- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Surface Coatings Modulate the Differences in the Adhesion Forces of Eukaryotic and Prokaryotic Cells as Detected by Single Cell Force Microscopy
摘要： Single cell force microscopy was used to investigate the maximum detachment force (MDF) of primary neuronal mouse cells (PNCs), osteoblastic cells (MC3T3), and prokaryotic cells (Staphylococcus capitis subsp. capitis) from different surfaces after contact times of 1 to 5 seconds. Positively charged silicon nitride surfaces were coated with positively charged polyethyleneimine (PEI) or poly-D-lysine. Laminin was used as the second coating. PEI induced MDFs of the order of 5 to 20 nN, slightly higher than silicon nitride did. Lower MDFs (1 to 5 nN) were detected on PEI/laminin with the lowest on PDL/laminin. To abstract from the individual cell properties, such as size, and to obtain cell type-specific MDFs, the MDFs of each cell on the different coatings were normalized to the silicon nitride reference for the longest contact time. The differences in MDF between prokaryotic and eukaryotic cells were generally of similar dimensions, except on PDL/laminin, which discriminated against the prokaryotic cells. We explain the lower MDFs on laminin by the spatial prevention of the electrostatic cell adhesion to the underlying polymers. However, PEI can form long flexible loops protruding from the surface-bound layer that may span the laminin layer and easily bind to cellular surfaces and the small prokaryotic cells. This was reflected in increased MDFs after two-second contact times on silicon nitride, whereas the two-second values were already observed after one second on PEI or PEI/laminin. We assume that the electrostatic charge interaction with the PEI loops is more important for the initial adhesion of the smaller prokaryotic cells than for eukaryotic cells.
关键词： prokaryotic cells,poly-D-lysine,silicon nitride,laminin,cell adhesion,single cell force microscopy,surface coatings,polyethyleneimine,eukaryotic cells,maximum detachment force
更新于2025-11-21 11:24:58
-
The green poly-lysine enantiomers as electron-extraction layers for high performance organic photovoltaics
摘要： In this study, we first revealed green materials – poly-lysines (poly-L-lysine and poly-L-lysine blend poly-D-lysine) – as electron-extraction layers (EELs) in organic photovoltaics (OPVs). The distinct configurations of poly-lysine enantiomers were verified by conducting zeta potential analysis, and their work function (WF)-tuning capabilities for indium tin oxide (ITO) were affirmed by ultraviolet photoelectron spectroscopy (UPS). These two poly-lysine groups, with different arrangements of the amino groups that built up different surface dipoles on the ITO substrate, altered the surface energy and WF of ITO. Poly-L-lysine optimized the WF of ITO for efficient carrier transport in the OPV device, in the electron transporting layer-free OPV devices, and we observed a high power conversion efficiency (PCE) of 10.01% in the device configuration of ITO/interlayer/BHJ/MoO3/Ag. As the first examination of poly-lysine enantiomers for OPVs, we provided the WF-tuning functions – increasing polarity as an interfacial dipole is formed at the corresponding interface, and discovered a promising interfacial material possessing high efficiency and benefitting from a long-term stability to perform in a stable PCE with about 80% of its original PCE remaining after continuous heat and light treatment for 400 hours.
关键词： interfacial dipole,organic photovoltaics,electron-extraction layers,poly-lysine,work function tuning
更新于2025-09-16 10:30:52
-
[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A Novel Directional Multilevel Method Using Waveguide Eigenmode Expansion
摘要： increased, both body weight gain (BWG) and gain:feed increased linearly and quadratically (P < 0.05). The SID lysine requirements for BWG and gain:feed were 1.06% and 1.08% for the one-slope broken-line, 1.17% and 1.22% for the quadratic broken-line, 1.11% and 1.16% for 95% of the upper asymptote of the quadratic model, and 1.12% and 1.17% for the first intercept between the plateau of the one-slope broken-line and quadratic models, respectively. In conclusion, the SID lysine requirements of Ross 308 broilers at the age of 10 to 21 days ranged from 1.06% to 1.17% for BWG and from 1.08% to 1.22% for gain:feed.
