ALGINATE AND CHITOSAN-BASED BIODEGRADABLE SYSTEMS: A VERSATILE FRAMEWORK FOR DIVERSE DELIVERY NEEDS
Delivery systems, which encapsulate materials within a protective shell, offer numerous advantages, including controlled release and enhanced stability. Natural polymers are attractive due to their biodegradability, non-toxicity, and gelation capabilities. This PhD thesis explores the development and characterization of delivery systems based on natural polymers (alginate and chitosan) for various applications.
The first part of the thesis focuses on encapsulating blue dye, a component of laundry detergents, in an interpenetrating network constituted of alginate and poly(ethylene glycol) (PEG), with the aim of replacing toxic formaldehyde-based capsules. Different parameters were investigated: the acrylate derived from PEG (dimethacrylate or diacrylate) and the time when the capsules were irradiated with UV light. Of all the systems analysed, capsules prepared using alginate and poly(ethylene glycol) diacrylate showed the best thermal and mechanical properties.
Secondly, we synthesized alginate-based capsules encapsulating lavender essential oil for acne treatment. Zinc-crosslinked capsules exhibited greater antibacterial activity than calcium-crosslinked capsules against Staphylococcus aureus and Staphylococcus epidermidis, attributed to the antibacterial properties of the released zinc ions and lavender essential oil.
Chitosan nanoparticles encapsulating ciprofloxacin, an antibiotic with anticancer potential, were also prepared. Their morphology and encapsulation efficiency were studied. Furthermore, their anticancer efficacy was evaluated using a 3D spheroid model of bladder cancer, demonstrating that these nanoparticles hold promising therapeutic potential.
Finally, wound pads coated with biopolymers and levofloxacin were prepared using an automated spray deposition system. The addition of biopolymers to the wound dressings increased their water vapor permeability, improved sustained drug release, and enhanced their antibacterial activity, transforming them into active therapeutic systems.
Download:
