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- ItemCorrigendum to "A Versatile Surface Bioengineering Strategy Based on Mussel-Inspired and Bioclickable Peptide Mimic"([Beijing] : China Association for Science and Technology, 2021) Xiao, Yu; Wang, Wenxuan; Tian, Xiaohua; Tan, Xing; Yang, Tong; Gao, Peng; Xiong, Kaiqing; Tu, Qiufen; Wang, Miao; Maitz, Manfred F.; Huang, Nan; Pan, Guoqing; Yang, Zhilu[This corrects the article DOI: 10.34133/2020/7236946.].
- ItemPlatelet Membrane-Coated Nanocarriers Targeting Plaques to Deliver Anti-CD47 Antibody for Atherosclerotic Therapy([Beijing] : China Association for Science and Technology, 2022) Chen, Liang; Zhou, Zhongyi; Hu, Cheng; Maitz, Manfred F.; Yang, Li; Luo, Rifang; Wang, YunbingAtherosclerosis, the principle cause of cardiovascular disease (CVD) worldwide, is mainly characterized by the pathological accumulation of diseased vascular cells and apoptotic cellular debris. Atherogenesis is associated with the upregulation of CD47, a key antiphagocytic molecule that is known to render malignant cells resistant to programmed cell removal, or "efferocytosis." Here, we have developed platelet membrane-coated mesoporous silicon nanoparticles (PMSN) as a drug delivery system to target atherosclerotic plaques with the delivery of an anti-CD47 antibody. Briefly, the cell membrane coat prolonged the circulation of the particles by evading the immune recognition and provided an affinity to plaques and atherosclerotic sites. The anti-CD47 antibody then normalized the clearance of diseased vascular tissue and further ameliorated atherosclerosis by blocking CD47. In an atherosclerosis model established in ApoE-/- mice, PMSN encapsulating anti-CD47 antibody delivery significantly promoted the efferocytosis of necrotic cells in plaques. Clearing the necrotic cells greatly reduced the atherosclerotic plaque area and stabilized the plaques reducing the risk of plaque rupture and advanced thrombosis. Overall, this study demonstrated the therapeutic advantages of PMSN encapsulating anti-CD47 antibodies for atherosclerosis therapy, which holds considerable promise as a new targeted drug delivery platform for efficient therapy of atherosclerosis.
- ItemA Versatile Surface Bioengineering Strategy Based on Mussel-Inspired and Bioclickable Peptide Mimic([Beijing] : China Association for Science and Technology, 2020) Xiao, Yu; Wang, Wenxuan; Tian, Xiaohua; Tan, Xing; Yang, Tong; Gao, Peng; Xiong, Kaiqing; Tu, Qiufen; Wang, Miao; Maitz, Manfred F.; Huang, Nan; Pan, Guoqing; Yang, ZhiluIn this work, we present a versatile surface engineering strategy by the combination of mussel adhesive peptide mimicking and bioorthogonal click chemistry. The main idea reflected in this work derived from a novel mussel-inspired peptide mimic with a bioclickable azide group (i.e., DOPA4-azide). Similar to the adhesion mechanism of the mussel foot protein (i.e., covalent/noncovalent comediated surface adhesion), the bioinspired and bioclickable peptide mimic DOPA4-azide enables stable binding on a broad range of materials, such as metallic, inorganic, and organic polymer substrates. In addition to the material universality, the azide residues of DOPA4-azide are also capable of a specific conjugation of dibenzylcyclooctyne- (DBCO-) modified bioactive ligands through bioorthogonal click reaction in a second step. To demonstrate the applicability of this strategy for diversified biofunctionalization, we bioorthogonally conjugated several typical bioactive molecules with DBCO functionalization on different substrates to fabricate functional surfaces which fulfil essential requirements of biomedically used implants. For instance, antibiofouling, antibacterial, and antithrombogenic properties could be easily applied to the relevant biomaterial surfaces, by grafting antifouling polymer, antibacterial peptide, and NO-generating catalyst, respectively. Overall, the novel surface bioengineering strategy has shown broad applicability for both the types of substrate materials and the expected biofunctionalities. Conceivably, the “clean” molecular modification of bioorthogonal chemistry and the universality of mussel-inspired surface adhesion may synergically provide a versatile surface bioengineering strategy for a wide range of biomedical materials.
