Exploring drug release performance of hollow-structured CS/SA/POSS composite gel spheres employing hydrophilic polymerizable AS-POSS as crosslinker

This study prepares a series of hollow-structured CS/SA/POSS composite gel spheres with a diameter of ~2.5 mm by using hydrophilic Janus-type polyhedral oligomeric silsesquioxane (AS-POSS) as a crosslinking agent in combination with sodium alginate and chitosan via electrostatic adsorption/free radical polymerization. As the content of POSS increases, the wall thickness of the gel spheres also increases from 20 to 30 μm, leading to a more compact and smooth wall structure in the polymerized CS/SA/POSS composite gel spheres. Additionally, the introduction and polymerization of POSS significantly enhance the stability, drug loading rate, and entrapment rate of the gel spheres, providing them with improved drug release capabilities. For hydrophilic drug doxorubicin, the loading rate and encapsulation rate reach 41.2% and 79.9%, respectively, while for the hydrophobic drug ibuprofen, they are 14.7% and 76.3%. Compared to some previously reported drug-loaded gel materials, the gels prepared in this study demonstrate relatively higher drug loading performance. Thus, these hollow-structured CS/SA/POSS composite gel spheres hold promise as innovative drug carriers in the biomedical field.