Polyelectrolyte multilayer films: A sponge for insulin?

Biomed Mater Eng. 2010;20(3):217-25. doi: 10.3233/BME-2010-0635.

Abstract

Considering restrictive diabetes treatments, new insulin administration strategies constitute a huge medical challenge. This study aimed at developing a new support for insulin reservoirs, using polyelectrolyte multilayer films (PEM films), and thus studying this hormone release in a progressive manner. At first, insulin was loaded in (PDADMAC-PAA)n films, by immerging them for various periods of time (2, 14 and 24 h) in a solution containing this protein. Confocal laser scanning microscopy (CLSM) revealed that insulin-FITC could diffuse inside the film with a bigger concentration in the upper part of the film (after 2 and 14 h in contact with the polypeptide solution), and then in the whole film (after 24 h) from a solution at pH=4.3 (below insulin's isolelectric point). Environmental scanning electron microscopy (ESEM) and CLSM showed that the film swells upon insulin loading. We finally investigated the insulin release by ATR-FTIR spectroscopy. It revealed that a loaded (PDADMAC-PAA)15 film, immerged in distilled water, showed no measurable insulin release. In contrast, a slow unloading was observed in the presence of a NaCl 0.15 M solution (salinity close to physiological serum). This study could open the route for a new way of insulin delivery.

MeSH terms

  • Absorption
  • Alanine / analogs & derivatives*
  • Alanine / chemistry
  • Biocompatible Materials / chemistry*
  • Diffusion
  • Electrolytes / chemistry*
  • Insulin / chemistry*
  • Materials Testing
  • Membranes, Artificial*
  • Polyethylenes / chemistry*
  • Quaternary Ammonium Compounds / chemistry*

Substances

  • Biocompatible Materials
  • Electrolytes
  • Insulin
  • Membranes, Artificial
  • Polyethylenes
  • Quaternary Ammonium Compounds
  • 3-(phenylamino)alanine
  • poly-N,N-dimethyl-N,N-diallylammonium chloride
  • Alanine