Stimuli-responsive emulsion-based hydrogels integrated with anti-inflammatory Ozoile molecules

In this work, we developed different types of alginate-based drug delivery system for the delivery of Ozoile. Ozoile is a pool of molecules with anti-inflammatory and regenerative properties obtained from extra virgin olive oil by a patented ozonation process [1]. Alginate is a natural polymer that is widely employed in drug delivery systems due to its numerous benefits. These advantages include easy preparation methods, biocompatibility, biodegradability, and pH-sensitivity [2]. Alginate finds application in several routes of drug administration, including targeted or localized drug delivery systems [3]. In a first step of the research work, we fabricated stimuli-responsive microspheres, responding to pH and temperature variations, for oral administration of Ozoile. For both types of microspheres, we used the electrospray technique starting from stable microemulsions obtained by high-intensity ultrasound. The microemulsions contain Ozoile at a weight percentage from 10 to 50. Poly(N-isopropylacrylamide) was used in the thermo-pH-responsive microspheres, observing a ratio of 1:1 to alginate. Next, a multilayer patch based on the alginate/Ozoile emulsion has been fabricated for use in the treatment of chronic wounds. The patch has different layers integrating various bioactive natural compounds, for example from blackcurrants, with healing and antioxidant properties. The different types of drug delivery systems were characterized using different experimental techniques, including Fourier transform infrared spectroscopy, optical microscopy, differential scanning calorimetry. Results in terms of chemical composition, pH and thermo-responsive properties, degradation behavior in physiological conditions were used to establish the potential use of the engineered systems for the therapeutic release of Ozoile at specific inflammatory sites.