Extracellular vesicles (EVs) play an important role in intercellular communication. Recently, there has been increasing interest in EVs as potential diagnostic biomarkers and therapeutic vehicles. However, the molecular properties and cargo information of EV subpopulations have not yet been fully investigated due to lack of reliable and reproducible EV separation technology. Current approaches have faced difficulties with efficiently isolating EVs from biofluids, especially subpopulations of small EVs. Here, we report an EV isolation method based on a size-selective microfluidic platform (ExoSMP) via nanomembrane filtration and electrophoretic force. This unique platform offers an enhanced approach to sorting a heterogeneous population of EVs based on size, with the additional advantages of being label-free and low-cost, and featuring a short processing time (<1 h), and convenient integration with downstream analysis. In this research, we used ExoSMP to demonstrate the isolation of cancer-derived small EVs (30–120 nm) with high recovery (94.2%) and reproducibility at an optimum sample flow rate. Furthermore, we investigated isolation of EV subpopulations by altering nanomembrane combinations with different pore size combinations (50 and 100 nm, 30 and 100 nm, 30 and 200 nm, and 30 and 50 nm). This ExoSMP technique can serve as a standardized EV isolation/separation tool, facilitating the clinical prospects of EVs and opening up a new avenue for future point-of-care applications in liquid biopsies.
This article introduces a gel-based separation-free point-ofcare (POC) device for whole blood glucose colorimetric detection. Enzymes and a chromogenic substrate needed for colorimetric detection of glucose were entrapped in a photopolymerized poly(ethylene) glycol diacrylate (PEG-DA) hydrogel that was cast-molded into a circular shape. Our method enables colorimetric detection without the need for preseparation of blood plasma as the nanometer-scale three-dimensional porous structure of the hydrogel allows the diffusion of small analytes such as glucose while blocking the much larger blood cells. Our method requires less enzymatic concentration and, hence, offers a cost-saving benefit. In addition, PEG-DA also acts as an enzyme stabilizer, and the shelf-life testing result shows that enzyme activity can be maintained in PEG-DA over a long period of time. The concept of this simple, cost-effective method was demonstrated by the colorimetric detection of blood glucose directly from human whole bloodthout any sample preparation steps. The results were compared with those of a spectrophotometry method and showed relative error ranging from 5 to 19%, and less than 9% when compared with a commercial glucose meter. The presented method has the potential to be broadly utilized for other whole blood biomolecule analyses in POC testing applications.
Per-
and poly-fluoroalkyl substances (PFASs) are man-made chemicals
that are toxic and widely detected in the environment, including drinking
water sources. A cost-effective treatment process for PFASs is currently
not available. We developed reusable hydrogel sorbents to remove long-
and short-chain perfluoroalkyl acids and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic
acid (GenX), which is are emerging PFAS. Through fluoridation and
amination of poly(ethylene glycol) diacrylate (PEGDA), the newly synthesized
sorbents can sorb the five targeted PFASs (perfluorooctanoic acid
(PFOA), perfluorooctanesulfonic acid (PFOS), perfluorobutanesulfonic
acid (PFBS), and perfluorobutanoic acid (PFBA) and GenX) to different
degrees from aqueous solution. Aminated PEGDA showed the highest sorption
capacity for all five PFASs, particularly for PFBA and PFBS. The bifunctionalized
PEGDA showed higher capacities for PFOA and PFOS, suggesting that
both hydrophobic interactions and charges contribute to the sorption.
Both aminated and bifunctionalized sorbents can remove GenX from water,
with the highest sorption capacity of 98.7 μmol g aminated PEGDA
–1
within 6 h. The absorbed PFASs on the sorbents were
observed and characterized by Fourier-transform infrared spectroscopy.
The spent sorbents were reusable after readily regenerated with 70%
methanol contained 1% NaCl.
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