Nanoscale anionic macromolecules for selective retention of low-density lipoproteins

Biomaterials. 2005 Jun;26(17):3749-58. doi: 10.1016/j.biomaterials.2004.09.038.

Abstract

Synthetically designed anionic nanocarriers that mimic the charge properties of glycosaminoglycans can potentially sequester low-density lipoproteins (LDL) during the treatment of atherosclerosis. In this study, we explore the LDL retentivity of 15-20 nm anionic micelles formed from amphiphilic scorpion-like macromolecules (AScMs) as building blocks. The macromolecules comprise four aliphatic chains attached to mucic acid and a linear polyethylene glycol (PEG) segment to form micellar nanocarriers with a hydrophobic core and hydrophilic corona. Dynamic light scattering and transmission electron microscopy studies indicate that the carboxylate-terminated nanocarriers (20 nm) sequester LDL (22 nm), resulting in complexes with a diameter of 60-90 nm, but neutral ethoxy-terminated nanocarriers do not retain LDL. Further, carboxylate-terminated nanocarriers consistently bound to unoxidized LDL (Relative Electrophoretic Mobility, REM=1.0) and mildly oxidized LDL (REM=1.5), but not highly oxidized LDL (REM=3.6), whereas the neutral nanocarriers displayed no preference/affinity at all, indicating that the nanocarrier-LDL binding is charge-dependent. The binding affinity of unoxidized LDL for differentially charged nanocarriers, formed from varying ratios of carboxylate- and ethoxy-terminated macromolecules, was quantified. The 100% carboxylated nanocarriers elicited the highest binding affinity (K(d)=567 nm), whereas mixed micelles elicited significantly lower levels of binding affinity. Our results highlight the promise of synthetically designed nanomaterials in lipoprotein retention, a key step in managing the escalation of atherosclerosis.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anions
  • Arteriosclerosis / blood
  • Arteriosclerosis / drug therapy
  • Biomimetic Materials
  • Blood Component Removal / methods
  • Drug Carriers / administration & dosage
  • Drug Carriers / chemistry
  • Glycosaminoglycans / administration & dosage*
  • Glycosaminoglycans / chemistry*
  • Humans
  • Lipoproteins, LDL / blood*
  • Lipoproteins, LDL / chemistry*
  • Macromolecular Substances / chemistry*
  • Macromolecular Substances / therapeutic use*
  • Micelles
  • Nanotubes / chemistry*
  • Nanotubes / ultrastructure

Substances

  • Anions
  • Drug Carriers
  • Glycosaminoglycans
  • Lipoproteins, LDL
  • Macromolecular Substances
  • Micelles