TY - JOUR A1 - Nie, Yan A1 - Wang, Weiwei A1 - Xu, Xun A1 - Ma, Nan A1 - Lendlein, Andreas T1 - The response of human induced pluripotent stem cells to cyclic temperature changes explored by BIO-AFM JF - MRS advances : a journal of the Materials Research Society (MRS) N2 - Human induced pluripotent stem cells (hiPSCs) are highly sensitive to extrinsic physical and biochemical signals from their extracellular microenvironments. In this study, we analyzed the effect of cyclic temperature changes on hiPSCs behaviors, especially by means of scanning force microscopy (BIO-AFM). The alternation in cellular mechanics, as well as the secretion and pattern of deposition of extracellular matrix (ECM) protein in hiPSCs were evaluated. The arrangement of the actin cytoskeleton changed with the variation of the temperature. The rearranged cytoskeleton architecture led to the subsequent changes in cell mechanics (Young's modulus of hiPSCs). With the exposure to the cyclic cold stimuli, an increase in the average surface roughness (Ra) and roughness mean square (RMS) was detected. This observation might be at least in part due to the upregulated secretion of Laminin alpha 5 during repeated temporary cooling. The expression of pluripotent markers, NANOG and SOX2, was not impaired in hiPSCs, when exposed to the cyclic cold stimuli for 24 h. Our findings provide an insight into the effect of temperature on the hiPSC behaviors, which may contribute to a better understanding of the application of locally controlled therapeutic hypothermia. Y1 - 2021 U6 - https://doi.org/10.1557/s43580-021-00110-4 SN - 2059-8521 VL - 6 IS - 31 SP - 745 EP - 749 PB - Springer CY - Cham ER - TY - JOUR A1 - Bhaskar, Thanga Bhuvanesh Vijaya A1 - Ma, Nan A1 - Lendlein, Andreas A1 - Roch, Toralf T1 - The interaction of human macrophage subsets with silicone as a biomaterial JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Silicones are widely used as biomaterials for medical devices such as extracorporeal equipments. However, there is often conflicting evidence about their supposed cell-and histocompatibility. Macrophages could mediate silicone-induced adverse responses such as foreign body reaction and fibrous encapsulation. The polarization behaviour of macrophages could determine the clinical outcome after implantation of biomaterials. Induction of classically activated macrophages (CAM) may induce and support uncontrolled inflammatory responses and undesired material degradation. In contrast, polarization into alternatively activated macrophages (AAM) is assumed to support healing processes and implant integration. This study compared the interaction of non-polarized macrophages (M0), CAM, and AAM with commercially available tissue culture polystyrene (TCP) and a medical grade silicone-based biomaterial, regarding the secretion of inflammatory mediators such as cytokines and chemokines. Firstly, by using the Limulus amoebocyte lysate (LAL) test the silicone films were shown to be free of soluble endotoxins, which is the prerequisite to investigate their interaction with primary immune cells. Primary human monocyte-derived macrophages (M0) were polarized into CAM and AAM by addition of suitable differentiation factors. These macrophage subsets were incubated on the materials for 24 hours and their viability and cytokine secretion was assessed. In comparison to TCP, cell adhesion was lower on silicone after 24 hours for all three macrophage subsets. However, compared to TCP, silicone induced higher levels of certain inflammatory and chemotactic cytokines in M0, CAM, and AAM macrophage subsets. Conclusively, it was shown that silicone has the ability to induce a pro-inflammatory state to different magnitudes dependent on the macrophage subsets. This priming of the macrophage phenotype by silicone could explain the incidence of severe foreign body complications observed in vivo. KW - Biomaterials KW - silicone KW - macrophage subsets KW - cytokines/chemokines Y1 - 2015 U6 - https://doi.org/10.3233/CH-151991 SN - 1386-0291 SN - 1875-8622 VL - 61 IS - 2 SP - 119 EP - 133 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Tung, Wing Tai A1 - Sun, Xianlei A1 - Wang, Weiwei A1 - Xu, Xun A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Structure, mechanical properties and degradation behavior of electrospun PEEU fiber meshes and films JF - MRS advances : a journal of the Materials Research Society (MRS) N2 - The capability of a degradable implant to provide mechanical support depends on its degradation behavior. Hydrolytic degradation was studied for a polyesteretherurethane (PEEU70), which consists of poly(p-dioxanone) (PPDO) and poly(epsilon-caprolactone) (PCL) segments with a weight ratio of 70:30 linked by diurethane junction units. PEEU70 samples prepared in the form of meshes with average fiber diameters of 1.5 mu m (mesh1.5) and 1.2 mu m (mesh1.2), and films were sterilized and incubated in PBS at 37 degrees C with 5 vol% CO2 supply for 1 to 6 weeks. Degradation features, such as cracks or wrinkles, became apparent from week 4 for all samples. Mass loss was found to be 11 wt%, 6 wt%, and 4 wt% for mesh1.2, mesh1.5, and films at week 6. The elongation at break decreased to under 20% in two weeks for mesh1.2. In case of the other two samples, this level of degradation was achieved after 4 weeks. The weight average molecular weight of both PEEU70 mesh and film samples decreased to below 30 kg/mol when elongation at break dropped below 20%. The time period of sustained mechanical stability of PEEU70-based meshes depends on the fiber diameter and molecular weight. Y1 - 2021 U6 - https://doi.org/10.1557/s43580-020-00001-0 SN - 2059-8521 VL - 6 IS - 10 SP - 276 EP - 282 PB - Springer Nature Switzerland AG CY - Cham ER - TY - JOUR A1 - Edlich, Alexander A1 - Gerecke, Christian A1 - Giulbudagian, Michael A1 - Neumann, Falko A1 - Hedtrich, Sarah A1 - Schaefer-Korting, Monika A1 - Ma, Nan A1 - Calderon, Marcelo A1 - Kleuser, Burkhard T1 - Specific uptake mechanisms of well-tolerated thermoresponsive polyglycerol-based nanogels in antigen-presenting cells of the skin JF - European Journal of Pharmaceutics and Biopharmaceutics N2 - Engineered nanogels are of high value for a targeted and controlled transport of compounds due to the ability to change their chemical properties by external stimuli. As it has been indicated that nanogels possess a high ability to penetrate the stratum corneum, it cannot be excluded that nanogels interact with dermal dendritic cells, especially in diseased skin. In this study the potential crosstalk of the thermore-sponsive nanogels (tNGs) with the dendritic cells of the skin was investigated with the aim to determine the immunotoxicological properties of the nanogels. The investigated tNGs were made of dendritic polyglycerol (dPG) and poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)), as polymer conferring thermoresponsive properties. Although the tNGs were taken up, they displayed neither cytotoxic and genotoxic effects nor any induction of reactive oxygen species in the tested cells. Interestingly, specific uptake mechanisms of the tNGs by the dendritic cells were depending on the nanogels cloud point temperature (Tcp), which determines the phase transition of the nanoparticle. The study points to caveolae-mediated endocytosis as being the major tNGs uptake mechanism at 37 degrees C, which is above the Tcp of the tNGs. Remarkably, an additional uptake mechanism, beside caveolae-mediated endocytosis, was observed at 29 degrees C, which is the Tcp of the tNGs. At this temperature, which is characterized by two different states of the tNGs, macropinocytosis was involved as well. In summary, our study highlights the impact of thermoresponsivity on the cellular uptake mechanisms which has to be taken into account if the tNGs are used as a drug delivery system. KW - Dendritic cells KW - Drug delivery systems KW - Nanogel KW - Nanoparticle KW - Nanoparticle uptake KW - Nanotoxicology Y1 - 2017 U6 - https://doi.org/10.1016/j.ejpb.2016.12.016 SN - 0939-6411 SN - 1873-3441 VL - 116 SP - 155 EP - 163 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Li, Zhengdong A1 - Xu, Xun A1 - Wang, Weiwei A1 - Kratz, Karl A1 - Sun, Xianlei A1 - Zou, Jie A1 - Deng, Zijun A1 - Jung, Friedrich Wilhelm A1 - Gossen, Manfred A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Modulation of the mesenchymal stem cell migration capacity via preconditioning with topographic microstructure JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Controlling mesenchymal stem cells (MSCs) behavior is necessary to fully exploit their therapeutic potential. Various approaches are employed to effectively influence the migration capacity of MSCs. Here, topographic microstructures with different microscale roughness were created on polystyrene (PS) culture vessel surfaces as a feasible physical preconditioning strategy to modulate MSC migration. By analyzing trajectories of cells migrating after reseeding, we demonstrated that the mobilization velocity of human adipose derived mesenchymal stem cells (hADSCs) could be promoted by and persisted after brief preconditioning with the appropriate microtopography. Moreover, the elevated activation levels of focal adhesion kinase (FAK) and