Hydrogel films based on sodium alginate modified with octane-1-amine: enhanced pore formation and potential applications in drug delivery systems

The use of wound dressings is gaining more and more popularity, especially in the field of tactical and military medicine. Developing wound dressings capable of facilitating wound treatment and reducing healing time is one of the challenges of modern science. So, sodium alginate (Alg) is a good candidate for the development of wound dressings due to its bio- and hemocompatibility and biodegradability. However, Alg has its shortcomings, which can be dispatched by modification. The purpose of this work was to investigate the effect of Alg modification on the kinetics of ethonium release from crosslinked with Ca2+ ions samples. For this purpose, a method of Alg modifying with octane-1-amine was developed without the use of organic solvents and with the use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDCl) as an initiator. The optimal parameters of alginate modification process were defined as 60 °С temperature and 24 hours duration. Physicochemical methods confirmed the success of the modification. Films based on the alginate modified with octane-1-amine (AlgM) were obtained using a calcium chloride solution as a crosslinker. The kinetics of swelling was studied and we found that the degree of swelling of the sample based on AlgM after 10 minutes is twice as large (α = 0.71) as for Alg (α = 0.37), which indicates a faster release of drugs. It has been found that the kinetics of release of ethonium depends not only on the kinetics of swelling but also on the chemical nature of the drug. The ethonium was immobilised in alginate films as a model of bactericidal drug. The kinetics of ethonium release was studied at different pH values corresponding to the pH of healthy skin (5.5), open wounds (7.2) and inflamed wounds (8.2). It was found that the release of ethonium from the sample based on AlgM is more pH-sensitive and prolonged, compared to the sample based on Alg. This effect is explained by the appearance of an additional mechanism of retention of ethonium by AlgM due to hydrophobic-hydrophobic interactions in the films. The prolonged release properties observed in the drug-loaded samples make them promising candidates for the development of targeted drug delivery systems and wound dressings, which are particularly relevant for the treatment of chronic and burn wounds. Future research will focus on optimizing the crosslinking method and exploring potential applications of modified alginate-based materials in biomedical sciences.