Pectinase-Responsive Mesoporous Silica Nanocarriers for Targeted Delivery of Carvacrol in Fungal Disease Management of Kiwifruit

Natural plant-derived bioactive compounds, particularly essential oils, have received increasing attention as eco-friendly alternatives for postharvest disease management in perishable fruits. In this work, a pectinase-responsive nanodelivery system was designed for controlled and localized release of carvacrol. This system was fabricated using aminated mesoporous silica nanoparticles serving as the delivery vehicle and pectin functioning as the enzyme-responsive regulator. These nanoparticles displayed a well-defined spherical shape with a mean diameter of 234 nm, while the loading capacity reached 8.42%. Carvacrol release was markedly enhanced in the presence of pectinase, mimicking pathogen-induced enzyme secretion. Antifungal assays demonstrated that the pectin-functionalized nanocarriers had greater antifungal efficacy against Botryosphaeria dothidea, showing a half-maximal effective concentration of 23.38 mg·L–1, and performed better than the conventional soluble carvacrol formulation. Furthermore, the nanoparticles adhered strongly to kiwifruit leaf surfaces, ensuring better surface retention. In postharvest trials, the system effectively delayed fruit softening and reduced the occurrence of soft rot. Safety assessments in human hepatocyte cells indicated high cell viability (>96.5%) at the maximum tested level and a markedly lower apoptosis rate compared with the control. Overall, this enzyme-responsive nanocarrier provides pathogen-triggered release of carvacrol and represents a sustainable and effective strategy for postharvest fruit disease control.