mitogen-activated protein kinase (MAPK) in hADSCs were also observed during and after the preconditioning process. These findings underline the potential enhancement of in vivo therapeutic efficacy in regenerative medicine via transplantation of topographic microstructure preconditioned stem cells. KW - Mesenchymal stem cells KW - precondition KW - microstructure KW - migration KW - FAK-MAPK Y1 - 2017 U6 - https://doi.org/10.3233/CH-179208 SN - 1386-0291 SN - 1875-8622 VL - 67 SP - 267 EP - 278 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Bhuvanesh, Thanga A1 - Saretia, Shivam A1 - Roch, Toralf A1 - Schöne, Anne-Christin A1 - Rottke, Falko O. A1 - Kratz, Karl A1 - Wang, Weiwei A1 - Ma, Nan A1 - Schulz, Burkhard A1 - Lendlein, Andreas T1 - Langmuir-Schaefer films of fibronectin as designed biointerfaces for culturing stem cells JF - Polymers for advanced technologies N2 - Glycoproteins adsorbing on an implant upon contact with body fluids can affect the biological response in vitro and in vivo, depending on the type and conformation of the adsorbed biomacromolecules. However, this process is poorly characterized and so far not controllable. Here, protein monolayers of high molecular cohesion with defined density are transferred onto polymeric substrates by the Langmuir-Schaefer (LS) technique and were compared with solution deposition (SO) method. It is hypothesized that on polydimethylsiloxane (PDMS), a substrate with poor cell adhesion capacity, the fibronectin (FN) layers generated by the LS and SO methods will differ in their organization, subsequently facilitating differential stem cell adhesion behavior. Indeed, atomic force microscopy visualization and immunofluorescence images indicated that organization of the FN layer immobilized on PDMS was uniform and homogeneous. In contrast, FN deposited by SO method was rather heterogeneous with appearance of structures resembling protein aggregates. Human mesenchymal stem cells showed reduced absolute numbers of adherent cells, and the vinculin expression seemed to be higher and more homogenously distributed after seeding on PDMS equipped with FN by LS in comparison with PDMS equipped with FN by SO. These divergent responses could be attributed to differences in the availability of adhesion molecule ligands such as the Arg-Gly-Asp (RGD) peptide sequence presented at the interface. The LS method allows to control the protein layer characteristics, including the thickness and the protein orientation or conformation, which can be harnessed to direct stem cell responses to defined outcomes, including migration and differentiation. Copyright (c) 2016 John Wiley & Sons, Ltd. KW - Langmuir-Schaefer method KW - protein adsorption KW - stem cell adhesion KW - cell culture KW - fibronectin Y1 - 2017 U6 - https://doi.org/10.1002/pat.3910 SN - 1042-7147 SN - 1099-1581 VL - 28 SP - 1305 EP - 1311 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Xu, Xun A1 - Nie, Yan A1 - Wang, Weiwei A1 - Ullah, Imran A1 - Tung, Wing Tai A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Generation of 2.5D lung bud organoids from human induced pluripotent stem cells JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Human induced pluripotent stem cells (hiPSCs) are a promising cell source to generate the patient-specific lung organoid given their superior differentiation potential. However, the current 3D cell culture approach is tedious and time-consuming with a low success rate and high batch-to-batch variability. Here, we explored the establishment of lung bud organoids by systematically adjusting the initial confluence levels and homogeneity of cell distribution. The efficiency of single cell seeding and clump seeding was compared. Instead of the traditional 3D culture, we established a 2.5D organoid culture to enable the direct monitoring of the internal structure via microscopy. It was found that the cell confluence and distribution prior to induction were two key parameters, which strongly affected hiPSC differentiation trajectories. Lung bud organoids with positive expression of NKX 2.1, in a single-cell seeding group with homogeneously distributed hiPSCs at 70% confluence (SC 70% hom) or a clump seeding group with heterogeneously distributed cells at 90% confluence (CL 90% het), can be observed as early as 9 days post induction. These results suggest that a successful lung bud organoid formation with single-cell seeding of hiPSCs requires a moderate confluence and homogeneous distribution of cells, while high confluence would be a prominent factor to promote the lung organoid formation when seeding hiPSCs as clumps. 