Cytotoxicity and pH-Responsive Release Properties of α-Mangostin-Loaded Nano Polydopamine-Alginate Hydrogel

Alginate is a nontoxic, biocompatible, and biodegradable natural polymer with very appealing physicochemical properties, suitable for a wide range of applications in drug delivery. In this study, we investigated the preparation and characterization of a novel nano polydopamine-alginate hydrogel as a drug delivery agent for alpha-mangostin. The alginate hydrogel beads were prepared through divalent chemical cross-linking in a solution containing CaCl2. The physicochemical characteristics were thoroughly examined using Fourier-transform infrared (FTIR) spectroscopy, C-13 cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR), thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and scanning electron microscopy (SEM). Incorporating polydopamine into the alginate hydrogel significantly improved its swelling properties, especially at higher pH levels (7.4 and 8.4), and increased the drug loading capacity to 6.6%, compared to 5.7% in native alginate hydrogels. In addition, the polydopamine-modified hydrogel demonstrated faster drug release kinetics at these pH levels, corresponding with their enhanced swelling characteristics. All hydrogel samples exhibited inhibitory activity on MC3T3-E1 cell development, with inhibition ranging from 61.5% to 71.4% at a hydrogel concentration of 60 mg mL(-1). These results suggest that nano polydopamine-modified alginate hydrogels have potential as carriers for alpha-mangostin.