Polydopamine microcapsules with different wall structures prepared by a template-mediated method for enzyme immobilization

ACS Appl Mater Interfaces. 2013 Oct 23;5(20):9991-7. doi: 10.1021/am403523d. Epub 2013 Oct 4.

Abstract

Microcapsules with diverse wall structures may exhibit different performance in specific applications. In the present study, three kinds of mussel-inspired polydopamine (PDA) microcapsules with different wall structures have been prepared by a template-mediated method. More specifically, three types of CaCO3 microspheres (poly(allylamine hydrochloride), (PAH)-doped CaCO3; pure-CaCO3; and poly(styrene sulfonate sodium), (PSS)-doped CaCO3) were synthesized as sacrificial templates, which were then treated by dopamine to obtain the corresponding PDA-CaCO3 microspheres. Through treating these microspheres with disodium ethylene diamine tetraacetic acid (EDTA-2Na) to remove CaCO3, three types of PDA microcapsules were acquired: that was (1) PAH-PDA microcapsule with a thick (∼600 nm) and highly porous capsule wall composed of interconnected networks, (2) pure-PDA microcapsule with a thick (∼600 nm) and less porous capsule wall, (3) PSS-PDA microcapsule with a thin (∼70 nm) and dense capsule wall. Several characterizations confirmed that a higher degree in porosity and interconnectivity of the capsule wall would lead to a higher mass transfer coefficient. When serving as the carrier for catalase (CAT) immobilization, these enzyme-encapsulated PDA microcapsules showed distinct structure-related activity and stability. In particular, PAH-PDA microcapsules with a wall of highly interconnected networks displayed several significant advantages, including increases in enzyme encapsulation efficiency and enzyme activity/stability and a decrease in enzyme leaching in comparison with other two types of PDA microcapsules. Besides, this hierarchically structured PAH-PDA microcapsule may find other promising applications in biocatalysis, biosensors, drug delivery, etc.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Biosensing Techniques
  • Calcium Carbonate / chemistry
  • Capsules / chemistry*
  • Catalase / chemistry*
  • Catalase / metabolism
  • Edetic Acid / chemistry
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Indoles / chemistry*
  • Kinetics
  • Polymers / chemistry*

Substances

  • Capsules
  • Enzymes, Immobilized
  • Indoles
  • Polymers
  • polydopamine
  • Edetic Acid
  • Catalase
  • Calcium Carbonate