Physicochemical and functional properties of lactoferrin-hyaluronic acid complexes: Effect of non-covalent and covalent interactions

Abstract The molecular characteristics and functional properties of lactoferrin (LF)-hyaluronic acid (HA) non-covalent complexes and conjugates formed by physical mixing and chemical conjugation were compared. LF and HA interactions were characterized using phase behavior, particle size, zeta-potential and isothermal titration calorimetry (ITC) analysis. The physicochemical and functional properties of the LF-HA complexes and conjugates were also measured, including their foaming, emulsifying, and antioxidant capacities. LF and HA formed molecular complexes over a wide range of pH values, resulting in changes in particle size, charge and structure. The net charge and thermal stability of the proteins in the LF-HA complexes and conjugates were higher than that of free proteins. Covalently attaching HA to LF significantly (p