Feasibility Study and Direct Extraction of Endogenous Free Metallic Cations Combining Hemodialysis and Chelating Polymer

In this article, we report the conception and the use of dialysis based medical device for extraction of metals. The medical device is obtained by addition in the dialysate of a functionnalized chitosan that can chelate endogenous metals like iron or copper. The water soluble functionnalized chitosan is obtained after controlled reacetylation and addition of DOTAGA. Due to the high mass of chitosan, the polymer cannot cross through the membrane and the metals are trapped in the dialysate during hemodialysis. Copper captation has been evaluated in vitro using an hemodialysis protocol. Feasibility study has been performed on healthy sheep showing no acute toxicity of the whole procedure and first insights of metallic extraction even on healthy animals.

A Mesoporous Chelating Polymer-Carbon Composite for the Hyper-Efficient Separation of Heavy Metal Ions

The removal of heavy-metal ions from wastewater is an important objective from a public-health perspective, and chelating agents can be used to achieve this aim. Herein, we report the synthesis of mesoporous carbon as a chelating polymer host using nanoarchitectonics approach. Carboxymethylated polyethyleneimine, a chelating polymer, was incorporated into the mesopore walls of mesoporous carbon to create a polymer-mesoporous-carbon composite. Nitrogen adsorption– desorption experiments and scanning electron microscopy (SEM) were used to illustrate the structural advantages of the composite. Co2+ adsorption by the composite material was examined using cobalt nitrate solutions at pH 3. The study revealed that the Co2+-absorption data are most closely modeled by the Langmuir isotherm. The maximum adsorption capacity, calculated by linear regression, was determined to be about 40 mg-Co/g-composite at pH 3. The composite exhibited about a six-times higher adsorption capacity toward a dilute Co solution (12.5 ppm) than that of the pristine mesoporous carbon. In addition, the composite showed a substantially higher distribution coefficient (Kd = 1.54×105) compared to that (Kd = 2.05×102) of the mesoporous carbon. Overall, we expect that the mesoporous composite, with its large mesopores (~20 nm), will be in high demand for adsorption applications.

An MRI contrast agent based on a zwitterionic metal-chelating polymer for hepatorenal angiography and tumor imaging

A zwitterionic MRI contrast agent Gd-PAA with exceptionally high r1 was designed for hepatorenal angiography and tumor imaging.