Engineering aerogel particles as next-generation drug delivery systems: a comprehensive review of recent advances

Aerogels, defined as low-density solid materials with high porosities, open pore structures, and high specific surface areas, have shown increasing interest among the scientific and industrial communities. The engineering of aerogels in the form of spherical particles has been well documented for several applications and recent studies have highlighted the promising potential of use them as drug delivery systems. Therefore, this review article consolidates the recent progress on aerogel particle technology by providing a comprehensive and focused synthesis of the state-of-the-art of aerogel particle design specifically intended to enhance biocompatibility, stability, and targeted drug delivery. The engineering technologies herein presented, based on droplets production and on the milling technology, are critically discussed, highlighting critical aspects used to control their features. Moreover, surface modification and coating techniques are critically examined as tools to enhance biocompatibility, colloidal stability, and targeted delivery. Then, key results in the diverse biomedical applications, namely for oral, skin and pulmonary drug delivery, were discussed. In oral delivery, their capacity to improve drug loading and enable sustained release is emphasized. In skin delivery, aerogels show potential to enhance dermal permeation and provide a sustained release. For pulmonary administration, their low density and aerodynamic properties make them ideal for deep lung deposition. By bridging particle engineering with therapeutic functionality, this review highlights the unique features and advantages of aerogel particles to become the next-generation aerogel-based therapeutic systems. Finally, the current challenges to be addressed and future trends are identified.