Development of L-Aspartic Acid Decorated Core/Shell Silica Particles for Adsorption of Hyaluronic Acid

In this study, core/shell-structured mesoporous hybrid silica gel particles were synthesized for the selective adsorption of hyaluronic acid. A non-ionic amphiphilic polymer core consisting of poly(methyl methacrylate) and poly(ethylene glycol) blocks were coated with SiO2 using the St & ouml;ber method in the presence of non-ionic and cationic surfactants to obtain mesoporous core-shell silica particles. The surface of silica particles was functionalized through modification of L-aspartic acid to improve their affinity against the targeted analyte, hyaluronic acid. Physico-chemical methods including Fourier transform infrared spectroscopy, thermal gravimetric analysis, zeta-size measurements, and transmission- and scanning-electron microscopies were utilized to evaluate the properties of core-silica particles. The surface functionalized core/shell particles have an average size of 254.7 (+/- 33.1) nm as confirmed by TEM analysis. The hyaluronic acid adsorption performance of the modified core-shell silica particles was optimized through varying pH, concentration, temperature, and contact time parameters. Thermodynamic parameters were estimated by applying adsorption isotherm and kinetics models to assess the favorability of the adsorption process. The models revealed that the hyaluronic acid adsorption processes follow monolayer adsorption (Langmuir model) and chemisorption (pseudo-second-order kinetics) processes. A core/shell hybrid mesoporous silica gel bearing amphiphilic polymer as the core and mesoporous silica gel as the shell is modified with L-aspartic acid and used as an efficient adsorbent for hyaluronic acid adsorption studies. the maximum adsorption capacity was calculated as 25.85 mg/g at pH 7.0 following the Langmuir isotherm model. image