Synthesis and characterization of self-assembling block copolymers containing bioadhesive end groups

Biomacromolecules. 2002 Mar-Apr;3(2):397-406. doi: 10.1021/bm015650p.

Abstract

3,4-Dihydroxyphenyl-L-alanine (DOPA) is an unusual amino acid found in mussel adhesive proteins (MAPs) that is believed to lend adhesive characteristics to these proteins. In this paper, we describe a route for the conjugation of DOPA moieties to poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers. Hydroxyl end groups of PEO-PPO-PEO block copolymers were activated by N,N'-disuccinimidyl carbonate and then reacted with DOPA or its methyl ester with high coupling efficiencies from both aqueous and organic solvents. DOPA-modified PEO-PPO-PEO block copolymers were freely soluble in cold water, and dye partitioning and differential scanning calorimetry analysis of these solutions revealed that the copolymers aggregated into micelles at a characteristic temperature that was dependent on block copolymer composition and concentration in solution. Oscillatory rheometry demonstrated that above a block copolymer concentration of approximately 20 wt %, solutions of DOPA-modified PEO-PPO-PEO block copolymers exhibited sol-gel transitions upon heating. The gelation temperature could be tailored between approximately 23 and 46 degrees C by changing the composition, concentration, and molecular weight of the block copolymer. Rheological measurement of the bioadhesive interaction between DOPA-modified Pluronic and bovine submaxillary mucin indicated that DOPA-modified Pluronic was significantly more bioadhesive than unmodified Pluronic.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calorimetry, Differential Scanning
  • Dihydroxyphenylalanine / chemistry
  • Hydrogels / chemistry
  • Molecular Structure
  • Poloxamer / chemistry*
  • Polyethylene Glycols / chemistry*
  • Polymers / chemistry*
  • Propylene Glycols / chemistry*
  • Solubility
  • Temperature

Substances

  • Hydrogels
  • PEO-PPO-PEO
  • Polymers
  • Propylene Glycols
  • Poloxamer
  • Polyethylene Glycols
  • Dihydroxyphenylalanine