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.

Enrichment of total steroidal saponins from the extracts of Trillium tschonoskii Maxim by macroporous resin and the simultaneous determination of eight steroidal saponins in the final product by HPLC.

An effective and simple method was established for the separation and enrichment of steroidal saponins from Trillium tschonoskii Maxim. The adsorption and desorption properties of seven macroporous resins were investigated. Among the tested resins, AB-8 resin showed the best adsorption and desorption capacities. The adsorption of steroidal saponins on AB-8 at 25°C was quite consistent with both the Freundlich isotherm model and the pseudo-second-order kinetics model. By optimizing the dynamic adsorption and desorption parameters, the content of steroidal saponins increased from 5.20% in the crude extracts to 51.93% in the final product, with a recovery yield of 86.67%. Furthermore, by scale-up separation, the concentration and recovery of total steroidal saponins were 43.8 and 85.5%, respectively, which suggested that AB-8 resin had great industrial and pharmaceutical potential because of its high efficiency and cost-effectiveness. In addition, a high-performance liquid chromatography method for the simultaneous determination of eight steroidal saponins was established for the first time, which was employed to qualitatively and quantitatively analyze the final product. Based on the methodological validation results, the high-performance liquid chromatography method can be widely applied to the quality control of steroidal saponins from Trillium tschonoskii Maxim due to its excellent accuracy, stability, and repeatability.