Apoptotic Bodies in the Pancreatic Tumor Cell Culture Media Enable Label‐Free Drug Sensitivity Assessment by Impedance Cytometry

2021 ◽  
pp. 2100438
Author(s):  
Carlos Honrado ◽  
Sara J. Adair ◽  
John H. Moore ◽  
Armita Salahi ◽  
Todd W. Bauer ◽  
...  
Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerardo A Lopez-Muñoz ◽  
Juan M Fernández-Costa ◽  
Maria Alejandra Ortega ◽  
Jordina Balaguer-Trias ◽  
Eduard Martin-Lasierra ◽  
...  

Abstract The development of nanostructured plasmonic biosensors has been widely widespread in the last years, motivated by the potential benefits they can offer in integration, miniaturization, multiplexing opportunities, and enhanced performance label-free biodetection in a wide field of applications. Between them, engineering tissues represent a novel, challenging, and prolific application field for nanostructured plasmonic biosensors considering the previously described benefits and the low levels of secreted biomarkers (≈pM–nM) to detect. Here, we present an integrated plasmonic nanocrystals-based biosensor using high throughput nanostructured polycarbonate substrates. Metallic film thickness and incident angle of light for reflectance measurements were optimized to enhance the detection of antibody–antigen biorecognition events using numerical simulations. We achieved an enhancement in biodetection up to 3× as the incident angle of light decreases, which can be related to shorter evanescent decay lengths. We achieved a high reproducibility between channels with a coefficient of variation below 2% in bulk refractive index measurements, demonstrating a high potential for multiplexed sensing. Finally, biosensing potential was demonstrated by the direct and label-free detection of interleukin-6 biomarker in undiluted cell culture media supernatants from bioengineered 3D skeletal muscle tissues stimulated with different concentrations of endotoxins achieving a limit of detection (LOD) of ≈ 0.03 ng/mL (1.4 pM).


2019 ◽  
Vol 281 ◽  
pp. 527-534 ◽  
Author(s):  
Jisoo Park ◽  
Gae Baik Kim ◽  
Andreas Lippitz ◽  
Young Mi Kim ◽  
Donggeun Jung ◽  
...  

Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
KB Killday ◽  
AS Freund ◽  
C Fischer ◽  
KL Colson

1992 ◽  
Vol 68 (05) ◽  
pp. 539-544 ◽  
Author(s):  
Catherine Lenich ◽  
Ralph Pannell ◽  
Jack Henkin ◽  
Victor Gurewich

SummaryWe previously found that human pro-UK expressed in Escherichia coli is more active in fibrinolysis than recombinant human pro-UK obtained from mammalian cell culture media. To determine whether this difference is related to the lack of glycosylation of the E. coli product, we compared the activity of E. coli-derived pro-UK [(-)pro-UK] with that of a glycosylated pro-UK [(+)pro-UK] and of a mutant of pro-UK missing the glycosylation site at Asn-302 [(-) (302) pro-UK]. The latter two pro-UKs were obtained by expression of the human gene in a mammalian cell. The nonglycosylated pro-UKs were activated by plasmin more efficiently (≈2-fold) and were more active in clot lysis (1.5-fold) than the (+)pro-UK. Similarly, the nonglycosylated two-chain derivatives (UKs) were more active against plasminogen and were more rapidly inactivated by plasma inhibitors than the (+)UK.These findings indicate that glycosylation at Asn-302 influences the activity of pro-UK/UK and could be the major factor responsible for the enhanced activity of E. coli-derived pro-UK.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingjing Zhang ◽  
Luong T. H. Nguyen ◽  
Richard Hickey ◽  
Nicole Walters ◽  
Xinyu Wang ◽  
...  

AbstractExtracellular vesicles (EVs) derived from tumor cells have the potential to provide a much-needed source of non-invasive molecular biomarkers for liquid biopsies. However, current methods for EV isolation have limited specificity towards tumor-derived EVs that limit their clinical use. Here, we present an approach called immunomagnetic sequential ultrafiltration (iSUF) that consists of sequential stages of purification and enrichment of EVs in approximately 2 h. In iSUF, EVs present in different volumes of biofluids (0.5–100 mL) can be significantly enriched (up to 1000 times), with up to 99% removal of contaminating proteins (e.g., albumin). The EV recovery rate by iSUF for cell culture media (CCM), serum, and urine corresponded to 98.0% ± 3.6%, 96.0% ± 2.0% and 94.0% ± 1.9%, respectively (p > 0.05). The final step of iSUF enables the separation of tumor-specific EVs by incorporating immunomagnetic beads to target EV subpopulations. Serum from a cohort of clinical samples from metastatic breast cancer (BC) patients and healthy donors were processed by the iSUF platform and the isolated EVs from patients showed significantly higher expression levels of BC biomarkers (i.e., HER2, CD24, and miR21).


2021 ◽  
pp. 106811
Author(s):  
Yuanbin Guo ◽  
Ming Shi ◽  
Xiujuan Liu ◽  
Huagang Liang ◽  
Liming Gao ◽  
...  

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