Magnetic Fluorescent Microparticles as Markers for Particle Transfer in Extracorporeal Blood Purification

Abstract

The microspheres-based detoxification system (MDS) is a combined membrane-adsorption system for extracorporeal blood purification in which adsorbent microparticles are recirculated in an extracorporeal filtrate circuit. Because the plasma filter represents the only barrier between the adsorbents and the patient's blood, there is the potential risk of particle entrance into the patient in case of a membrane rupture. To guarantee first fault safety of the system required for clinical application, magnetic fluorescent microparticles are added as markers to the adsorbent circuit. Detection of these particles in the venous blood line results in immediate shutdown of the pumps. Magnetic beads were functionalized with cresyl violet and tested with an in vitro setup of the particle detector to assess the detection limit in different matrices (water versus blood) as well as the influence of flow rate and particle size on the signal. In addition, biocompatibility and influence of sterilization on the performance of the particles were assessed. Functionalization of the magnetic particles with cresyl violet yielded fluorescent particles that were stable at 4 degrees C for at least 12 months. No leakage of dye was detectable, and the particles were neither cytotoxic nor mutagenic. The particles could be steam sterilized without significant loss in fluorescence intensity. With an in vitro setup of the particle detector, 0.1 mg and 5 mg of particles were reproducibly detectable in water and blood, respectively.

Theoretical and Experimental Analysis of Anti-A Antibody Capture in Novel Integrated Bead and Hollow Fiber Modules

“…Incorporation of a simple bead recirculation loop provided a solution for optimum antibody capture, with no negative effect on the accuracy of the theoretical model. Although the bead recirculation loop used in this study appears similar to that used in microspheres-based detoxification system (MDS), 10,35,36 its only purpose is keeping the beads continuously recirculated through the shell compartment and uniformly distributed. We are further improving this design by integrating the mixing mechanism to minimize the external tubing and simplify the operation of the device.…”

“…Next, k L m B /Q s was kept at a constant value and the reservoir volume was increased to test the ability of our model to predict the decrease in removal rate associated with a decrease in the magnitude of starling flow rate relative to the reservoir volume (Q s /V R ), see Eq. (10). The specific parameters that were changed in each experiment are summarized in Table 2.…”

“…BSAF devices are similar in principal to the microspheres-based detoxification system (MDS), being developed for blood detoxification in liver failure and sepsis. 10,35,36 The key difference between the two systems is the way in which the adsorbents are incorporated within the capture loop. The MDS combines the dialysate side of a standard plasma filter with a secondary extracorporeal flow loop in which adsorbent particles are suspended.…”

Luminescent magnetic particles: structures, syntheses, multimodal imaging, and analytical applications

“…An interesting system with LuMaPs acting as markers for a broken blood purification system was presented by Ettenauer et al [217]. In this system, LuMaPs were mixed to a blood purification liquid to introduce an emergency stop after membrane rupture.…”

Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

“…too high transmembrane pressure) or a broken filter embedding, we add a small amount of labeled particles to the microadsorbent circuit. The used particles are commercial monodisperse and ferromagnetic polystyrene microparticles, and in our laboratory are covalently labeled with the fluorescence dye cresyl violet [2].…”