title: Erythrocyte interactions - Comparison of the aggregation power of polymer molecules used in medicine - Not only size does matter.
abstract: BACKGROUND
  Different colloids are used as a part of solutions for fluid resuscitation and organ preservation: hydroxyethyl starches (HES), dextran (Dx), polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP). Some of the problems associated with their application are addressed to alteration in erythrocyte (ERY) rheology.
  
  
  OBJECTIVE
  We intended to estimate in vitro and compare the aggregation power (AP) of these molecules related to ERY interactions.
  
  
  METHODS
  Washed human ERY are used during the study. The zeta sedimentation technique is used to quantify the cell aggregation. Zeta sedimentation ratio (ZSR) based indices (AI) are calculated. The hydrodynamic radius (Rh) of the polymer molecules is determined using viscometry.
  
  
  RESULTS
  For all polymers tested a linear range in the relationship AI - concentration was found. The slope of the calculated line was interpreted as measure of the molecule's AP. The following ranking was obtained: PEG >PVP >DX >HES. Within the same chemical type of polymer, increasing Rh of the molecules leads to elevated AI. Comparison of the AP of molecules with similar Rh reveals a significant dependence on their chemical nature.
  
  
  CONCLUSIONS
  Our results show that molecule's AP is significantly dependent on their chemical nature - i.e. not only molecular size does matter.
authors: S
authors: S
authors: Jovtchev
authors: S
authors: S
authors: Alexandrov
authors: N
authors: N
authors: Hristova-Avakumova
authors: S
authors: S
authors: Miteva
authors: L
authors: L
authors: Traikov
authors: D
authors: D
authors: Gerasimova
authors: S
authors: S
authors: Stoeff
mesh_terms: D004903:Erythrocyte Aggregation / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000378:metabolism*; D012212:Rheology / Q000379:methods
chemical_list: D011108:Polymers; D011092:Polyethylene Glycols
keywords: Erythrocyte; Zeta sedimentation ratio; aggregation; hydrodynamic radius; polymer