Self-Assembled Nanocarriers Based on Modified Chitosan for Biomedical Applications: Preparation and Characterization

Protein-polysaccharide systems are of increasing interest as their combined attributes allow for fulfilling a broad range of applications in biomedical and pharmaceutical fields. In this study, the preparation of nanogels based on maleic anhydride chitosan derivatives (MAC) and bovine serum albumin (BSA) was achieved through a self-assembly process performed in aqueous phase. A series of experiments performed by varying the concentrations of MAC and BSA were conducted to find an appropriate mixing ratio for the polymer solutions leading to thermodynamically stable nanogels with the ability to encapsulate active compounds. The influence of temperature on the formation of nanogels was also studied. The consequent conformational changes were monitored using ultraviolet-visible (UV-VIS) spectrophotometry. The spectrophotometric investigations combined with diffraction light scattering (DLS) technique and zeta potential measurement results were correlated to determine the interaction mechanism and assess the self-assembling processes during nanogel formation. It was found that the hydrodynamic diameter (D(h)) of the nanoparticles increased slightly at acidic pH, and the protonation of ionizable amino groups with the pH was confirmed by the zeta potential measurements. MAC/BSA nanogels also exhibited antimicrobial properties after being loaded with amoxicillin (Amox), which is an antibiotic used for the treatment of various infections. The experimental data resulting from this study provide theoretical guidance for the design and development of attractive nanocarriers for a large variety of biomedical applications.