(160e) Electrochemically Regulated Polyelectrolyte Complex for Smart Wound Dressings

Precise control over the release of drug from devices on the wound sites, such as quantity, timing, is highly desirable in order to optimize wound treatment. The aim of this study is to obtain and characterize an electro responsive alginate/ferrocene (Fc)-chitosan polyelectrolyte complex (PEC) hydrogel. Natural chitosan was chemically branched with ferrocene moieties and used as part of the wound dressing. First, the PEC composed of alginate and chitosan (or Fc-chitosan) with different ratios were tested for optimizing the hydrogel. The PECs were characterized by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Scanning Electron Microscopy (SEM). Comparative analysis of the ATR-FTIR spectra of alginate, chitosan and their mixtures indicated the formation of the polyelectrolyte complex. The SEM images showed the porosity of the PEC. To demonstrate the drug delivery potential of the developed PEC-based wound dressing, fluorescence (FITC) and FITC-Dextran with different molecular weights were used as model drugs. By controlling the applied voltage and its duration, the drug release kinetics could be controlled. The drug loading and release properties of the PEC in solutions and on the agarose gel as a layer of phantom skin were further investigated with fluorescence microscopy and plate reader. In 3 days, about 51%, 42%, 22% were released of the FITC, FITC-Dextran (Mw = 3 kDa) and FITC-Dextran (Mw = 70 kDa), respectively. While 5.3% only of the FITC-Dextran (Mw = 2000 kDa) were released in the phosphate buffer saline (PBS). The diffusion coefficients for different drug models were estimated by analyzing images obtained after a time series of acquisition. On the basis of the results, the developed PEC hydrogel may be integrated with therapeutic/diagnostic point of care devices.