Sodium alginate hydrogel beads loaded with clove essential oil liposomes: Preparation, characterization and fumigant activity

This study successfully developed a stable and effective delivery system for clove essential oil (CEO) using combination of liposomes and hydrogel beads via thin-film hydration method. Chitosan (CH) was incorporated for protection, and β-cyclodextrin (β-CD) was used in combination with sodium alginate and calcium ions to form the hydrogel beads. The liposome encapsulation efficiency of CEO was 87.26 % and loading efficiency was 27.08 %, while the hydrogel beads (HB) were 71.78 % and 14.35 %, respectively. The incorporation of CH and β-CD into sodium alginate hydrogel beads improved the thermal stability of CEO. The HB displayed excellent slow-release properties, retaining 22.47 % of the essential oil after 30 days of storage. The hydrogel beads facilitated a gradual release of CEO over 24 h, minimizing direct cellular exposure and mitigating toxicity. CEO exhibited fumigant toxicity towards Sitophilus oryzae adults, and the slow-release HB maintained a lethality rate of 11.11 % to S. oryzae adults after 30 days, which inhibited the activities of detoxification enzymes, acetylcholinesterase, and antioxidant enzymes. This delivery system provides a foundation for developing eco-friendly and effective pest control solutions using essential oils encapsulated in liposomal hydrogel beads.