title: Antibacterial, anti-inflammatory and neuroprotective layer-by-layer coatings for neural implants.
abstract: OBJECTIVE
  Infection, inflammation, and neuronal loss are common issues that seriously affect the functionality and longevity of chronically implanted neural prostheses. Minocycline hydrochloride (MH) is a broad-spectrum antibiotic and effective anti-inflammatory drug that also exhibits potent neuroprotective activities. In this study, we investigated the development of biocompatible thin film coatings capable of sustained release of MH for improving the long term performance of implanted neural electrodes.
  
  
  METHODS
  We developed a novel magnesium binding-mediated drug delivery mechanism for controlled and sustained release of MH from an ultrathin hydrophilic layer-by-layer (LbL) coating and characterized the parameters that control MH loading and release. The anti-biofilm, anti-inflammatory and neuroprotective potencies of the LbL coating and released MH were also examined.
  
  
  RESULTS
  Sustained release of physiologically relevant amount of MH for 46 days was achieved from the Mg(2+)-based LbL coating at a thickness of 1.25 μm. In addition, MH release from the LbL coating is pH-sensitive. The coating and released MH demonstrated strong anti-biofilm, anti-inflammatory, and neuroprotective potencies.
  
  
  CONCLUSIONS
  This study reports, for the first time, the development of a bioactive coating that can target infection, inflammation, and neuroprotection simultaneously, which may facilitate the translation of neural interfaces to clinical applications.
authors.affiliation: School of Biomedical Engineering, Science and Health Systems Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
authors.forename: Zhiling
authors.initials: Z
authors.lastname: Zhang
authors.forename: Jia
authors.initials: J
authors.lastname: Nong
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Zhong
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000737:chemistry; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000737:chemistry; D018441:Biofilms / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage* / Q000138:chemical synthesis; D016207:Cytokines / Q000276:immunology; D004343:Drug Implants / Q000008:administration & dosage / Q000737:chemistry; D004567:Electrodes, Implanted; D019544:Equipment Failure Analysis; D008422:Materials Testing; D051379:Mice; D008911:Minocycline / Q000008:administration & dosage* / Q000737:chemistry; D009474:Neurons / Q000187:drug effects; D018696:Neuroprotective Agents / Q000008:administration & dosage* / Q000737:chemistry; D066330:Printing, Three-Dimensional; D011474:Prosthesis Design; D000067996:RAW 264.7 Cells; D051381:Rats
chemical_list: D000900:Anti-Bacterial Agents; D000893:Anti-Inflammatory Agents; D020099:Coated Materials, Biocompatible; D016207:Cytokines; D004343:Drug Implants; D018696:Neuroprotective Agents; D008911:Minocycline