关键词： Requirement,Broiler,Standardized ileal digestibility,Lysine,Amino acid
更新于2025-09-11 14:15:04
-
Doxorubicin-loaded protease-activated near-infrared fluorescent polymeric nanoparticles for imaging and therapy of cancer
摘要： Despite significant progress in the field of oncology, cancer remains one of the leading causes of death. Chemotherapy is one of the most common treatment options for cancer patients but is well known to result in off-target toxicity. Theranostic nanomedicines that integrate diagnostic and therapeutic functions within an all-in-one platform can increase tumor selectivity for more effective chemotherapy and aid in diagnosis and monitoring of therapeutic responses. Material and methods: In this work, theranostic nanoparticles were synthesized with commonly used biocompatible and biodegradable polymers and used as cancer contrast and therapeutic agents for optical imaging and treatment of breast cancer. These core–shell nanoparticles were prepared by nanoprecipitation of blends of the biodegradable and biocompatible amphiphilic copolymers poly(lactic-co-glycolic acid)-b-poly-l-lysine and poly(lactic acid)-b-poly(ethylene glycol). Poly-l-lysine in the first copolymer was covalently decorated with near-infrared fluorescent Alexa Fluor 750 molecules. Results: The spherical nanoparticles had an average size of 60–80 nm. The chemotherapeutic drug doxorubicin was encapsulated in the core of nanoparticles at a loading of 3% (w:w) and controllably released over a period of 30 days. A 33-fold increase in near-infrared fluorescence, mediated by protease-mediated cleavage of the Alexa Fluor 750-labeled poly-l-lysine on the surface of the nanoparticles, was observed upon interaction with the model protease trypsin. The cytocompatibility of drug-free nanoparticles and growth inhibition of drug-loaded nanoparticles on MDA-MB-231 breast cancer cells were investigated with a luminescence cell-viability assay. Drug-free nanoparticles were found to cause minimal toxicity, even at high concentrations (0.2–2,000 μg/mL), while doxorubicin-loaded nanoparticles significantly reduced cell viability at drug concentrations .10 μM. Finally, the interaction of the nanoparticles with breast cancer cells was studied utilizing fluorescence microscopy, demonstrating the potential of the nanoparticles to act as near-infrared fluorescence optical imaging agents and drug-delivery carriers. Conclusion: Doxorubicin-loaded, enzymatically activatable nanoparticles of less than 100 nm were prepared successfully by nanoprecipitation of copolymer blends. These nanoparticles were found to be suitable as controlled drug delivery systems and contrast agents for imaging of cancer cells.
关键词： enzymatic activation,nanoprecipitation,theranostics,PEG,poly-l-lysine,PLGA,block copolymers,nanomedicine,fluorescence imaging,drug delivery,nanoparticles,PLA
更新于2025-09-10 09:29:36
-
Effective GQD/AuNPs nanosensors for selectively bifunctional detection of lysine and cysteine under different photophysical properties
摘要： This work presented the development of the optical nanosensor based on AuNPs and GQDs which perform the efficiency dual optical sensor. Importantly, the AuNPs with GQDs was prepared by one-pot chemical reaction by using GQDs as an excellent bifunction of the reducing agent and stabilizer to obtain the disaggregated AuNPs/GQDs in red color property. Apart from its photophysical sensing ability, this hybrid material demonstrated the dual sensing of cysteine and lysine regarding to colorimetric and fluorometric techniques, respectively, in PBS solution pH 7.4. The presence of Cys in the AuNPs/GQDs solution rapidly lead to the color change from red to blue with concomitant of the red shift of the absorption band at 525 to 645 nm undergone the aggregation process. On the other hand, AuNPs/GQDs nanosensor in the presence of Lys performs the off-on fluorescence at 450 nm without color change in PBS solution pH 7.4. Interestingly, no interference of any amino acids towards Cys and Lys detection highlighted a high efficacy in selective sensing aspect. For sensing application, the detection limit of Cys and Lys was 5.88 μM and 16.14 μM, respectively, with an acceptable % recovery of 101–106 in real samples.
关键词： Graphene quantum dot,Gold nanoparticles,Aggregation,Lysine,Cysteine,Displacement
更新于2025-09-10 09:29:36