Development of core-shell silica particles for purification of hyaluronic acid

In this study, the aim is to develop amphiphilic polymer core-silica shell hybrid particles with high affinity for the purification and separation of Hyaluronic Acid (HA), which has significant economic value. In line with this objective, hybrid core-shell silica particles were synthesized using the Stober method for the separation and purification of HA, which is widely used in the aesthetic, health, and cosmetic sectors. It was observed that the obtained particles are suitable for hydrophilic interaction liquid chromatography (HILIC), a chromatographic technique that has become popular in recent years. Additionally, particles with core-shell technology are increasingly gaining commercial ground among chromatographic packing materials due to their superior properties. To enhance the affinity of the synthesized particles against hyaluronic acid, the surface was modified with L-aspartic acid, chosen as a functional ligand. The surface area of the prepared 0,6 µm L-aspartic acid modified core-shell hybrid silica particles (mod-SiO2@P1) was determined to be 240 m²/g and the surface area of the prepared 5,3 µm L-aspartic acid modified core-shell hybrid silica particles (mod-SiO2@P2) was determined to be 440 m²/g. These particles were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), Dynamic Light Scattering (DLS) particle size analysis, and surface area measurements (BET). Adsorption and desorption of hyaluronic acid in aqueous solution and bacterial lysate were carried out using mod-SiO2@P1 and mod-SiO2@P2 hybrid core-shell particles. It was observed that the buffer system used affected the adsorption, with maximum hyaluronic acid adsorption of 25.85 mg/g for mod-SiO2@P1 and that for mod-SiO2@P2 is 65.25 mg/g occurring in the presence of phosphate buffer at pH 7. No significant decrease in adsorption capacity was observed for mod-SiO2@P1 and mod-SiO2@P2 hybrid core-shell particles after adsorption-desorption cycles. In addition to batch-wise set-up, continuous system studies were also conducted with mod-SiO2@P2 particles. The reusability of the particles was also examined. Eperimental data were confirmed by HPLC analysis.