Calcium binding-mediated sustained release of minocycline from hydrophilic multilayer coatings targeting infection and inflammation

PLoS One. 2014 Jan 7;9(1):e84360. doi: 10.1371/journal.pone.0084360. eCollection 2014.

Abstract

Infection and inflammation are common complications that seriously affect the functionality and longevity of implanted medical implants. Systemic administration of antibiotics and anti-inflammatory drugs often cannot achieve sufficient local concentration to be effective, and elicits serious side effects. Local delivery of therapeutics from drug-eluting coatings presents a promising solution. However, hydrophobic and thick coatings are commonly used to ensure sufficient drug loading and sustained release, which may limit tissue integration and tissue device communications. A calcium-mediated drug delivery mechanism was developed and characterized in this study. This novel mechanism allows controlled, sustained release of minocycline, an effective antibiotic and anti-inflammatory drug, from nanoscale thin hydrophilic polyelectrolyte multilayers for over 35 days at physiologically relevant concentrations. pH-responsive minocycline release was observed as the chelation between minocycline and Ca(2+) is less stable at acidic pH, enabling 'smart' drug delivery in response to infection and/or inflammation-induced tissue acidosis. The release kinetics of minocycline can be controlled by varying initial loading, Ca(2+) concentration, and Ca(2+) incorporation into different layers, enabling facile development of implant coatings with versatile release kinetics. This drug delivery platform can potentially be used for releasing any drug that has high Ca(2+) binding affinity, enabling its use in a variety of biomedical applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / administration & dosage*
  • Anti-Bacterial Agents / pharmacokinetics
  • Calcium / metabolism*
  • Drug Delivery Systems*
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Infections / drug therapy
  • Infections / etiology
  • Inflammation / drug therapy
  • Inflammation / etiology
  • Minocycline / administration & dosage*
  • Minocycline / pharmacokinetics
  • Prostheses and Implants / adverse effects

Substances

  • Anti-Bacterial Agents
  • Minocycline
  • Calcium

Grants and funding

This work was supported by the startup fund from Drexel University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.