Enhancing pearl luster by targeted delivery of astaxanthin using submicron hollow ordered mesoporous silica to the mantle of pearl oysters

Pearl luster is a key determinant of pearl quality, and enhancing pearl luster remains a major challenge in current pearl production. Despite astaxanthin holding great potential in regulating pearl luster, its poor bioavailability and insufficient accumulation at target sites significantly limit its practical application. Herein, we developed a submicron hollow ordered mesoporous silica (HOMSS) carrier highly loaded with ASX to achieve enhanced and controlled delivery for pearl luster improvement. The HOMSS system demonstrated high ASX loading capacity and enabled sustained release of ASX. In vivo fluorescence imaging confirmed targeted accumulation of HOMSS in the mantle and visceral mass of Hyriopsis cumingii . Notably, pearl oysters treated with HOMSS-ASX demonstrated significantly enhanced antioxidant capacity and a 35.75 % increase in purple luster intensity. Integrated transcriptomic and molecular docking analyses revealed that ASX specifically interacts with the aryl hydrocarbon receptor (AHR), triggering upregulation of cytochrome P450 family genes expression and promoting the biosynthesis of hydroxyserotonin. This metabolite deposits in the mantle, intensifying the purple luster of pearls. In summary, our innovative nanodelivery strategy based on the HOMSS system not only promoted physiological status and metabolic balance of pearl oysters but also significantly enhanced pearl luster. These findings provide valuable insights for the development of novel nanodelivery applications in shellfish aquaculture and the pearl industry.