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Synthesis and characterization of self-assembling block copolymers containing bioadhesive end groups
Kui Huang1, Bruce P Lee, Dale R Ingram
1Biomedical Engineering Department, Robert R. McCormick School of Engineering and Applied Sciences, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Biomacromolecules
|March 13, 2002
Summary
Researchers conjugated 3,4-Dihydroxyphenyl-L-alanine (DOPA) to PEO-PPO-PEO block copolymers, creating temperature-responsive materials. These DOPA-modified copolymers form gels and exhibit enhanced bioadhesion, showing promise for biomedical applications.
Area of Science:
- Polymer Chemistry
- Biomaterials Science
- Surface Chemistry
Background:
- Mussel adhesive proteins (MAPs) utilize 3,4-Dihydroxyphenyl-L-alanine (DOPA) for their remarkable adhesive properties.
- Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers are known for their thermoresponsive behavior.
Purpose of the Study:
- To develop a method for conjugating DOPA moieties onto PEO-PPO-PEO block copolymers.
- To investigate the thermoresponsive and bioadhesive properties of the resulting DOPA-modified block copolymers.
Main Methods:
- Activation of hydroxyl end groups of PEO-PPO-PEO block copolymers using N,N'-disuccinimidyl carbonate.
- Reaction of activated copolymers with DOPA or its methyl ester.
- Analysis of micelle formation using dye partitioning and differential scanning calorimetry.
- Investigation of sol-gel transitions using oscillatory rheometry.
- Assessment of bioadhesion via rheological measurements with bovine submaxillary mucin.
Main Results:
- Successful conjugation of DOPA to PEO-PPO-PEO block copolymers with high efficiency in both aqueous and organic solvents.
- DOPA-modified copolymers exhibited temperature-dependent micelle formation and sol-gel transitions above 20 wt % concentration.
- Gelation temperature was tunable between 23 and 46 °C by adjusting copolymer composition, concentration, and molecular weight.
- DOPA-modified Pluronic demonstrated significantly enhanced bioadhesion compared to unmodified Pluronic when interacting with bovine submaxillary mucin.
Conclusions:
- A robust method for DOPA conjugation to PEO-PPO-PEO block copolymers was established.
- The DOPA-modified copolymers display tunable thermoresponsive sol-gel properties.
- Enhanced bioadhesion suggests potential applications in drug delivery, tissue engineering, and bioadhesives.