- ItemPressure-based lift estimation and its application to feedforward load control employing trailing-edge flaps(Göttingen : Copernicus Publications, 2021) Bartholomay, Sirko; Wester, Tom T. B.; Perez-Becker, Sebastian; Konze, Simon; Menzel, Christian; Hölling, Michael; Spickenheuer, Axel; Peinke, Joachim; Nayeri, Christian N.; Paschereit, Christian Oliver; Oberleithner, KilianThis experimental load control study presents results of an active trailing-edge flap feedforward controller for wind turbine applications. The controller input is derived from pressure-based lift estimation methods that rely either on a quasi-steady method, based on a three-hole probe, or on an unsteady method that is based on three selected surface pressure ports. Furthermore, a standard feedback controller, based on force balance measurements, is compared to the feedforward control. A Clark-Y airfoil is employed for the wing that is equipped with a trailing-edge flap of chordwise extension. Inflow disturbances are created by a two-dimensional active grid. The Reynolds number is Re=290 000, and reduced frequencies of k=0.07 up to k=0.32 are analyzed. Within the first part of the paper, the lift estimation methods are compared. The surface-pressure-based method shows generally more accurate results, whereas the three-hole probe estimate overpredicts the lift amplitudes with increasing frequencies. Nonetheless, employing the latter as input to the feedforward controller is more promising as a beneficial phase lead is introduced by this method. A successful load alleviation was achieved up to reduced frequencies of k=0.192.
- ItemAdhesive and Self-Healing Polyurethanes with Tunable Multifunctionality([Beijing] : China Association for Science and Technology, 2022) Zhou, Lei; Zhang, Lu; Li, Peichuang; Maitz, Manfred F.; Wang, Kebing; Shang, Tengda; Dai, Sheng; Fu, Yudie; Zhao, Yuancong; Yang, Zhilu; Wang, Jin; Li, XinMany polyurethanes (PUs) are blood-contacting materials due to their good mechanical properties, fatigue resistance, cytocompatibility, biosafety, and relatively good hemocompatibility. Further functionalization of the PUs using chemical synthetic methods is especially attractive for expanding their applications. Herein, a series of catechol functionalized PU (CPU-PTMEG) elastomers containing variable molecular weight of polytetramethylene ether glycol (PTMEG) soft segment are reported by stepwise polymerization and further introduction of catechol. Tailoring the molecular weight of PTMEG fragment enables a regulable catechol content, mobility of the chain segment, hydrogen bond and microphase separation of the C-PU-PTMEG elastomers, thus offering tunability of mechanical strength (such as breaking strength from 1.3 MPa to 5.7 MPa), adhesion, self-healing efficiency (from 14.9% to 96.7% within 2 hours), anticoagulant, antioxidation, anti-inflammatory properties and cellular growth behavior. As cardiovascular stent coatings, the C-PU-PTMEGs demonstrate enough flexibility to withstand deformation during the balloon dilation procedure. Of special importance is that the C-PU-PTMEG-coated surfaces show the ability to rapidly scavenge free radicals to maintain normal growth of endothelial cells, inhibit smooth muscle cell proliferation, mediate inflammatory response, and reduce thrombus formation. With the universality of surface adhesion and tunable multifunctionality, these novel C-PU-PTMEG elastomers should find potential usage in artificial heart valves and surface engineering of stents.
- ItemAssessment of Subsampling Strategies in Microspectroscopy of Environmental Microplastic Samples(Lausanne : Frontiers Media, 2021) Brandt, Josef; Fischer, Franziska; Kanaki, Elisavet; Enders, Kristina; Labrenz, Matthias; Fischer, DieterThe analysis of environmental occurrence of microplastic (MP) particles has gained notable attention within the past decade. An effective risk assessment of MP litter requires elucidating sources of MP particles, their pathways of distribution and, ultimately, sinks. Therefore, sampling has to be done in high frequency, both spatially and temporally, resulting in a high number of samples to analyze. Microspectroscopy techniques, such as FTIR imaging or Raman particle measurements allow an accurate analysis of MP particles regarding their chemical classification and size. However, these methods are time-consuming, which gives motivation to establish subsampling protocols that require measuring less particles, while still obtaining reliable results. The challenge regarding the subsampling of environmental MP samples lies in the heterogeneity of MP types and the relatively low numbers of target particles. Herein, we present a comprehensive assessment of different proposed subsampling methods on a selection of real-world samples from different environmental compartments. The methods are analyzed and compared with respect to resulting MP count errors, which eventually allows giving recommendations for staying within acceptable error margins. Our results are based on measurements with Raman microspectroscopy, but are applicable to any other analysis technique. We show that the subsampling-errors are mainly due to statistical counting errors (i.e., extrapolation from low numbers) and only in edge cases additionally impacted by inhomogeneous distribution of particles on the filters. Keeping the subsampling-errors low can mainly be realized by increasing the fraction of MP particles in the samples.