2.5D organoids generated with defined culture conditions could become a simple, efficient, and valuable tool facilitating drug screening, disease modeling and personalized medicine. KW - lung organoid KW - human induced pluripotent stem cell KW - cell culture Y1 - 2021 U6 - https://doi.org/10.3233/CH-219111 SN - 1386-0291 SN - 1875-8622 VL - 79 IS - 1 SP - 217 EP - 230 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Hausmann, Christian A1 - Zoschke, Christian A1 - Wolff, Christopher A1 - Darvin, Maxim E. A1 - Sochorova, Michaela A1 - Kovacik, Andrej A1 - Wanjiku, Barbara A1 - Schumacher, Fabian A1 - Tigges, Julia A1 - Kleuser, Burkhard A1 - Lademann, Juergen A1 - Fritsche, Ellen A1 - Vavrova, Katerina A1 - Ma, Nan A1 - Schaefer-Korting, Monika T1 - Fibroblast origin shapes tissue homeostasis, epidermal differentiation, and drug uptake JF - Scientific reports N2 - Preclinical studies frequently lack predictive value for human conditions. Human cell-based disease models that reflect patient heterogeneity may reduce the high failure rates of preclinical research. Herein, we investigated the impact of primary cell age and body region on skin homeostasis, epidermal differentiation, and drug uptake. Fibroblasts derived from the breast skin of female 20- to 30-yearolds or 60- to 70-year-olds and fibroblasts from juvenile foreskin (<10 years old) were compared in cell monolayers and in reconstructed human skin (RHS). RHS containing aged fibroblasts differed from its juvenile and adult counterparts, especially in terms of the dermal extracellular matrix composition and interleukin-6 levels. The site from which the fibroblasts were derived appeared to alter fibroblast-keratinocyte crosstalk by affecting, among other things, the levels of granulocyte-macrophage colony-stimulating factor. Consequently, the epidermal expression of filaggrin and e-cadherin was increased in RHS containing breast skin fibroblasts, as were lipid levels in the stratum corneum. In conclusion, the region of the body from which fibroblasts are derived appears to affect the epidermal differentiation of RHS, while the age of the fibroblast donors determines the expression of proteins involved in wound healing. Emulating patient heterogeneity in preclinical studies might improve the treatment of age-related skin conditions. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-39770-6 SN - 2045-2322 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Zou, Jie A1 - Wang, Weiwei A1 - Neffe, Axel T. A1 - Xu, Xun A1 - Li, Zhengdong A1 - Deng, Zijun A1 - Sun, Xianlei A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Adipogenic differentiation of human adipose derived mesenchymal stem cells in 3D architectured gelatin based hydrogels (ArcGel) JF - Clinical hemorheology and microcirculation : blood flow and vessels N2 - Polymeric matrices mimicking multiple functions of the ECM are expected to enable a material induced regeneration of tissues. Here, we investigated the adipogenic differentiation of human adipose derived mesenchymal stem cells (hADSCs) in a 3D architectured gelatin based hydrogel (ArcGel) prepared from gelatin and L-lysine diisocyanate ethyl ester (LDI) in an one-step process, in which the formation of an open porous morphology and the chemical network formation were integrated. The ArcGel was designed to support adipose tissue regeneration with its 3D porous structure, high cell biocompatibility, and mechanical properties compatible with human subcutaneous adipose tissue. The ArcGel could support initial cell adhesion and survival of hADSCs. Under static culture condition, the cells could migrate into the inner part of the scaffold with a depth of 840 +/- 120 mu m after 4 days, and distributed in the whole scaffold (2mm in thickness) within 14 days. The cells proliferated in the scaffold and the fold increase of cell number after 7 days of culture was 2.55 +/- 0.08. The apoptotic rate of hADSCs in the scaffold was similar to that of cells maintained on tissue culture plates. When cultured in adipogenic induction medium, the hADSCs in the scaffold differentiated into adipocytes with a high efficiency (93 +/- 1%). Conclusively, this gelatin based 3D scaffold presented high cell compatibility for hADSC cultivation and differentiation, which could serve as a potential implant material in clinical applications for adipose tissue reparation and regeneration. KW - Mesenchymal stem cells KW - gelatin based scaffold KW - adipose tissue regeneration KW - adipogenic differentiation Y1 - 2017 U6 - https://doi.org/10.3233/CH-179210 SN - 1386-0291 SN - 1875-8622 VL - 67 IS - 3-4 SP - 297 EP - 307 PB - IOS Press CY - Amsterdam ER -