Polydopamine/polyethyleneimine complex adhered to micrometer-sized magnetic carbon fibers for high-efficiency hemoperfusion.

Carbon-based nanomaterials have recently attracted tremendous attention in adsorption, separation and biological fields. However, such modification is not always straightforward when the surface is not chemically reactive. Given this reason, most carbon materials modification processes employ reactive linkers or coupling agents, which are complicated and time-consuming. Herein, we report on a dopamine-polyethyleneimine (PEI) coating strategy to fabricate micrometer-sized magnetic carbon fiber (MSMCF)-based extracorporeal blood-cleansing sorbent for hemoperfusion. Results showed that the dopamine/PEI-coated MSMCF had a twisted fiber shape with a size range of 80-120 µm in diameter and porous structure with a specific surface area of 146 m2 g-1. Adsorption behavior of dopamine/PEI-modified MSMCF was examined by using bilirubin as a toxin model compound. Equilibrium data were well fitted to the Langmuir isotherm model with a maximal adsorption capacity of 335.1 mg g-1 at ambient temperature. The as-obtained material had relatively high bilirubin adsorption selectivity against albumin at a normal albumin concentration. In particular, the dopamine/PEI-coated MSMCF has excellent adsorption capacity and hemocompatibility compared to the MSMCF decorated only by dopamine or PEI. Therefore, this work may pave the way for enhancing the property of the extracorporeal blood-cleansing sorbent during hemoperfusion.

Two angiotensin-converting enzyme-inhibitory peptides from almond protein and the protective action on vascular endothelial function.

This study aimed to discover and prepare novel angiotensin converting enzyme (ACE) inhibitory peptides from almond protein and further evaluate the effect on endothelial function of human umbilical vascular endothelial cells (HUVECs). Almond protein was hydrolyzed using a two-stage alcalase-protamex hydrolysis process, and the hydrolysates were subjected to a series of separations, ultrafiltration, gel filtration chromatography, and reversed-phased preparative chromatography, to obtain the active peptides. Seven ACE inhibitory fractions with the molecular weight below 1.5 kDa were isolated and prepared, and two purified ACE inhibitory peptides with the IC50 values of 67.52 ± 0.05 and 43.18 ± 0.07 µg mL(-1), were identified as Met-His-Thr-Asp-Asp and Gln-His-Thr-Asp-Asp, respectively. Then the effect of two ACE inhibitory peptides on the endothelial function of HUVECs was evaluated. Results showed that the two potent ACE inhibitory peptides significantly regulated the release of nitric oxide and endothelin in HUVECs. These results suggest that almond peptides have potential as an antihypertensive nutraceuticals or a functional food ingredient.