SEARCH

SEARCH BY CITATION

Keywords:

  • adsorption;
  • biomaterials;
  • blood purification;
  • cellulose;
  • sepsis

Abstract

Therapeutic apheresis is established as supportive therapy for various diseases, such as hypercholesterolemia, autoimmune diseases, liver failure, and sepsis. In combined membrane-adsorption systems, the patient's plasma is continuously separated from whole blood by means of a hollow fiber filter, and pathogenic factors are removed from the plasma by selective or specific adsorbents. While adsorbent particles with a size range of 300–800 µm are used in conventional systems, we are currently developing a system based on adsorbent microparticles (1–5 µm), the Microspheres-Based Detoxification System (MDS). The characteristics of the matrix used for immobilization of specific ligands influence the performance of the resulting adsorbents. Desirable matrix characteristics are an open porous structure with an inner surface accessible for target molecules, mechanical stability, narrow particle size distribution, and ease of derivatization. In addition, biocompatibility is a critical issue, since the particles are in direct contact with the patient's plasma. Cellulose represents an ideal support matrix, as it combines all the above-mentioned features, and cellulosic polymers are widely applied in medicine and generally regarded as biocompatible. Cellulose microparticles can be activated using e.g. sodium periodate and functionalized with Polymyxin B or anti-tumor necrosis factor (TNF) antibodies to generate specific adsorbents for endotoxins or TNF. In summary, cellulose microparticles represent an excellent matrix as basis for adsorbent development in blood purification.