Characterisation of polyurethane nanocomposite hydrogel systems for wound dressing application

In recent years significant efforts have been made by many research groups for designing a new type of wound dressing. Large number of studies concern application of nontoxic, biodegradable polyurethanes which, moreover, are... [ view full abstract ]

In recent years significant efforts have been made by many research groups for designing a new type of wound dressing. Large number of studies concern application of nontoxic, biodegradable polyurethanes which, moreover, are easy accessible and have wide possibilities to change their properties with modification. The goal which we would like to achieve is to obtain wound dressing with capabilities to faster wound healing and alleviation of pain by release of drug by delivery diffusion process. In order to obtain these properties, the process of increase of swelling ability of polymer matrix is important to achieved, for example, by adding nanoparticles which extend the intermolecular spaces in polyurethane matrix. The main purpose of our research is to achieved material with predetermined and well defined hardness, elasticity, and with appropriate swelling and release profiles. In previous papers we described method of synthesis and studies of basic mechanical properties (using DMA technique) and we examined structure of polyurethane nanocomposite by means of X-­ray diffraction. The naproxen sodium – commonly used inflammatory drug, was chosen as an active substance potentially released from wound dressing. Before molecule reaches the target receptor, it changes the environment from polar protic – body fluids, to nonpolar cavity receptor. Understanding possible interaction between drug and solvent molecules in the ground and/or excited states was one of the main aim of this work. To achieve this goal, steady­-state absorption and fluorescence spectra of naproxen in solvents of different polarities were registered. In addition, using steady­state spectroscopy methods, positive influence of presence of nanoparticles (organofilized montmorillonite – Cloisite®30B) in polymer matrix was observed. Analysis of release active substance from polyurethane matrix were determined basing on light absorption spectra. The concentration of naproxen was registered as a function of time. The most common mechanism of drug release from hydrogels is passive diffusion. In our case this process is guaranteed by presence of nanoparticles. Obtained results confirmed the high possibilities of polyurethane nanocomposite hydrogels as a new type of wound dressing material with the ability to release of drugs.