Dexamethasone-pDMAEMA polymeric conjugates reduce inflammatory biomarkers in human intestinal epithelial monolayers

J Control Release. 2009 Apr 2;135(1):35-43. doi: 10.1016/j.jconrel.2008.12.001. Epub 2008 Dec 6.

Abstract

The mucoadhesive polymer, poly(dimethylamino)ethyl methacrylate, (pDMAEMA), was synthesised by living radical polymerisation and subsequently conjugated by quaternisation reaction to a functionalised anti-inflammatory corticosteroid dexamethasone, to separately yield two conjugates with either 9:1 or 18:1 molar ratios of dexamethasone:polymer respectively. The hypothesis was to test whether the active agent maintained in vitro bioactivity when exposed to the apical side of human intestinal epithelial monolayers, Caco-2 and mucus-covered HT29-MTX-E12 (E12). HPLC analysis indicated high conjugate purity. Similar to pDMAEMA, fluorescently-labelled dexamethasone-pDMAEMA conjugates were bioadhesive to Caco-2 and mucoadhesive to E12. Apical addition of conjugates suppressed mRNA expression of the inflammatory markers, NURR1 and ICAM-1 in E12 following stimulation by PGE(2) and TNF-alpha, respectively. Conjugates also suppressed TNF-alpha stimulated cytokine secretion to the basolateral side of Caco-2 monolayers. Measurement of dexamethasone permeability from conjugates across monolayers suggested that conjugation reduced permeability compared to free dexamethasone. LDH assay indicated that conjugates were not cytotoxic to monolayers. Anti-inflammatory agents can therefore be successfully conjugated to polymers and they retain adhesion and bioactivity and have potential to be formulated for topical administration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Inflammatory Agents / administration & dosage*
  • Anti-Inflammatory Agents / pharmacology
  • Biomarkers / analysis
  • Caco-2 Cells
  • Cell Adhesion
  • Cell Survival / drug effects
  • Cytokines / biosynthesis*
  • Cytokines / immunology
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / immunology
  • Dexamethasone / administration & dosage*
  • Dexamethasone / pharmacology
  • Drug Carriers / chemistry*
  • Humans
  • Intercellular Adhesion Molecule-1 / biosynthesis
  • Intercellular Adhesion Molecule-1 / immunology
  • Interleukins / biosynthesis
  • Interleukins / immunology
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / drug effects*
  • Intestinal Mucosa / immunology
  • Methacrylates / chemistry*
  • Nuclear Receptor Subfamily 4, Group A, Member 2
  • Nylons / chemistry*
  • Time Factors
  • Transcription Factors / biosynthesis
  • Transcription Factors / immunology
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Tumor Necrosis Factor-alpha / immunology

Substances

  • Anti-Inflammatory Agents
  • Biomarkers
  • Cytokines
  • DNA-Binding Proteins
  • Drug Carriers
  • Interleukins
  • Methacrylates
  • NR4A2 protein, human
  • Nuclear Receptor Subfamily 4, Group A, Member 2
  • Nylons
  • Transcription Factors
  • Tumor Necrosis Factor-alpha
  • poly(2-(dimethylamino)ethyl methacrylate)
  • Intercellular Adhesion Molecule-1
  • Dexamethasone