechanical signals applied to mesenchymal stem cells (MSC5). Using a grid on its underside, the shape change of polymer sheet, as well as cell morphology, calcium (Ca2+) influx, and focal adhesion assembly, could be visualized and quantified. This paper gives compelling evidence that the temperature sensing and mechanosensing of MSC5 are interconnected via intracellular Ca2+. Up-regulated Ca2+ levels lead to a remarkable alteration of histone H3K9 acetylation and activation of osteogenic related genes. The interplay of physical, thermal, and biochemical signaling was utilized to accelerate the cell differentiation toward osteogenic lineage. The approach of programmable bioinstructivity provides a fundamental principle for functional biomaterials exhibiting multifaceted stimuli on differentiation programs. Technological impact is expected in the tissue engineering of periosteum for treating bone defects.},
  language  = {en}
}
@article{DengZouWangetal.2019,
  author    = {Deng, Zijun and Zou, Jie and Wang, Weiwei and Nie, Yan and Tung, Wing-Tai and Ma, Nan and Lendlein, Andreas},
  title     = {Dedifferentiation of mature adipocytes with periodic exposure to cold},
  series = {Clinical hemorheology and microcirculation : blood flow and vessels},
  volume    = {71},
  journal   = {Clinical hemorheology and microcirculation : blood flow and vessels},
  number    = {4},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1386-0291},
  doi       = {10.3233/CH-199005},
  pages     = {415 -- 424},
  year      = {2019},
  abstract  = {Lipid-containing adipocytes can dedifferentiate into fibroblast-like cells under appropriate culture conditions, which are known as dedifferentiated fat (DFAT) cells. However, the relative low dedifferentiation efficiency with the established protocols limit their widespread applications. In this study, we found that adipocyte dedifferentiation could be promoted via periodic exposure to cold (10 degrees C) in vitro. The lipid droplets in mature adipocytes were reduced by culturing the cells in periodic cooling/heating cycles (10-37 degrees C) for one week. The periodic temperature change led to the down-regulation of the adipogenic genes (FABP4, Leptin) and up-regulation of the mitochondrial uncoupling related genes (UCP1, PGC-1 alpha, and PRDM16). In addition, the enhanced expression of the cell proliferation marker Ki67 was observed in the dedifferentiated fibroblast-like cells after periodic exposure to cold, as compared to the cells cultured in 37 degrees C. Our in vitro model provides a simple and effective approach to promote lipolysis and can be used to improve the dedifferentiation efficiency of adipocytes towards multipotent DFAT cells.},
  language  = {en}
}
@article{WangNaolouMaetal.2017,
  author    = {Wang, Weiwei and Naolou, Toufik and Ma, Nan and Deng, Zijun and Xu, Xun and Mansfeld, Ulrich and Wischke, Christian and Gossen, Manfred and Neffe, Axel T. and Lendlein, Andreas},
  title     = {Polydepsipeptide Block-Stabilized Polyplexes for Efficient Transfection of Primary Human Cells},
  series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences},
  volume    = {18},
  journal   = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1525-7797},
  doi       = {10.1021/acs.biomac.7b01034},
  pages     = {3819 -- 3833},
  year      = {2017},
  abstract  = {The rational design of a polyplex gene carrier aims to balance maximal effectiveness of nucleic acid transfection into cells with minimal adverse effects. Depsipeptide blocks with an M (n) similar to 5 kDa exhibiting strong physical interactions were conjugated with PEI moieties (2.5 or 10 kDa) to di- and triblock copolymers. Upon nanoparticle formation and complexation with DNA, the resulting polyplexes (sizes typically 60-150 nm) showed remarkable stability compared to PEI-only or lipoplex and facilitated efficient gene delivery. Intracellular trafficking was visualized by observing fluorescence-labeled pDNA and highlighted the effective cytoplasmic uptake of polyplexes and release of DNA to the perinuclear space. Specifically, a triblock copolymer with a middle depsipeptide block and two 10 kDa PEI swallowtail structures mediated the highest levels of transgenic VEGF secretion in mesenchymal stem cells with low cytotoxicity. These nanocarriers form the basis for a delivery platform technology, especially for gene transfer to primary human cells.},
  language  = {en}
}